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Ffmpeg concat video and keep audio3/1/2023 ![]() ![]() ![]() ![]() Step 3 Insert the audio from LargeClip ffmpeg -i spliced-vid.mp4 -i LargeClip.mp4 -c copy -map 0:v -map 1:a Final. ffmpeg -f concat -i concat.txt -an -c:v libx264 -crf 23 -fflags genpts spliced-vid.mp4 ffmpeg -i chunk1.mp4 -i chunk2.m4a -i chunk3.mp4 -filtercomplex \ 'colorblack:sWxH:rN:dT 1v \ 0:v:0 0:a:0 1v 1:a:0 2:v:0 2:a:0 concatn3:v1:a1 v a' -map ' v' -map ' a' -strict -2 result.mp4. This command will skip the audio since we don't to splice the audio streams. after switching to SmallClip for 12 seconds, you want to resume LargeClip 12 seconds later from where you left it off. if not you will need to pick a format and then use ffmpeg or some other program (such as avidemux) to convert all segments to the same audio and video formats and then do the concatenation. ![]() Make sure that the sync of LargeClip isn't broken, i.e. These timecodes, in seconds, refer to the source file timecode, not of the assembled output. This shows the first 10 seconds of LargeClip, then the first two seconds of smallclip, then resumes the Largeclip at 12:00, shows it for 5 seconds, then splices in 23:00 to 27:00 of small clip, switches back to LargeClip at its 21:00 and keeps it till its end. You must first create a plaintext file, say, concat.txt, like this file 'LargeClip.mp4' appending video to video and audio to audio, and then. The ffmpeg cat separates all the streams, appends each extended stream, e.g. All that stuff has to line up in a continuous way. ffmpeg -i 'concat:' -c copy out. So the calls were for the concat protocol. My goal was to copy the packages, not to remux them. Theres header information and interleaving of streams together. Concat demux with AVC (MPEG-PS - High Profile) skips frames and mixes some frames from the second clip into the first. For accurate splicing, re-encoding is needed which is what the commands below do. Think about it like doing cat with 2 zip files if that makes sense. You can use the concat demuxer in ffmpeg to do this. ![]()
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