HydrogenAudio

Lossy Audio Compression => MP3 => MP3 - Tech => Topic started by: njsain on 2012-11-02 15:26:29

Title: Does "Lame -m j -V 4 -q 2 -lowpass 11 -b 64" produce a VBR o
Post by: njsain on 2012-11-02 15:26:29
The parameters "-m j -V 4 -q 2 -lowpass 11 -b 64" and Lame version 3.98r are reported by mediainfo when I open a audiobook mp3 file I downloaded from e-music. Both mediainfo and mp3tag report this file as being a CBR file, but from reading the VBR documentation here http://lame.sourceforge.net/vbr.php (http://lame.sourceforge.net/vbr.php) using the -V option produces a VBR file even without the -v parameter and the -b parameter sets the minimum bit rate instead of forcing a constant bit rate. Is that correct or am I missing something? What would be the advantage of using -V 4 when encoding a CBR file?

Nathan
Title: Does "Lame -m j -V 4 -q 2 -lowpass 11 -b 64" produce a VBR o
Post by: lvqcl on 2012-11-02 16:07:20
Encode a file with "-h -b 64" and MediaInfo will show the parameters you quoted.
Title: Does "Lame -m j -V 4 -q 2 -lowpass 11 -b 64" produce a VBR o
Post by: njsain on 2012-11-02 16:56:39
Thanks lvqcl! Any idea why mediainfo is reporting the encoding settings that way? Is it a mediainfo error or is it from the Lame header of the file?
Title: Does "Lame -m j -V 4 -q 2 -lowpass 11 -b 64" produce a VBR o
Post by: [JAZ] on 2012-11-04 18:59:05
-m j, V4 (when using only -v) are defaults (and -h equals to -q2).
I think it probably has to do with the Lame header, which stores a "quality" value and some related data (but not the switches themselves).
From there, part of the information can be obtained, but part of it might have no sense.