<br><br><div><span class="gmail_quote">On 8/16/05, <b class="gmail_sendername">gLaNDix (Jesse Kaufman)</b> <<a href="mailto:glandix@lloydnet.org">glandix@lloydnet.org</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Neil Davidson wrote:<br>> How are your DVDs stored? If they are as ISOs or the raw VOB/IFO files you<br>> could try ripping out unused audio tracks, subtitles etc.<br><br>what app do you use to rip out unused audio tracks, etc from just
<br>straight VOB rips? no IFO files or anything, I just have the VOBS themself.<br><br>thanks,<br>-g-</blockquote><div><br>
<br>
Depending on your tolerance for artifacts, sound quality, and a few
other issues, DVD's can be reduced dramatically by using a more
efficient codec. The recent threads on DVD languages contain
discussion of this.<br>
<br>
A full high quality DVD can run up to 8GB (That I've personally seen)
due to using MPEG2, multiple audio tracks, subtitles, and very high
bitrates. How much of that you want to retain is up to you, but
most people are quite content bringing them down considerable.<br>
<br>
Questions to ask yourself:<br>
What parts of the movie are the most important to you? Do you
need subtitles, multiple languages? Do you have a full
multichannel stereo set up or are you willing to compress the
audio? Are you extremely sensitive to audio distortion?<br>
<br>
<br>
<br>
As an experiment to help you answer some of these questions, try this:<br>
<br>
1) Test various audio settings, using mencoder to dump out part of the
audio tracks: (Note: These assume you want the english track) (Note2:
I'm taking a chunk a minute or two into the movie to give a
representative sample, if you know there's a portion of sound you think
you'd hear the difference on, use that instead)<br>
<br>
Digital Quality AC3 audio: <br>
mplayer MOVIE.vob -aid 128 -dumpaudio -dumpfile moviesound.ac3 -ss 200 -endpos 120<br>
<br>
"Normal" audio 128 kbs:<span style="font-family: monospace;"><br>
</span>mencoder -oac mp3lame -lameopts mode=2:cbr:br=128:vol=0 \<br>
-ovc frameno -o frameno.avi MOVIE.vob -ss 200 -endpos 120<br>
<br>
"Reduced" audio 96 kbs:<br>
mencoder -oac mp3lame -lameopts mode=2:cbr:br=96:vol=0 \<br>
-ovc frameno -o frameno.avi MOVIE.vob -ss 200 -endpos 120<br>
<br>
<br>
Compare how they sound, and then compare the sizes, to get a rough estimate of the order of magnitude each size gives you.<br>
<br>
After that, try converting the same portion of vob to the xvid codec at
different bitrates, with 2 pass encoding. (Note, this command
expects you to have one of those frameno.avi audio clips in the same
directory)<br>
<br>
<pre id="mencoder_out"># video track (pass: 1, bitrate: XXX)<br>nice -n 3 mencoder -sws 2 -oac copy -ovc lavc \<br> -lavcopts vcodec=mpeg4:vbitrate=XXX:vhq:vpass=1 \<br> -ffourcc XVID -ss 200 -endpos 120 MOVIE.vob -o /dev/null
<br><br># video track (pass: 2, bitrate: XXX)<br>nice -n 3 mencoder -sws 2 -oac copy -ovc lavc \<br> -lavcopts vcodec=mpeg4:vbitrate=XXX:vhq:vpass=2 \<br> -ffourcc XVID -ss 200 -endpos 120 MOVIE.vob -o "movie.avi"
</pre>
Just put in different bitrates in the XXX spot each time. Be sure
to delete the divx2pass.log file after each second run. The
bitrate must match for each pass, however. A value of 800 for the
bitrate will give you results around 700MB for a full DVD depending on
your audio settings. Values around 1500 give bigger files, but
are very nice looking.<br>
<br>
I like to use this free tool to generate my mencoder command lines: <a href="http://f0rked.com/core/simplerip">http://f0rked.com/core/simplerip</a><br>
<br>
--Ryan<br>
<br>
</div></div>