[vorbis] Re: [MP3 ENCODER] Re: Quality problem reencoding

[Greg Wooledge]

Dan Nelson (dnelson at allantgroup.com) wrote:

> I guess the problem might be oggenc's option parser, then.  Given a
> stereo 22050hz input file, I can't seem to get oggenc to encode less
> than 22kbits.  The lowest bitrate it will allow on the commandline (for
> 22050hz/2ch input) is -b 30, but if you also add -M 1, it will generate
> a file with an average bitrate of 22.

$ sox -V War\ -\ Low\ Rider.wav -r 22050 foo.wav
[...]
sox: Finished writing Wave file, 17102568 data bytes 8551284 samples

$ oggenc -b 16 -M 16 --downmix foo.wav foo.ogg 
Enabling bitrate management engine
Opening with wav module: WAV file reader
Downmixing stereo to mono
Encoding "foo.wav" to 
         "foo.ogg" 
at average bitrate 16 kbps (no min, max 16 kbps), 
using full bitrate management engine
        [100.0%] [ 0m00s remaining] -

Done encoding file "foo.ogg"

        File length:  3m 13.0s
        Elapsed time: 0m 22.2s
        Rate:         8.7477
        Average bitrate: 15.7 kb/s

Of course, the resulting file sounds pretty bad.  (It's actually not
as bad as I expected it to be, but it has horrible artifacts in the
mid-range frequencies, and the high frequencies are gone.  A lowpass
might help a bit.)

Are you sure you're using Vorbis 1.0?


-- 
Greg Wooledge                  |   "Truth belongs to everybody."
greg at wooledge.org              |    - The Red Hot Chili Peppers
http://wooledge.org/~greg/     |


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