[FFmpeg-devel,v3,2/5] avfilter/vf_libopencv: add opencv HaarCascade classifier simple face detection filter

From: Limin Wang <lance.lmwang@gmail.com>

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
---
change the update_metadata() to postprocess() only, I'll add opencv drawbox
filter and it need preprocess() to get the meta, so I prefer to change the
function name for better readablity, in future, it may have other processing
than metadata only.

 configure                  |   1 +
 doc/filters.texi           |  29 +++++++
 libavfilter/vf_libopencv.c | 164 ++++++++++++++++++++++++++++++++++++-
 3 files changed, 191 insertions(+), 3 deletions(-)

This opencv module is obsolete for latest opencv.

Instead there should be C++ wrapper.

On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> From: Limin Wang <lance.lmwang@gmail.com>
>
> Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> ---
> change the update_metadata() to postprocess() only, I'll add opencv drawbox
> filter and it need preprocess() to get the meta, so I prefer to change the
> function name for better readablity, in future, it may have other processing
> than metadata only.
>
>  configure                  |   1 +
>  doc/filters.texi           |  29 +++++++
>  libavfilter/vf_libopencv.c | 164 ++++++++++++++++++++++++++++++++++++-
>  3 files changed, 191 insertions(+), 3 deletions(-)
>
> diff --git a/configure b/configure
> index 34afdaad28..281b67efc4 100755
> --- a/configure
> +++ b/configure
> @@ -2123,6 +2123,7 @@ HEADERS_LIST="
>      machine_ioctl_meteor_h
>      malloc_h
>      opencv2_core_core_c_h
> +    opencv2_objdetect_objdetect_c_h
>      OpenGL_gl3_h
>      poll_h
>      sys_param_h
> diff --git a/doc/filters.texi b/doc/filters.texi
> index d9ba0fffa1..f938dd04de 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -14177,6 +14177,35 @@ other parameters is 0.
>  These parameters correspond to the parameters assigned to the
>  libopencv function @code{cvSmooth}.
>
> +@subsection facedetect
> +Face detection using Haar Feature-based Cascade Classifiers.
> +
> +The filter takes the following parameters:
> +@var{xml_model}|@var{qoffset}.
> +
> +@var{xml_model} is the path of pre-trained classifiers, The C API still
> +does not support the newer cascade format, please use the old format
> +haarcascade_frontalface_alt.xml which type_id is opencv-haar-classifier.
> +
> +@var{qoffset}
> +If you want export the detected faces by ROI side data in frame, please set
> the
> +parameters, See also the @ref{addroi} filter. The range of qoffset is from
> [-1.0, 1.0]
> +
> +By default the filter will report these metadata values if face are
> +detected:
> +@table @option
> +@item lavfi.facedetect.nb_faces
> +Display the detected face number
> +
> +@item lavfi.facedetect.face_id.x, lavfi.facedetect.face_id.y
> +Display x and y of every faces, face_id is the face index which is range
> +from [0, nb_faces-1]
> +
> +@item lavfi.facedetect.face_id.w, lavfi.facedetect.face_id.h
> +Display width and height of every faces, face_id is the face index
> +which is range from [0, nb_faces-1]
> +@end table
> +
>  @section oscilloscope
>
>  2D Video Oscilloscope.
> diff --git a/libavfilter/vf_libopencv.c b/libavfilter/vf_libopencv.c
> index 8128030b8c..b2d19bb241 100644
> --- a/libavfilter/vf_libopencv.c
> +++ b/libavfilter/vf_libopencv.c
> @@ -1,5 +1,6 @@
>  /*
>   * Copyright (c) 2010 Stefano Sabatini
> + * Copyright (c) 2020 Limin Wang
>   *
>   * This file is part of FFmpeg.
>   *
> @@ -27,10 +28,16 @@
>  #if HAVE_OPENCV2_CORE_CORE_C_H
>  #include <opencv2/core/core_c.h>
>  #include <opencv2/imgproc/imgproc_c.h>
> +#if HAVE_OPENCV2_OBJECTDETECT_OBJECTDETECT_C_H
> +#include <opencv2/objdetect/objdetect_c.h>
> +#else
> +#include <opencv/cv.h>
> +#endif
>  #else
>  #include <opencv/cv.h>
>  #include <opencv/cxcore.h>
>  #endif
> +
>  #include "libavutil/avstring.h"
>  #include "libavutil/common.h"
>  #include "libavutil/file.h"
> @@ -82,6 +89,7 @@ typedef struct OCVContext {
>      int (*init)(AVFilterContext *ctx, const char *args);
>      void (*uninit)(AVFilterContext *ctx);
>      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
> IplImage *outimg);
> +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
>      void *priv;
>  } OCVContext;
>
> @@ -326,18 +334,152 @@ static void erode_end_frame_filter(AVFilterContext
> *ctx, IplImage *inimg, IplIma
>      cvErode(inimg, outimg, dilate->kernel, dilate->nb_iterations);
>  }
>
> +typedef struct FaceDetectContext {
> +    char *xml_model;
> +    CvHaarClassifierCascade* cascade;
> +    CvMemStorage* storage;
> +    int nb_faces;
> +    CvSeq *faces;
> +    int add_roi;
> +    AVRational qoffset;
> +} FaceDetectContext;
> +
> +static av_cold int facedetect_init(AVFilterContext *ctx, const char *args)
> +{
> +    OCVContext *s = ctx->priv;
> +    FaceDetectContext *facedetect = s->priv;
> +    const char *buf = args;
> +    double qoffset;
> +
> +    if (args) {
> +        facedetect->xml_model = av_get_token(&buf, "|");
> +        if (!facedetect->xml_model) {
> +            av_log(ctx, AV_LOG_ERROR, "failed to get %s, %s\n", args,
> facedetect->xml_model);
> +            return AVERROR(EINVAL);
> +        }
> +
> +        if (buf && sscanf(buf, "|%lf", &qoffset) == 1) {
> +            if (qoffset < -1.0 || qoffset > 1.0) {
> +                av_log(ctx, AV_LOG_ERROR, "failed to get valid
> qoffset(%f))\n", qoffset);
> +                return AVERROR(EINVAL);
> +            }
> +            facedetect->add_roi = 1;
> +            facedetect->qoffset = av_d2q(qoffset, 255);
> +        }
> +    } else {
> +        av_log(ctx, AV_LOG_ERROR, "failed to get
> haarcascade_frontalface_alt.xml model file\n");
> +        return AVERROR(EINVAL);
> +    }
> +
> +    av_log(ctx, AV_LOG_VERBOSE, "xml_model: %s add_roi: %d qoffset:
> %d/%d\n",
> +           facedetect->xml_model, facedetect->add_roi,
> facedetect->qoffset.num, facedetect->qoffset.den);
> +
> +    facedetect->storage = cvCreateMemStorage(0);
> +    if (!facedetect->storage) {
> +        av_log(ctx, AV_LOG_ERROR, "cvCreateMemStorage() failed\n");
> +        return AVERROR(EINVAL);
> +    }
> +    cvClearMemStorage(facedetect->storage);
> +
> +    facedetect->cascade = (CvHaarClassifierCascade*)cvLoad(
> facedetect->xml_model, NULL, NULL, NULL );
> +    if (!facedetect->cascade) {
> +        av_log(ctx, AV_LOG_ERROR, "failed to load classifier cascade: %s
> \n", facedetect->xml_model);
> +        return AVERROR(EINVAL);
> +    }
> +
> +    return 0;
> +}
> +
> +static av_cold void facedetect_uninit(AVFilterContext *ctx)
> +{
> +    OCVContext *s = ctx->priv;
> +    FaceDetectContext *facedetect = s->priv;
> +
> +    if (facedetect->cascade)
> +        cvReleaseHaarClassifierCascade(&facedetect->cascade);
> +    if (facedetect->storage)
> +        cvReleaseMemStorage(&facedetect->storage);
> +}
> +
> +static void set_meta_int(AVDictionary **metadata, const char *key, int idx,
> int d)
> +{
> +    char value[128];
> +    char key2[128];
> +
> +    snprintf(value, sizeof(value), "%d", d);
> +    snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", idx, key);
> +    av_dict_set(metadata, key2, value, 0);
> +}
> +
> +static void facedetect_end_frame_filter(AVFilterContext *ctx, IplImage
> *inimg, IplImage *outimg)
> +{
> +    OCVContext *s = ctx->priv;
> +    FaceDetectContext *facedetect = s->priv;
> +
> +    facedetect->faces = cvHaarDetectObjects(inimg, facedetect->cascade,
> facedetect->storage,
> +            1.25, 3, CV_HAAR_DO_CANNY_PRUNING,
> +            cvSize(inimg->width/16,inimg->height/16), cvSize(0,0));
> +
> +    facedetect->nb_faces = facedetect->faces ? facedetect->faces->total :
> 0;
> +}
> +
> +static void facedetect_postprocess(AVFilterContext *ctx, AVFrame *out)
> +{
> +    OCVContext *s = ctx->priv;
> +    FaceDetectContext *facedetect = s->priv;
> +    AVRegionOfInterest *roi;
> +    AVFrameSideData *sd;
> +    AVBufferRef *roi_buf;
> +    int i;
> +
> +    if (facedetect->add_roi && facedetect->nb_faces > 0) {
> +        sd = av_frame_new_side_data(out, AV_FRAME_DATA_REGIONS_OF_INTEREST,
> +                facedetect->nb_faces * sizeof(AVRegionOfInterest));
> +        if (!sd) {
> +            return AVERROR(ENOMEM);
> +        }
> +        roi = (AVRegionOfInterest*)sd->data;
> +        for(i = 0; i < facedetect->nb_faces; i++ ) {
> +            CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
> +
> +            roi[i] = (AVRegionOfInterest) {
> +                .self_size = sizeof(*roi),
> +                .top       = r->y,
> +                .bottom    = r->y + r->height,
> +                .left      = r->x,
> +                .right     = r->x + r->width,
> +                .qoffset   = facedetect->qoffset,
> +            };
> +        }
> +    }
> +
> +    if (facedetect->nb_faces > 0)
> +        av_dict_set_int(&out->metadata, "lavfi.facedetect.nb_faces",
> facedetect->nb_faces, 0);
> +
> +    for(i = 0; i < facedetect->nb_faces; i++ ) {
> +        CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
> +
> +        set_meta_int(&out->metadata, "x", i, r->x);
> +        set_meta_int(&out->metadata, "y", i, r->y);
> +        set_meta_int(&out->metadata, "w", i, r->width);
> +        set_meta_int(&out->metadata, "h", i, r->height);
> +    }
> +}
> +
>  typedef struct OCVFilterEntry {
>      const char *name;
>      size_t priv_size;
>      int  (*init)(AVFilterContext *ctx, const char *args);
>      void (*uninit)(AVFilterContext *ctx);
>      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
> IplImage *outimg);
> +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
>  } OCVFilterEntry;
>
>  static const OCVFilterEntry ocv_filter_entries[] = {
> -    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
> dilate_end_frame_filter },
> -    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
> erode_end_frame_filter  },
> -    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
> smooth_end_frame_filter },
> +    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
> dilate_end_frame_filter, NULL },
> +    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
> erode_end_frame_filter, NULL },
> +    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
> smooth_end_frame_filter, NULL },
> +    { "facedetect", sizeof(FaceDetectContext), facedetect_init,
> facedetect_uninit, facedetect_end_frame_filter, facedetect_postprocess },
>  };
>
>  static av_cold int init(AVFilterContext *ctx)
> @@ -355,6 +497,7 @@ static av_cold int init(AVFilterContext *ctx)
>              s->init             = entry->init;
>              s->uninit           = entry->uninit;
>              s->end_frame_filter = entry->end_frame_filter;
> +            s->postprocess      = entry->postprocess;
>
>              if (!(s->priv = av_mallocz(entry->priv_size)))
>                  return AVERROR(ENOMEM);
> @@ -383,18 +526,33 @@ static int filter_frame(AVFilterLink *inlink, AVFrame
> *in)
>      AVFrame *out;
>      IplImage inimg, outimg;
>
> +    /* facedetect filter will passthrought the input frame */
> +    if (strcmp(s->name, "facedetect")) {
>      out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
>      if (!out) {
>          av_frame_free(&in);
>          return AVERROR(ENOMEM);
>      }
>      av_frame_copy_props(out, in);
> +    } else {
> +        out = in;
> +    }
>
>      fill_iplimage_from_frame(&inimg , in , inlink->format);
> +
> +    if (strcmp(s->name, "facedetect")) {
>      fill_iplimage_from_frame(&outimg, out, inlink->format);
>      s->end_frame_filter(ctx, &inimg, &outimg);
>      fill_frame_from_iplimage(out, &outimg, inlink->format);
> +    } else {
> +        s->end_frame_filter(ctx, &inimg, NULL);
> +    }
> +
> +    if (s->postprocess) {
> +        s->postprocess(ctx, out);
> +    }
>
> +    if (out != in)
>      av_frame_free(&in);
>
>      return ff_filter_frame(outlink, out);
> --
> 2.21.0
>
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> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

On Mon, May 18, 2020 at 01:11:12PM +0200, Paul B Mahol wrote:
> This opencv module is obsolete for latest opencv.
> 
> Instead there should be C++ wrapper.

Sorry, where is the C++ wrapper? Now Opencv 2.x and 3.x is good
to use for my current function. By my initial testing, the performance is
very good, we can easily to get realtime for HD, the drawbacks are: 
1. The face is not directly opposite and cannot be recognized.
2. there are some false detect for video.

If have any old discussion for that, please give the discussion link for 
reference. I'm not keep track of the ML before.


