Hi, We're working on a project to have a highly parallelized video rescaling pipeline but we're finding that small audio and video jumps are being introduced into the video when we put the video back together. Can anyone point out anything we're doing wrong?
The pipeline has 3 stages. First we split the video using the segment muxer $ ./ffmpeg -i samples/2160p-h264-aac-20mbs-2m.mp4 -muxdelay 0 -muxpreload 0 -g 96 -keyint_min 96 -sc_threshold 0 -c copy -copyts -f segment -fflags +genpts -segment_time 4 -segment_format mpegts out/segments/%04d.ts Then we change the scale for each of the segments using: $ ./ffmpeg -i out/segments/0000.ts -muxdelay 0 -vf scale=1920:1080 -c:v libx264 -profile:v main -c:a aac -copyts out/segments/out00.ts And then we rejoin $ ./ffmpeg -i "concat:out/segments/out00.ts|out/segments/out01.ts|out/segments/out02.ts" -c copy -copyts out/transcoded.mp4 The jumps seem to correlate to the segment boundaries. The jumps are even worse if we have to change audio codec from ac3 to aac in the middle transcode stage. It we skip the middle rescaling stage then we don't get any jumps in the output video so it's something that's going wrong in that command. For reference the commands are using ffmpeg 4.1.3 and the video I tested the commands with http://downloads.4ksamples.com/videos/PUPPIES%20BATH%20IN%204K%20(ULTRA%20HD)(Original_H.264-AAC)%20(4ksamples.com).mp4 Thanks, Paul _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
