tor 2022-12-15 klockan 01:37 +0800 skrev Zhao Zhili: > On Wed, 2022-12-14 at 18:08 +0100, Tomas Härdin wrote: > > > > > I think we might want something for this inside lavf somewhere, so > > that > > encoders can signal dimension alignment requirements. Some > > containers > > (MXF, MOV) support such cropping in a codec-agnostic manner. > > From my own experience, dimension mismatch between codec and > container > makes a lot of trouble. ISO base format specification specified how > to > crop/scale after decoding clear, however, I don't think it has been > widely supported, including FFmpeg. We can fix that inside of FFmpeg, > but we should avoid such cases as much as we can.
This is the difference between stored, sampled and display dimensions in MXF. For example 1080i video has StoredHeight = 544, SampledHeight = 540 and DisplayHeight = 540 (see AS-10). When you add VBLANK and HBLANK to the mix then all three dimensions are typically different. Anyway specifying at the NAL level whenever the essence isn't a multiple of 16x16 is obviously normal. The only complication I can think of is 4:2:2 and 4:4:4. Does MC require 16x16 also in those cases? I'd expect 16x8 and 8x8 respectively. /Tomas _______________________________________________ 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".
