ffmpeg -i episode_01.mkv -map 0:a:0 -c:a flac audio_ep01.flac If audio drifts after remuxing:
ffmpeg -i episode_01.mkv -c:v libx264 -crf 23 -preset medium -c:a aac -b:a 128k output.mp4 p-valley s02 ffmpeg
ffmpeg -i episode_01.mkv -itsoffset 0.5 -i episode_01.mkv -map 1:v -map 0:a -c copy synced_ep01.mkv (adjust 0.5 seconds as needed) Loop over S02E01 – S02E10: ffmpeg -i episode_01
ffmpeg -i episode_01.mkv -map 0:v -map 0:a:m:language:eng -map 0:s:m:language:eng -c copy clean_ep01.mkv P-Valley S2 episodes (~50 min each) can be large in HEVC. Transcode to H.264 for better compatibility or smaller HEVC with CRF: p-valley s02 ffmpeg