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Here is another example: ffmpeg -i input.mkv -filter_complex "[0:V:0]setpts=25/24*PTS[vout];[0:a:0]asetrate=46080,aresample=resampler=soxr:osr=48k[aout]" -map "[vout]" -map "[aout]" -r:v 24/1 -vsync vfr output.mkvA new problem is introduced when you have subtitles. If the subtitle track has already been timestamped to match the PAL video, the subtitles will lose synchronization with the newly corrected video. This is especially troublesome with Forced Subtitles that are in their own track, like an srt embedded into an mkv file. If the track is forced subtitles you might find that editing the timestamps in the file by hand with a text editor your only remedy. This is less practical with a full line by line subtitle track. Additional software is required or a clever bash script involving regex. The audio file is not stretched, but processed so that the pitch is decreased to match the original pitch of the sound. However, speech and audio will still be delivered faster than the original. Imagine the actor being perceived as delivering a line faster than the original and yet not sounding higher pitched, just seeming to talk faster. Human perception is not likely to notice the subtle time shift as long as the actor does not seem higher pitch in sound.