[MPlayer-users] encoding problems after upgrade to 1.0-pre3

[Corey Hickey]

Tathagata Banerjee wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> 
> 
> ------------------------------------------------------------------------
> 
> i'm having to re-send this because no one answered the original post for 
> four days. someone please take notice, because this problem has stopped 
> all my encoding completely. i am now thinking of going back to 0.90. 
>  

Actually, 1.0pre3 is rather old by now. There have been many bugfixes to
both mplayer and lavc recently, so try compiling from CVS.

>  
> mencoder -sws 2 -ovc lavc -lavcopts\ 
> vcodec=mpeg4:vbitrate=800:
> vhq

vhq has been succeeded by mbd=2, which, though slower, gives much higher
PSNR.

 > :v4mv:trell:\
> precmp=3:cmp=3:subcmp=3:vmax_b_frames=1:

 > qpel:

Nobody recently has been able to provide an example where qpel improves
anything. Every time I try using it, it decreases PSNR significantly.

> vlelim=-2:vcelim=7:\ 
> lumi_mask=0.05:dark_mask=0.05

If I recall correctly, Rich, who originally suggested using the above
options, has his doubts that they are worthwhile. I haven't tested them
extensively, but they seem to make the picture look worse (lower
contrast, slightly different colors) without improving anything else. I
would suggest either using less agressive values or abandoning the above
options completely.

> :naq:vqcomp=0.7:mbcmp=2:psnr:vpass=x\ 
> -oac mp3lame -lameopts q=0:aq=0
 > -vop crop=700:372:8:104

Rather than using -vop, use -vf. It's just the same as -vop, but
applies the filters from left to right. That is, -vf crop=...:scale=...
would crop and then scale. I'm pretty sure -vop is deprecated.

> -o castaway.avi\  
> castaway.vob 
>  
> sorry about the wrapping lines. 
>  
> for some movies, i need to add -ofps 23.976, or the resulting video is 
> jerky, because of something called telecine which i don't really 
> understand. i'm doing most of this parrot-fashion, without understanding 
> what does what, because i'm quite ignorant about video.

Writing a howto on telecine is beyond the amount of energy I have right
now. I suppose I ought to write a file for DOCS/tech... Anyway, if you
search the mailing list archives for "ofps", "telecine", you should be
able to learn why. For more advanced topics, search for "hard telecine",
"soft telecine", "softpulldown", "pullup", and "filmdint".

>  
> now the above commandline used to work pretty well in 0.90, but it has 
> stopped working after the upgrade. stopped working in any useful way, that 
> is. the first pass goes through, but gives almost no compression. 
> castaway.vob was 5.2 gigs, the resulting castaway.avi was 4.8 gigs. 
> antz.vob was 2.3 gigs, antz.avi 2.1 gigs. this was not the case in 0.90, 
> where the same commandline produced an antz.avi that was less than 700 
> megs. 

Possibly there's a bug in lavc somewhere. If it still happens with CVS
of both mplayer and ffmpeg, try to narrow it down to one particular
option. Sometimes this can be difficult and/or time consuming. If you
have trouble or get impatient, mail back and I'll give you a couple
tips.

-Corey