B.Wavs at 23.98 from Pro Tools?

[jamesnardi]

Hi

I have found an issue when exporting B.Wavs from Pro Tools 8 (HD).

My session is set to 23.98 & once i have consolidated my final wav & export my region, but the t/c embeded within the files is incorrect.

Am i doing something wrong or am i not able to create a Broadcast Wav with a T/C running at 23.98?

Thanks in advance.

[Max Holland]

What is the incorrect time code? Pro Tools handles 23.98 as 23.976.

[jamesnardi]

Originally Posted by diamondschwin

What is the incorrect time code? Pro Tools handles 23.98 as 23.976.

Well the start of my file is:

00:59:59:00 (Pro Toos set to 23.976)

I then export this region from PT.




When i veiw my files in B.WAV Reader it says they start at:

01:00:02:10

[PlatinumSamples]

What's the actual Pro Tools session sample rate - not the clock sample rate?

Rail

[jamesnardi]

Originally Posted by PlatinumSamples

What's the actual Pro Tools session sample rate - not the clock sample rate?

Rail

23.976

[iluvcapra]

Originally Posted by jamesnardi

23.976

That's a timecode rate, not a sample rate.

I think a problem you're having here is that WAV files don't have a timecode rate or a literal numeric timecode stamp in them (not like an 80-bit SMPTE word, anyways). WAV files know nothing about timecode. They have a sample rate, and if they have a timestamp it's expressed in terms of a count of samples from midnight. Frames never enter into the equation until the receiving software tries to reinterpret the WAV timestamps as TC. (presumably it's taking these from the broadcast extention) Whenever consumers of a WAV file have a problem it's usually because they are interpreting the sample count timestamp modulo an incorrect frame rate.

What tool are you importing the files into, er what's telling you the timestamps are incorrect? You might be running into the infamous Final Cut Pro issue.

[jamesnardi]

Originally Posted by iluvcapra

That's a timecode rate, not a sample rate.

I think a problem you're having here is that WAV files don't have a timecode rate or a literal numeric timecode stamp in them (not like an 80-bit SMPTE word, anyways). WAV files know nothing about timecode. They have a sample rate, and if they have a timestamp it's expressed in terms of a count of samples from midnight. Frames never enter into the equation until the receiving software tries to reinterpret the WAV timestamps as TC. (presumably it's taking these from the broadcast extention) Whenever consumers of a WAV file have a problem it's usually because they are interpreting the sample count timestamp modulo an incorrect frame rate.

What tool are you importing the files into, er what's telling you the timestamps are incorrect? You might be running into the infamous Final Cut Pro issue.

Thanks for the help mate.


I'll just quickly run through what i am doing.

I'm conforming 5.1 from (25fps PAL to an HD SR tape running at 23.98)
It's all done & in sync. So i'm consolidating my files, then exporting the reigions as Wavs.

My PT session is set to 23.976 & the session start t/c matches the tapes t/c & the start of my files are lined up at 00:59:59:00.

These files are then sent off to Amercia to be used by a Bluray authroung company. They are saying my files have the wrong t/c & they cant not sync them to picture...
I opened my exported Wavs in BWAVReader 1.0b & also in Final Cut & both tell me the same (incorrect T/C) (01:00:14:01)

I know the Wavs wont carry timecode exactly, but thought it would stamp the start t/c at the beginning of the file..??

Any help would be great.

[iluvcapra]

Originally Posted by jamesnardi

I know the Wavs wont carry timecode exactly, but thought it would stamp the start t/c at the beginning of the file..??

It's supposed to, but it really depends on how they interpret it on the other end. So you have a difference of 00:00:15:01. If you were having a PAL-Film problem the differential, if you started counting from midnight would be over a hundred seconds, so that probably isn't it. If it were just an NTSC error, counting from midnight, you'd only be off by about three seconds, so that isn't it either, and neither a sum or difference of those two give you 15:01...

What's your session sample rate, and do you have any audio rate pull up/pull down on? When you have the regions, what do the original time stamp and user time stamps in the timeline say, when you show them with View > Region?

The files that you ship, what does the Workspace say their original timestamp is?

When you export the regions, do you do it with "Export Regions"? Because this will keep the underlying file's original timestamp and user timstamp. If you consolidate the files first by option-shift-3 duplicating this rewrites the files timestamps (or should), but if you consolidate with "Compact" it won't.

You couldn't get the authoring company to use the leaders, could you?

[Etch-A-Sketch]

Originally Posted by iluvcapra

When you export the regions, do you do it with "Export Regions"? Because this will keep the underlying file's original timestamp and user timstamp. If you consolidate the files first by option-shift-3 duplicating this rewrites the files timestamps (or should), but if you consolidate with "Compact" it won't.

This is exactly what I was thinking. If you took the 5.1 mix as given you, and just slid it left/right in the timeline so the 2pop lines up then you export it using Cmd+Shft+K, it isn't putting the new timecode in anywhere. You have to consolidate the mix by selecting the whole thing, hitting Opt+Shft+3 (which creates a new audio file with the PT timeline stamped into it) then when you export the audio file will have the correct timecode.

Try it and see if it fixes the problem.

[jamesnardi]

Originally Posted by Etch-A-Sketch

This is exactly what I was thinking. If you took the 5.1 mix as given you, and just slid it left/right in the timeline so the 2pop lines up then you export it using Cmd+Shft+K, it isn't putting the new timecode in anywhere. You have to consolidate the mix by selecting the whole thing, hitting Opt+Shft+3 (which creates a new audio file with the PT timeline stamped into it) then when you export the audio file will have the correct timecode.

Try it and see if it fixes the problem.

yeah, i always consolidate first, then export.