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A good friend of mine sent me a wma format rough mix of a track she has been working on with some other folks. I guess they're using pro tools on the PC.

I converted the thing to WAV using EasyWMA (which cost $10 and I highly recommend if you have to deal with audio file format conversions - also converts to mp3.

I was inspired to add some guitar parts to the song so I dragged it into a DP audio track and then started tracking other audio parts over it. I then bounced my tracks to wav files and sent them to their engineer. Yay DP! That was EASY and FUN!

However, the engineer I sent them to expressed reservations about possible timing issues since I was working off of a rough mixed WMA file rather than an unencoded WAV.

Which raises my question - what is the timing fidelity of compressed formats like mp3 and WMA vs uncompressed formats like WAV? Should they match exactly or might we encounter drift?

I haven´t encountered problems with MP3 yet, exporting from DP or Audiofinder when I send demos and similar.
This is a very interesting issue though. I´d would like to know too.

I have experienced timing issues with mp3 tracking demos.

For instance, say somebody sends me a basic demo in mp3 and I work up parts for it. I match the tempo in DP to the click countoff on the mp3, and by the middle of the tune, the timing has drifted. mp3 is NOT sample accurate.

Billster wrote:I have experienced timing issues with mp3 tracking demos.

For instance, say somebody sends me a basic demo in mp3 and I work up parts for it. I match the tempo in DP to the click countoff on the mp3, and by the middle of the tune, the timing has drifted. mp3 is NOT sample accurate.

Good to know. I think WMA is a variable bit encoded format sponsored by Microsoft. So - given that it is variable bit rate, and especially given that it comes from Microsoft - a bunch of idiot savants - I'll bet I have similar issues. I'll post a followup when I hear back from the mix guy.

At least my parts are all mostly riffage - he can nudge them around pretty easily I think.

Billster wrote:I have experienced timing issues with mp3 tracking demos.

For instance, say somebody sends me a basic demo in mp3 and I work up parts for it. I match the tempo in DP to the click countoff on the mp3, and by the middle of the tune, the timing has drifted. mp3 is NOT sample accurate.

Depends if they use Constant Bit Rate (CBR) or Variable Bit Rate (VBR).
If I put anything in mpcrap I usually go 320 kbps and use CBR @ 44.1. That way it doesn't vary the sample bit rate to what it thinks it should be @. If it hears a low frequency it samples @ a lower bit rate to save memory because why sample @ a higher frequency if the nyquist theory says you have to double the sample frequency to the fundamental frequency in order to sample the complete cycle of the waveform. That's why I don't use VBR.
But I wouldn't even accept a WMA file... especially if they are in PT's he he...
And they should make sure that they send you out any compressed format @ the same sample rate of your projects... DP will do the math, but the less it has to do the better.

newrigel wrote:I wouldn't even accept a WMA file... especially if they are in PT's he he...
And they should make sure that they send you out any compressed format @ the same sample rate of your projects... DP will do the math, but the less it has to do the better.

Oh well, my friend was "just showing" me her new track so she sent the WMA she got from her engineer. I doubt she even knows how it was produced. It was a middle eastern sounding rock tune and I just got one of those Jerry Jones sitars and I thought "this would be great on that tune" so I added parts and sent it back and they decided to use it.

Its not like there was a plan with forethought.

Next time I'll ask them to produce me a WAV, but most WAV's don't fit through an email gateway (it came out to about 80M and 20M is the limit).

When I do sessions over the internet I always request uncompressed file formats; I noticed early on (by zooming in on the file) that mp3s are always offset enough to screw with timing.

SixStringGeek wrote:

newrigel wrote:I wouldn't even accept a WMA file... especially if they are in PT's he he...
And they should make sure that they send you out any compressed format @ the same sample rate of your projects... DP will do the math, but the less it has to do the better.

Oh well, my friend was "just showing" me her new track so she sent the WMA she got from her engineer. I doubt she even knows how it was produced. It was a middle eastern sounding rock tune and I just got one of those Jerry Jones sitars and I thought "this would be great on that tune" so I added parts and sent it back and they decided to use it.

Its not like there was a plan with forethought.

Next time I'll ask them to produce me a WAV, but most WAV's don't fit through an email gateway (it came out to about 80M and 20M is the limit).

You send it has a free thing.