| Message ID | 20230401174737.85192-1-chemag@gmail.com |
|---|---|
| State | Accepted |
| Commit | 7311fcc869a68fd6ae90944421820b3c9821ebeb |
| Headers | show |
| Series | [FFmpeg-devel,1/3] lavfi/vf_psnr: add warning when color ranges differ | expand |
| Context | Check | Description |
|---|---|---|
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
On Sat, 01 Apr 2023 10:47:35 -0700 Chema Gonzalez <chemag@gmail.com> wrote: > The PSNR filter uses the pixel values without considering > the color ranges. This is incorrect. Patch adds a warning > so at least the user knows it. > > Let's see an example: > > (1) Let's get a simple black pixel/white pixel image. > ``` > $ echo -n -e "\x00\x00\x00\xff\xff\xff" > /tmp/foo.rgb24 > ``` > > (2) From this image, let's distill full and limited range y4m > copies. > > ``` > $ ffmpeg -y -f rawvideo -video_size 2x1 -pix_fmt rgb24 -i /tmp/foo.rgb24 -vf scale="out_range=full" -pix_fmt yuv420p /tmp/foo.full.y4m > $ xxd /tmp/foo.full.y4m > 00000000: 5955 5634 4d50 4547 3220 5732 2048 3120 YUV4MPEG2 W2 H1 > 00000010: 4632 353a 3120 4970 2041 303a 3020 4334 F25:1 Ip A0:0 C4 > 00000020: 3230 6a70 6567 2058 5953 4353 533d 3432 20jpeg XYSCSS=42 > 00000030: 304a 5045 4720 5843 4f4c 4f52 5241 4e47 0JPEG XCOLORRANG > 00000040: 453d 4655 4c4c 0a46 5241 4d45 0a00 ff80 E=FULL.FRAME.... > 00000050: 80 . > ``` > > and > > ``` > $ ffmpeg -y -f rawvideo -video_size 2x1 -pix_fmt rgb24 -i /tmp/foo.rgb24 -vf scale="out_range=limited" -pix_fmt yuv420p /tmp/foo.limited.y4m > $ xxd /tmp/foo.limited.y4m > 00000000: 5955 5634 4d50 4547 3220 5732 2048 3120 YUV4MPEG2 W2 H1 > 00000010: 4632 353a 3120 4970 2041 303a 3020 4334 F25:1 Ip A0:0 C4 > 00000020: 3230 6a70 6567 2058 5953 4353 533d 3432 20jpeg XYSCSS=42 > 00000030: 304a 5045 4720 5843 4f4c 4f52 5241 4e47 0JPEG XCOLORRANG > 00000040: 453d 4c49 4d49 5445 440a 4652 414d 450a E=LIMITED.FRAME. > 00000050: 10eb 8080 .... > ``` > > Note that the 2x images are the same (both have 1x pixel at the > darkest black, and one at the brightest white). Only difference > is the range. > > (3) Let's calculate the PSNR score: > ``` > $ ./ffmpeg -filter_threads 1 -filter_complex_threads 1 -i /tmp/foo.full.y4m -i /tmp/foo.limited.y4m -lavfi "psnr" -f null - > ... > [Parsed_psnr_0 @ 0x2f5dac0] PSNR y:22.972065 u:inf v:inf average:25.982365 min:25.982365 max:25.982365 > ``` > > As we are comparing an image with itself, we expect "y:inf" as the > luma PSNR. Issue here is that the PSNR filter just uses the pixel > values, ignoring the color ranges. > > A possible solution would be to have the filter do the conversion. > > Proposed solution is to add a warning. > > ``` > $ ./ffmpeg -filter_threads 1 -filter_complex_threads 1 -i /tmp/foo.full.y4m -i /tmp/foo.limited.y4m -lavfi "psnr" -f null - > ... > [Parsed_psnr_0 @ 0x2f5dac0] master and reference frames use different color ranges (pc != tv) > ... > [Parsed_psnr_0 @ 0x2f5dac0] PSNR y:22.972065 u:inf v:inf average:25.982365 min:25.982365 max:25.982365 > ``` > > Tested: > > Ran fate. > ``` > $ make fate -j > ... > TEST seek-lavf-ppmpipe > TEST seek-lavf-pgmpipe > TEST seek-lavf-mxf_opatom > ``` > --- > libavfilter/vf_psnr.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/libavfilter/vf_psnr.c b/libavfilter/vf_psnr.c > index 15cde7e8c8..058a8932f4 100644 > --- a/libavfilter/vf_psnr.c > +++ b/libavfilter/vf_psnr.c > @@ -188,6 +188,13 @@ static int do_psnr(FFFrameSync *fs) > td.planeheight[c] = s->planeheight[c]; > } > > + if (master->color_range != ref->color_range) { > + av_log(ctx, AV_LOG_WARNING, "master and reference " > + "frames use different color ranges (%s != %s)\n", > + av_color_range_name(master->color_range), > + av_color_range_name(ref->color_range)); > + } > + > ff_filter_execute(ctx, compute_images_mse, &td, NULL, > FFMIN(s->planeheight[1], s->nb_threads)); > > -- > 2.39.2 > > _______________________________________________ > 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". LGTM. The warning will probably be removed once filter graph color range negotiation exists.
diff --git a/libavfilter/vf_psnr.c b/libavfilter/vf_psnr.c index 15cde7e8c8..058a8932f4 100644 --- a/libavfilter/vf_psnr.c +++ b/libavfilter/vf_psnr.c @@ -188,6 +188,13 @@ static int do_psnr(FFFrameSync *fs) td.planeheight[c] = s->planeheight[c]; } + if (master->color_range != ref->color_range) { + av_log(ctx, AV_LOG_WARNING, "master and reference " + "frames use different color ranges (%s != %s)\n", + av_color_range_name(master->color_range), + av_color_range_name(ref->color_range)); + } + ff_filter_execute(ctx, compute_images_mse, &td, NULL, FFMIN(s->planeheight[1], s->nb_threads));