[FFmpeg-devel] lavfi: add colorkey_opencl filter

Submitted by Jarek Samic on April 10, 2019, 3:37 a.m.

Details

Message ID 20190410033720.21172-1-cldfire3@gmail.com
State New
Headers show

Commit Message

Jarek Samic April 10, 2019, 3:37 a.m.
This is a direct port of the CPU filter.

Signed-off-by: Jarek Samic <cldfire3@gmail.com>
---
This is my submission for the GSoC OpenCL video filters project qualification task.

Command you can use to try it out:

./ffmpeg -i some_video -i some_img -init_hw_device opencl=gpu -filter_hw_device gpu -filter_complex "[0:v]format=rgba, hwupload, colorkey_opencl=yellow:0.4:0.2, hwdownload, format=rgba[over];[1:v][over]overlay" output

Based on simple observation of that command running vs. an equivalent one with the CPU
colorkey filter, it would appear that the OpenCL version is ~10-20% faster including
the overhead to upload / download from the GPU (at least with my test input and
hardware).

You will notice that I am using overlay rather than overlay_opencl above. I am not
sure what's going on, but the overlay_opencl filter is not working for me: every time
I try to use it it either stops after the first couple of frames or spits out
duplicate frames forever. Even just running this command that is basically a copy of
the example command to overlay an image logo on the top-left corner of an input video:

./ffmpeg -i ../video.mp4 -i ../img.png -init_hw_device opencl=gpu -filter_hw_device gpu -filter_complex "[0:v]hwupload[a], [1:v]format=yuv420p, hwupload[b], [a][b]overlay_opencl, hwdownload, format=yuv420p" ../vid_test.mp4

Results in an infinite number of duplicate frames. (The format of the input video is
yuv420p, to be clear.)

Before I take the time to dig in and investigate what's going on, is anyone else
aware of what could be causing this (or any existing known issues)?

 configure                        |   1 +
 doc/filters.texi                 |  33 +++++
 libavfilter/Makefile             |   2 +
 libavfilter/allfilters.c         |   1 +
 libavfilter/opencl/colorkey.cl   |  45 ++++++
 libavfilter/opencl_source.h      |   1 +
 libavfilter/vf_colorkey_opencl.c | 234 +++++++++++++++++++++++++++++++
 7 files changed, 317 insertions(+)
 create mode 100644 libavfilter/opencl/colorkey.cl
 create mode 100644 libavfilter/vf_colorkey_opencl.c

Comments

Carl Eugen Hoyos April 10, 2019, 8:30 p.m.
2019-04-10 5:37 GMT+02:00, Jarek Samic <cldfire3@gmail.com>:

> +        // Make sure the input is a format we support
> +        if (fmt != AV_PIX_FMT_ARGB &&
> +            fmt != AV_PIX_FMT_RGBA &&
> +            fmt != AV_PIX_FMT_ABGR &&
> +            fmt != AV_PIX_FMT_BGRA &&
> +            fmt != AV_PIX_FMT_NONE
> +        ) {
> +            av_log(avctx, AV_LOG_ERROR, "unsupported (non-RGB) format in
> colorkey_opencl.\n");
> +            err = AVERROR(ENOSYS);
> +            goto fail;
> +        }

I would have expected that you export a list of supported
pix_fmts and that you can assert on the actual format being
one of them (if you need to).

Carl Eugen
Jarek Samic April 11, 2019, 2:22 a.m.
On Wed, Apr 10, 2019 at 4:30 PM Carl Eugen Hoyos <ceffmpeg@gmail.com> wrote:

> 2019-04-10 5:37 GMT+02:00, Jarek Samic <cldfire3@gmail.com>:
>
> > +        // Make sure the input is a format we support
> > +        if (fmt != AV_PIX_FMT_ARGB &&
> > +            fmt != AV_PIX_FMT_RGBA &&
> > +            fmt != AV_PIX_FMT_ABGR &&
> > +            fmt != AV_PIX_FMT_BGRA &&
> > +            fmt != AV_PIX_FMT_NONE
> > +        ) {
> > +            av_log(avctx, AV_LOG_ERROR, "unsupported (non-RGB) format in
> > colorkey_opencl.\n");
> > +            err = AVERROR(ENOSYS);
> > +            goto fail;
> > +        }
>
> I would have expected that you export a list of supported
> pix_fmts and that you can assert on the actual format being
> one of them (if you need to).
>

