SD 744T Problem with files

[carbonhobbit]

I received this by e-mail yesterday. Anybody having these problems?

Sound Devices would like to make our 7-Series owners, users, and

resellers aware of a know issue relating to WAV files generated by

7-Series recorders.

ISSUE

***************

Wave files (Broadcast Wave) recorded by a 7-Series recorder with the

attributes below may not properly import into the latest release of

Avid or Pro Tools. These files may appear to the application as

unreadable. File attributes must include the following for the

condition to occur:

- 24-bit depth,

- 1-track (monophonic) or 3-track polyphonic

From our experience, files with the above attributes fail to import

roughly 50% of the time.

SOLUTION

***************

Until a new release of 7-Series firmware is available correcting this

bug we recommend selecting either two-track or four-track 24-bit files

when recording material that will be posted in Avid or Pro Tools.

Two-track and four-track files do not have any issues importing into

these applications, nor do any files recorded at 16-bits.

This behavior exists with all Sound Devices firmware releases up to

and including the present version, 2.10.

BACKGROUND

***************

Wave files use a RIFF (Resource Interchange File Format) structure to

represent their file metadata. One requirement of RIFF file chunks is

that they must be word aligned. This means that their total size must

be a multiple of 2 bytes (ie. 2, 4, 6, 8, and so on). Most audio

software applications do not rely on even byte RIFF chunks to parse

metadata properly. The latest releases of Avid Technologies Inc.

software, namely the Digidesign ProTools and Avid family of products,

do require WAV files to meet this part of the RIFF standard and can

have difficulty properly importing files which do not meet this

requirement. Sound Devices Wave files generated with odd track counts

at 24-bits have the possibility of producing an odd byte RIFF header.

Problems do NOT occur with 2- or 4-track poly files, or ANY file that

records at 16-bit, since the number of bytes for these types of files

will always come out even.

If you have additional questions concerning this condition please

contact our support staff at support@sounddevices.com.

Support Staff

Sound Devices, LLC

   

Scott.

[Jeff Wexler]

I received this notification also and I am puzzled as to whether this is just a new statement about an old problem, or something new (and related just to Sound Devices). What confuses me is that we have known for a long time that older Avids have a problem with ODD track counts (3 tracks recorded, 5 tracks recorded, etc.). Several years ago I had to record BLANK tracks as files were being imported directly into an older Avid system. So, if I really only wanted to record 3 tracks, I had to record a total of 4 tracks so they Avid would even recognize the file. I thought this problem went away with most newer versions of Avid software but the SD post seems to be implicatiung newer software versions (and even Digidesign ProTools systems --- Digi of course being owned by Avid now).

I always record POLYphonic files but 80% of the time this is only 1 track "wide" and I have not yet had any problems with newer Avids or any of the devices in daily transfer, most typically the DV40 or 824. I have recorded several things with 3 tracks enabled (an ODD track count) and this also has not been a problem. The Fostex machines do NOT see these 3 tracks as they were assigned (for example, track 1, track 7 and track 8 making up the poly file that is 3 tracks wide) but this is also not a major problem.

I hope someone can clarify all of this. My experiences, of course, are with the Deva but it seems that SD is talking about some of the same issues.

Regards,  Jeff Wexler

[Jeff Wexler]

Just chime in on recording Poly files. It has been my experiance that it is best to record Mono files. I have hundreds (if not more) of hours of audio recorded this way and it always works no matter what system they use for post. I have had nothing but problems when we sent in Poly files. No matter what machine we used to record with.

In the beginning for me, and this was over 10 years ago with the original Deva, I always recorded mono files as well, staying clear of the whole idea of a poly file. I did this primarily to make certain that the track, or tracks, that I wanted post to use on a daily basis, was the right track. In my case, this would almost always be Track 1 ONLY and it was clear that it was the intended track because it was always its own FILE (even if I had recorded other mono tracks for that scene).

I was talked out of using mono files somewhere along the way, mostly dealing with the ease that multiple tracks in a poly file could be brought into various systems (notably the Avid) and so I have stuck with poly files. I still make the request and the directive that it is Track 1 only for dailies even if the poly file is several tracks wide. This has worked out well for me.

I still do not have a good answer to my original question: whether this Sound Devices memo relates to the old Avid problem of odd track counts --- this I would like to know.

-  Jeff Wexler

[Philip Perkins]

Just chime in on recording Poly files. It has been my experiance that it is best to record Mono files. I have hundreds (if not more) of hours of audio recorded this way and it always works no matter what system they use for post. I have had nothing but problems when we sent in Poly files. No matter what machine we used to record with.

Since Avid would admit it is a problem on there end then recording makers are let out in the cold. I have spent serveal hours talking with them and it is always the same story Our system isnt the problem.

Apple's FCP has never given me half the trouble that the Avids do. And InDaw just works no matter what the file is.

Interesting.  On  my 2 track recorders I've always used poly w/ no issues on any edit or telecine system.  On Metacorder it's been mostly mono files, to stay under the 2GB limit in concert recordings mainly, and to avoid the old "odd track count" issues completely.  So you 744T folks--if you need 3 tracks are you still recording 4 (as a poly) with #4 empty just in case?

Philip Perkins

[t.elder]

I just asked Sound Devices about the mono / polyphonic file issue as I'm about to work on a small job with the audio files going directly into the latest version of FCP.  According to Sound Devices, FCP 5 can recognize polyphonic .WAV (not .BWF) files, including metadata, with a caveat that these files must be recorded non-drop frame.  I have previously always recorded monophonic files but have always wanted to make things easier for the editor, so I am excited, if a bit trepidatious, about using polyphonic files.

Tim

[Fernando]

Interesting.  (...) So you 744T folks--if you need 3 tracks are you still recording 4 (as a poly) with #4 empty just in case?

Philip Perkins

I do with my Deva. Always even number of tracks, just in case (unless I can check before shooting)