[gstreamer-bugs] [Bug 498004] preset is ignored by lame plugin

[GStreamer (bugzilla.gnome.org)]

If you have any questions why you received this email, please see the text at
the end of this email. Replies to this email are NOT read, please see the text
at the end of this email. You can add comments to this bug at:
  http://bugzilla.gnome.org/show_bug.cgi?id=498004

  GStreamer | gst-plugins-ugly | Ver: 0.10.7




------- Comment #11 from Rob  2008-07-29 00:17 UTC -------
Thanks for the update.

Until the bug fix flows down to the distros, the work-around appears to be
simple.  Just set vbr-max-bitrate=320.  

e.g. for preset standard use this the pipeline in Sound Juicer or Rhythmbox:

audio/x-raw-int,rate=44100,channels=2 ! lame name=enc mode=1 vbr=4 quality=1
preset=1001 vbr-max-bitrate=320 ! xingmux ! id3v2mux


It does not look like you need to set or over-ride the vbr-min-bitrate or
vbr-mean-bitrate.  Just setting vbr-max-bitrate seems to do the trick.  

But I could be wrong. If I understand Sabastian correctly, the bug is caused by
gstreamer-lame setting the (min-max and mean) bit rates when vbr presets are
being used.  It should not set the bit-rates when vbr presets are being used. 
That makes sense.  If gstreamer always uses the default gstreamer
vbr-max-bitrate of 160, then the resulting mp3's will be a lot smaller than
expected (when using preset standard or higher).

Perhaps, you need to set or over-ride the min and mean vbr bitrates as well.
The default vbr-min-bitrate is 112.  Perhaps, LAME CLI may use an even lower
min-bit-rate when executed at the command line with --preset-standard option. 
In any event, it probably won't make much difference to the final mp3 if you do
not over-ride the vbr-min-bitrate (until the bug fix makes it to your distro).

I suspect this bug also occurs if you just use vbr-quality instead of presets. 
My understanding is that vbr-quality=2 is the same as preset standard when
using LAME for the CLI.

Lets hope this bug fix makes it way to the distros soon so we don't have to do
work-arounds!


-- 
See http://bugzilla.gnome.org/page.cgi?id=email.html for more info about why you received
this email, why you can't respond via email, how to stop receiving
emails (or reduce the number you receive), and how to contact someone
if you are having problems with the system.

You can add comments to this bug at http://bugzilla.gnome.org/show_bug.cgi?id=498004.