WAV files not the same size after record/extract cycle -Sound Forge - PC

Subject:WAV files not the same size after record/extract cycle Posted by: davodavo Date:1/29/2003 11:13:24 PM Hi all. This is sort of a newbie question. I'm using SonicFoundry to record home-brew WAV files (from an analog source). When I put a WAV file onto a CD-R, and then extract that same file off the CD-R I just made, the new WAV file is a few percent larger than the original. Is there some sort of encryption or other alteration to my WAV files? I thought that a record/extract cycle would get me back exactly the same contents. ???
Subject:RE: WAV files not the same size after record/extract cycle Reply by: ATP Date:1/31/2003 5:29:33 AM how much bigger is it exactly? a few mb's, kb's or bits? if there is a huge difference it could be that the source waves are recorded with a lower sample rate.
Subject:RE: WAV files not the same size after record/extract cycle Reply by: Geoff_Wood Date:1/31/2003 6:14:00 AM A CD track is always written to fill a number of 'frames' of fixed size. A wav that itself would not fit exactly is presumably padded ot to fit the 'little boxes'. geoff
Subject:RE: WAV files not the same size after record/extract cycle Reply by: davodavo Date:2/1/2003 8:54:34 AM It's just a few percent / ?50kB? bigger than the original I recorded. There are enough differences that window's FC program can't keep track of them (it "loses sync" and gives up). Acoustically, it can't hear the difference but that's not really the point. The WAV was sampled at CD-quality (44.1 kHz, 16 bit stereo), so I don't think the sampling is the issue. The "frame" issue makes sense, but that should only account for a few hundred bytes...and when you extract the file back from the CD to a WAV file on the hard disk these bytes would be thrown away, right?? Is there possibly some watermark signature being added by SoundForge? Or some sort of compression or "sound improvement" algorithm??

Subject:WAV files not the same size after record/extract cycle

Posted by: davodavo

Date:1/29/2003 11:13:24 PM

Hi all. This is sort of a newbie question.

I'm using SonicFoundry to record home-brew WAV files (from an analog source).
When I put a WAV file onto a CD-R, and then extract that same file off the
CD-R I just made, the new WAV file is a few percent larger than the original.

Is there some sort of encryption or other alteration to my WAV files? I thought
that a record/extract cycle would get me back exactly the same contents.

???

Subject:RE: WAV files not the same size after record/extract cycle

Reply by: ATP

Date:1/31/2003 5:29:33 AM

how much bigger is it exactly? a few mb's, kb's or bits? if there is a huge difference it could be that the source waves are recorded with a lower sample rate.

Subject:RE: WAV files not the same size after record/extract cycle

Reply by: Geoff_Wood

Date:1/31/2003 6:14:00 AM

A CD track is always written to fill a number of 'frames' of fixed size. A wav that itself would not fit exactly is presumably padded ot to fit the 'little boxes'.

geoff

Subject:RE: WAV files not the same size after record/extract cycle

Reply by: davodavo

Date:2/1/2003 8:54:34 AM

It's just a few percent / ?50kB? bigger than the original I recorded.
There are enough differences that window's FC program can't keep track of
them (it "loses sync" and gives up). Acoustically, it can't hear the difference
but that's not really the point.

The WAV was sampled at CD-quality (44.1 kHz, 16 bit stereo), so I don't think
the sampling is the issue.

The "frame" issue makes sense, but that should only account for a few hundred
bytes...and when you extract the file back from the CD to a WAV file on the hard
disk these bytes would be thrown away, right??

Is there possibly some watermark signature being added by SoundForge? Or some sort of compression or "sound improvement" algorithm??