> 
> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> > From: Limin Wang <lance.lmwang@gmail.com>
> >
> > Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> > ---
> > change the update_metadata() to postprocess() only, I'll add opencv drawbox
> > filter and it need preprocess() to get the meta, so I prefer to change the
> > function name for better readablity, in future, it may have other processing
> > than metadata only.
> >
> >  configure                  |   1 +
> >  doc/filters.texi           |  29 +++++++
> >  libavfilter/vf_libopencv.c | 164 ++++++++++++++++++++++++++++++++++++-
> >  3 files changed, 191 insertions(+), 3 deletions(-)
> >
> > diff --git a/configure b/configure
> > index 34afdaad28..281b67efc4 100755
> > --- a/configure
> > +++ b/configure
> > @@ -2123,6 +2123,7 @@ HEADERS_LIST="
> >      machine_ioctl_meteor_h
> >      malloc_h
> >      opencv2_core_core_c_h
> > +    opencv2_objdetect_objdetect_c_h
> >      OpenGL_gl3_h
> >      poll_h
> >      sys_param_h
> > diff --git a/doc/filters.texi b/doc/filters.texi
> > index d9ba0fffa1..f938dd04de 100644
> > --- a/doc/filters.texi
> > +++ b/doc/filters.texi
> > @@ -14177,6 +14177,35 @@ other parameters is 0.
> >  These parameters correspond to the parameters assigned to the
> >  libopencv function @code{cvSmooth}.
> >
> > +@subsection facedetect
> > +Face detection using Haar Feature-based Cascade Classifiers.
> > +
> > +The filter takes the following parameters:
> > +@var{xml_model}|@var{qoffset}.
> > +
> > +@var{xml_model} is the path of pre-trained classifiers, The C API still
> > +does not support the newer cascade format, please use the old format
> > +haarcascade_frontalface_alt.xml which type_id is opencv-haar-classifier.
> > +
> > +@var{qoffset}
> > +If you want export the detected faces by ROI side data in frame, please set
> > the
> > +parameters, See also the @ref{addroi} filter. The range of qoffset is from
> > [-1.0, 1.0]
> > +
> > +By default the filter will report these metadata values if face are
> > +detected:
> > +@table @option
> > +@item lavfi.facedetect.nb_faces
> > +Display the detected face number
> > +
> > +@item lavfi.facedetect.face_id.x, lavfi.facedetect.face_id.y
> > +Display x and y of every faces, face_id is the face index which is range
> > +from [0, nb_faces-1]
> > +
> > +@item lavfi.facedetect.face_id.w, lavfi.facedetect.face_id.h
> > +Display width and height of every faces, face_id is the face index
> > +which is range from [0, nb_faces-1]
> > +@end table
> > +
> >  @section oscilloscope
> >
> >  2D Video Oscilloscope.
> > diff --git a/libavfilter/vf_libopencv.c b/libavfilter/vf_libopencv.c
> > index 8128030b8c..b2d19bb241 100644
> > --- a/libavfilter/vf_libopencv.c
> > +++ b/libavfilter/vf_libopencv.c
> > @@ -1,5 +1,6 @@
> >  /*
> >   * Copyright (c) 2010 Stefano Sabatini
> > + * Copyright (c) 2020 Limin Wang
> >   *
> >   * This file is part of FFmpeg.
> >   *
> > @@ -27,10 +28,16 @@
> >  #if HAVE_OPENCV2_CORE_CORE_C_H
> >  #include <opencv2/core/core_c.h>
> >  #include <opencv2/imgproc/imgproc_c.h>
> > +#if HAVE_OPENCV2_OBJECTDETECT_OBJECTDETECT_C_H
> > +#include <opencv2/objdetect/objdetect_c.h>
> > +#else
> > +#include <opencv/cv.h>
> > +#endif
> >  #else
> >  #include <opencv/cv.h>
> >  #include <opencv/cxcore.h>
> >  #endif
> > +
> >  #include "libavutil/avstring.h"
> >  #include "libavutil/common.h"
> >  #include "libavutil/file.h"
> > @@ -82,6 +89,7 @@ typedef struct OCVContext {
> >      int (*init)(AVFilterContext *ctx, const char *args);
> >      void (*uninit)(AVFilterContext *ctx);
> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
> > IplImage *outimg);
> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
> >      void *priv;
> >  } OCVContext;
> >
> > @@ -326,18 +334,152 @@ static void erode_end_frame_filter(AVFilterContext
> > *ctx, IplImage *inimg, IplIma
> >      cvErode(inimg, outimg, dilate->kernel, dilate->nb_iterations);
> >  }
> >
> > +typedef struct FaceDetectContext {
> > +    char *xml_model;
> > +    CvHaarClassifierCascade* cascade;
> > +    CvMemStorage* storage;
> > +    int nb_faces;
> > +    CvSeq *faces;
> > +    int add_roi;
> > +    AVRational qoffset;
> > +} FaceDetectContext;
> > +
> > +static av_cold int facedetect_init(AVFilterContext *ctx, const char *args)
> > +{
> > +    OCVContext *s = ctx->priv;
> > +    FaceDetectContext *facedetect = s->priv;
> > +    const char *buf = args;
> > +    double qoffset;
> > +
> > +    if (args) {
> > +        facedetect->xml_model = av_get_token(&buf, "|");
> > +        if (!facedetect->xml_model) {
> > +            av_log(ctx, AV_LOG_ERROR, "failed to get %s, %s\n", args,
> > facedetect->xml_model);
> > +            return AVERROR(EINVAL);
> > +        }
> > +
> > +        if (buf && sscanf(buf, "|%lf", &qoffset) == 1) {
> > +            if (qoffset < -1.0 || qoffset > 1.0) {
> > +                av_log(ctx, AV_LOG_ERROR, "failed to get valid
> > qoffset(%f))\n", qoffset);
> > +                return AVERROR(EINVAL);
> > +            }
> > +            facedetect->add_roi = 1;
> > +            facedetect->qoffset = av_d2q(qoffset, 255);
> > +        }
> > +    } else {
> > +        av_log(ctx, AV_LOG_ERROR, "failed to get
> > haarcascade_frontalface_alt.xml model file\n");
> > +        return AVERROR(EINVAL);
> > +    }
> > +
> > +    av_log(ctx, AV_LOG_VERBOSE, "xml_model: %s add_roi: %d qoffset:
> > %d/%d\n",
> > +           facedetect->xml_model, facedetect->add_roi,
> > facedetect->qoffset.num, facedetect->qoffset.den);
> > +
> > +    facedetect->storage = cvCreateMemStorage(0);
> > +    if (!facedetect->storage) {
> > +        av_log(ctx, AV_LOG_ERROR, "cvCreateMemStorage() failed\n");
> > +        return AVERROR(EINVAL);
> > +    }
> > +    cvClearMemStorage(facedetect->storage);
> > +
> > +    facedetect->cascade = (CvHaarClassifierCascade*)cvLoad(
> > facedetect->xml_model, NULL, NULL, NULL );
> > +    if (!facedetect->cascade) {
> > +        av_log(ctx, AV_LOG_ERROR, "failed to load classifier cascade: %s
> > \n", facedetect->xml_model);
> > +        return AVERROR(EINVAL);
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +static av_cold void facedetect_uninit(AVFilterContext *ctx)
> > +{
> > +    OCVContext *s = ctx->priv;
> > +    FaceDetectContext *facedetect = s->priv;
> > +
> > +    if (facedetect->cascade)
> > +        cvReleaseHaarClassifierCascade(&facedetect->cascade);
> > +    if (facedetect->storage)
> > +        cvReleaseMemStorage(&facedetect->storage);
> > +}
> > +
> > +static void set_meta_int(AVDictionary **metadata, const char *key, int idx,
> > int d)
> > +{
> > +    char value[128];
> > +    char key2[128];
> > +
> > +    snprintf(value, sizeof(value), "%d", d);
> > +    snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", idx, key);
> > +    av_dict_set(metadata, key2, value, 0);
> > +}
> > +
> > +static void facedetect_end_frame_filter(AVFilterContext *ctx, IplImage
> > *inimg, IplImage *outimg)
> > +{
> > +    OCVContext *s = ctx->priv;
> > +    FaceDetectContext *facedetect = s->priv;
> > +
> > +    facedetect->faces = cvHaarDetectObjects(inimg, facedetect->cascade,
> > facedetect->storage,
> > +            1.25, 3, CV_HAAR_DO_CANNY_PRUNING,
> > +            cvSize(inimg->width/16,inimg->height/16), cvSize(0,0));
> > +
> > +    facedetect->nb_faces = facedetect->faces ? facedetect->faces->total :
> > 0;
> > +}
> > +
> > +static void facedetect_postprocess(AVFilterContext *ctx, AVFrame *out)
> > +{
> > +    OCVContext *s = ctx->priv;
> > +    FaceDetectContext *facedetect = s->priv;
> > +    AVRegionOfInterest *roi;
> > +    AVFrameSideData *sd;
> > +    AVBufferRef *roi_buf;
> > +    int i;
> > +
> > +    if (facedetect->add_roi && facedetect->nb_faces > 0) {
> > +        sd = av_frame_new_side_data(out, AV_FRAME_DATA_REGIONS_OF_INTEREST,
> > +                facedetect->nb_faces * sizeof(AVRegionOfInterest));
> > +        if (!sd) {
> > +            return AVERROR(ENOMEM);
> > +        }
> > +        roi = (AVRegionOfInterest*)sd->data;
> > +        for(i = 0; i < facedetect->nb_faces; i++ ) {
> > +            CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
> > +
> > +            roi[i] = (AVRegionOfInterest) {
> > +                .self_size = sizeof(*roi),
> > +                .top       = r->y,
> > +                .bottom    = r->y + r->height,
> > +                .left      = r->x,
> > +                .right     = r->x + r->width,
> > +                .qoffset   = facedetect->qoffset,
> > +            };
> > +        }
> > +    }
> > +
> > +    if (facedetect->nb_faces > 0)
> > +        av_dict_set_int(&out->metadata, "lavfi.facedetect.nb_faces",
> > facedetect->nb_faces, 0);
> > +
> > +    for(i = 0; i < facedetect->nb_faces; i++ ) {
> > +        CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
> > +
> > +        set_meta_int(&out->metadata, "x", i, r->x);
> > +        set_meta_int(&out->metadata, "y", i, r->y);
> > +        set_meta_int(&out->metadata, "w", i, r->width);
> > +        set_meta_int(&out->metadata, "h", i, r->height);
> > +    }
> > +}
> > +
> >  typedef struct OCVFilterEntry {
> >      const char *name;
> >      size_t priv_size;
> >      int  (*init)(AVFilterContext *ctx, const char *args);
> >      void (*uninit)(AVFilterContext *ctx);
> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
> > IplImage *outimg);
> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
> >  } OCVFilterEntry;
> >
> >  static const OCVFilterEntry ocv_filter_entries[] = {
> > -    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
> > dilate_end_frame_filter },
> > -    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
> > erode_end_frame_filter  },
> > -    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
> > smooth_end_frame_filter },
> > +    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
> > dilate_end_frame_filter, NULL },
> > +    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
> > erode_end_frame_filter, NULL },
> > +    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
> > smooth_end_frame_filter, NULL },
> > +    { "facedetect", sizeof(FaceDetectContext), facedetect_init,
> > facedetect_uninit, facedetect_end_frame_filter, facedetect_postprocess },
> >  };
> >
> >  static av_cold int init(AVFilterContext *ctx)
> > @@ -355,6 +497,7 @@ static av_cold int init(AVFilterContext *ctx)
> >              s->init             = entry->init;
> >              s->uninit           = entry->uninit;
> >              s->end_frame_filter = entry->end_frame_filter;
> > +            s->postprocess      = entry->postprocess;
> >
> >              if (!(s->priv = av_mallocz(entry->priv_size)))
> >                  return AVERROR(ENOMEM);
> > @@ -383,18 +526,33 @@ static int filter_frame(AVFilterLink *inlink, AVFrame
> > *in)
> >      AVFrame *out;
> >      IplImage inimg, outimg;
> >
> > +    /* facedetect filter will passthrought the input frame */
> > +    if (strcmp(s->name, "facedetect")) {
> >      out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
> >      if (!out) {
> >          av_frame_free(&in);
> >          return AVERROR(ENOMEM);
> >      }
> >      av_frame_copy_props(out, in);
> > +    } else {
> > +        out = in;
> > +    }
> >
> >      fill_iplimage_from_frame(&inimg , in , inlink->format);
> > +
> > +    if (strcmp(s->name, "facedetect")) {
> >      fill_iplimage_from_frame(&outimg, out, inlink->format);
> >      s->end_frame_filter(ctx, &inimg, &outimg);
> >      fill_frame_from_iplimage(out, &outimg, inlink->format);
> > +    } else {
> > +        s->end_frame_filter(ctx, &inimg, NULL);
> > +    }
> > +
> > +    if (s->postprocess) {
> > +        s->postprocess(ctx, out);
> > +    }
> >
> > +    if (out != in)
> >      av_frame_free(&in);
> >
> >      return ff_filter_frame(outlink, out);
> > --
> > 2.21.0
> >
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel@ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> On Mon, May 18, 2020 at 01:11:12PM +0200, Paul B Mahol wrote:
>> This opencv module is obsolete for latest opencv.
>>
>> Instead there should be C++ wrapper.
>
> Sorry, where is the C++ wrapper? Now Opencv 2.x and 3.x is good
> to use for my current function. By my initial testing, the performance is
> very good, we can easily to get realtime for HD, the drawbacks are:
> 1. The face is not directly opposite and cannot be recognized.
> 2. there are some false detect for video.
>
> If have any old discussion for that, please give the discussion link for
> reference. I'm not keep track of the ML before.

Nope, i'm not doing others people work for free.

