[MPlayer-users] Re: terrible terrible quality for 3 pass divx's...what gives?

[christopher j bottaro]

ahh thanks, i didn't realize that once vbitrate got over 16000, its measured 
in bits/sec.

thanks for the help,
-- christopher

On Saturday 04 January 2003 11:19 pm, Michael Waters wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> On Sat, Jan 04, 2003 at 22:14 -0600, christopher j bottaro wrote:
> ...
>
> > here is roughtly how i'm doing it, any help would be >greatly<
> > appreciated. note how i'm using the vbitrate recommended from the
> > previous passes to determine the vbitrates of the current passes?  am i
> > doing that correctly?
> >
> > first pass:
> > mencoder -dvd 1 -chapter 1-1 -ovc frameno -oac mp3lame -lameopts vbr=3 -o
> > frameno.avi
> > output:
> > <snip>
> > Recommended video bitrate for 700MB CD: 28325
>
> this is relevant if you plan to use 700mb for whatever you're
> encoding... so if you're only testing encoding for a segment, I'd use a
> bitrate between for example 700 and 1000 kbps.
>
> > second pass:
> > mencoder -dvd 1 -chapter 1-1 -aspect 16:9 -ovc lavc -lavcopts
> > vcodec=mpeg4:vhq:vpass=1:vbitrate=28325 -oac copy -vop eq -o
> > matrix_test.avi output:
> > <snip>
> > Video stream:  250.140 kbit/s  (31267 bps)  size: 6450694 bytes  206.307
> > secs 4946 frames
> > <snip>
> > am i suppose to use the 250.140 kbit/s in the vbitrate option in the next
> > pass?
> >
> > third pass:
> > mencoder -dvd 1 -chapter 1-1 -aspect 16:9 -ovc lavc -lavcopts
> > vcodec=mpeg4:vhq:vpass=1:vbitrate=250140 -oac copy -vop eq -o
> > matrix_test.avi
> >
> > done.  and the resulting quality is terrible...why?  thanks for the help,
> > christopher
>
> 250 kbps is way too low.  from the manpage:
>
> vbitrate=<value>    specify bitrate (pass 1/2) in
>                                         kBit <4-16000> or
>                                         Bit  <16001-24000000>
>                                         (warning: 1kBit = 1000 Bits)
>                                         (default: 800)
>
> I don't think -vop eq is useful for mencoder, only mplayer.
>
> > P.S.  i get this error when i do the 2nd and 3rd pass:  Sorry, selected
> > video_out device is incompatible with this codec.
> > VDecoder init failed :(.  could that have anything to do with it?
>
> I see this too... not sure what it means but I've never worried about
> it.  :)
>
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