 Hmm, would you be able to clarify what you mean by that? The code above is
modeled after
code from the tonemap_opencl filter, lines 398-402:

if (input_frames_ctx->sw_format != AV_PIX_FMT_P010) {
    av_log(ctx, AV_LOG_ERROR, "unsupported format in tonemap_opencl.\n");
    err = AVERROR(ENOSYS);
    goto fail;
}

Patch hide | download patch | download mbox

diff --git a/configure b/configure
index f6123f53e5..a4dd9ee167 100755
--- a/configure
+++ b/configure
@@ -3410,6 +3410,7 @@  boxblur_filter_deps="gpl"
 boxblur_opencl_filter_deps="opencl gpl"
 bs2b_filter_deps="libbs2b"
 colormatrix_filter_deps="gpl"
+colorkey_opencl_filter_deps="opencl"
 convolution_opencl_filter_deps="opencl"
 convolve_filter_deps="avcodec"
 convolve_filter_select="fft"
diff --git a/doc/filters.texi b/doc/filters.texi
index 867607d870..390c8b97cf 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -19030,6 +19030,39 @@  Apply erosion filter with threshold0 set to 30, threshold1 set 40, threshold2 se
 @end example
 @end itemize
 
+@section colorkey_opencl
+RGB colorspace color keying.
+
+The filter accepts the following options:
+
+@table @option
+@item color
+The color which will be replaced with transparency.
+
+@item similarity
+Similarity percentage with the key color.
+
+0.01 matches only the exact key color, while 1.0 matches everything.
+
+@item blend
+Blend percentage.
+
+0.0 makes pixels either fully transparent, or not transparent at all.
+
+Higher values result in semi-transparent pixels, with a higher transparency
+the more similar the pixels color is to the key color.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Make every semi-green pixel in the input transparent with some slight blending:
+@example
+-i INPUT -vf "hwupload, colorkey_opencl=green:0.3:0.1, hwdownload" OUTPUT
+@end example
+@end itemize
+
 @section overlay_opencl
 
 Overlay one video on top of another.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index fef6ec5c55..9589dd8747 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -176,6 +176,8 @@  OBJS-$(CONFIG_CODECVIEW_FILTER)              += vf_codecview.o
 OBJS-$(CONFIG_COLORBALANCE_FILTER)           += vf_colorbalance.o
 OBJS-$(CONFIG_COLORCHANNELMIXER_FILTER)      += vf_colorchannelmixer.o
 OBJS-$(CONFIG_COLORKEY_FILTER)               += vf_colorkey.o
+OBJS-$(CONFIG_COLORKEY_OPENCL_FILTER)        += vf_colorkey_opencl.o opencl.o \
+                                                opencl/colorkey.o
 OBJS-$(CONFIG_COLORLEVELS_FILTER)            += vf_colorlevels.o
 OBJS-$(CONFIG_COLORMATRIX_FILTER)            += vf_colormatrix.o
 OBJS-$(CONFIG_COLORSPACE_FILTER)             += vf_colorspace.o colorspace.o colorspacedsp.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index c51ae0f3c7..ff4eb5bf6b 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -165,6 +165,7 @@  extern AVFilter ff_vf_codecview;
 extern AVFilter ff_vf_colorbalance;
 extern AVFilter ff_vf_colorchannelmixer;
 extern AVFilter ff_vf_colorkey;
+extern AVFilter ff_vf_colorkey_opencl;
 extern AVFilter ff_vf_colorlevels;
 extern AVFilter ff_vf_colormatrix;
 extern AVFilter ff_vf_colorspace;
diff --git a/libavfilter/opencl/colorkey.cl b/libavfilter/opencl/colorkey.cl
new file mode 100644
index 0000000000..5d8a0bb8df
--- /dev/null
+++ b/libavfilter/opencl/colorkey.cl
@@ -0,0 +1,45 @@ 
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+__kernel void colorkey(
+    __read_only  image2d_t src,
+    __write_only image2d_t dst,
+    uchar4 colorkey_rgba,
+    float similarity,
+    float blend
+) {
+    const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE |
+                              CLK_FILTER_NEAREST;
+    int2 loc = (int2)(get_global_id(0), get_global_id(1));
+    float4 pixel = read_imagef(src, sampler, loc);
+
+    float dr = pixel.s0 - (float)colorkey_rgba.s0 / 255.0;
+    float dg = pixel.s1 - (float)colorkey_rgba.s1 / 255.0;
+    float db = pixel.s2 - (float)colorkey_rgba.s2 / 255.0;
+
+    double diff = sqrt(dr * dr + dg * dg + db * db);
+
+    if (blend > 0.0001) {
+        pixel.s3 = clamp((diff - similarity) / blend, 0.0, 1.0);
+    } else {
+        pixel.s3 = (diff > similarity) ? 1.0 : 0.0;
+    }
+
+    write_imagef(dst, loc, pixel);
+}
+
diff --git a/libavfilter/opencl_source.h b/libavfilter/opencl_source.h
index 4118138c30..51f7178cf2 100644
--- a/libavfilter/opencl_source.h
+++ b/libavfilter/opencl_source.h
@@ -20,6 +20,7 @@ 
 #define AVFILTER_OPENCL_SOURCE_H
 