>
>
>>
>> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
>> > From: Limin Wang <lance.lmwang@gmail.com>
>> >
>> > Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
>> > ---
>> > change the update_metadata() to postprocess() only, I'll add opencv
>> > drawbox
>> > filter and it need preprocess() to get the meta, so I prefer to change
>> > the
>> > function name for better readablity, in future, it may have other
>> > processing
>> > than metadata only.
>> >
>> >  configure                  |   1 +
>> >  doc/filters.texi           |  29 +++++++
>> >  libavfilter/vf_libopencv.c | 164 ++++++++++++++++++++++++++++++++++++-
>> >  3 files changed, 191 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/configure b/configure
>> > index 34afdaad28..281b67efc4 100755
>> > --- a/configure
>> > +++ b/configure
>> > @@ -2123,6 +2123,7 @@ HEADERS_LIST="
>> >      machine_ioctl_meteor_h
>> >      malloc_h
>> >      opencv2_core_core_c_h
>> > +    opencv2_objdetect_objdetect_c_h
>> >      OpenGL_gl3_h
>> >      poll_h
>> >      sys_param_h
>> > diff --git a/doc/filters.texi b/doc/filters.texi
>> > index d9ba0fffa1..f938dd04de 100644
>> > --- a/doc/filters.texi
>> > +++ b/doc/filters.texi
>> > @@ -14177,6 +14177,35 @@ other parameters is 0.
>> >  These parameters correspond to the parameters assigned to the
>> >  libopencv function @code{cvSmooth}.
>> >
>> > +@subsection facedetect
>> > +Face detection using Haar Feature-based Cascade Classifiers.
>> > +
>> > +The filter takes the following parameters:
>> > +@var{xml_model}|@var{qoffset}.
>> > +
>> > +@var{xml_model} is the path of pre-trained classifiers, The C API still
>> > +does not support the newer cascade format, please use the old format
>> > +haarcascade_frontalface_alt.xml which type_id is
>> > opencv-haar-classifier.
>> > +
>> > +@var{qoffset}
>> > +If you want export the detected faces by ROI side data in frame, please
>> > set
>> > the
>> > +parameters, See also the @ref{addroi} filter. The range of qoffset is
>> > from
>> > [-1.0, 1.0]
>> > +
>> > +By default the filter will report these metadata values if face are
>> > +detected:
>> > +@table @option
>> > +@item lavfi.facedetect.nb_faces
>> > +Display the detected face number
>> > +
>> > +@item lavfi.facedetect.face_id.x, lavfi.facedetect.face_id.y
>> > +Display x and y of every faces, face_id is the face index which is
>> > range
>> > +from [0, nb_faces-1]
>> > +
>> > +@item lavfi.facedetect.face_id.w, lavfi.facedetect.face_id.h
>> > +Display width and height of every faces, face_id is the face index
>> > +which is range from [0, nb_faces-1]
>> > +@end table
>> > +
>> >  @section oscilloscope
>> >
>> >  2D Video Oscilloscope.
>> > diff --git a/libavfilter/vf_libopencv.c b/libavfilter/vf_libopencv.c
>> > index 8128030b8c..b2d19bb241 100644
>> > --- a/libavfilter/vf_libopencv.c
>> > +++ b/libavfilter/vf_libopencv.c
>> > @@ -1,5 +1,6 @@
>> >  /*
>> >   * Copyright (c) 2010 Stefano Sabatini
>> > + * Copyright (c) 2020 Limin Wang
>> >   *
>> >   * This file is part of FFmpeg.
>> >   *
>> > @@ -27,10 +28,16 @@
>> >  #if HAVE_OPENCV2_CORE_CORE_C_H
>> >  #include <opencv2/core/core_c.h>
>> >  #include <opencv2/imgproc/imgproc_c.h>
>> > +#if HAVE_OPENCV2_OBJECTDETECT_OBJECTDETECT_C_H
>> > +#include <opencv2/objdetect/objdetect_c.h>
>> > +#else
>> > +#include <opencv/cv.h>
>> > +#endif
>> >  #else
>> >  #include <opencv/cv.h>
>> >  #include <opencv/cxcore.h>
>> >  #endif
>> > +
>> >  #include "libavutil/avstring.h"
>> >  #include "libavutil/common.h"
>> >  #include "libavutil/file.h"
>> > @@ -82,6 +89,7 @@ typedef struct OCVContext {
>> >      int (*init)(AVFilterContext *ctx, const char *args);
>> >      void (*uninit)(AVFilterContext *ctx);
>> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
>> > IplImage *outimg);
>> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
>> >      void *priv;
>> >  } OCVContext;
>> >
>> > @@ -326,18 +334,152 @@ static void
>> > erode_end_frame_filter(AVFilterContext
>> > *ctx, IplImage *inimg, IplIma
>> >      cvErode(inimg, outimg, dilate->kernel, dilate->nb_iterations);
>> >  }
>> >
>> > +typedef struct FaceDetectContext {
>> > +    char *xml_model;
>> > +    CvHaarClassifierCascade* cascade;
>> > +    CvMemStorage* storage;
>> > +    int nb_faces;
>> > +    CvSeq *faces;
>> > +    int add_roi;
>> > +    AVRational qoffset;
>> > +} FaceDetectContext;
>> > +
>> > +static av_cold int facedetect_init(AVFilterContext *ctx, const char
>> > *args)
>> > +{
>> > +    OCVContext *s = ctx->priv;
>> > +    FaceDetectContext *facedetect = s->priv;
>> > +    const char *buf = args;
>> > +    double qoffset;
>> > +
>> > +    if (args) {
>> > +        facedetect->xml_model = av_get_token(&buf, "|");
>> > +        if (!facedetect->xml_model) {
>> > +            av_log(ctx, AV_LOG_ERROR, "failed to get %s, %s\n", args,
>> > facedetect->xml_model);
>> > +            return AVERROR(EINVAL);
>> > +        }
>> > +
>> > +        if (buf && sscanf(buf, "|%lf", &qoffset) == 1) {
>> > +            if (qoffset < -1.0 || qoffset > 1.0) {
>> > +                av_log(ctx, AV_LOG_ERROR, "failed to get valid
>> > qoffset(%f))\n", qoffset);
>> > +                return AVERROR(EINVAL);
>> > +            }
>> > +            facedetect->add_roi = 1;
>> > +            facedetect->qoffset = av_d2q(qoffset, 255);
>> > +        }
>> > +    } else {
>> > +        av_log(ctx, AV_LOG_ERROR, "failed to get
>> > haarcascade_frontalface_alt.xml model file\n");
>> > +        return AVERROR(EINVAL);
>> > +    }
>> > +
>> > +    av_log(ctx, AV_LOG_VERBOSE, "xml_model: %s add_roi: %d qoffset:
>> > %d/%d\n",
>> > +           facedetect->xml_model, facedetect->add_roi,
>> > facedetect->qoffset.num, facedetect->qoffset.den);
>> > +
>> > +    facedetect->storage = cvCreateMemStorage(0);
>> > +    if (!facedetect->storage) {
>> > +        av_log(ctx, AV_LOG_ERROR, "cvCreateMemStorage() failed\n");
>> > +        return AVERROR(EINVAL);
>> > +    }
>> > +    cvClearMemStorage(facedetect->storage);
>> > +
>> > +    facedetect->cascade = (CvHaarClassifierCascade*)cvLoad(
>> > facedetect->xml_model, NULL, NULL, NULL );
>> > +    if (!facedetect->cascade) {
>> > +        av_log(ctx, AV_LOG_ERROR, "failed to load classifier cascade:
>> > %s
>> > \n", facedetect->xml_model);
>> > +        return AVERROR(EINVAL);
>> > +    }
>> > +
>> > +    return 0;
>> > +}
>> > +
>> > +static av_cold void facedetect_uninit(AVFilterContext *ctx)
>> > +{
>> > +    OCVContext *s = ctx->priv;
>> > +    FaceDetectContext *facedetect = s->priv;
>> > +
>> > +    if (facedetect->cascade)
>> > +        cvReleaseHaarClassifierCascade(&facedetect->cascade);
>> > +    if (facedetect->storage)
>> > +        cvReleaseMemStorage(&facedetect->storage);
>> > +}
>> > +
>> > +static void set_meta_int(AVDictionary **metadata, const char *key, int
>> > idx,
>> > int d)
>> > +{
>> > +    char value[128];
>> > +    char key2[128];
>> > +
>> > +    snprintf(value, sizeof(value), "%d", d);
>> > +    snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", idx, key);
>> > +    av_dict_set(metadata, key2, value, 0);
>> > +}
>> > +
>> > +static void facedetect_end_frame_filter(AVFilterContext *ctx, IplImage
>> > *inimg, IplImage *outimg)
>> > +{
>> > +    OCVContext *s = ctx->priv;
>> > +    FaceDetectContext *facedetect = s->priv;
>> > +
>> > +    facedetect->faces = cvHaarDetectObjects(inimg, facedetect->cascade,
>> > facedetect->storage,
>> > +            1.25, 3, CV_HAAR_DO_CANNY_PRUNING,
>> > +            cvSize(inimg->width/16,inimg->height/16), cvSize(0,0));
>> > +
>> > +    facedetect->nb_faces = facedetect->faces ? facedetect->faces->total
>> > :
>> > 0;
>> > +}
>> > +
>> > +static void facedetect_postprocess(AVFilterContext *ctx, AVFrame *out)
>> > +{
>> > +    OCVContext *s = ctx->priv;
>> > +    FaceDetectContext *facedetect = s->priv;
>> > +    AVRegionOfInterest *roi;
>> > +    AVFrameSideData *sd;
>> > +    AVBufferRef *roi_buf;
>> > +    int i;
>> > +
>> > +    if (facedetect->add_roi && facedetect->nb_faces > 0) {
>> > +        sd = av_frame_new_side_data(out,
>> > AV_FRAME_DATA_REGIONS_OF_INTEREST,
>> > +                facedetect->nb_faces * sizeof(AVRegionOfInterest));
>> > +        if (!sd) {
>> > +            return AVERROR(ENOMEM);
>> > +        }
>> > +        roi = (AVRegionOfInterest*)sd->data;
>> > +        for(i = 0; i < facedetect->nb_faces; i++ ) {
>> > +            CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
>> > +
>> > +            roi[i] = (AVRegionOfInterest) {
>> > +                .self_size = sizeof(*roi),
>> > +                .top       = r->y,
>> > +                .bottom    = r->y + r->height,
>> > +                .left      = r->x,
>> > +                .right     = r->x + r->width,
>> > +                .qoffset   = facedetect->qoffset,
>> > +            };
>> > +        }
>> > +    }
>> > +
>> > +    if (facedetect->nb_faces > 0)
>> > +        av_dict_set_int(&out->metadata, "lavfi.facedetect.nb_faces",
>> > facedetect->nb_faces, 0);
>> > +
>> > +    for(i = 0; i < facedetect->nb_faces; i++ ) {
>> > +        CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
>> > +
>> > +        set_meta_int(&out->metadata, "x", i, r->x);
>> > +        set_meta_int(&out->metadata, "y", i, r->y);
>> > +        set_meta_int(&out->metadata, "w", i, r->width);
>> > +        set_meta_int(&out->metadata, "h", i, r->height);
>> > +    }
>> > +}
>> > +
>> >  typedef struct OCVFilterEntry {
>> >      const char *name;
>> >      size_t priv_size;
>> >      int  (*init)(AVFilterContext *ctx, const char *args);
>> >      void (*uninit)(AVFilterContext *ctx);
>> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
>> > IplImage *outimg);
>> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
>> >  } OCVFilterEntry;
>> >
>> >  static const OCVFilterEntry ocv_filter_entries[] = {
>> > -    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
>> > dilate_end_frame_filter },
>> > -    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
>> > erode_end_frame_filter  },
>> > -    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
>> > smooth_end_frame_filter },
>> > +    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
>> > dilate_end_frame_filter, NULL },
>> > +    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
>> > erode_end_frame_filter, NULL },
>> > +    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
>> > smooth_end_frame_filter, NULL },
>> > +    { "facedetect", sizeof(FaceDetectContext), facedetect_init,
>> > facedetect_uninit, facedetect_end_frame_filter, facedetect_postprocess
>> > },
>> >  };
>> >
>> >  static av_cold int init(AVFilterContext *ctx)
>> > @@ -355,6 +497,7 @@ static av_cold int init(AVFilterContext *ctx)
>> >              s->init             = entry->init;
>> >              s->uninit           = entry->uninit;
>> >              s->end_frame_filter = entry->end_frame_filter;
>> > +            s->postprocess      = entry->postprocess;
>> >
>> >              if (!(s->priv = av_mallocz(entry->priv_size)))
>> >                  return AVERROR(ENOMEM);
>> > @@ -383,18 +526,33 @@ static int filter_frame(AVFilterLink *inlink,
>> > AVFrame
>> > *in)
>> >      AVFrame *out;
>> >      IplImage inimg, outimg;
>> >
>> > +    /* facedetect filter will passthrought the input frame */
>> > +    if (strcmp(s->name, "facedetect")) {
>> >      out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
>> >      if (!out) {
>> >          av_frame_free(&in);
>> >          return AVERROR(ENOMEM);
>> >      }
>> >      av_frame_copy_props(out, in);
>> > +    } else {
>> > +        out = in;
>> > +    }
>> >
>> >      fill_iplimage_from_frame(&inimg , in , inlink->format);
>> > +
>> > +    if (strcmp(s->name, "facedetect")) {
>> >      fill_iplimage_from_frame(&outimg, out, inlink->format);
>> >      s->end_frame_filter(ctx, &inimg, &outimg);
>> >      fill_frame_from_iplimage(out, &outimg, inlink->format);
>> > +    } else {
>> > +        s->end_frame_filter(ctx, &inimg, NULL);
>> > +    }
>> > +
>> > +    if (s->postprocess) {
>> > +        s->postprocess(ctx, out);
>> > +    }
>> >
>> > +    if (out != in)
>> >      av_frame_free(&in);
>> >
>> >      return ff_filter_frame(outlink, out);
>> > --
>> > 2.21.0
>> >
>> > _______________________________________________
>> > ffmpeg-devel mailing list
>> > ffmpeg-devel@ffmpeg.org
>> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> >
>> > To unsubscribe, visit link above, or email
>> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
> --
> Thanks,
> Limin Wang
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

Am Mo., 18. Mai 2020 um 13:11 Uhr schrieb Paul B Mahol <onemda@gmail.com>:
>
> This opencv module is obsolete for latest opencv.

Which is not supported by FFmpeg so I don't think
this is a useful argument.

> Instead there should be C++ wrapper.

If you don't plan to implement the wrapper, it
shouldn't be an argument against this patch, no?

Carl Eugen

On Thu, May 21, 2020 at 04:12:56PM +0200, Paul B Mahol wrote:
> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> > On Mon, May 18, 2020 at 01:11:12PM +0200, Paul B Mahol wrote:
> >> This opencv module is obsolete for latest opencv.
> >>
> >> Instead there should be C++ wrapper.
> >
> > Sorry, where is the C++ wrapper? Now Opencv 2.x and 3.x is good
> > to use for my current function. By my initial testing, the performance is
> > very good, we can easily to get realtime for HD, the drawbacks are:
> > 1. The face is not directly opposite and cannot be recognized.
> > 2. there are some false detect for video.
> >
> > If have any old discussion for that, please give the discussion link for
> > reference. I'm not keep track of the ML before.
> 
> Nope, i'm not doing others people work for free.

So are you against continuing to develop existing opencv features？Now I
have tested with opencv 2.10 and 3.10, 3.13, but > 4.0 will not working as
expected for known issue.

