[MEncoder-users] VHS capturing 2 avi

[Matthias Wieser]

Am Freitag, 16. Dezember 2005 22:42 schrieb Allen:
> Rich,
>
> Thanks for your advice.  I have been scouring the net and mencoder list
> archives, and have been going in circles at times with all the options.
>
> On Fri, 2005-12-16 at 14:46 -0500, Rich Felker wrote:
> > On Sat, Dec 17, 2005 at 12:09:47AM +1100, Allen wrote:
> > > The command I use at the moment is:
> > >
> > > mencoder -tv driver=v4l2:input=1:width=720:height=576:norm=PAL -ovc
> > > lavc -oac lavc -lavcopts
> > > vcodec=mpeg4:trell:ildct:ilme:vbitrate=1400:acodec=mp2:abitrate=112
> > > -endpos 5336 -o my-movie.avi tv://
> >
> > You also need to use -mc 0 and -noskip when capturing interlaced
> > content. Any frame skips/duplication will be very very bad. However
> > this can lead to a/v sync issues if your timers aren't in sync.
> > Unfortunately mencoder sucks and has no good solution for tv
> > capture..
> >
> > :(
>
> I'll use your suggestions on my next captures.  What do you use to
> capture from TV?  And do you playback on the PC or TV?  I am running
> under Linux 2.6.11.4-21.9-smp, but can also boot into windoze if I
> really really must.

You don't need to boot into Windows, Mencoder is suited very well for TV 
capture. Maybe you want to ty one of the mencoder-as-video-recorder GUIs 
like Kalva:
http://www.kde-apps.org/content/show.php?content=23381


> > > I have tried to capture and scale to a smaller size, but no matter
> > > the bitrate I seem to end up with very blocky content, and the file
> > > size ends up the same as above anyway.
> > >
> > > Any comments or suggestions are much appreciated.
> >
> > You need a much higher bitrate than 1400 for one-pass encoding (which
> > TV capture will always be). Interlacing increases the bitrate
> > requirement even more. Try 5000 or so. :)
>
> I picked 1400 as a compromise between size and quality.  You're right,
> it probably should be better.

1400 might be OK if you do some denoising. 2000kbit/s or 2400kbit/s should 
be enough for most videos.

> When I convert the movies to SVCD the 
> quality is reasonable, but there is some flaring in bright colours and
> a little bit of lost detail in some parts.  But again, this allows me
> to store an hour of captured interlaced content in 650mb.
>
> Here is my command to then turn the above capture into a SVCD
>
> mencoder -oac lavc -ovc lavc -of mpeg -mpegopts format=xsvcd -vf
> scale=480:288,harddup -srate 44100 -lavcopts
> vcodec=mpeg2video:mbd=2:keyint=15:vrc_buf_size=917:vrc_minrate=600:vbit
>rate=2500:vrc_maxrate=2500:acodec=mp2:abitrate=224 -ofps 25 -endpos 180
> -o shrek.mpg shrek.avi

Keyint is very short, many DVD players support larger keyints as well.
You wrote "interlaced content". Either deinterlace or use ildct and ilme.


Regards,
  Matthias