[MEncoder-users] VHS capturing 2 avi

Allen lists at iisys.com.au
Fri Dec 16 22:42:08 CET 2005


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, but can also boot into windoze if I
really really must.

> > I think for animated shows, I think I need to deinterlace the content,
> > rather than recording interlaced.
> No, you need to do pulldown reversal. This is true for movies too, and
> for anything not produced with an (interlaced) video camera.
> However: animation is normally created at 24fps and telecined to 60
> fields/sec in _NTSC_ form. If you have animation recorded in PAL and
> the show was not originally produced in a PAL country, it's ruined
> beyond all hope of repair. The only way you can keep it watchable even
> on TV is just encoding as interlaced.

Most of my recordings are home movies recorded on video8 that have been
transferred to standard VHS.  I do have a few commercial tapes I bought
for the kids (mostly animated stuff) that I would like to keep on the PC
for later playback on TV.

> > 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.  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:vbitrate=2500:vrc_maxrate=2500:acodec=mp2:abitrate=224 -ofps 25 -endpos 180 -o shrek.mpg shrek.avi

The home movies I did with these two steps looked virtually like the
original.  The only other thing I need to add really is a crop to get
rid of the noise at the bottom.

Thanks again for your suggestions,


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