> 
> >
> >
> >>
> >> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> >> > From: Limin Wang <lance.lmwang@gmail.com>
> >> >
> >> > Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> >> > ---
> >> > change the update_metadata() to postprocess() only, I'll add opencv
> >> > drawbox
> >> > filter and it need preprocess() to get the meta, so I prefer to change
> >> > the
> >> > function name for better readablity, in future, it may have other
> >> > processing
> >> > than metadata only.
> >> >
> >> >  configure                  |   1 +
> >> >  doc/filters.texi           |  29 +++++++
> >> >  libavfilter/vf_libopencv.c | 164 ++++++++++++++++++++++++++++++++++++-
> >> >  3 files changed, 191 insertions(+), 3 deletions(-)
> >> >
> >> > diff --git a/configure b/configure
> >> > index 34afdaad28..281b67efc4 100755
> >> > --- a/configure
> >> > +++ b/configure
> >> > @@ -2123,6 +2123,7 @@ HEADERS_LIST="
> >> >      machine_ioctl_meteor_h
> >> >      malloc_h
> >> >      opencv2_core_core_c_h
> >> > +    opencv2_objdetect_objdetect_c_h
> >> >      OpenGL_gl3_h
> >> >      poll_h
> >> >      sys_param_h
> >> > diff --git a/doc/filters.texi b/doc/filters.texi
> >> > index d9ba0fffa1..f938dd04de 100644
> >> > --- a/doc/filters.texi
> >> > +++ b/doc/filters.texi
> >> > @@ -14177,6 +14177,35 @@ other parameters is 0.
> >> >  These parameters correspond to the parameters assigned to the
> >> >  libopencv function @code{cvSmooth}.
> >> >
> >> > +@subsection facedetect
> >> > +Face detection using Haar Feature-based Cascade Classifiers.
> >> > +
> >> > +The filter takes the following parameters:
> >> > +@var{xml_model}|@var{qoffset}.
> >> > +
> >> > +@var{xml_model} is the path of pre-trained classifiers, The C API still
> >> > +does not support the newer cascade format, please use the old format
> >> > +haarcascade_frontalface_alt.xml which type_id is
> >> > opencv-haar-classifier.
> >> > +
> >> > +@var{qoffset}
> >> > +If you want export the detected faces by ROI side data in frame, please
> >> > set
> >> > the
> >> > +parameters, See also the @ref{addroi} filter. The range of qoffset is
> >> > from
> >> > [-1.0, 1.0]
> >> > +
> >> > +By default the filter will report these metadata values if face are
> >> > +detected:
> >> > +@table @option
> >> > +@item lavfi.facedetect.nb_faces
> >> > +Display the detected face number
> >> > +
> >> > +@item lavfi.facedetect.face_id.x, lavfi.facedetect.face_id.y
> >> > +Display x and y of every faces, face_id is the face index which is
> >> > range
> >> > +from [0, nb_faces-1]
> >> > +
> >> > +@item lavfi.facedetect.face_id.w, lavfi.facedetect.face_id.h
> >> > +Display width and height of every faces, face_id is the face index
> >> > +which is range from [0, nb_faces-1]
> >> > +@end table
> >> > +
> >> >  @section oscilloscope
> >> >
> >> >  2D Video Oscilloscope.
> >> > diff --git a/libavfilter/vf_libopencv.c b/libavfilter/vf_libopencv.c
> >> > index 8128030b8c..b2d19bb241 100644
> >> > --- a/libavfilter/vf_libopencv.c
> >> > +++ b/libavfilter/vf_libopencv.c
> >> > @@ -1,5 +1,6 @@
> >> >  /*
> >> >   * Copyright (c) 2010 Stefano Sabatini
> >> > + * Copyright (c) 2020 Limin Wang
> >> >   *
> >> >   * This file is part of FFmpeg.
> >> >   *
> >> > @@ -27,10 +28,16 @@
> >> >  #if HAVE_OPENCV2_CORE_CORE_C_H
> >> >  #include <opencv2/core/core_c.h>
> >> >  #include <opencv2/imgproc/imgproc_c.h>
> >> > +#if HAVE_OPENCV2_OBJECTDETECT_OBJECTDETECT_C_H
> >> > +#include <opencv2/objdetect/objdetect_c.h>
> >> > +#else
> >> > +#include <opencv/cv.h>
> >> > +#endif
> >> >  #else
> >> >  #include <opencv/cv.h>
> >> >  #include <opencv/cxcore.h>
> >> >  #endif
> >> > +
> >> >  #include "libavutil/avstring.h"
> >> >  #include "libavutil/common.h"
> >> >  #include "libavutil/file.h"
> >> > @@ -82,6 +89,7 @@ typedef struct OCVContext {
> >> >      int (*init)(AVFilterContext *ctx, const char *args);
> >> >      void (*uninit)(AVFilterContext *ctx);
> >> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
> >> > IplImage *outimg);
> >> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
> >> >      void *priv;
> >> >  } OCVContext;
> >> >
> >> > @@ -326,18 +334,152 @@ static void
> >> > erode_end_frame_filter(AVFilterContext
> >> > *ctx, IplImage *inimg, IplIma
> >> >      cvErode(inimg, outimg, dilate->kernel, dilate->nb_iterations);
> >> >  }
> >> >
> >> > +typedef struct FaceDetectContext {
> >> > +    char *xml_model;
> >> > +    CvHaarClassifierCascade* cascade;
> >> > +    CvMemStorage* storage;
> >> > +    int nb_faces;
> >> > +    CvSeq *faces;
> >> > +    int add_roi;
> >> > +    AVRational qoffset;
> >> > +} FaceDetectContext;
> >> > +
> >> > +static av_cold int facedetect_init(AVFilterContext *ctx, const char
> >> > *args)
> >> > +{
> >> > +    OCVContext *s = ctx->priv;
> >> > +    FaceDetectContext *facedetect = s->priv;
> >> > +    const char *buf = args;
> >> > +    double qoffset;
> >> > +
> >> > +    if (args) {
> >> > +        facedetect->xml_model = av_get_token(&buf, "|");
> >> > +        if (!facedetect->xml_model) {
> >> > +            av_log(ctx, AV_LOG_ERROR, "failed to get %s, %s\n", args,
> >> > facedetect->xml_model);
> >> > +            return AVERROR(EINVAL);
> >> > +        }
> >> > +
> >> > +        if (buf && sscanf(buf, "|%lf", &qoffset) == 1) {
> >> > +            if (qoffset < -1.0 || qoffset > 1.0) {
> >> > +                av_log(ctx, AV_LOG_ERROR, "failed to get valid
> >> > qoffset(%f))\n", qoffset);
> >> > +                return AVERROR(EINVAL);
> >> > +            }
> >> > +            facedetect->add_roi = 1;
> >> > +            facedetect->qoffset = av_d2q(qoffset, 255);
> >> > +        }
> >> > +    } else {
> >> > +        av_log(ctx, AV_LOG_ERROR, "failed to get
> >> > haarcascade_frontalface_alt.xml model file\n");
> >> > +        return AVERROR(EINVAL);
> >> > +    }
> >> > +
> >> > +    av_log(ctx, AV_LOG_VERBOSE, "xml_model: %s add_roi: %d qoffset:
> >> > %d/%d\n",
> >> > +           facedetect->xml_model, facedetect->add_roi,
> >> > facedetect->qoffset.num, facedetect->qoffset.den);
> >> > +
> >> > +    facedetect->storage = cvCreateMemStorage(0);
> >> > +    if (!facedetect->storage) {
> >> > +        av_log(ctx, AV_LOG_ERROR, "cvCreateMemStorage() failed\n");
> >> > +        return AVERROR(EINVAL);
> >> > +    }
> >> > +    cvClearMemStorage(facedetect->storage);
> >> > +
> >> > +    facedetect->cascade = (CvHaarClassifierCascade*)cvLoad(
> >> > facedetect->xml_model, NULL, NULL, NULL );
> >> > +    if (!facedetect->cascade) {
> >> > +        av_log(ctx, AV_LOG_ERROR, "failed to load classifier cascade:
> >> > %s
> >> > \n", facedetect->xml_model);
> >> > +        return AVERROR(EINVAL);
> >> > +    }
> >> > +
> >> > +    return 0;
> >> > +}
> >> > +
> >> > +static av_cold void facedetect_uninit(AVFilterContext *ctx)
> >> > +{
> >> > +    OCVContext *s = ctx->priv;
> >> > +    FaceDetectContext *facedetect = s->priv;
> >> > +
> >> > +    if (facedetect->cascade)
> >> > +        cvReleaseHaarClassifierCascade(&facedetect->cascade);
> >> > +    if (facedetect->storage)
> >> > +        cvReleaseMemStorage(&facedetect->storage);
> >> > +}
> >> > +
> >> > +static void set_meta_int(AVDictionary **metadata, const char *key, int
> >> > idx,
> >> > int d)
> >> > +{
> >> > +    char value[128];
> >> > +    char key2[128];
> >> > +
> >> > +    snprintf(value, sizeof(value), "%d", d);
> >> > +    snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", idx, key);
> >> > +    av_dict_set(metadata, key2, value, 0);
> >> > +}
> >> > +
> >> > +static void facedetect_end_frame_filter(AVFilterContext *ctx, IplImage
> >> > *inimg, IplImage *outimg)
> >> > +{
> >> > +    OCVContext *s = ctx->priv;
> >> > +    FaceDetectContext *facedetect = s->priv;
> >> > +
> >> > +    facedetect->faces = cvHaarDetectObjects(inimg, facedetect->cascade,
> >> > facedetect->storage,
> >> > +            1.25, 3, CV_HAAR_DO_CANNY_PRUNING,
> >> > +            cvSize(inimg->width/16,inimg->height/16), cvSize(0,0));
> >> > +
> >> > +    facedetect->nb_faces = facedetect->faces ? facedetect->faces->total
> >> > :
> >> > 0;
> >> > +}
> >> > +
> >> > +static void facedetect_postprocess(AVFilterContext *ctx, AVFrame *out)
> >> > +{
> >> > +    OCVContext *s = ctx->priv;
> >> > +    FaceDetectContext *facedetect = s->priv;
> >> > +    AVRegionOfInterest *roi;
> >> > +    AVFrameSideData *sd;
> >> > +    AVBufferRef *roi_buf;
> >> > +    int i;
> >> > +
> >> > +    if (facedetect->add_roi && facedetect->nb_faces > 0) {
> >> > +        sd = av_frame_new_side_data(out,
> >> > AV_FRAME_DATA_REGIONS_OF_INTEREST,
> >> > +                facedetect->nb_faces * sizeof(AVRegionOfInterest));
> >> > +        if (!sd) {
> >> > +            return AVERROR(ENOMEM);
> >> > +        }
> >> > +        roi = (AVRegionOfInterest*)sd->data;
> >> > +        for(i = 0; i < facedetect->nb_faces; i++ ) {
> >> > +            CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
> >> > +
> >> > +            roi[i] = (AVRegionOfInterest) {
> >> > +                .self_size = sizeof(*roi),
> >> > +                .top       = r->y,
> >> > +                .bottom    = r->y + r->height,
> >> > +                .left      = r->x,
> >> > +                .right     = r->x + r->width,
> >> > +                .qoffset   = facedetect->qoffset,
> >> > +            };
> >> > +        }
> >> > +    }
> >> > +
> >> > +    if (facedetect->nb_faces > 0)
> >> > +        av_dict_set_int(&out->metadata, "lavfi.facedetect.nb_faces",
> >> > facedetect->nb_faces, 0);
> >> > +
> >> > +    for(i = 0; i < facedetect->nb_faces; i++ ) {
> >> > +        CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
> >> > +
> >> > +        set_meta_int(&out->metadata, "x", i, r->x);
> >> > +        set_meta_int(&out->metadata, "y", i, r->y);
> >> > +        set_meta_int(&out->metadata, "w", i, r->width);
> >> > +        set_meta_int(&out->metadata, "h", i, r->height);
> >> > +    }
> >> > +}
> >> > +
> >> >  typedef struct OCVFilterEntry {
> >> >      const char *name;
> >> >      size_t priv_size;
> >> >      int  (*init)(AVFilterContext *ctx, const char *args);
> >> >      void (*uninit)(AVFilterContext *ctx);
> >> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
> >> > IplImage *outimg);
> >> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
> >> >  } OCVFilterEntry;
> >> >
> >> >  static const OCVFilterEntry ocv_filter_entries[] = {
> >> > -    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
> >> > dilate_end_frame_filter },
> >> > -    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
> >> > erode_end_frame_filter  },
> >> > -    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
> >> > smooth_end_frame_filter },
> >> > +    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
> >> > dilate_end_frame_filter, NULL },
> >> > +    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
> >> > erode_end_frame_filter, NULL },
> >> > +    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
> >> > smooth_end_frame_filter, NULL },
> >> > +    { "facedetect", sizeof(FaceDetectContext), facedetect_init,
> >> > facedetect_uninit, facedetect_end_frame_filter, facedetect_postprocess
> >> > },
> >> >  };
> >> >
> >> >  static av_cold int init(AVFilterContext *ctx)
> >> > @@ -355,6 +497,7 @@ static av_cold int init(AVFilterContext *ctx)
> >> >              s->init             = entry->init;
> >> >              s->uninit           = entry->uninit;
> >> >              s->end_frame_filter = entry->end_frame_filter;
> >> > +            s->postprocess      = entry->postprocess;
> >> >
> >> >              if (!(s->priv = av_mallocz(entry->priv_size)))
> >> >                  return AVERROR(ENOMEM);
> >> > @@ -383,18 +526,33 @@ static int filter_frame(AVFilterLink *inlink,
> >> > AVFrame
> >> > *in)
> >> >      AVFrame *out;
> >> >      IplImage inimg, outimg;
> >> >
> >> > +    /* facedetect filter will passthrought the input frame */
> >> > +    if (strcmp(s->name, "facedetect")) {
> >> >      out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
> >> >      if (!out) {
> >> >          av_frame_free(&in);
> >> >          return AVERROR(ENOMEM);
> >> >      }
> >> >      av_frame_copy_props(out, in);
> >> > +    } else {
> >> > +        out = in;
> >> > +    }
> >> >
> >> >      fill_iplimage_from_frame(&inimg , in , inlink->format);
> >> > +
> >> > +    if (strcmp(s->name, "facedetect")) {
> >> >      fill_iplimage_from_frame(&outimg, out, inlink->format);
> >> >      s->end_frame_filter(ctx, &inimg, &outimg);
> >> >      fill_frame_from_iplimage(out, &outimg, inlink->format);
> >> > +    } else {
> >> > +        s->end_frame_filter(ctx, &inimg, NULL);
> >> > +    }
> >> > +
> >> > +    if (s->postprocess) {
> >> > +        s->postprocess(ctx, out);
> >> > +    }
> >> >
> >> > +    if (out != in)
> >> >      av_frame_free(&in);
> >> >
> >> >      return ff_filter_frame(outlink, out);
> >> > --
> >> > 2.21.0
> >> >
> >> > _______________________________________________
> >> > ffmpeg-devel mailing list
> >> > ffmpeg-devel@ffmpeg.org
> >> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >> >
> >> > To unsubscribe, visit link above, or email
> >> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> >
> > --
> > Thanks,
> > Limin Wang
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel@ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

On 5/21/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> On Thu, May 21, 2020 at 04:12:56PM +0200, Paul B Mahol wrote:
>> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
>> > On Mon, May 18, 2020 at 01:11:12PM +0200, Paul B Mahol wrote:
>> >> This opencv module is obsolete for latest opencv.
>> >>
>> >> Instead there should be C++ wrapper.
>> >
>> > Sorry, where is the C++ wrapper? Now Opencv 2.x and 3.x is good
>> > to use for my current function. By my initial testing, the performance
>> > is
>> > very good, we can easily to get realtime for HD, the drawbacks are:
>> > 1. The face is not directly opposite and cannot be recognized.
>> > 2. there are some false detect for video.
>> >
>> > If have any old discussion for that, please give the discussion link for
>> > reference. I'm not keep track of the ML before.
>>
>> Nope, i'm not doing others people work for free.
>
> So are you against continuing to develop existing opencv features？Now I
> have tested with opencv 2.10 and 3.10, 3.13, but > 4.0 will not working as
> expected for known issue.

