[MEncoder-users] Encodes for slow laptop

[James Hastings-Trew]

Stella-Terra Clemens wrote:
> Ok, I think I've basically found what I was looking for. I wrote a small
> script to help with automation, let me know if there is anything glaringly
> wrong here. It's based on h264enc script, RC's suggestions, and a 
> couple of
> gentoo dvd rip pages.
>
> #!/bin/bash
>
> TITLE="The Princess Bride"
> IN_FILE="movie.vob"
> OUT_FILE="thePrincessBride.mkv"
> CROP="704:464:10:6"
> SCALE="384:256"
> VF_FRAMECONVERT=""
> #VF_FRAMECONVERT="pullup"
> FPS="24000/1001"
> BITRATE=800
> AID=128
>
> # Video
> mencoder ${IN_FILE} -o /dev/null -ofps ${FPS} -vf
> ${VF_FRAMECONVERT}crop=${CROP},softskip,scale=${SCALE},harddup 
> -nosound -of
> rawvideo -ovc x264 -x264encopts
> pass=1:bitrate=${BITRATE}:turbo=2:me=umh:me_range=24:nodct_decimate:nointerlaced:8x8dct:nofast_pskip:trellis=1:partitions=none:mixed_refs:bime:keyint=240:keyint_min=24:frameref=4:bframes=16:b_adapt:b_pyramid:weight_b:direct_pred=auto:subq=6:brdo:chroma_me:nocabac:nodeblock:nossim:nopsnr:threads=auto
>
> mencoder ${IN_FILE} -o movie.264 -ofps ${FPS} -vf
> ${VF_FRAMECONVERT}crop=${CROP},softskip,scale=${SCALE},harddup 
> -nosound -of
> rawvideo -ovc x264 -x264encopts
> pass=2:bitrate=${BITRATE}:me=umh:me_range=24:nodct_decimate:nointerlaced:8x8dct:nofast_pskip:trellis=1:partitions=none:mixed_refs:keyint=240:keyint_min=24:frameref=4:bframes=16:bime:b_adapt:b_pyramid:weight_b:direct_pred=auto:subq=6:brdo:chroma_me:nocabac:nodeblock:nossim:nopsnr:threads=auto
>
> # Audio
> mplayer movie.vob -aid ${AID} -ao pcm:fast:waveheader:file=audio${AID}.wav
> -vc null -vo null
> oggenc audio${AID}.wav
>
> # Container
> mkvmerge --title "${TITLE}" -o ${OUT_FILE} --default-duration 0:${FPS}fps
> movie.264 audio${AID}.ogg
>
> The Matrix went off without a hitch,
> but The Princess Bride came out with the audio 200 ms in front of the
> video. This wasn't a big problem. Even if I could no longer get at the
> source files, I was able to change the timing using mkv merge and the
> existing streams, and even failing that I could just press the minus key
> twice and things would be alright, but it would be great if there 
> could be a
> way to prevent this in the future.
The best way to ensure AV synch is to encode the audio at the same time 
as the video.
You could do the following (I won't mess with too many of your settings):

#pass 1
mencoder ${IN_FILE} -o /dev/null -ofps ${FPS} -aid ${AID} -oac pcm 
-channels 2 -srate 48000 -vf 
${VF_FRAMECONVERT}crop=${CROP},softskip,scale=${SCALE},harddup -ovc x264 
-x264encopts 
pass=1:bitrate=${BITRATE}:turbo=2:me=umh:me_range=24:nodct_decimate:nointerlaced:8x8dct:nofast_pskip:trellis=1:partitions=none:mixed_refs:bime:keyint=240:keyint_min=24:frameref=4:bframes=16:b_adapt:b_pyramid:weight_b:direct_pred=auto:subq=6:brdo:chroma_me:nocabac:nodeblock:nossim:nopsnr:threads=auto 


#pass 2
mencoder ${IN_FILE} -o temp.avi -ofps ${FPS} -aid ${AID} -oac pcm 
-channels 2 -srate 48000 -vf 
${VF_FRAMECONVERT}crop=${CROP},softskip,scale=${SCALE},harddup -of avi 
-noodml -ovc x264 -x264encopts 
pass=2:bitrate=${BITRATE}:me=umh:me_range=24:nodct_decimate:nointerlaced:8x8dct:nofast_pskip:trellis=1:partitions=none:mixed_refs:keyint=240:keyint_min=24:frameref=4:bframes=16:bime:b_adapt:b_pyramid:weight_b:direct_pred=auto:subq=6:brdo:chroma_me:nocabac:nodeblock:nossim:nopsnr:threads=auto

#extract video
mencoder -o movie.264 -ovc copy -nosound -of rawvideo temp.avi

#extract audio
mplayer temp.avi -ao pcm:fast:waveheader:file=audio${AID}.wav -vc null 
-vo null

#encode audio
oggenc audio${AID}.wav

#mux
mkvmerge --title "${TITLE}" -o ${OUT_FILE} --default-duration 
0:${FPS}fps movie.264 audio${AID}.ogg

I'll just add in passing that 16 is a LOT of b-frames. Try something 
more reasonable, like a number between 3 and 6. The more bframes your 
stream has, the larger the buffers required to decode the video. You can 
also speed up the first pass by reducing the frameref and subq values to 
1 without really hurting the final encode too much. I'm actually a 
little curious where you got your 264 options from because they look a 
bit unusual to me.