Use FFmpeg from the command line to convert back these three files to wav:.

Use FFmpeg from the command line to create three test files:įfmpeg -i export.wav c:a aac export_aac.aacįfmpeg -i export.wav c:a aac export_m4a.m4aįfmpeg -i export.wav c:a aac export_mp4.mp4.

Export the test track from Audacity as wav PCM 24 bits 48 kHz export.wav.

At least recent versions of FFmpeg are able to use this metadata.

Some containers (m4a and mp4 for instance) include a metadata describing how many silent samples are to skip when decoding the aac bitstream. There is a potential issue depending on the container used and the FFmpeg version. So here are some clues using FFmpeg version 4.1 with libavformat.58.20.100.dylib on macOS. This is more a workaround than an answer as I did not manage to link the libavformat library to Audacity. I notice audacity uses ffmpeg 2.2.2 version, and ffmpeg has many newer versions since uld using those newer versions fix the issue maybe? Under preferences library it says:įfmpeg library version: F(55.33.100),C(55.52.102),U(52.66.100)Īnd how would I make audacity use the newer versions? I don't really understand if it just calls up ffmpeg or if it needs to be this 2.2.2 version because they designed it to allow and work with that version specifically. Is there a fix I can do using audacity (using newest version 2.3.0) or some other freeware program? I have ffmpeg command prompt, and handbrake, if there's a command that can manually trim the audio or assign the right alignment. But when I puts it out of sync once more, and I'd also rather avoid the loss generated by exporting an aac as an aac. I corrected it manually in audacity with my eyes. When I follow the instructions and export it creates a sync delay by about half a second or so.enough to give a noticable echo when they are played in tandem. mp4 container (is this the highest quality codec I can convert to and fit in a mp4? I want the highest audio quality I can get). I then wanted to export this track to an aac with highest bitrate (320 seems to be highest audacity allows) in order to place it in an. wav s16's and I mixed those down into a single.

m4a in ffmpeg using the basic ffmpeg -i input.wav output.m4a, and I used the newest release of ffmpeg for that. ALso the problem occurs when converting the wav to. Edit: it's 0.0330s delay, not half a second sorry.

Convert m4a to mp3 in audacity