Yes, and I want that known issue with latest opencv to be properly
fixed, instead
of using shortcut hacks that will work with old versions only.

>
>>
>> >
>> >
>> >>
>> >> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
>> >> > From: Limin Wang <lance.lmwang@gmail.com>
>> >> >
>> >> > Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
>> >> > ---
>> >> > change the update_metadata() to postprocess() only, I'll add opencv
>> >> > drawbox
>> >> > filter and it need preprocess() to get the meta, so I prefer to
>> >> > change
>> >> > the
>> >> > function name for better readablity, in future, it may have other
>> >> > processing
>> >> > than metadata only.
>> >> >
>> >> >  configure                  |   1 +
>> >> >  doc/filters.texi           |  29 +++++++
>> >> >  libavfilter/vf_libopencv.c | 164
>> >> > ++++++++++++++++++++++++++++++++++++-
>> >> >  3 files changed, 191 insertions(+), 3 deletions(-)
>> >> >
>> >> > diff --git a/configure b/configure
>> >> > index 34afdaad28..281b67efc4 100755
>> >> > --- a/configure
>> >> > +++ b/configure
>> >> > @@ -2123,6 +2123,7 @@ HEADERS_LIST="
>> >> >      machine_ioctl_meteor_h
>> >> >      malloc_h
>> >> >      opencv2_core_core_c_h
>> >> > +    opencv2_objdetect_objdetect_c_h
>> >> >      OpenGL_gl3_h
>> >> >      poll_h
>> >> >      sys_param_h
>> >> > diff --git a/doc/filters.texi b/doc/filters.texi
>> >> > index d9ba0fffa1..f938dd04de 100644
>> >> > --- a/doc/filters.texi
>> >> > +++ b/doc/filters.texi
>> >> > @@ -14177,6 +14177,35 @@ other parameters is 0.
>> >> >  These parameters correspond to the parameters assigned to the
>> >> >  libopencv function @code{cvSmooth}.
>> >> >
>> >> > +@subsection facedetect
>> >> > +Face detection using Haar Feature-based Cascade Classifiers.
>> >> > +
>> >> > +The filter takes the following parameters:
>> >> > +@var{xml_model}|@var{qoffset}.
>> >> > +
>> >> > +@var{xml_model} is the path of pre-trained classifiers, The C API
>> >> > still
>> >> > +does not support the newer cascade format, please use the old format
>> >> > +haarcascade_frontalface_alt.xml which type_id is
>> >> > opencv-haar-classifier.
>> >> > +
>> >> > +@var{qoffset}
>> >> > +If you want export the detected faces by ROI side data in frame,
>> >> > please
>> >> > set
>> >> > the
>> >> > +parameters, See also the @ref{addroi} filter. The range of qoffset
>> >> > is
>> >> > from
>> >> > [-1.0, 1.0]
>> >> > +
>> >> > +By default the filter will report these metadata values if face are
>> >> > +detected:
>> >> > +@table @option
>> >> > +@item lavfi.facedetect.nb_faces
>> >> > +Display the detected face number
>> >> > +
>> >> > +@item lavfi.facedetect.face_id.x, lavfi.facedetect.face_id.y
>> >> > +Display x and y of every faces, face_id is the face index which is
>> >> > range
>> >> > +from [0, nb_faces-1]
>> >> > +
>> >> > +@item lavfi.facedetect.face_id.w, lavfi.facedetect.face_id.h
>> >> > +Display width and height of every faces, face_id is the face index
>> >> > +which is range from [0, nb_faces-1]
>> >> > +@end table
>> >> > +
>> >> >  @section oscilloscope
>> >> >
>> >> >  2D Video Oscilloscope.
>> >> > diff --git a/libavfilter/vf_libopencv.c b/libavfilter/vf_libopencv.c
>> >> > index 8128030b8c..b2d19bb241 100644
>> >> > --- a/libavfilter/vf_libopencv.c
>> >> > +++ b/libavfilter/vf_libopencv.c
>> >> > @@ -1,5 +1,6 @@
>> >> >  /*
>> >> >   * Copyright (c) 2010 Stefano Sabatini
>> >> > + * Copyright (c) 2020 Limin Wang
>> >> >   *
>> >> >   * This file is part of FFmpeg.
>> >> >   *
>> >> > @@ -27,10 +28,16 @@
>> >> >  #if HAVE_OPENCV2_CORE_CORE_C_H
>> >> >  #include <opencv2/core/core_c.h>
>> >> >  #include <opencv2/imgproc/imgproc_c.h>
>> >> > +#if HAVE_OPENCV2_OBJECTDETECT_OBJECTDETECT_C_H
>> >> > +#include <opencv2/objdetect/objdetect_c.h>
>> >> > +#else
>> >> > +#include <opencv/cv.h>
>> >> > +#endif
>> >> >  #else
>> >> >  #include <opencv/cv.h>
>> >> >  #include <opencv/cxcore.h>
>> >> >  #endif
>> >> > +
>> >> >  #include "libavutil/avstring.h"
>> >> >  #include "libavutil/common.h"
>> >> >  #include "libavutil/file.h"
>> >> > @@ -82,6 +89,7 @@ typedef struct OCVContext {
>> >> >      int (*init)(AVFilterContext *ctx, const char *args);
>> >> >      void (*uninit)(AVFilterContext *ctx);
>> >> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
>> >> > IplImage *outimg);
>> >> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
>> >> >      void *priv;
>> >> >  } OCVContext;
>> >> >
>> >> > @@ -326,18 +334,152 @@ static void
>> >> > erode_end_frame_filter(AVFilterContext
>> >> > *ctx, IplImage *inimg, IplIma
>> >> >      cvErode(inimg, outimg, dilate->kernel, dilate->nb_iterations);
>> >> >  }
>> >> >
>> >> > +typedef struct FaceDetectContext {
>> >> > +    char *xml_model;
>> >> > +    CvHaarClassifierCascade* cascade;
>> >> > +    CvMemStorage* storage;
>> >> > +    int nb_faces;
>> >> > +    CvSeq *faces;
>> >> > +    int add_roi;
>> >> > +    AVRational qoffset;
>> >> > +} FaceDetectContext;
>> >> > +
>> >> > +static av_cold int facedetect_init(AVFilterContext *ctx, const char
>> >> > *args)
>> >> > +{
>> >> > +    OCVContext *s = ctx->priv;
>> >> > +    FaceDetectContext *facedetect = s->priv;
>> >> > +    const char *buf = args;
>> >> > +    double qoffset;
>> >> > +
>> >> > +    if (args) {
>> >> > +        facedetect->xml_model = av_get_token(&buf, "|");
>> >> > +        if (!facedetect->xml_model) {
>> >> > +            av_log(ctx, AV_LOG_ERROR, "failed to get %s, %s\n",
>> >> > args,
>> >> > facedetect->xml_model);
>> >> > +            return AVERROR(EINVAL);
>> >> > +        }
>> >> > +
>> >> > +        if (buf && sscanf(buf, "|%lf", &qoffset) == 1) {
>> >> > +            if (qoffset < -1.0 || qoffset > 1.0) {
>> >> > +                av_log(ctx, AV_LOG_ERROR, "failed to get valid
>> >> > qoffset(%f))\n", qoffset);
>> >> > +                return AVERROR(EINVAL);
>> >> > +            }
>> >> > +            facedetect->add_roi = 1;
>> >> > +            facedetect->qoffset = av_d2q(qoffset, 255);
>> >> > +        }
>> >> > +    } else {
>> >> > +        av_log(ctx, AV_LOG_ERROR, "failed to get
>> >> > haarcascade_frontalface_alt.xml model file\n");
>> >> > +        return AVERROR(EINVAL);
>> >> > +    }
>> >> > +
>> >> > +    av_log(ctx, AV_LOG_VERBOSE, "xml_model: %s add_roi: %d qoffset:
>> >> > %d/%d\n",
>> >> > +           facedetect->xml_model, facedetect->add_roi,
>> >> > facedetect->qoffset.num, facedetect->qoffset.den);
>> >> > +
>> >> > +    facedetect->storage = cvCreateMemStorage(0);
>> >> > +    if (!facedetect->storage) {
>> >> > +        av_log(ctx, AV_LOG_ERROR, "cvCreateMemStorage() failed\n");
>> >> > +        return AVERROR(EINVAL);
>> >> > +    }
>> >> > +    cvClearMemStorage(facedetect->storage);
>> >> > +
>> >> > +    facedetect->cascade = (CvHaarClassifierCascade*)cvLoad(
>> >> > facedetect->xml_model, NULL, NULL, NULL );
>> >> > +    if (!facedetect->cascade) {
>> >> > +        av_log(ctx, AV_LOG_ERROR, "failed to load classifier
>> >> > cascade:
>> >> > %s
>> >> > \n", facedetect->xml_model);
>> >> > +        return AVERROR(EINVAL);
>> >> > +    }
>> >> > +
>> >> > +    return 0;
>> >> > +}
>> >> > +
>> >> > +static av_cold void facedetect_uninit(AVFilterContext *ctx)
>> >> > +{
>> >> > +    OCVContext *s = ctx->priv;
>> >> > +    FaceDetectContext *facedetect = s->priv;
>> >> > +
>> >> > +    if (facedetect->cascade)
>> >> > +        cvReleaseHaarClassifierCascade(&facedetect->cascade);
>> >> > +    if (facedetect->storage)
>> >> > +        cvReleaseMemStorage(&facedetect->storage);
>> >> > +}
>> >> > +
>> >> > +static void set_meta_int(AVDictionary **metadata, const char *key,
>> >> > int
>> >> > idx,
>> >> > int d)
>> >> > +{
>> >> > +    char value[128];
>> >> > +    char key2[128];
>> >> > +
>> >> > +    snprintf(value, sizeof(value), "%d", d);
>> >> > +    snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", idx,
>> >> > key);
>> >> > +    av_dict_set(metadata, key2, value, 0);
>> >> > +}
>> >> > +
>> >> > +static void facedetect_end_frame_filter(AVFilterContext *ctx,
>> >> > IplImage
>> >> > *inimg, IplImage *outimg)
>> >> > +{
>> >> > +    OCVContext *s = ctx->priv;
>> >> > +    FaceDetectContext *facedetect = s->priv;
>> >> > +
>> >> > +    facedetect->faces = cvHaarDetectObjects(inimg,
>> >> > facedetect->cascade,
>> >> > facedetect->storage,
>> >> > +            1.25, 3, CV_HAAR_DO_CANNY_PRUNING,
>> >> > +            cvSize(inimg->width/16,inimg->height/16), cvSize(0,0));
>> >> > +
>> >> > +    facedetect->nb_faces = facedetect->faces ?
>> >> > facedetect->faces->total
>> >> > :
>> >> > 0;
>> >> > +}
>> >> > +
>> >> > +static void facedetect_postprocess(AVFilterContext *ctx, AVFrame
>> >> > *out)
>> >> > +{
>> >> > +    OCVContext *s = ctx->priv;
>> >> > +    FaceDetectContext *facedetect = s->priv;
>> >> > +    AVRegionOfInterest *roi;
>> >> > +    AVFrameSideData *sd;
>> >> > +    AVBufferRef *roi_buf;
>> >> > +    int i;
>> >> > +
>> >> > +    if (facedetect->add_roi && facedetect->nb_faces > 0) {
>> >> > +        sd = av_frame_new_side_data(out,
>> >> > AV_FRAME_DATA_REGIONS_OF_INTEREST,
>> >> > +                facedetect->nb_faces * sizeof(AVRegionOfInterest));
>> >> > +        if (!sd) {
>> >> > +            return AVERROR(ENOMEM);
>> >> > +        }
>> >> > +        roi = (AVRegionOfInterest*)sd->data;
>> >> > +        for(i = 0; i < facedetect->nb_faces; i++ ) {
>> >> > +            CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces,
>> >> > i);
>> >> > +
>> >> > +            roi[i] = (AVRegionOfInterest) {
>> >> > +                .self_size = sizeof(*roi),
>> >> > +                .top       = r->y,
>> >> > +                .bottom    = r->y + r->height,
>> >> > +                .left      = r->x,
>> >> > +                .right     = r->x + r->width,
>> >> > +                .qoffset   = facedetect->qoffset,
>> >> > +            };
>> >> > +        }
>> >> > +    }
>> >> > +
>> >> > +    if (facedetect->nb_faces > 0)
>> >> > +        av_dict_set_int(&out->metadata, "lavfi.facedetect.nb_faces",
>> >> > facedetect->nb_faces, 0);
>> >> > +
>> >> > +    for(i = 0; i < facedetect->nb_faces; i++ ) {
>> >> > +        CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
>> >> > +
>> >> > +        set_meta_int(&out->metadata, "x", i, r->x);
>> >> > +        set_meta_int(&out->metadata, "y", i, r->y);
>> >> > +        set_meta_int(&out->metadata, "w", i, r->width);
>> >> > +        set_meta_int(&out->metadata, "h", i, r->height);
>> >> > +    }
>> >> > +}
>> >> > +
>> >> >  typedef struct OCVFilterEntry {
>> >> >      const char *name;
>> >> >      size_t priv_size;
>> >> >      int  (*init)(AVFilterContext *ctx, const char *args);
>> >> >      void (*uninit)(AVFilterContext *ctx);
>> >> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
>> >> > IplImage *outimg);
>> >> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
>> >> >  } OCVFilterEntry;
>> >> >
>> >> >  static const OCVFilterEntry ocv_filter_entries[] = {
>> >> > -    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
>> >> > dilate_end_frame_filter },
>> >> > -    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
>> >> > erode_end_frame_filter  },
>> >> > -    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
>> >> > smooth_end_frame_filter },
>> >> > +    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
>> >> > dilate_end_frame_filter, NULL },
>> >> > +    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
>> >> > erode_end_frame_filter, NULL },
>> >> > +    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
>> >> > smooth_end_frame_filter, NULL },
>> >> > +    { "facedetect", sizeof(FaceDetectContext), facedetect_init,
>> >> > facedetect_uninit, facedetect_end_frame_filter,
>> >> > facedetect_postprocess
>> >> > },
>> >> >  };
>> >> >
>> >> >  static av_cold int init(AVFilterContext *ctx)
>> >> > @@ -355,6 +497,7 @@ static av_cold int init(AVFilterContext *ctx)
>> >> >              s->init             = entry->init;
>> >> >              s->uninit           = entry->uninit;
>> >> >              s->end_frame_filter = entry->end_frame_filter;
>> >> > +            s->postprocess      = entry->postprocess;
>> >> >
>> >> >              if (!(s->priv = av_mallocz(entry->priv_size)))
>> >> >                  return AVERROR(ENOMEM);
>> >> > @@ -383,18 +526,33 @@ static int filter_frame(AVFilterLink *inlink,
>> >> > AVFrame
>> >> > *in)
>> >> >      AVFrame *out;
>> >> >      IplImage inimg, outimg;
>> >> >
>> >> > +    /* facedetect filter will passthrought the input frame */
>> >> > +    if (strcmp(s->name, "facedetect")) {
>> >> >      out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
>> >> >      if (!out) {
>> >> >          av_frame_free(&in);
>> >> >          return AVERROR(ENOMEM);
>> >> >      }
>> >> >      av_frame_copy_props(out, in);
>> >> > +    } else {
>> >> > +        out = in;
>> >> > +    }
>> >> >
>> >> >      fill_iplimage_from_frame(&inimg , in , inlink->format);
>> >> > +
>> >> > +    if (strcmp(s->name, "facedetect")) {
>> >> >      fill_iplimage_from_frame(&outimg, out, inlink->format);
>> >> >      s->end_frame_filter(ctx, &inimg, &outimg);
>> >> >      fill_frame_from_iplimage(out, &outimg, inlink->format);
>> >> > +    } else {
>> >> > +        s->end_frame_filter(ctx, &inimg, NULL);
>> >> > +    }
>> >> > +
>> >> > +    if (s->postprocess) {
>> >> > +        s->postprocess(ctx, out);
>> >> > +    }
>> >> >
>> >> > +    if (out != in)
>> >> >      av_frame_free(&in);
>> >> >
>> >> >      return ff_filter_frame(outlink, out);
>> >> > --
>> >> > 2.21.0
>> >> >
>> >> > _______________________________________________
>> >> > ffmpeg-devel mailing list
>> >> > ffmpeg-devel@ffmpeg.org
>> >> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> >> >
>> >> > To unsubscribe, visit link above, or email
>> >> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>> >
>> > --
>> > Thanks,
>> > Limin Wang
>> > _______________________________________________
>> > ffmpeg-devel mailing list
>> > ffmpeg-devel@ffmpeg.org
>> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> >
>> > To unsubscribe, visit link above, or email
>> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
> --
> Thanks,
> Limin Wang
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

