Need help with corrupted WAV-multitrack file

[Bernhard Guettler]

Hi all,

a colleague asked me for help with a file, that was recorded in Pyramix in WAV format. The recording engineer forgot to activate "one file per track" before recording. So we have one 19 GB file which contains 46 tracks.

What file exactly is this "multitrack"-wav file ? They tried to import the file in Sequoia (7.2) but that didn't work. The big shock came afterwards, when they went back to the recording venue, and there they couldn't open their own file from Pyramix anymore with the very same Workstation the file was recorded on. Since they had kept a backup on their machine, it's not likely, that the file was corrupted while the import in Sequoia was attempted.

Has anybody experienced this and what could be the possible solutions?

Can Pyramix usually read back it's own "multitrack"-wav files ?

Thanks for your help
Bernhard

[Pyromanic]

Of course it can, but my guess is, that the file got corrupted during the import trial. Its not usual but could be.
If you have a backup, use this.
If you only have the corupted file, try it in a very new arrangement.
if nothing helps, contact merging, maybe they can reparse the file even with a defect header!?

[Visiteur]

As Bernhard has stated, the file wasn't being corrupted by the vain import. As an experienced Sequoia user I would exclude this, too. Sequoia ignores unknown chunks totally. The only possibility would be that there are chunks implemented in a way that uses official chunks for proprietary reasons. But I hve never experienced this. I understand Bernhard in a way that the backup is broken as well...hm.

Visiteur

[Jakob Händel]

Hi all,

a colleague asked me for help with a file, that was recorded in Pyramix in WAV format. The recording engineer forgot to activate "one file per track" before recording. So we have one 19 GB file which contains 46 tracks.

What file exactly is this "multitrack"-wav file ? They tried to import the file in Sequoia (7.2) but that didn't work. The big shock came afterwards, when they went back to the recording venue, and there they couldn't open their own file from Pyramix anymore with the very same Workstation the file was recorded on. Since they had kept a backup on their machine, it's not likely, that the file was corrupted while the import in Sequoia was attempted.

Has anybody experienced this and what could be the possible solutions?

Can Pyramix usually read back it's own "multitrack"-wav files ?

Thanks for your help
Bernhard

Hi Bernhard,

if you are able to open the file, render it by selecting "one file per track", then it should work on any other DAW. To invert the process, the "multi file fixer" to create pmf-files from wav-files works fine.

Here are my suggestions:
Merging should implement the separation of pmf-files in their "multi file fixer" to avoid the time consuming rendering process.

Additionally, merging should automatically activate "one file per track" when selecting any other format than PMF! Consequently, we avoid to generate incompatible multitrack files by accident.

Best,
Jakob

[Bernhard Guettler]

Hi all,

if you are able to open the file, render it by selecting "one file per track", then it should work on any other DAW. To invert the process, the "multi file fixer" to create pmf-files from wav-files works fine.

Sure, that's what I wanted to do, but unfortunately the file and even the backup file can't even be opened anymore in Pyramix, very strange.

Additionally, merging should automatically activate "one file per track" when selecting any other format than PMF! Consequently, we avoid to generate incompatible multitrack files by accident.

Very good idea, Jakob. That's the way to go.

Thank you all,
Bernhard

[Bernhard Guettler]

Additionally, merging should automatically activate "one file per track" when selecting any other format than PMF! Consequently, we avoid to generate incompatible multitrack files by accident.

Very good idea, Jakob. That's the way to go.

P.S. ...except for two-track/stereo recordings to formats that allow them.

[benoit]

"backup file can't even be opened anymore in Pyramix"

...but you didn't touch this backup file, did you?

Benoit

[Pierre-André Aebischer]

Hello Bernhard,

Due to the 32bit adressing (not resolution) format of the WAV et BWF file, you are limited to 2GB per file, be it mono, stereo or multitrack.

Unfortunately there is no way to repair this damaged file, but this also explains why your back-up copy is damaged too. Still there is the need for multitrack WAV or BWF in some cases, so this can be done even though it potentially is dangerous.

This was one of the reasons that led to the creation of the 64bit PMF file format, which allows much larger file sizes. Extraordinarely larger in fact.

I hope this helps, kind regards

[phaseboy]

Since this is the case it would be nice if you could implement a control so that pyramix simply stops recording if you reach the maximum file size for any given format (and open a window saying as much). It would be better to have that happen in a live situation (then you could simply go back into record) than to have the entire recording lost.

Also perhaps more argument for the comment that by default all formats other than pmf should be "one file pre track". I have had several colleagues bring material to me for "separation" that they recorded on pyramix intending to edit on something else but didn't know about the "one file per track" option.

In an ideal world we'd all use pmf format all the time, but that's an unrealistic expectation. One of the great things about pyramix is it's ability to work easily with so many file formats - allowing easy collaboration with people on other systems.

Best,

Mark

[Pierre-André Aebischer]

Hi, we totally agree.

We need to give multitrack capability to WAV, BWF and other formats for performances purposes, but we are thinking about a way of improving the 2GB (respectively 4GB for AIF) limit.

For Bernahrd,

We will contact you by e-mail and see if we can come up with a way of fixing you WAV file, in fact we may have a solution, provided you know the exact file data such as bit rate, sample rate, number of tracks and file format. The solution already exists for PMF and we will look into extanding it to other formats, if this may help with your current issue.

Kind regards

[Dominique Brulhart]

Hi all,

Wave files unfortunately don't support more than 2GB, size that can be exceeded when recording multiple tracks.

As Bernhard stated 'One file per track' should have been checked in the case of 46 tracks. Even if the 2GB limit wouldn't have been reached, there's not a lot of programs allowing reading interleaved wave files with so many tracks.

This is one of the reasons why we've created the PMF format that avoids all this problem (and many others).

In Pyramix the choice of Wave clearly indicates the 2GB limit, but we do not stop the recording if the 2GB size is reached as the file still contains all the data, it's just not a valid Wave file anymore.

YOUR RECORDING IS NOT LOST !

If this problem happens, please send us a report and we'll send you a little program that recovers all samples in the file and generates a set of valid mono wave files.

This recovering program will be installed as standard in a further version of Pyramix.

Please don't hesitate to contact me in case of emmergency.

Best regards,

Dominique

[Dominique Brulhart]

Dear Visiteur,

As Product Specialist for Sequoia you’re certainly in a very good position to give your opinion on subjects like Source Destination Editing or Auto-tuning, but we’re less sure about your skill in Hardware, DSP, File Format or Video Synchronization…

We, at Merging, feel sad that you’re trying to help our customers having problems by advertising your product which, in most of the present cases, couldn’t help at all.

This is particularly sad as we have the greatest admiration for Sequoia, a truly wonderful product we know very well since many years as the person who occupied your position some years ago has become a Pyramix distributor…

So, as a tribute to your professionalism, and to help you better supporting our customers, Merging is willing to offer you a full blown Pyramix Workstation next time you come “visit” us at our office.

With our greatest respect,

Sincerely,

Dominique Brulhart



Mr Visiteur is best known as:

Sebastian Gabler MAGIX
Diplom-Tonmeister/Pro Audio Engineer
product specialist broadcast
phone: (Germany) +49 (0)30 29392-363
fax: +49 (0)30 29392-400
e-mail: sequoia@magix.net