Subject:Time Added To MP3s

Posted by: eightieschild

Date:6/21/2006 7:29:49 AM

I've noticed in Sound Forge Audio Studio 8.0 that my Wave files are fractionally longer once saved as MP3s. Is this supposed to happen? Is this normal?

For example, I was working on a uncompressed audio file. I saved it as an MP3 file, with a bit rate of 192 kbps. When I re-opened it, the file had gained 00:00:00:030 seconds at the beginning, and 00:00:00:038 at the end.

Subject:RE: Time Added To MP3s

Reply by: Chienworks

Date:6/21/2006 8:39:55 AM

Yes, this is normal and it is supposed to happen. The MP3 spec specifies short silences at the beginning and end of the file.

Subject:RE: Time Added To MP3s

Reply by: eightieschild

Date:6/21/2006 8:56:59 AM

Ok, thanks for that information. But what if the uncompressed Wave file already contains short silences at the beginning and end? Will the MP3 compression use these, or add more of it's own?

Subject:RE: Time Added To MP3s

Reply by: Chienworks

Date:6/21/2006 9:54:20 AM

It will add it's own because the MP3 compressor doesn't know whether those silences are added extras or part of the recording.