On Thu, May 21, 2020 at 04:44:26PM +0200, Paul B Mahol wrote:
> On 5/21/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> > On Thu, May 21, 2020 at 04:12:56PM +0200, Paul B Mahol wrote:
> >> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> >> > On Mon, May 18, 2020 at 01:11:12PM +0200, Paul B Mahol wrote:
> >> >> This opencv module is obsolete for latest opencv.
> >> >>
> >> >> Instead there should be C++ wrapper.
> >> >
> >> > Sorry, where is the C++ wrapper? Now Opencv 2.x and 3.x is good
> >> > to use for my current function. By my initial testing, the performance
> >> > is
> >> > very good, we can easily to get realtime for HD, the drawbacks are:
> >> > 1. The face is not directly opposite and cannot be recognized.
> >> > 2. there are some false detect for video.
> >> >
> >> > If have any old discussion for that, please give the discussion link for
> >> > reference. I'm not keep track of the ML before.
> >>
> >> Nope, i'm not doing others people work for free.
> >
> > So are you against continuing to develop existing opencv features？Now I
> > have tested with opencv 2.10 and 3.10, 3.13, but > 4.0 will not working as
> > expected for known issue.
> 
> Yes, and I want that known issue with latest opencv to be properly
> fixed, instead
> of using shortcut hacks that will work with old versions only.

The question is without my patchset, the current opencv didn't work with the
latest opencv still, it's not new issue.  Or we should mark the opencv filter
deprecated and remove it, or someone write a c++ wrapper to replace it.

Also the current function haven't depend on the latest opencv version yet.

> 
> >
> >>
> >> >
> >> >
> >> >>
> >> >> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> >> >> > From: Limin Wang <lance.lmwang@gmail.com>
> >> >> >
> >> >> > Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> >> >> > ---
> >> >> > change the update_metadata() to postprocess() only, I'll add opencv
> >> >> > drawbox
> >> >> > filter and it need preprocess() to get the meta, so I prefer to
> >> >> > change
> >> >> > the
> >> >> > function name for better readablity, in future, it may have other
> >> >> > processing
> >> >> > than metadata only.
> >> >> >
> >> >> >  configure                  |   1 +
> >> >> >  doc/filters.texi           |  29 +++++++
> >> >> >  libavfilter/vf_libopencv.c | 164
> >> >> > ++++++++++++++++++++++++++++++++++++-
> >> >> >  3 files changed, 191 insertions(+), 3 deletions(-)
> >> >> >
> >> >> > diff --git a/configure b/configure
> >> >> > index 34afdaad28..281b67efc4 100755
> >> >> > --- a/configure
> >> >> > +++ b/configure
> >> >> > @@ -2123,6 +2123,7 @@ HEADERS_LIST="
> >> >> >      machine_ioctl_meteor_h
> >> >> >      malloc_h
> >> >> >      opencv2_core_core_c_h
> >> >> > +    opencv2_objdetect_objdetect_c_h
> >> >> >      OpenGL_gl3_h
> >> >> >      poll_h
> >> >> >      sys_param_h
> >> >> > diff --git a/doc/filters.texi b/doc/filters.texi
> >> >> > index d9ba0fffa1..f938dd04de 100644
> >> >> > --- a/doc/filters.texi
> >> >> > +++ b/doc/filters.texi
> >> >> > @@ -14177,6 +14177,35 @@ other parameters is 0.
> >> >> >  These parameters correspond to the parameters assigned to the
> >> >> >  libopencv function @code{cvSmooth}.
> >> >> >
> >> >> > +@subsection facedetect
> >> >> > +Face detection using Haar Feature-based Cascade Classifiers.
> >> >> > +
> >> >> > +The filter takes the following parameters:
> >> >> > +@var{xml_model}|@var{qoffset}.
> >> >> > +
> >> >> > +@var{xml_model} is the path of pre-trained classifiers, The C API
> >> >> > still
> >> >> > +does not support the newer cascade format, please use the old format
> >> >> > +haarcascade_frontalface_alt.xml which type_id is
> >> >> > opencv-haar-classifier.
> >> >> > +
> >> >> > +@var{qoffset}
> >> >> > +If you want export the detected faces by ROI side data in frame,
> >> >> > please
> >> >> > set
> >> >> > the
> >> >> > +parameters, See also the @ref{addroi} filter. The range of qoffset
> >> >> > is
> >> >> > from
> >> >> > [-1.0, 1.0]
> >> >> > +
> >> >> > +By default the filter will report these metadata values if face are
> >> >> > +detected:
> >> >> > +@table @option
> >> >> > +@item lavfi.facedetect.nb_faces
> >> >> > +Display the detected face number
> >> >> > +
> >> >> > +@item lavfi.facedetect.face_id.x, lavfi.facedetect.face_id.y
> >> >> > +Display x and y of every faces, face_id is the face index which is
> >> >> > range
> >> >> > +from [0, nb_faces-1]
> >> >> > +
> >> >> > +@item lavfi.facedetect.face_id.w, lavfi.facedetect.face_id.h
> >> >> > +Display width and height of every faces, face_id is the face index
> >> >> > +which is range from [0, nb_faces-1]
> >> >> > +@end table
> >> >> > +
> >> >> >  @section oscilloscope
> >> >> >
> >> >> >  2D Video Oscilloscope.
> >> >> > diff --git a/libavfilter/vf_libopencv.c b/libavfilter/vf_libopencv.c
> >> >> > index 8128030b8c..b2d19bb241 100644
> >> >> > --- a/libavfilter/vf_libopencv.c
> >> >> > +++ b/libavfilter/vf_libopencv.c
> >> >> > @@ -1,5 +1,6 @@
> >> >> >  /*
> >> >> >   * Copyright (c) 2010 Stefano Sabatini
> >> >> > + * Copyright (c) 2020 Limin Wang
> >> >> >   *
> >> >> >   * This file is part of FFmpeg.
> >> >> >   *
> >> >> > @@ -27,10 +28,16 @@
> >> >> >  #if HAVE_OPENCV2_CORE_CORE_C_H
> >> >> >  #include <opencv2/core/core_c.h>
> >> >> >  #include <opencv2/imgproc/imgproc_c.h>
> >> >> > +#if HAVE_OPENCV2_OBJECTDETECT_OBJECTDETECT_C_H
> >> >> > +#include <opencv2/objdetect/objdetect_c.h>
> >> >> > +#else
> >> >> > +#include <opencv/cv.h>
> >> >> > +#endif
> >> >> >  #else
> >> >> >  #include <opencv/cv.h>
> >> >> >  #include <opencv/cxcore.h>
> >> >> >  #endif
> >> >> > +
> >> >> >  #include "libavutil/avstring.h"
> >> >> >  #include "libavutil/common.h"
> >> >> >  #include "libavutil/file.h"
> >> >> > @@ -82,6 +89,7 @@ typedef struct OCVContext {
> >> >> >      int (*init)(AVFilterContext *ctx, const char *args);
> >> >> >      void (*uninit)(AVFilterContext *ctx);
> >> >> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
> >> >> > IplImage *outimg);
> >> >> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
> >> >> >      void *priv;
> >> >> >  } OCVContext;
> >> >> >
> >> >> > @@ -326,18 +334,152 @@ static void
> >> >> > erode_end_frame_filter(AVFilterContext
> >> >> > *ctx, IplImage *inimg, IplIma
> >> >> >      cvErode(inimg, outimg, dilate->kernel, dilate->nb_iterations);
> >> >> >  }
> >> >> >
> >> >> > +typedef struct FaceDetectContext {
> >> >> > +    char *xml_model;
> >> >> > +    CvHaarClassifierCascade* cascade;
> >> >> > +    CvMemStorage* storage;
> >> >> > +    int nb_faces;
> >> >> > +    CvSeq *faces;
> >> >> > +    int add_roi;
> >> >> > +    AVRational qoffset;
> >> >> > +} FaceDetectContext;
> >> >> > +
> >> >> > +static av_cold int facedetect_init(AVFilterContext *ctx, const char
> >> >> > *args)
> >> >> > +{
> >> >> > +    OCVContext *s = ctx->priv;
> >> >> > +    FaceDetectContext *facedetect = s->priv;
> >> >> > +    const char *buf = args;
> >> >> > +    double qoffset;
> >> >> > +
> >> >> > +    if (args) {
> >> >> > +        facedetect->xml_model = av_get_token(&buf, "|");
> >> >> > +        if (!facedetect->xml_model) {
> >> >> > +            av_log(ctx, AV_LOG_ERROR, "failed to get %s, %s\n",
> >> >> > args,
> >> >> > facedetect->xml_model);
> >> >> > +            return AVERROR(EINVAL);
> >> >> > +        }
> >> >> > +
> >> >> > +        if (buf && sscanf(buf, "|%lf", &qoffset) == 1) {
> >> >> > +            if (qoffset < -1.0 || qoffset > 1.0) {
> >> >> > +                av_log(ctx, AV_LOG_ERROR, "failed to get valid
> >> >> > qoffset(%f))\n", qoffset);
> >> >> > +                return AVERROR(EINVAL);
> >> >> > +            }
> >> >> > +            facedetect->add_roi = 1;
> >> >> > +            facedetect->qoffset = av_d2q(qoffset, 255);
> >> >> > +        }
> >> >> > +    } else {
> >> >> > +        av_log(ctx, AV_LOG_ERROR, "failed to get
> >> >> > haarcascade_frontalface_alt.xml model file\n");
> >> >> > +        return AVERROR(EINVAL);
> >> >> > +    }
> >> >> > +
> >> >> > +    av_log(ctx, AV_LOG_VERBOSE, "xml_model: %s add_roi: %d qoffset:
> >> >> > %d/%d\n",
> >> >> > +           facedetect->xml_model, facedetect->add_roi,
> >> >> > facedetect->qoffset.num, facedetect->qoffset.den);
> >> >> > +
> >> >> > +    facedetect->storage = cvCreateMemStorage(0);
> >> >> > +    if (!facedetect->storage) {
> >> >> > +        av_log(ctx, AV_LOG_ERROR, "cvCreateMemStorage() failed\n");
> >> >> > +        return AVERROR(EINVAL);
> >> >> > +    }
> >> >> > +    cvClearMemStorage(facedetect->storage);
> >> >> > +
> >> >> > +    facedetect->cascade = (CvHaarClassifierCascade*)cvLoad(
> >> >> > facedetect->xml_model, NULL, NULL, NULL );
> >> >> > +    if (!facedetect->cascade) {
> >> >> > +        av_log(ctx, AV_LOG_ERROR, "failed to load classifier
> >> >> > cascade:
> >> >> > %s
> >> >> > \n", facedetect->xml_model);
> >> >> > +        return AVERROR(EINVAL);
> >> >> > +    }
> >> >> > +
> >> >> > +    return 0;
> >> >> > +}
> >> >> > +
> >> >> > +static av_cold void facedetect_uninit(AVFilterContext *ctx)
> >> >> > +{
> >> >> > +    OCVContext *s = ctx->priv;
> >> >> > +    FaceDetectContext *facedetect = s->priv;
> >> >> > +
> >> >> > +    if (facedetect->cascade)
> >> >> > +        cvReleaseHaarClassifierCascade(&facedetect->cascade);
> >> >> > +    if (facedetect->storage)
> >> >> > +        cvReleaseMemStorage(&facedetect->storage);
> >> >> > +}
> >> >> > +
> >> >> > +static void set_meta_int(AVDictionary **metadata, const char *key,
> >> >> > int
> >> >> > idx,
> >> >> > int d)
> >> >> > +{
> >> >> > +    char value[128];
> >> >> > +    char key2[128];
> >> >> > +
> >> >> > +    snprintf(value, sizeof(value), "%d", d);
> >> >> > +    snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", idx,
> >> >> > key);
> >> >> > +    av_dict_set(metadata, key2, value, 0);
> >> >> > +}
> >> >> > +
> >> >> > +static void facedetect_end_frame_filter(AVFilterContext *ctx,
> >> >> > IplImage
> >> >> > *inimg, IplImage *outimg)
> >> >> > +{
> >> >> > +    OCVContext *s = ctx->priv;
> >> >> > +    FaceDetectContext *facedetect = s->priv;
> >> >> > +
> >> >> > +    facedetect->faces = cvHaarDetectObjects(inimg,
> >> >> > facedetect->cascade,
> >> >> > facedetect->storage,
> >> >> > +            1.25, 3, CV_HAAR_DO_CANNY_PRUNING,
> >> >> > +            cvSize(inimg->width/16,inimg->height/16), cvSize(0,0));
> >> >> > +
> >> >> > +    facedetect->nb_faces = facedetect->faces ?
> >> >> > facedetect->faces->total
> >> >> > :
> >> >> > 0;
> >> >> > +}
> >> >> > +
> >> >> > +static void facedetect_postprocess(AVFilterContext *ctx, AVFrame
> >> >> > *out)
> >> >> > +{
> >> >> > +    OCVContext *s = ctx->priv;
> >> >> > +    FaceDetectContext *facedetect = s->priv;
> >> >> > +    AVRegionOfInterest *roi;
> >> >> > +    AVFrameSideData *sd;
> >> >> > +    AVBufferRef *roi_buf;
> >> >> > +    int i;
> >> >> > +
> >> >> > +    if (facedetect->add_roi && facedetect->nb_faces > 0) {
> >> >> > +        sd = av_frame_new_side_data(out,
> >> >> > AV_FRAME_DATA_REGIONS_OF_INTEREST,
> >> >> > +                facedetect->nb_faces * sizeof(AVRegionOfInterest));
> >> >> > +        if (!sd) {
> >> >> > +            return AVERROR(ENOMEM);
> >> >> > +        }
> >> >> > +        roi = (AVRegionOfInterest*)sd->data;
> >> >> > +        for(i = 0; i < facedetect->nb_faces; i++ ) {
> >> >> > +            CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces,
> >> >> > i);
> >> >> > +
> >> >> > +            roi[i] = (AVRegionOfInterest) {
> >> >> > +                .self_size = sizeof(*roi),
> >> >> > +                .top       = r->y,
> >> >> > +                .bottom    = r->y + r->height,
> >> >> > +                .left      = r->x,
> >> >> > +                .right     = r->x + r->width,
> >> >> > +                .qoffset   = facedetect->qoffset,
> >> >> > +            };
> >> >> > +        }
> >> >> > +    }
> >> >> > +
> >> >> > +    if (facedetect->nb_faces > 0)
> >> >> > +        av_dict_set_int(&out->metadata, "lavfi.facedetect.nb_faces",
> >> >> > facedetect->nb_faces, 0);
> >> >> > +
> >> >> > +    for(i = 0; i < facedetect->nb_faces; i++ ) {
> >> >> > +        CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
> >> >> > +
> >> >> > +        set_meta_int(&out->metadata, "x", i, r->x);
> >> >> > +        set_meta_int(&out->metadata, "y", i, r->y);
> >> >> > +        set_meta_int(&out->metadata, "w", i, r->width);
> >> >> > +        set_meta_int(&out->metadata, "h", i, r->height);
> >> >> > +    }
> >> >> > +}
> >> >> > +
> >> >> >  typedef struct OCVFilterEntry {
> >> >> >      const char *name;
> >> >> >      size_t priv_size;
> >> >> >      int  (*init)(AVFilterContext *ctx, const char *args);
> >> >> >      void (*uninit)(AVFilterContext *ctx);
> >> >> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage *inimg,
> >> >> > IplImage *outimg);
> >> >> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
> >> >> >  } OCVFilterEntry;
> >> >> >
> >> >> >  static const OCVFilterEntry ocv_filter_entries[] = {
> >> >> > -    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
> >> >> > dilate_end_frame_filter },
> >> >> > -    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
> >> >> > erode_end_frame_filter  },
> >> >> > -    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
> >> >> > smooth_end_frame_filter },
> >> >> > +    { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit,
> >> >> > dilate_end_frame_filter, NULL },
> >> >> > +    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit,
> >> >> > erode_end_frame_filter, NULL },
> >> >> > +    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
> >> >> > smooth_end_frame_filter, NULL },
> >> >> > +    { "facedetect", sizeof(FaceDetectContext), facedetect_init,
> >> >> > facedetect_uninit, facedetect_end_frame_filter,
> >> >> > facedetect_postprocess
> >> >> > },
> >> >> >  };
> >> >> >
> >> >> >  static av_cold int init(AVFilterContext *ctx)
> >> >> > @@ -355,6 +497,7 @@ static av_cold int init(AVFilterContext *ctx)
> >> >> >              s->init             = entry->init;
> >> >> >              s->uninit           = entry->uninit;
> >> >> >              s->end_frame_filter = entry->end_frame_filter;
> >> >> > +            s->postprocess      = entry->postprocess;
> >> >> >
> >> >> >              if (!(s->priv = av_mallocz(entry->priv_size)))
> >> >> >                  return AVERROR(ENOMEM);
> >> >> > @@ -383,18 +526,33 @@ static int filter_frame(AVFilterLink *inlink,
> >> >> > AVFrame
> >> >> > *in)
> >> >> >      AVFrame *out;
> >> >> >      IplImage inimg, outimg;
> >> >> >
> >> >> > +    /* facedetect filter will passthrought the input frame */
> >> >> > +    if (strcmp(s->name, "facedetect")) {
> >> >> >      out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
> >> >> >      if (!out) {
> >> >> >          av_frame_free(&in);
> >> >> >          return AVERROR(ENOMEM);
> >> >> >      }
> >> >> >      av_frame_copy_props(out, in);
> >> >> > +    } else {
> >> >> > +        out = in;
> >> >> > +    }
> >> >> >
> >> >> >      fill_iplimage_from_frame(&inimg , in , inlink->format);
> >> >> > +
> >> >> > +    if (strcmp(s->name, "facedetect")) {
> >> >> >      fill_iplimage_from_frame(&outimg, out, inlink->format);
> >> >> >      s->end_frame_filter(ctx, &inimg, &outimg);
> >> >> >      fill_frame_from_iplimage(out, &outimg, inlink->format);
> >> >> > +    } else {
> >> >> > +        s->end_frame_filter(ctx, &inimg, NULL);
> >> >> > +    }
> >> >> > +
> >> >> > +    if (s->postprocess) {
> >> >> > +        s->postprocess(ctx, out);
> >> >> > +    }
> >> >> >
> >> >> > +    if (out != in)
> >> >> >      av_frame_free(&in);
> >> >> >
> >> >> >      return ff_filter_frame(outlink, out);
> >> >> > --
> >> >> > 2.21.0
> >> >> >
> >> >> > _______________________________________________
> >> >> > ffmpeg-devel mailing list
> >> >> > ffmpeg-devel@ffmpeg.org
> >> >> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >> >> >
> >> >> > To unsubscribe, visit link above, or email
> >> >> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> >> >
> >> > --
> >> > Thanks,
> >> > Limin Wang
> >> > _______________________________________________
> >> > ffmpeg-devel mailing list
> >> > ffmpeg-devel@ffmpeg.org
> >> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >> >
> >> > To unsubscribe, visit link above, or email
> >> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> >> _______________________________________________
> >> ffmpeg-devel mailing list
> >> ffmpeg-devel@ffmpeg.org
> >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >>
> >> To unsubscribe, visit link above, or email
> >> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> >
> > --
> > Thanks,
> > Limin Wang
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel@ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

