[MEncoder-users] composite input a/v sync issue

[Miroslav Rovis]

> Not, "mplayer -forceidx incomplete.avi" works just fine to enable
> seeking on an AVI file that was not completely written.
> There is no need to make a copy.
>   
Yes, you are right.
>> It's all back in sync after a second or two, which is nearly what I can
>> leave with, giving the absolutely incomparable quality which I get with
>> my Gentoo Linux with nicely compiled recent MPlayer...
>>     
>
> That "sync slowly correcting itself" is usually due to MPlayer limiting
> the sync correction and most of the time can be improved with e.g. -mc 100
> (as I already suggested).
>   
Yes, but I still don't understand it, and I got a little lost in all of
this, as other things are there that I can't figure out and I can only
keep guessing what to really do.
-mc <seconds/frame>
maximum A-V sync correction per frame (in seconds)
Pasted from man mplayer.
So "-mc 100" would mean a correction of 100 seconds on one frame.
Illogical. My mind is short of understanding this.
Thanks for your patience.
>> Note also in the command that I put: "vpass=1" in there. That is beacuse
>> the size that I got so far (and it is nearly two (2) hours now, is 16GB.
>> Of course I have to further work on it.
>>     
>
> Not sure what you are trying to say.
>   
Of course, vpass=1 is out of use here, and it is wrong here.
> If the size is too big, try using vqscale=3 instead of vqscale=2, also
> try adding something like nr=100 (particularly if the video is noisy).
>   
I will try.
>> #!/bin/bash
>> # This is my script Make_avi_h264_00.sh
>> mencoder $1.avi -o $1_p1_`date +%H%M%S`.avi -ss 0 -ovc x264 \
>> -x264encopts pass=1:turbo:bitrate=900:bframes=1:\
>> me=umh:partitions=all:trellis=1:qp_step=4:qcomp=0.7:direct_pred=auto:keyint=300
>> \
>> -vf harddup \
>> -oac faac -faacopts br=192:mpeg=4:object=2 -channels 2 -srate 48000 \
>> -ofps 24000/1001
>> mencoder $1.avi -o $1_p2_`date +%H%M%S`.avi -ss 0 -ovc x264 \
>> -x264encopts pass=2:turbo:bitrate=900:frameref=5:bframes=1:\
>> me=umh:partitions=all:trellis=1:qp_step=4:qcomp=0.7:direct_pred=auto:keyint=300
>> \
>> -vf harddup \
>> -oac faac -faacopts br=192:mpeg=4:object=2 -channels 2 -srate 48000 \
>> -ofps 24000/1001
>>     
>
> Particularly with x264 unless you need to target a specific hardware
> play or file size you should use quality-based encoding (similar to
> vqscale) with something like crf=22 instead of setting bitrate.
> (note that in both cases 2-pass only makes sense with bitrate setting,
> you only need one pass with crf or vqscale).
> Unless you still have a system with only one CPU you also should be
> using the "threads" option.
>   
One CPU, and it' only old Athlon 1800 (nominally 3000). But it's two
RAID Gentoo boxes of the same kind. Can be mutually cloned (so less
emerge compilation and less maintenance). So no"threads" option.
Thanks again. I am back once I've tried all these suggestions.
Consoling is the understanding that it can be done and with superior
quality encoding than with the Windows programs.
Truly, once I set up the right encoding options, the file containing the
digitized VHS tape is of superb quality.
But this is breaking my back...