On 11/7/22, Tobias Rapp <[email protected]> wrote: > On 07/11/2022 10:56, Paul B Mahol wrote: >> On 11/7/22, Tobias Rapp <[email protected]> wrote: >>> Hi, >>> >>> recently when testing I stumbled over the situation that a specific >>> 10-bit YUV input file was encoded separately using two different >>> loss-less encoders V210 and FFV1. When comparing the FrameMD5 checksum >>> of both output files most of the checksums did match, but some of them >>> where different (approx. 3% of the frames). >>> >>> When trying to reproduce the scenario with the attached batch script >>> using a video source filter the resulting files even differ in every >>> frame. My assumption would have been that the FrameMD5 checksums of both >>> files would be the same, as they originate from the same input file and >>> the intermediate encoding should be loss-less. >>> >>> Can someone give a hint where the differences come from? Is there some >>> command-line option for bit-exactness missing, or is there something >>> going wrong in the decoder/encoders? >> >> The v210 encoder or decoder is buggy. Strange that both C and asm is >> buggy. >> The first pixels at start and end of each scanline are wrong. > > When I replace "-vcodec v210" in the shell script with "-vcodec ffvhuff" > it matches the output of FFV1. So yes, there seems to be an issue with > v210 encoding or decoding in FFmpeg. > > Looking into the bugtracker, could this be related to ticket #8195 "v210 > encoding clips to 4-1019"?
Ah, probably yes, and yuvtestsrc gives you 0-1023 ramp > > Regards, > Tobias > > _______________________________________________ > ffmpeg-user mailing list > [email protected] > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