I kindly ask everybody including you to stop wasting time on
supporting only old opencv versions features, and instead to use such
resources in writing C++ filter wrapper with same name which will work
with latest opencv version.

Consider this module/file deprecated.

On 5/21/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
> On Thu, May 21, 2020 at 04:44:26PM +0200, Paul B Mahol wrote:
>> On 5/21/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
>> > On Thu, May 21, 2020 at 04:12:56PM +0200, Paul B Mahol wrote:
>> >> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
>> >> > On Mon, May 18, 2020 at 01:11:12PM +0200, Paul B Mahol wrote:
>> >> >> This opencv module is obsolete for latest opencv.
>> >> >>
>> >> >> Instead there should be C++ wrapper.
>> >> >
>> >> > Sorry, where is the C++ wrapper? Now Opencv 2.x and 3.x is good
>> >> > to use for my current function. By my initial testing, the
>> >> > performance
>> >> > is
>> >> > very good, we can easily to get realtime for HD, the drawbacks are:
>> >> > 1. The face is not directly opposite and cannot be recognized.
>> >> > 2. there are some false detect for video.
>> >> >
>> >> > If have any old discussion for that, please give the discussion link
>> >> > for
>> >> > reference. I'm not keep track of the ML before.
>> >>
>> >> Nope, i'm not doing others people work for free.
>> >
>> > So are you against continuing to develop existing opencv features？Now I
>> > have tested with opencv 2.10 and 3.10, 3.13, but > 4.0 will not working
>> > as
>> > expected for known issue.
>>
>> Yes, and I want that known issue with latest opencv to be properly
>> fixed, instead
>> of using shortcut hacks that will work with old versions only.
>
> The question is without my patchset, the current opencv didn't work with the
> latest opencv still, it's not new issue.  Or we should mark the opencv
> filter
> deprecated and remove it, or someone write a c++ wrapper to replace it.
>
> Also the current function haven't depend on the latest opencv version yet.
>
>>
>> >
>> >>
>> >> >
>> >> >
>> >> >>
>> >> >> On 5/18/20, lance.lmwang@gmail.com <lance.lmwang@gmail.com> wrote:
>> >> >> > From: Limin Wang <lance.lmwang@gmail.com>
>> >> >> >
>> >> >> > Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
>> >> >> > ---
>> >> >> > change the update_metadata() to postprocess() only, I'll add
>> >> >> > opencv
>> >> >> > drawbox
>> >> >> > filter and it need preprocess() to get the meta, so I prefer to
>> >> >> > change
>> >> >> > the
>> >> >> > function name for better readablity, in future, it may have other
>> >> >> > processing
>> >> >> > than metadata only.
>> >> >> >
>> >> >> >  configure                  |   1 +
>> >> >> >  doc/filters.texi           |  29 +++++++
>> >> >> >  libavfilter/vf_libopencv.c | 164
>> >> >> > ++++++++++++++++++++++++++++++++++++-
>> >> >> >  3 files changed, 191 insertions(+), 3 deletions(-)
>> >> >> >
>> >> >> > diff --git a/configure b/configure
>> >> >> > index 34afdaad28..281b67efc4 100755
>> >> >> > --- a/configure
>> >> >> > +++ b/configure
>> >> >> > @@ -2123,6 +2123,7 @@ HEADERS_LIST="
>> >> >> >      machine_ioctl_meteor_h
>> >> >> >      malloc_h
>> >> >> >      opencv2_core_core_c_h
>> >> >> > +    opencv2_objdetect_objdetect_c_h
>> >> >> >      OpenGL_gl3_h
>> >> >> >      poll_h
>> >> >> >      sys_param_h
>> >> >> > diff --git a/doc/filters.texi b/doc/filters.texi
>> >> >> > index d9ba0fffa1..f938dd04de 100644
>> >> >> > --- a/doc/filters.texi
>> >> >> > +++ b/doc/filters.texi
>> >> >> > @@ -14177,6 +14177,35 @@ other parameters is 0.
>> >> >> >  These parameters correspond to the parameters assigned to the
>> >> >> >  libopencv function @code{cvSmooth}.
>> >> >> >
>> >> >> > +@subsection facedetect
>> >> >> > +Face detection using Haar Feature-based Cascade Classifiers.
>> >> >> > +
>> >> >> > +The filter takes the following parameters:
>> >> >> > +@var{xml_model}|@var{qoffset}.
>> >> >> > +
>> >> >> > +@var{xml_model} is the path of pre-trained classifiers, The C API
>> >> >> > still
>> >> >> > +does not support the newer cascade format, please use the old
>> >> >> > format
>> >> >> > +haarcascade_frontalface_alt.xml which type_id is
>> >> >> > opencv-haar-classifier.
>> >> >> > +
>> >> >> > +@var{qoffset}
>> >> >> > +If you want export the detected faces by ROI side data in frame,
>> >> >> > please
>> >> >> > set
>> >> >> > the
>> >> >> > +parameters, See also the @ref{addroi} filter. The range of
>> >> >> > qoffset
>> >> >> > is
>> >> >> > from
>> >> >> > [-1.0, 1.0]
>> >> >> > +
>> >> >> > +By default the filter will report these metadata values if face
>> >> >> > are
>> >> >> > +detected:
>> >> >> > +@table @option
>> >> >> > +@item lavfi.facedetect.nb_faces
>> >> >> > +Display the detected face number
>> >> >> > +
>> >> >> > +@item lavfi.facedetect.face_id.x, lavfi.facedetect.face_id.y
>> >> >> > +Display x and y of every faces, face_id is the face index which
>> >> >> > is
>> >> >> > range
>> >> >> > +from [0, nb_faces-1]
>> >> >> > +
>> >> >> > +@item lavfi.facedetect.face_id.w, lavfi.facedetect.face_id.h
>> >> >> > +Display width and height of every faces, face_id is the face
>> >> >> > index
>> >> >> > +which is range from [0, nb_faces-1]
>> >> >> > +@end table
>> >> >> > +
>> >> >> >  @section oscilloscope
>> >> >> >
>> >> >> >  2D Video Oscilloscope.
>> >> >> > diff --git a/libavfilter/vf_libopencv.c
>> >> >> > b/libavfilter/vf_libopencv.c
>> >> >> > index 8128030b8c..b2d19bb241 100644
>> >> >> > --- a/libavfilter/vf_libopencv.c
>> >> >> > +++ b/libavfilter/vf_libopencv.c
>> >> >> > @@ -1,5 +1,6 @@
>> >> >> >  /*
>> >> >> >   * Copyright (c) 2010 Stefano Sabatini
>> >> >> > + * Copyright (c) 2020 Limin Wang
>> >> >> >   *
>> >> >> >   * This file is part of FFmpeg.
>> >> >> >   *
>> >> >> > @@ -27,10 +28,16 @@
>> >> >> >  #if HAVE_OPENCV2_CORE_CORE_C_H
>> >> >> >  #include <opencv2/core/core_c.h>
>> >> >> >  #include <opencv2/imgproc/imgproc_c.h>
>> >> >> > +#if HAVE_OPENCV2_OBJECTDETECT_OBJECTDETECT_C_H
>> >> >> > +#include <opencv2/objdetect/objdetect_c.h>
>> >> >> > +#else
>> >> >> > +#include <opencv/cv.h>
>> >> >> > +#endif
>> >> >> >  #else
>> >> >> >  #include <opencv/cv.h>
>> >> >> >  #include <opencv/cxcore.h>
>> >> >> >  #endif
>> >> >> > +
>> >> >> >  #include "libavutil/avstring.h"
>> >> >> >  #include "libavutil/common.h"
>> >> >> >  #include "libavutil/file.h"
>> >> >> > @@ -82,6 +89,7 @@ typedef struct OCVContext {
>> >> >> >      int (*init)(AVFilterContext *ctx, const char *args);
>> >> >> >      void (*uninit)(AVFilterContext *ctx);
>> >> >> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage
>> >> >> > *inimg,
>> >> >> > IplImage *outimg);
>> >> >> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
>> >> >> >      void *priv;
>> >> >> >  } OCVContext;
>> >> >> >
>> >> >> > @@ -326,18 +334,152 @@ static void
>> >> >> > erode_end_frame_filter(AVFilterContext
>> >> >> > *ctx, IplImage *inimg, IplIma
>> >> >> >      cvErode(inimg, outimg, dilate->kernel,
>> >> >> > dilate->nb_iterations);
>> >> >> >  }
>> >> >> >
>> >> >> > +typedef struct FaceDetectContext {
>> >> >> > +    char *xml_model;
>> >> >> > +    CvHaarClassifierCascade* cascade;
>> >> >> > +    CvMemStorage* storage;
>> >> >> > +    int nb_faces;
>> >> >> > +    CvSeq *faces;
>> >> >> > +    int add_roi;
>> >> >> > +    AVRational qoffset;
>> >> >> > +} FaceDetectContext;
>> >> >> > +
>> >> >> > +static av_cold int facedetect_init(AVFilterContext *ctx, const
>> >> >> > char
>> >> >> > *args)
>> >> >> > +{
>> >> >> > +    OCVContext *s = ctx->priv;
>> >> >> > +    FaceDetectContext *facedetect = s->priv;
>> >> >> > +    const char *buf = args;
>> >> >> > +    double qoffset;
>> >> >> > +
>> >> >> > +    if (args) {
>> >> >> > +        facedetect->xml_model = av_get_token(&buf, "|");
>> >> >> > +        if (!facedetect->xml_model) {
>> >> >> > +            av_log(ctx, AV_LOG_ERROR, "failed to get %s, %s\n",
>> >> >> > args,
>> >> >> > facedetect->xml_model);
>> >> >> > +            return AVERROR(EINVAL);
>> >> >> > +        }
>> >> >> > +
>> >> >> > +        if (buf && sscanf(buf, "|%lf", &qoffset) == 1) {
>> >> >> > +            if (qoffset < -1.0 || qoffset > 1.0) {
>> >> >> > +                av_log(ctx, AV_LOG_ERROR, "failed to get valid
>> >> >> > qoffset(%f))\n", qoffset);
>> >> >> > +                return AVERROR(EINVAL);
>> >> >> > +            }
>> >> >> > +            facedetect->add_roi = 1;
>> >> >> > +            facedetect->qoffset = av_d2q(qoffset, 255);
>> >> >> > +        }
>> >> >> > +    } else {
>> >> >> > +        av_log(ctx, AV_LOG_ERROR, "failed to get
>> >> >> > haarcascade_frontalface_alt.xml model file\n");
>> >> >> > +        return AVERROR(EINVAL);
>> >> >> > +    }
>> >> >> > +
>> >> >> > +    av_log(ctx, AV_LOG_VERBOSE, "xml_model: %s add_roi: %d
>> >> >> > qoffset:
>> >> >> > %d/%d\n",
>> >> >> > +           facedetect->xml_model, facedetect->add_roi,
>> >> >> > facedetect->qoffset.num, facedetect->qoffset.den);
>> >> >> > +
>> >> >> > +    facedetect->storage = cvCreateMemStorage(0);
>> >> >> > +    if (!facedetect->storage) {