 extern const char *ff_opencl_source_avgblur;
+extern const char *ff_opencl_source_colorkey;
 extern const char *ff_opencl_source_colorspace_common;
 extern const char *ff_opencl_source_convolution;
 extern const char *ff_opencl_source_neighbor;
diff --git a/libavfilter/vf_colorkey_opencl.c b/libavfilter/vf_colorkey_opencl.c
new file mode 100644
index 0000000000..4769c529b0
--- /dev/null
+++ b/libavfilter/vf_colorkey_opencl.c
@@ -0,0 +1,234 @@ 
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/opt.h"
+#include "libavutil/imgutils.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "opencl.h"
+#include "opencl_source.h"
+#include "video.h"
+
+typedef struct ColorkeyOpenCLContext {
+    OpenCLFilterContext ocf;
+    // Whether or not the above `OpenCLFilterContext` has been initialized
+    int initialized;
+
+    cl_command_queue command_queue;
+    cl_kernel kernel_colorkey;
+
+    // The color we are supposed to replace with transparency
+    cl_uchar4 colorkey_rgba[4];
+    // Similarity percentage compared to `colorkey_rgba`, ranging from `0.01` to `1.0`
+    // where `0.01` matches only the key color and `1.0` matches all colors
+    float similarity;
+    // Blending percentage where `0.0` results in fully transparent pixels, `1.0` results
+    // in fully opaque pixels, and numbers in between result in transparency that varies
+    // based on the similarity to the key color
+    float blend;
+} ColorkeyOpenCLContext;
+
+static int colorkey_opencl_init(AVFilterContext* avctx) 
+{
+    ColorkeyOpenCLContext *ctx = avctx->priv;
+    cl_int cle;
+    int err;
+
+    err = ff_opencl_filter_load_program(avctx, &ff_opencl_source_colorkey, 1);
+    if (err < 0)
+        goto fail;
+
+    ctx->command_queue = clCreateCommandQueue(
+        ctx->ocf.hwctx->context,
+        ctx->ocf.hwctx->device_id,
+        0, &cle
+    );
+
+    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to create OpenCL "
+                     "command queue %d.\n", cle);
+
+    ctx->kernel_colorkey = clCreateKernel(ctx->ocf.program, "colorkey", &cle);
+    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to create horizontal "
+                     "kernel %d.\n", cle);
+
+    ctx->initialized = 1;
+    return 0;
+
+fail:
+    if (ctx->command_queue)
+        clReleaseCommandQueue(ctx->command_queue);
+    if (ctx->kernel_colorkey)
+        clReleaseKernel(ctx->kernel_colorkey);
+    return err;
+}
+
+static int filter_frame(AVFilterLink* link, AVFrame* input_frame)
+{
+    AVFilterContext* avctx = link->dst;
+    AVFilterLink* outlink = avctx->outputs[0];
+    ColorkeyOpenCLContext* colorkey_ctx = avctx->priv;
+    AVFrame* output_frame = NULL;
+    int err;
+    cl_int cle;
+    size_t global_work[2];
+    cl_mem src, dst;
+
+    if (!input_frame->hw_frames_ctx)
+        return AVERROR(EINVAL);
+
+    if (!colorkey_ctx->initialized) {
+        AVHWFramesContext *input_frames_ctx =
+            (AVHWFramesContext*)input_frame->hw_frames_ctx->data;
+        int fmt = input_frames_ctx->sw_format;
+
+        // Make sure the input is a format we support
+        if (fmt != AV_PIX_FMT_ARGB &&
+            fmt != AV_PIX_FMT_RGBA &&
+            fmt != AV_PIX_FMT_ABGR &&
+            fmt != AV_PIX_FMT_BGRA &&
+            fmt != AV_PIX_FMT_NONE
+        ) {
+            av_log(avctx, AV_LOG_ERROR, "unsupported (non-RGB) format in colorkey_opencl.\n");
+            err = AVERROR(ENOSYS);
+            goto fail;
+        }
+
+        err = colorkey_opencl_init(avctx);
+        if (err < 0)
+            goto fail;
+    }
+
+    // This filter only operates on RGB data and we know that will be on the first plane
+    src = (cl_mem)input_frame->data[0];
