I'm fairly new to After Effects, but have come across a problem I so far haven't found a solution to by browsing these forums and beyond.
I'm having an audio issue with an *.mp4 file in After Effects. Its audio waveform seems to play at twice the speed of the video file within After Effects, yet only playing half the audio track per second.
The raw file plays back just fine in other media players, so it shouldn't be corrupt. Within AE, it looks like the waveform speed doubles (i.e. it only plays half the audio frames per second before skipping the remaining half of that second, clipping and leapfrogging ahead of the video, ultimately leading to the audio finishing at the video's halfway mark). I can stretch the audio track, but since half of every second of audio is missing according to AE, that fixes nothing.
I'm using AE version 184.108.40.206.
The input file is an *.mp4 file, 29.97 FPS, 48khz audio. Several other files recorded in the exact same manner plays back just fine in AE. Given that audio settings are unchanged between these files (both in my recording software and within AE) and the file in question works fine outside AE, I can't quite figure out why this one file is having issues, let alone how to fix it.
As per related topics on the forums, I've tried altering the Preferences - Audio Hardware setting, changing related output devices and their bitrate, but this gives no change in the playback within AE that fixes this issue. The project settings are set to match the input file (29.97 FPS, 48khz audio), so I don't think it's that either.
I'm not quite sure how to proceed from this point, short of finishing the editing in a different tool.
Transcode the file in a tool like Handbrake. The time reference strema is quite likely damaged, causing it to be misinterpreted.
Thank you - after processing the file through Handbrake, After Effects plays it back correctly.
Looks like I'll have to fiddle with my recording software to avoid repeats of this, then.
May be a simple performance issue. Sometimes hiccups in drive speed or delayed writing from a device driver and the CoDec streams is enough. It may not be at all your recording software. anyway, now at least you know how to fix it.