Vorbis - May 2003 - Ogg/Vorbis Python modules problem

Is anyone else using the Python modules?  I'm working on a Python-based
music player that will support, among other things, re-encoding music to
low-bitrate Ogg Vorbis for streaming.  Reading from a wav or raw file and
encoding to Vorbis works, and reading from a Vorbis file and saving to a wav or
raw audio file, or playing via the audio device also works, but I encounter
problems whenever I try to encode from a Vorbis or mp3 file.  When encoding from
Vorbis, reading the the python Vorbis module, it sounds like small portions of
the recording are missing, and  the encoded file is shorter than the original. 
With mp3 (read with pymad), there is noise introduced when re-encoding to Vorbis
which does not appear if i decode to a file and then encode to Vorbis as a
separate step.  The only thing that seems to be able to fix this is unpacking
the data to an array of ints, scaling and converting to floats, and repacking to
a string in Python, but this is much slower and seems to leak memory.  I'm
guessing it has so
mething to do with passing a Python string to write_wav instead of the buffer
objects that both MadFile and VorbisFile return, but I'm not sure.  Does
anyone else have any experience with using Vorbis in Python which might be
helpful?
--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to
'vorbis-request@xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is
needed.
Unsubscribe messages sent to the list will be ignored/filtered.

On Mon, 2003-05-05 at 13:18, 8ut3ww302@sneakemail.com
wrote:
> Is anyone else using the Python modules?  I'm working on a Python-based
music player that will support, among other things, re-encoding music to
low-bitrate Ogg Vorbis for streaming.  Reading from a wav or raw file and
encoding to Vorbis works, and reading from a Vorbis file and saving to a wav or
raw audio file, or playing via the audio device also works, but I encounter
problems whenever I try to encode from a Vorbis or mp3 file.  When encoding from
Vorbis, reading the the python Vorbis module, it sounds like small portions of
the recording are missing, and  the encoded file is shorter than the original. 
With mp3 (read with pymad), there is noise introduced when re-encoding to Vorbis
which does not appear if i decode to a file and then encode to Vorbis as a
separate step.  The only thing that seems to be able to fix this is unpacking
the data to an array of ints, scaling and converting to floats, and repacking to
a string in Python, but this is much slower and seems to !
 lea
>  k memory.  I'm guessing it has something to do with passing a Python
string to write_wav instead of the buffer objects that both MadFile and
VorbisFile return, but I'm not sure.  Does anyone else have any experience
with using Vorbis in Python which might be helpful?
Does oggenc.py have the same problem for you? I haven't noticed this
issue before, but I don't have the most discerning ears, so it may be
there.

And you should have a very, very good reason for transcoding mp3s to
vorbis, or you'll get yelled at :)

Andrew

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to
'vorbis-request@xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is
needed.
Unsubscribe messages sent to the list will be ignored/filtered.