[MPlayer-users] 2 pass divx encoding from .VOB/dvd - Targeted filesize (bitrate)

[Arpi]

Hi,

don't skip audio at 1st pass!

> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> Hey
> 
> I'm trying to encode a ~2 hour DVD, targeting two 80 min CDRs (about 
> 1400MB). My problem is essentially that the bitrate I specify to 
> libavcodec is not respected at all and the movie ended up at half of the 
> filesize I had targeted(resulting in rather poor quality). (It turned 
> out to be ~700MB when I specified an average bitrate that should result 
> in a file close to 1400MB (audio stream taken into consideration)). To 
> clear things up, here are the two command lines I used:
> 
> 1. pass:
> mencoder dogma.vob -nosound -ovc lavc -lavcopts 
> vcodec=mpeg4:vbitrate=1400:vhq:vpass=1 -vop scale=672:288,crop=701:429 
> -sws 2 -o /dev/null
> 
> This resulted, as expected, in a lavc_stats.txt file. (I threw away the 
> video to /dev/null in this pass, wrong??)
> 
> 2. pass
> mencoder dogma.vob -oac mp3lame -lameopts abr:br=128:aq=0:mode=1:vol=3 
> -aid 128 -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=1400:vhq:vpass=2 
> -vobsubout dogmasub -ifo vts_01_0.ifo -sid 5 -vop 
> scale=672:288,crop=701:429 -sws 2 -o dogma.avi
> 
> This time I included the audio, naturally, as this was to be the final 
> avi before splitting. (and I extracted some subtitles in vobsub format). 
> The resulting average bitrate was NOT 1400, but rather around 
> 600-700kbit. Why does it end up so wrong ? I know mencoder/libavcodec 
> loaded the statsfile, because of the startup time of mencoder and the 
> size of the mencoder process (the stats file was about 15MB large).
> 
> Finally, some more details:
> The movie is 720x576 PAL 25fps, about two hours long. I also got 
> indications (from a reply to a previous post I sent), that the movie 
> probably was a field based interlaced stream. It was ripped using Smart 
> Ripper on a windows box, and the .vob file (concatenated all vobs to 
> one) is about 6GIGs, and contains video, two ac3 streams (one 2.0 and 
> one 5.1), and some subtitle stuff.
> 
> Also, when I try to use the external -pass 1/2 parameter (instead of 
> libavcodec internal vpass), the bitrate goes much much higher than it 
> should, so that's a no-no. (Does the external -pass 1/2 really work well 
> with libavcodec ?? It looks very DivX5 oriented)
> 
> mplayer 0.90pre6-gcc3.1
> 
> Thanks in advance for all help/tips, it's all appreciated.
> 
> --
> .yvind S.
> 
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> 


A'rpi / Astral & ESP-team

--
Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu