Re: [Avid-L2] Audio Stems Time Code Wavs read differently in Avid vs. Wave Agent?

The speed is in the BEXT chunk, as well as in the iXML (That might or might not be present.)

Not all apps honour that, and Avid does sometimes, depending if you're importing or linking.

The BEXT chunk has very little space, and might contain other precious metadata that I'd rather not trash, hence it's not (yet) in QTchange.

WaveAgent is ancient (and still in 'beta').

It is 'sometimes' handy, but does not support RF64 (So no long / modern files)

Note that Sound Devices makes location sound gear, so it's aimed at that.

Interleaved means multiple channels in one file, where the samples are ordered after each other.

Wave cannot be different, but QuickTime can, making it harder for a system to read them in sync, as the data comes from multiple places.

This was done for things like CD, where there is only one head, so to avoid caching / jumping around, everything has to be in the same place.

In WaveAgent lingo a 'file' can also consists of multiple mono files, depending on the recorder setup.

(Poly vs Mono) Together they form the clip.

This has NOTHING to do with the channel assignment. If you have a stereo mic, a 2 channel file will have Left and Right.

But when you have a boom and a wav, it will be dual mono. 

Your OS does not know what a boom nor wav is, if it sees a 2 channel file, it will call it 'stereo', no matter the content.

Bouke / edit 'B

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On 2 Sep 2023, at 03:26, John Moore <bigfish@pacbell.net> wrote:

After the mixer said I should just change the wav time codes using QT change instead of him fixing them, I assume he would have to re-export, I've been playing around with QT Change and Wave Agent on these WAV files.  I've fixed them but I'm curious about some of the things I see bouncing between Wave Agent and QT Change.  The start time code change is straight forward in QT Change.  Then when I bring those files into Wave Agent I have to tell Wave Agent the files frame rates are 23.97 ND and then it reads the start time code correctly.  If I then save this change in Wave Agent the files will come back into Wave Agent knowing they are frame rate 23.97 ND.  This makes sense to me.  Is it correct that the wav files came out of protools with no Frame Rate metadata?  Bouke had mentioned ProTools is very lacking in generating wav metadata so I assume this is what is going on.

My other curiosity is that at the desktop level the wave files are discrete left and right individual files but in Wave Agent it sees them as Interleaved Channels = 2(MONO) and in the case of the 5.1 stems Wave Agent sees them as Interleaved Channels = 6(MONO).  If I alter the time code start of a right or left stem it breaks the 2(MONO) to 1(MONO) until I set the file back to matching start time codes.  This makes sense but I'm wondering given the files appear individually on the desktop what aspect of these seemingly individual files is tell Wave Agent they are in fact Interleaved?

So many widgets spinning in a circle.  I've accomplished the goal but as all too often the more I think I learn the more I realize how much I don't know.