HydrogenAudio

Lossy Audio Compression => MP3 => MP3 - General => Topic started by: wlae on 2013-05-04 00:14:21

Title: rebuilding vbr header: how?
Post by: wlae on 2013-05-04 00:14:21
You guys would do me a huge favor solving following issue:

When recording a radio show directly into vbr mp3 (using lame), my vbr header is wasted after I edited my recording. Of course
its the editing which is the cause (I changed the mp3). Right now I am using razorlame to re-encode the mp3 so it has a working vbr header again.
But in fact I am encoding the mp3 two times, while recording and after editing. Which tool can be used just to rebuild the vbr header and check the crc after I've edited my vbr mp3? This way I won't have to re-encode the mp3 after editing. I've been searching on the internet for a while now, nothing seems to solve this.

Thanks in advance.



Title: rebuilding vbr header: how?
Post by: saratoga on 2013-05-04 01:10:53
Usually if you're going to edit you should be recording to wav or other lossless.

But if you need to fix VBR headers, foobar2000 can do that.
Title: rebuilding vbr header: how?
Post by: flaminio on 2013-05-06 01:12:10
MP3 Diags can rebuild VBR headers -- worth a try => http://mp3diags.sourceforge.net/ (http://mp3diags.sourceforge.net/)
Title: rebuilding vbr header: how?
Post by: slks on 2013-05-06 10:58:18
What are you using to do the editing in the first place? And what kind of editing? It sounds like that's what's really messing up the VBR header and would be a good place to start.

If you're doing complex edits that need a decode/encode, just do your required edits in the program, then output the file as .wav. Once you've got the .wav, do the encode with a good encoder or frontend, and you should have valid VBR headers just by virtue of the encoder working correctly.

If you're doing fade/cut/paste type edits that don't require another round of compression, like with MP3DirectCut, that's a more special application since you're keeping the same MP3 stream for the most part. If that's corrupting your VBR headers, look for a bug fix to that app, consider using a different one, or attempt to repair it after the fact with foobar.