[MPlayer-users] Problems encoding interlaced DVD
Corey Hickey
bugfood-ml at fatooh.org
Sat Sep 6 21:26:49 CEST 2003
Chris Phillips wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> Ripping the DVD works fine (using vobcopy).
Out of curiosity, is there an advantage to using vobcopy rather
than mplayer dvd://1 -dumpstream ?
> Simple
> playing with mplayer shows bad interlacing, but the
> -vf pullup option fixed the problem OK.
>
If pullup fixed the problem, that probably means the interlacing
was telecine. However, you might want to verify that. Play the video
with -fps 2 (or -fps 1) and see if progressive and interlaced frames
follow each other in this pattern:
p,p,p,i,i,p,p,p,i,i
That's the usual pattern for 3:2 pulldown, which can be removed easily.
However, I've seen some weird (usually old) movies that follow a
different pattern, and sometimes there are movies where every frames is
interlaced. In these cases, you may be stuck with using the
deinterlacing filter of your choice, such as -vf pp=lb, pp=md, pp=fd,
etc.
You said, however, that playing the movie with pullup worked ok, so
perhaps encoding with pullup would work. I haven't tried pullup since
the first iteration, and Rich made some changes since then. By now it
might work quite well, and I'm sure it will before too long.
> When I use the -vf ivtc=1 options, the video quality
> is fine, but the video playback is too fast (and not
> synchronized to audio). The option -ofps 23.976 does
> not seem to help.
>
I never use 3-pass encoding, so I can't say for sure, but this
might be an effect of the first (audio) pass expecting more frames
per second of video. When you filter the video, this reduces the number
of frames, and makes the audio out sync. For now, try encoding with only
one pass (to keep it simple), and once you get things worked out, then
try going back to 3-pass. 3-pass might work properly if you use the ivtc
filter for the first pass, too.
>
> On a slightly different tack - for a fix bitrate (say
> 850 kbps) do I get best quality on screen and/or on
> Tvout leaving the video size as 720 x 576 or scaling
> to 640x480?
>
Try using TOOLS/calcbpp.pl for this. The first part of
DOCS/tech/encoding-tips.txt describes aspect ratio and bpp, and if you
want to jump to the calcbpp.pl section, just search for "attached". In
any case, once you get the interlacing stuff straightened out, you
should consider encoding with some more advanced options than just vhq.
My looks-like-it-gets-great-quality-and-I-don't-care-if-it-takes-all-day
set of options is here:
-lavcopts vbitrate=800:vcodec=mpeg4:vhq:v4mv:trell:precmp=3:cmp=3:\
subcmp=3:vmax_b_frames=1:qpel:vlelim=-2:vcelim=7:lumi_mask=0.05:naq:\
vqcomp=0.7:mbcmp=2:vpass=2
I would use mbd=2 instead of vhq, but there's a bug in mencoder that
prevents me from using any version after April 25th:
http://www.mplayerhq.hu/pipermail/mplayer-dev-eng/2003-August/020145.html
Sorry for the shameless reference to a bug I want fixed, :) but I really
wish someone would take a look at that.
-Corey
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