Subject:Max record length - I'm confused

Posted by: jackn2mpu

Date:7/21/2008 6:00:53 AM

I'm confused. What's the maximum length of a recorded file in Sound Forge 9? Tried researching this and came up with so many different answers that I got a headache. If you look at a blank cd it'll say 700 meg and 80 minutes time. Extrapolate that out to 2 gig and you get one number. Do the math multiplying sample rate by recording bit depth dividing by 8 bits per word and multiply that by time and you get another number (you have to rework the equation so that the unknown value is file length) for file length. One reference to an online calculator gives yet a third number. The reason I mention 2 gig for a file size because I've seen many references that the max file size in 32 bit WinXP is that number.
Questions are: is 2 gig max file size? If not, what is? And what would be the max recording time for a 44.1 khz, 16 bit 2 track file? I would assume that a single track would then be double the time, right?
This is not an academic question as I have a need to record ambient sound overnight for an investigation where things could go upwards of 8 hours without human intervention. And I don't have a portable digital recorder or the money to spend on one at this time.
Thanks all.
Jack

Subject:RE: Max record length - I'm confused

Reply by: ForumAdmin

Date:7/21/2008 7:29:29 AM

You can record as long as you like or have space for (edit: NTFS assumed).

The 2GB/4GB limitation comes into play if you choose to save the result to a .wav file. In that case, the default limit in 9.0e is either 2GB or 4GB depending on whether "Allow Wave renders up to 4 GB" option in Options->Preferences->General is enabled (older versions of Forge limited .wav to 2GB to remain compatible with certain applications).

Alternatively, you can save to .w64, .pca, or some other format that does not suffer from this limitation. I'd suggest .w64, as that is the native format of the recorded temporary file once it crosses the 4 GB boundary.

J.

Subject:RE: Max record length - I'm confused

Reply by: Geoff_Wood

Date:7/21/2008 4:30:21 PM

You've been readinfg too much and have got a bunch of different things muddled.

Maximum size for a WAV file is 2GB (although the latest release of SF9 can allow 'illegal' 4GB WAV files, which may not be 'portable').

The maximum FILE size on a FAT32 partition is 4GB.

XP with NTFS file system (and SF) can effectively handle any size file you like - certainly bigger than any HDD yet thought of.

The usual alternative to WAV in SF for large LPCM files is Sony's W64 file format, which can be selected to be used by default.

However you may be imagining a problem that isn't there. What are you doing thaht needs a filesize of more than several whole CDs ? Most editing work is far better done in smaller chunks.

geoff

Subject:RE: Max record length - I'm confused

Reply by: rraud

Date:7/21/2008 5:55:19 PM

I think Jack's question is: Can SF record 8+ hours of (surveillance) audio BEFORE saving as... a particular file format...

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I don't really have an answer.... except to record mono and if high quality is not an issue, the sample rate & bit depth can be set to reduce acquisition data size and of course.. available hard drive space.
Good question: Maybe Forum Admin. has a definitive.

Subject:RE: Max record length - I'm confused

Reply by: Chienworks

Date:7/21/2008 6:20:47 PM

44KHz 16 bit mono comes out to just a hair under 4 hours per GB. 4GB would be at least 15 hours. If you've got NTFS then a 500GB drive would let you record about 74 days straight in one single file. If you need stereo then halve those times. If mono is ok and quality isn't terribly important then go for 22KHz and get about 5 continuous months' recording time in one file.

Subject:RE: Max record length - I'm confused

Reply by: jackn2mpu

Date:7/22/2008 10:15:46 AM

Yes, it's 8 hours of surveillance audio; 2 tracks preferred but can go to 1 track and an omni mic. And I really need the capability of 44.1 KHz sample rate, at least on the initial recording run.
I know editing a file is much easier in smaller chunks. I plan on breaking down the file after it's recorded; it's just that the original file will be huge.
I have a standard XP installation, so I would assume that it's NTFS (I'm not in front of my daw at the moment).
Jack

Subject:RE: Max record length - I'm confused

Reply by: Chienworks

Date:7/22/2008 10:19:32 AM

If you don't have NTFS, well, why don't you? And why haven't you converted your drives to it already? But ... anyway ... assuming you are stuck with FAT32 and the 4GB limitation, 2 channel 16 bit 32KHz should let you get about 10.4 hours in one file. 32KHz should be more than plenty for surveillance audio. 22KHz Will give you about 15 hours.

And if you do have NTFS then you're only limited by available drive space.

Subject:RE: Max record length - I'm confused

Reply by: jackn2mpu

Date:7/26/2008 10:06:17 AM

chienworks:
I never said I didn't have NTFS; what I sadi was that at the time I was posting I didn't remember, and that I was not in front of my daw to be able to check. All my drives are NTFS. It's just that I'd read some things that gave me different numbers and I needed the help. And thank you to all that have helped.
Also, as I mentioned, I really need to run 16 bit 44.1 Khz for at least the first run, which is coming up tonight (Saturday).
Jack

Subject:RE: Max record length - I'm confused

Reply by: Chienworks

Date:7/26/2008 7:01:00 PM

Yep, i was just mentioning the info for FAT32 in case someone wants to do the same thing and that's all they have.

Now, my biggest and best advice i can ever give you about anything is ... TRY IT OUT FIRST! before you get to the event. Never attempt something for the first time at the event itself. Try recording something, anything, for 8 hours and see how it goes. Does the recording continue the whole time? Can you open and edit the file? You want to know the answers to these before you start recording the real thing.

Sadly, you'll probably see this reply too late.