>> >> >> > +        av_log(ctx, AV_LOG_ERROR, "cvCreateMemStorage()
>> >> >> > failed\n");
>> >> >> > +        return AVERROR(EINVAL);
>> >> >> > +    }
>> >> >> > +    cvClearMemStorage(facedetect->storage);
>> >> >> > +
>> >> >> > +    facedetect->cascade = (CvHaarClassifierCascade*)cvLoad(
>> >> >> > facedetect->xml_model, NULL, NULL, NULL );
>> >> >> > +    if (!facedetect->cascade) {
>> >> >> > +        av_log(ctx, AV_LOG_ERROR, "failed to load classifier
>> >> >> > cascade:
>> >> >> > %s
>> >> >> > \n", facedetect->xml_model);
>> >> >> > +        return AVERROR(EINVAL);
>> >> >> > +    }
>> >> >> > +
>> >> >> > +    return 0;
>> >> >> > +}
>> >> >> > +
>> >> >> > +static av_cold void facedetect_uninit(AVFilterContext *ctx)
>> >> >> > +{
>> >> >> > +    OCVContext *s = ctx->priv;
>> >> >> > +    FaceDetectContext *facedetect = s->priv;
>> >> >> > +
>> >> >> > +    if (facedetect->cascade)
>> >> >> > +        cvReleaseHaarClassifierCascade(&facedetect->cascade);
>> >> >> > +    if (facedetect->storage)
>> >> >> > +        cvReleaseMemStorage(&facedetect->storage);
>> >> >> > +}
>> >> >> > +
>> >> >> > +static void set_meta_int(AVDictionary **metadata, const char
>> >> >> > *key,
>> >> >> > int
>> >> >> > idx,
>> >> >> > int d)
>> >> >> > +{
>> >> >> > +    char value[128];
>> >> >> > +    char key2[128];
>> >> >> > +
>> >> >> > +    snprintf(value, sizeof(value), "%d", d);
>> >> >> > +    snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", idx,
>> >> >> > key);
>> >> >> > +    av_dict_set(metadata, key2, value, 0);
>> >> >> > +}
>> >> >> > +
>> >> >> > +static void facedetect_end_frame_filter(AVFilterContext *ctx,
>> >> >> > IplImage
>> >> >> > *inimg, IplImage *outimg)
>> >> >> > +{
>> >> >> > +    OCVContext *s = ctx->priv;
>> >> >> > +    FaceDetectContext *facedetect = s->priv;
>> >> >> > +
>> >> >> > +    facedetect->faces = cvHaarDetectObjects(inimg,
>> >> >> > facedetect->cascade,
>> >> >> > facedetect->storage,
>> >> >> > +            1.25, 3, CV_HAAR_DO_CANNY_PRUNING,
>> >> >> > +            cvSize(inimg->width/16,inimg->height/16),
>> >> >> > cvSize(0,0));
>> >> >> > +
>> >> >> > +    facedetect->nb_faces = facedetect->faces ?
>> >> >> > facedetect->faces->total
>> >> >> > :
>> >> >> > 0;
>> >> >> > +}
>> >> >> > +
>> >> >> > +static void facedetect_postprocess(AVFilterContext *ctx, AVFrame
>> >> >> > *out)
>> >> >> > +{
>> >> >> > +    OCVContext *s = ctx->priv;
>> >> >> > +    FaceDetectContext *facedetect = s->priv;
>> >> >> > +    AVRegionOfInterest *roi;
>> >> >> > +    AVFrameSideData *sd;
>> >> >> > +    AVBufferRef *roi_buf;
>> >> >> > +    int i;
>> >> >> > +
>> >> >> > +    if (facedetect->add_roi && facedetect->nb_faces > 0) {
>> >> >> > +        sd = av_frame_new_side_data(out,
>> >> >> > AV_FRAME_DATA_REGIONS_OF_INTEREST,
>> >> >> > +                facedetect->nb_faces *
>> >> >> > sizeof(AVRegionOfInterest));
>> >> >> > +        if (!sd) {
>> >> >> > +            return AVERROR(ENOMEM);
>> >> >> > +        }
>> >> >> > +        roi = (AVRegionOfInterest*)sd->data;
>> >> >> > +        for(i = 0; i < facedetect->nb_faces; i++ ) {
>> >> >> > +            CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces,
>> >> >> > i);
>> >> >> > +
>> >> >> > +            roi[i] = (AVRegionOfInterest) {
>> >> >> > +                .self_size = sizeof(*roi),
>> >> >> > +                .top       = r->y,
>> >> >> > +                .bottom    = r->y + r->height,
>> >> >> > +                .left      = r->x,
>> >> >> > +                .right     = r->x + r->width,
>> >> >> > +                .qoffset   = facedetect->qoffset,
>> >> >> > +            };
>> >> >> > +        }
>> >> >> > +    }
>> >> >> > +
>> >> >> > +    if (facedetect->nb_faces > 0)
>> >> >> > +        av_dict_set_int(&out->metadata,
>> >> >> > "lavfi.facedetect.nb_faces",
>> >> >> > facedetect->nb_faces, 0);
>> >> >> > +
>> >> >> > +    for(i = 0; i < facedetect->nb_faces; i++ ) {
>> >> >> > +        CvRect *r = (CvRect*) cvGetSeqElem(facedetect->faces, i);
>> >> >> > +
>> >> >> > +        set_meta_int(&out->metadata, "x", i, r->x);
>> >> >> > +        set_meta_int(&out->metadata, "y", i, r->y);
>> >> >> > +        set_meta_int(&out->metadata, "w", i, r->width);
>> >> >> > +        set_meta_int(&out->metadata, "h", i, r->height);
>> >> >> > +    }
>> >> >> > +}
>> >> >> > +
>> >> >> >  typedef struct OCVFilterEntry {
>> >> >> >      const char *name;
>> >> >> >      size_t priv_size;
>> >> >> >      int  (*init)(AVFilterContext *ctx, const char *args);
>> >> >> >      void (*uninit)(AVFilterContext *ctx);
>> >> >> >      void (*end_frame_filter)(AVFilterContext *ctx, IplImage
>> >> >> > *inimg,
>> >> >> > IplImage *outimg);
>> >> >> > +    void (*postprocess)(AVFilterContext *ctx, AVFrame *out);
>> >> >> >  } OCVFilterEntry;
>> >> >> >
>> >> >> >  static const OCVFilterEntry ocv_filter_entries[] = {
>> >> >> > -    { "dilate", sizeof(DilateContext), dilate_init,
>> >> >> > dilate_uninit,
>> >> >> > dilate_end_frame_filter },
>> >> >> > -    { "erode",  sizeof(DilateContext), dilate_init,
>> >> >> > dilate_uninit,
>> >> >> > erode_end_frame_filter  },
>> >> >> > -    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
>> >> >> > smooth_end_frame_filter },
>> >> >> > +    { "dilate", sizeof(DilateContext), dilate_init,
>> >> >> > dilate_uninit,
>> >> >> > dilate_end_frame_filter, NULL },
>> >> >> > +    { "erode",  sizeof(DilateContext), dilate_init,
>> >> >> > dilate_uninit,
>> >> >> > erode_end_frame_filter, NULL },
>> >> >> > +    { "smooth", sizeof(SmoothContext), smooth_init, NULL,
>> >> >> > smooth_end_frame_filter, NULL },
>> >> >> > +    { "facedetect", sizeof(FaceDetectContext), facedetect_init,
>> >> >> > facedetect_uninit, facedetect_end_frame_filter,
>> >> >> > facedetect_postprocess
>> >> >> > },
>> >> >> >  };
>> >> >> >
>> >> >> >  static av_cold int init(AVFilterContext *ctx)
>> >> >> > @@ -355,6 +497,7 @@ static av_cold int init(AVFilterContext *ctx)
>> >> >> >              s->init             = entry->init;
>> >> >> >              s->uninit           = entry->uninit;
>> >> >> >              s->end_frame_filter = entry->end_frame_filter;
>> >> >> > +            s->postprocess      = entry->postprocess;
>> >> >> >
>> >> >> >              if (!(s->priv = av_mallocz(entry->priv_size)))
>> >> >> >                  return AVERROR(ENOMEM);
>> >> >> > @@ -383,18 +526,33 @@ static int filter_frame(AVFilterLink
>> >> >> > *inlink,
>> >> >> > AVFrame
>> >> >> > *in)
>> >> >> >      AVFrame *out;
>> >> >> >      IplImage inimg, outimg;
>> >> >> >
>> >> >> > +    /* facedetect filter will passthrought the input frame */
>> >> >> > +    if (strcmp(s->name, "facedetect")) {
>> >> >> >      out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
>> >> >> >      if (!out) {
>> >> >> >          av_frame_free(&in);
>> >> >> >          return AVERROR(ENOMEM);
>> >> >> >      }
>> >> >> >      av_frame_copy_props(out, in);
>> >> >> > +    } else {
>> >> >> > +        out = in;
>> >> >> > +    }
>> >> >> >
>> >> >> >      fill_iplimage_from_frame(&inimg , in , inlink->format);
>> >> >> > +
>> >> >> > +    if (strcmp(s->name, "facedetect")) {
>> >> >> >      fill_iplimage_from_frame(&outimg, out, inlink->format);
>> >> >> >      s->end_frame_filter(ctx, &inimg, &outimg);
>> >> >> >      fill_frame_from_iplimage(out, &outimg, inlink->format);
>> >> >> > +    } else {
>> >> >> > +        s->end_frame_filter(ctx, &inimg, NULL);
>> >> >> > +    }
>> >> >> > +
>> >> >> > +    if (s->postprocess) {
>> >> >> > +        s->postprocess(ctx, out);
>> >> >> > +    }
>> >> >> >
>> >> >> > +    if (out != in)
>> >> >> >      av_frame_free(&in);
>> >> >> >
>> >> >> >      return ff_filter_frame(outlink, out);
>> >> >> > --
>> >> >> > 2.21.0
>> >> >> >
>> >> >> > _______________________________________________
>> >> >> > ffmpeg-devel mailing list
>> >> >> > ffmpeg-devel@ffmpeg.org
>> >> >> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> >> >> >
>> >> >> > To unsubscribe, visit link above, or email
>> >> >> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>> >> >
>> >> > --
>> >> > Thanks,
>> >> > Limin Wang
>> >> > _______________________________________________
>> >> > ffmpeg-devel mailing list
>> >> > ffmpeg-devel@ffmpeg.org
>> >> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> >> >
>> >> > To unsubscribe, visit link above, or email
>> >> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>> >> _______________________________________________
>> >> ffmpeg-devel mailing list
>> >> ffmpeg-devel@ffmpeg.org
>> >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> >>
>> >> To unsubscribe, visit link above, or email
>> >> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>> >
>> > --
>> > Thanks,
>> > Limin Wang
>> > _______________________________________________
>> > ffmpeg-devel mailing list
>> > ffmpeg-devel@ffmpeg.org
>> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> >
>> > To unsubscribe, visit link above, or email
>> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
> --
> Thanks,
> Limin Wang
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".