+    output_frame = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!output_frame) {
+        err = AVERROR(ENOMEM);
+        goto fail;
+    }
+    dst = (cl_mem)output_frame->data[0];
+
+    CL_SET_KERNEL_ARG(colorkey_ctx->kernel_colorkey, 0, cl_mem, &src);
+    CL_SET_KERNEL_ARG(colorkey_ctx->kernel_colorkey, 1, cl_mem, &dst);
+    CL_SET_KERNEL_ARG(colorkey_ctx->kernel_colorkey, 2, cl_uchar4, &colorkey_ctx->colorkey_rgba);
+    CL_SET_KERNEL_ARG(colorkey_ctx->kernel_colorkey, 3, float, &colorkey_ctx->similarity);
+    CL_SET_KERNEL_ARG(colorkey_ctx->kernel_colorkey, 4, float, &colorkey_ctx->blend);
+
+    err = ff_opencl_filter_work_size_from_image(avctx, global_work, input_frame, 0, 0);
+    if (err < 0)
+        goto fail;
+
+    cle = clEnqueueNDRangeKernel(
+        colorkey_ctx->command_queue,
+        colorkey_ctx->kernel_colorkey,
+        2,
+        NULL,
+        global_work,
+        NULL,
+        0,
+        NULL,
+        NULL
+    );
+
+    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to enqueue colorkey kernel: %d.\n", cle);
+
+    // Run queued kernel
+    cle = clFinish(colorkey_ctx->command_queue);
+    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to finish command queue: %d.\n", cle);
+
+    err = av_frame_copy_props(output_frame, input_frame);
+    if (err < 0)
+        goto fail;
+
+    av_frame_free(&input_frame);
+
+    return ff_filter_frame(outlink, output_frame);
+
+fail:
+    clFinish(colorkey_ctx->command_queue);
+    av_frame_free(&input_frame);
+    av_frame_free(&output_frame);
+    return err;
+}
+
+static av_cold void colorkey_opencl_uninit(AVFilterContext* avctx)
+{
+    ColorkeyOpenCLContext *ctx = avctx->priv;
+    cl_int cle;
+
+    if (ctx->kernel_colorkey) {
+        cle = clReleaseKernel(ctx->kernel_colorkey);
+        if (cle != CL_SUCCESS)
+            av_log(avctx, AV_LOG_ERROR, "Failed to release "
+                   "kernel: %d.\n", cle);
+    }
+
+    if (ctx->command_queue) {
+        cle = clReleaseCommandQueue(ctx->command_queue);
+        if (cle != CL_SUCCESS)
+            av_log(avctx, AV_LOG_ERROR, "Failed to release "
+                   "command queue: %d.\n", cle);
+    }
+
+    ff_opencl_filter_uninit(avctx);
+}
+
+static const AVFilterPad colorkey_opencl_inputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+        .config_props = &ff_opencl_filter_config_input,
+    },
+    { NULL }
+};
+
+static const AVFilterPad colorkey_opencl_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+        .config_props = &ff_opencl_filter_config_output,
+    },
+    { NULL }
+};
+
+#define OFFSET(x) offsetof(ColorkeyOpenCLContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption colorkey_opencl_options[] = {
+    { "color", "set the colorkey key color", OFFSET(colorkey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
+    { "similarity", "set the colorkey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
+    { "blend", "set the colorkey key blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(colorkey_opencl);
+
+AVFilter ff_vf_colorkey_opencl = {
+    .name           = "colorkey_opencl",
+    .description    = NULL_IF_CONFIG_SMALL("Turns a certain color into transparency. Operates on RGB colors."),
+    .priv_size      = sizeof(ColorkeyOpenCLContext),
+    .priv_class     = &colorkey_opencl_class,
+    .init           = &ff_opencl_filter_init,
+    .uninit         = &colorkey_opencl_uninit,
+    .query_formats  = &ff_opencl_filter_query_formats,
+    .inputs         = colorkey_opencl_inputs,
+    .outputs        = colorkey_opencl_outputs,
+    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE
+};
+