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m4a file timing wrong, renaming to mp4 fixes it

New Here ,
Aug 15, 2020

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This is on a Windows 10 Pro machine using Premiere Pro, all the most current updates. I have lots of memory and disk.

 

I recorded a Zoom session with separate audio tracks for each participant. Zoom doesn't record muted speakers, but the audio file saved for that speaker has the unmuted sections put together with no breaks. That is if a speaker says 1,2,3 then mutes, then 2 minutes later says 4,5, they're all togther. Zoom also converts the audio files to m4a files which Premiere Pro can import.


However after one of these breaks, the audio track shows a waveform, but it doesn't actually play anything. That is I place the playhead at the start of a waveform, press play and there's no sound. However, later in the sequence the sound actually plays although there may be no waveforms there, or completely different waveforms. It looks like the waveform display is way out of synch with the played sound.

 

If I make a copy of the m4a file and just rename it to mp4 and import that, it works correctly. The two files fc to be identical, but the displayed waveforms are not even close to in synch.

 

Attached is a screen shot of the two files, top is the m4a, bottom the mp4. The bottom plays correctly, the top is silent up to the point the waveform starts in the bottom track. Before that, the waveforms are in synch and both play the same.

 

M4A vs MP4.jpg

Topics

Audio, Error or problem, Formats, Import

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19

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m4a file timing wrong, renaming to mp4 fixes it

New Here ,
Aug 15, 2020

Copy link to clipboard

Copied

This is on a Windows 10 Pro machine using Premiere Pro, all the most current updates. I have lots of memory and disk.

 

I recorded a Zoom session with separate audio tracks for each participant. Zoom doesn't record muted speakers, but the audio file saved for that speaker has the unmuted sections put together with no breaks. That is if a speaker says 1,2,3 then mutes, then 2 minutes later says 4,5, they're all togther. Zoom also converts the audio files to m4a files which Premiere Pro can import.


However after one of these breaks, the audio track shows a waveform, but it doesn't actually play anything. That is I place the playhead at the start of a waveform, press play and there's no sound. However, later in the sequence the sound actually plays although there may be no waveforms there, or completely different waveforms. It looks like the waveform display is way out of synch with the played sound.

 

If I make a copy of the m4a file and just rename it to mp4 and import that, it works correctly. The two files fc to be identical, but the displayed waveforms are not even close to in synch.

 

Attached is a screen shot of the two files, top is the m4a, bottom the mp4. The bottom plays correctly, the top is silent up to the point the waveform starts in the bottom track. Before that, the waveforms are in synch and both play the same.

 

M4A vs MP4.jpg

Topics

Audio, Error or problem, Formats, Import

Views

20

Likes

Translate

Translate

Report

Report
Community Guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more

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