| Message ID | 20221109193603.55080-1-dima.buzdyk@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,RFC] lavd/v4l2: cover all bufer if bytesperline is set by driver | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
Reminder On Thu, 2022-11-10 at 01:36 +0600, Dima Buzdyk wrote: > Some drivers may set bytesperline if hardware use padding bytes for > alignment. In this case lavd/v4l2 will expect W*H bytes per frame, > but > driver will provide Pitch*H bytes which makes v4l2 unhappy. > > This change adjusts frame width to cover entire data buffer aligning > lavd/v4l2 expectations with data provided by the driver. As a result > user will be able to get image stream from device, albeit having > garbage in padding bytes. > > Signed-off-by: Dima Buzdyk <dima.buzdyk@gmail.com> > --- > libavdevice/v4l2.c | 32 +++++++++++++++++++++++++++----- > 1 file changed, 27 insertions(+), 5 deletions(-) > > diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c > index 5e85d1a2b3..b1e837f740 100644 > --- a/libavdevice/v4l2.c > +++ b/libavdevice/v4l2.c > @@ -83,7 +83,7 @@ struct video_data { > AVClass *class; > int fd; > int pixelformat; /* V4L2_PIX_FMT_* */ > - int width, height; > + int width, height, pitch; > int frame_size; > int interlaced; > int top_field_first; > @@ -202,7 +202,7 @@ fail: > } > > static int device_init(AVFormatContext *ctx, int *width, int > *height, > - uint32_t pixelformat) > + int *pitch, uint32_t pixelformat) > { > struct video_data *s = ctx->priv_data; > struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE > }; > @@ -224,6 +224,7 @@ static int device_init(AVFormatContext *ctx, int > *width, int *height, > *width, *height, fmt.fmt.pix.width, > fmt.fmt.pix.height); > *width = fmt.fmt.pix.width; > *height = fmt.fmt.pix.height; > + *pitch = fmt.fmt.pix.bytesperline; > } > > if (pixelformat != fmt.fmt.pix.pixelformat) { > @@ -779,6 +780,7 @@ static int device_try_init(AVFormatContext *ctx, > enum AVPixelFormat pix_fmt, > int *width, > int *height, > + int *pitch, > uint32_t *desired_format, > enum AVCodecID *codec_id) > { > @@ -787,7 +789,7 @@ static int device_try_init(AVFormatContext *ctx, > *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id); > > if (*desired_format) { > - ret = device_init(ctx, width, height, *desired_format); > + ret = device_init(ctx, width, height, pitch, > *desired_format); > if (ret < 0) { > *desired_format = 0; > if (ret != AVERROR(EINVAL)) > @@ -804,7 +806,7 @@ static int device_try_init(AVFormatContext *ctx, > (char > *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt) > , "none")); > > *desired_format = > ff_fmt_conversion_table[i].v4l2_fmt; > - ret = device_init(ctx, width, height, > *desired_format); > + ret = device_init(ctx, width, height, pitch, > *desired_format); > if (ret >= 0) > break; > else if (ret != AVERROR(EINVAL)) > @@ -933,11 +935,13 @@ static int v4l2_read_header(AVFormatContext > *ctx) > > s->width = fmt.fmt.pix.width; > s->height = fmt.fmt.pix.height; > + s->pitch = fmt.fmt.pix.bytesperline; > av_log(ctx, AV_LOG_VERBOSE, > "Setting frame size to %dx%d\n", s->width, s- > >height); > } > > - res = device_try_init(ctx, pix_fmt, &s->width, &s->height, > &desired_format, &codec_id); > + res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &s- > >pitch, > + &desired_format, &codec_id); > if (res < 0) > goto fail; > > @@ -948,6 +952,24 @@ static int v4l2_read_header(AVFormatContext > *ctx) > if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == > AV_CODEC_ID_NONE) > ctx->video_codec_id = codec_id; > > + /* If bytesperpixel is set by driver then set width co cover > full > + * buffer area even if there are garbage data to be displayed. > + * It is better to display padding bytes and give application > ability > + * to crop image later than fail to display image stream > completely */ > + if (s->pitch) { > + int linesize; > + > + pix_fmt = ff_fmt_v4l2ff(desired_format, codec_id); > + linesize = av_image_get_linesize(pix_fmt, s->width, 0); > + if (linesize > 0) { > + s->width = s->pitch * s->width / linesize; > + > + av_log(ctx, AV_LOG_INFO, > + "Expand frame width to %dx%d to cover full > buffer\n", > + s->width, s->height); > + } > + } > + > if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < > 0) > goto fail; >
diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c index 5e85d1a2b3..b1e837f740 100644 --- a/libavdevice/v4l2.c +++ b/libavdevice/v4l2.c @@ -83,7 +83,7 @@ struct video_data { AVClass *class; int fd; int pixelformat; /* V4L2_PIX_FMT_* */ - int width, height; + int width, height, pitch; int frame_size; int interlaced; int top_field_first; @@ -202,7 +202,7 @@ fail: } static int device_init(AVFormatContext *ctx, int *width, int *height, - uint32_t pixelformat) + int *pitch, uint32_t pixelformat) { struct video_data *s = ctx->priv_data; struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE }; @@ -224,6 +224,7 @@ static int device_init(AVFormatContext *ctx, int *width, int *height, *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height); *width = fmt.fmt.pix.width; *height = fmt.fmt.pix.height; + *pitch = fmt.fmt.pix.bytesperline; } if (pixelformat != fmt.fmt.pix.pixelformat) { @@ -779,6 +780,7 @@ static int device_try_init(AVFormatContext *ctx, enum AVPixelFormat pix_fmt, int *width, int *height, + int *pitch, uint32_t *desired_format, enum AVCodecID *codec_id) { @@ -787,7 +789,7 @@ static int device_try_init(AVFormatContext *ctx, *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id); if (*desired_format) { - ret = device_init(ctx, width, height, *desired_format); + ret = device_init(ctx, width, height, pitch, *desired_format); if (ret < 0) { *desired_format = 0; if (ret != AVERROR(EINVAL)) @@ -804,7 +806,7 @@ static int device_try_init(AVFormatContext *ctx, (char *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt), "none")); *desired_format = ff_fmt_conversion_table[i].v4l2_fmt; - ret = device_init(ctx, width, height, *desired_format); + ret = device_init(ctx, width, height, pitch, *desired_format); if (ret >= 0) break; else if (ret != AVERROR(EINVAL)) @@ -933,11 +935,13 @@ static int v4l2_read_header(AVFormatContext *ctx) s->width = fmt.fmt.pix.width; s->height = fmt.fmt.pix.height; + s->pitch = fmt.fmt.pix.bytesperline; av_log(ctx, AV_LOG_VERBOSE, "Setting frame size to %dx%d\n", s->width, s->height); } - res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id); + res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &s->pitch, + &desired_format, &codec_id); if (res < 0) goto fail; @@ -948,6 +952,24 @@ static int v4l2_read_header(AVFormatContext *ctx) if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE) ctx->video_codec_id = codec_id; + /* If bytesperpixel is set by driver then set width co cover full + * buffer area even if there are garbage data to be displayed. + * It is better to display padding bytes and give application ability + * to crop image later than fail to display image stream completely */ + if (s->pitch) { + int linesize; + + pix_fmt = ff_fmt_v4l2ff(desired_format, codec_id); + linesize = av_image_get_linesize(pix_fmt, s->width, 0); + if (linesize > 0) { + s->width = s->pitch * s->width / linesize; + + av_log(ctx, AV_LOG_INFO, + "Expand frame width to %dx%d to cover full buffer\n", + s->width, s->height); + } + } + if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0) goto fail;
Some drivers may set bytesperline if hardware use padding bytes for alignment. In this case lavd/v4l2 will expect W*H bytes per frame, but driver will provide Pitch*H bytes which makes v4l2 unhappy. This change adjusts frame width to cover entire data buffer aligning lavd/v4l2 expectations with data provided by the driver. As a result user will be able to get image stream from device, albeit having garbage in padding bytes. Signed-off-by: Dima Buzdyk <dima.buzdyk@gmail.com> --- libavdevice/v4l2.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-)