[mdlug] Speaking of audio formats...

[Dan Pritts]

it's tricky to rip DVDs from their native VOB files ; they are typically
not broken up into chapters or tracks, just all munged together
into a few huge VOB files.  So you can't just easily grab the audio
track out of the files you want from the command line.

My simplest suggestion is to use some standard dvd-ripper tool, as
if you wanted the audio AND video.  Then extract the audio you want
from the result.  I'd choose a crappy video codec (eg, xvid over
h.264) and low video framerate and bitrate, and maybe downscale the
video radically, which ought to result in fast video encoding.

Simplest to choose the audio format you want during this transcoding
process. 

To extract the audio from an avi file (or any other format your ffmpeg supports), you can use:

 ffmpeg -i foo.avi -acodec copy audiofile

If you were stuck with transcoding, you could

 ffmpeg -i foo.avi -acodec libmp3lame -ab 192 audiofile

I use Handbrake to do this on my mac but handbrake is available for
linux too.  I think on any platform but mac you need to de-css the DVD
first.  I'm sure there are other tools on linux for this.

The most recent version only does AAC audio, but previous versions
will do MP3.

Aaron K is right that in general a lossless format like flac is better,
all things being equal.  Note that the source material on a DVD is already 
lossy, though.  Transcoding it will degrade the quality, so there may be
a point in doing flac, but I probably wouldn't bother; if you want the best
quality find the songs on a CD.  

Of course, the simplest solution to your problem probably involves bittorrent.

re: streaming, there's no reason any tcp-based audio streaming protocol
won't work over an ssh tunnel.  You may need to increase buffering.

A plain ssh tunnel won't forward UDP.  You can work around this, eg:
  http://www.qcnetwork.com/vince/doc/divers/udp_over_ssh_tunnel.html

danno


On Sat, Jan 02, 2010 at 10:50:56PM -0500, David Lee Lambert wrote:
> Today I tried to rip the soundtrack from a DVD (actually, from the bonus 
> material: music videos of the songs) using VLC.  "Media -> 
> Convert/Save...", specify the right chapter, select an output format;  I 
> tried several MPEG variants but kept getting error-messages, then 
> selected Ogg Vorbis and got it to work. 
> 
> However,  what I obtained is four huge video files that only VLC can 
> play;  about 200 MB for a 10-minute song.  Is there some way to 
> re-encode just the audio tracks as MP3 or WMA, so I can copy them to a 
> portable music player?
> 
> Working under Ubuntu Intrepid, but I played one of the files back using 
> vlc under Debian Etch.
> 
> Also,  has anyone gotten some sort of streaming audio protocol to work 
> over an SSH tunnel?
> 
> --
> DLL
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danno
--
dan pritts
danno at umich.edu
734-929-9770