On Mon, 29 Jan 2024 04:19:43 +0100 Michael Niedermayer <mich...@niedermayer.cc> wrote: > On Sun, Dec 31, 2023 at 09:49:47PM +0000, Niklas Haas wrote: > > ffmpeg | branch: master | Niklas Haas <g...@haasn.dev> | Tue Oct 31 > > 13:52:53 2023 +0100| [45e09a30419cc2a7251e72689142e021ecdfe6d9] | > > committer: Niklas Haas > > > > vf_scale: use colorspace negotiation API > > > > This filter will always accept any input format, even if the user sets > > a specific in_range/in_color_matrix. This is to preserve status quo with > > current behavior, where passing a specific in_color_matrix merely > > overrides the incoming frames' attributes. (Use `vf_format` to force > > a specific input range) > > > > Because changing colorspace and color_range now requires reconfiguring > > the link, we can lift sws_setColorspaceDetails out of scale_frame and > > into config_props. (This will also get re-called if the input frame > > properties change) > > > > > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=45e09a30419cc2a7251e72689142e021ecdfe6d9 > > --- > > > > libavfilter/vf_scale.c | 188 > > +++++++++++++++++++++++++++---------------------- > > 1 file changed, 103 insertions(+), 85 deletions(-) > > This seems to remove metadata > > ./ffmpeg -f lavfi -i color=black -pix_fmt yuv422p10le -bitexact -vframes 1 -f > framecrc - > > Stream #0:0: Video: rawvideo (Y3[10][10] / 0xA0A3359), yuv422p10le(tv, > progressive), 320x240 [SAR 1:1 DAR 4:3], q=2-31, 38400 kb/s, 25 fps, 25 tbn > vs > Stream #0:0: Video: rawvideo (Y3[10][10] / 0xA0A3359), > yuv422p10le(progressive), 320x240 [SAR 1:1 DAR 4:3], q=2-31, 38400 kb/s, 25 > fps, 25 tbn > > > when its stored in a file, it results in a different output, example: > ./ffmpeg -f lavfi -i color=black -pix_fmt yuv422p10le -bitexact -vframes 1 > -c:v ffv1 -level 3 -y ffv1-lavf-black-4636-new.mkv > > > I have not investigated what is correct, but i would think "no range > information" > would seem worse than whatever the correct is
Looking at this quickly, what is happening here is not that vf_scale is stripping metadata, it's that vf_scale used to *add* default metadata after a pixel format conversion - even though it did not touch the pixel range, and the incoming frames were untagged. This was arguably a bug. The new behavior is actually less surprising here - the vsrc generates untagged frames, so vf_scale preserves them being untagged. (Observe -vf showinfo,format=yuv422p10le,showinfo before vs after patch) In any case, the *proper* fix here would be to make vsrc_testsrc aware of the colorspace negotiation API. Ideally, it should switch from ff_draw_init to ff_draw_init2, and use the negotiated YUV colorspace and range. (pal(75|100)bars are also bugged) _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
