[vox-tech] wincast tv: video4linux and copying movies
Mark K. Kim
vox-tech@lists.lugod.org
Mon, 13 Oct 2003 23:43:12 -0700 (PDT)
I think samplerate is for audio and fps is for video. I recommand keeping
fps at 15 (or higher, if your system can handle it) and samplerate low.
It should be decent.
Because the avi created by xawtv has no compression, you'll need to
compress it after generating the video. mplayer comes with a program
called mencoder that's *really* nice for that purpose. After a successful
installation of mplayer with all of Windows codecs, you can generate a
small MPEG4 avi with something like this:
in=input.avi
out=output.avi
for p in 1 2
do
mencoder $in -channels 1 -srate 11025 -oac copy \
-ovc lavc -lavcopts \
vcodec=msmpeg4:vbitrate=496:vpass=$p -o $out
done
You can also compresses audio with lame (see the man page for the -oac
option) but I'm not sure how legal that is. Anyway, the above is a
two-pass system and a webpage I've read recommended that technique but
there are other ways to make it happen, too. The above is just one way.
Play with the bitrate for better quality.
I hope that helps!
-Mark
On Mon, 13 Oct 2003 p@dirac.org wrote:
> ok, i've been playing around with this for awhile, and the results are
> not great. i recorded the opening theme of southpark under different
> settings. the default settings of:
>
> samplerate: 44100
> frames: 12 fps
>
> produce a file of 72MB for about 26s of video. the video is bad,
> but watchable if i'm jonesing for southpark. if it weren't a cartoon,
> it would truly be unwatchable.
>
> i bumped the sample rate up to 48000, however both the video quality and
> filesize don't change. what exactly is the difference between
> samplerate and fps anyhow? so then i bumped it up:
>
> samplerate: 44100
> frames: 20 fps
>
> the video quality was ok. certainly watchable, but not "high quality"
> by any stretch of the imagination. the filesize is 120MB for 26s. i'm
> already at about 1/6 - 1/7 of the capacity of a CD. there's no way a 20
> minute video will fit on a CD. just out of curiosity, i bumped it up
> again to:
>
> samplerate: 44100
> frames: 30 fps
>
> the video was good, but still not high quality. the filesize is a
> whopping 183MB for 26s. my computer (1.4MHz athlon) is working hard to
> keep sync with audio.
>
>
> i just upgraded my kernel to 2.4.22, and didn't bother installing the
> low latency patch this time around. i guess i can try that tomorrow
> evening.
>
> i'm a little disheartened. quake3 can get to very high framerates with
> ease; my machine does q3 very nicely. but then again, that's all
> hardware accelerated opengl stuff.
>
> but in any event, it's filesize that seems to be the show stopper here.
> at this rate, a 20min video will take somewhere between 5GB and 8GB.
> this is unreasonable.
>
>
>
> i'm exhausted and about to call it a night. does anybody have
> suggestions on how to get good quality video at reasonable filesize?
>
> should i be working in a format other than AVI?
>
> pete
>
>
>
>
>
>
> On Mon 13 Oct 03, 9:06 PM, Mark K. Kim <markslist@cbreak.org> said:
> > I think the driver needs to support saving videos.
> >
> > Assuming it does, run xawtv with -noxv option, 'cuz it can't save videos
> > when the video is coming through the xvideo extension. Then select
> > "Record Movie" from the menu, then change "movie driver: multiple image
> > files" to one of the valid movie formats. Supply the "movie/images
> > filename", then click "start/stop recording." That works for me but I
> > don't use hauppauge so...
> >
> > Good luck!
> >
> > -Mark
> >
> >
> > On Mon, 13 Oct 2003 p@dirac.org wrote:
> >
> > > hi all,
> > >
> > > i owned a microsoft OS for a few weeks before switching to linux. in
> > > those few weeks, i bought a hauppauge wincast TV card. it worked
> > > marginarlly well, but the driver had "issues".
> > >
> > > anyway, i installed linux soon after and completely forgot about the
> > > card, giving up on it ever being supported by linux. that was back in
> > > the redhat 5.1 days, and supported hardware was ... sparse.
> > >
> > > anyway, i recently came across the card and did some research. it's now
> > > supported by linux! hooray! after...
> > >
> > > reading ~linux/Documentation/video4linux/bttv
> > > recompiling the kernel
> > > figuring out how to connect the card to my soundcard
> > > playing with sound settings
> > > hooking the card up to my VCR
> > >
> > > i got the card to work. it took a bit long to get working under linux,
> > > but it's much less flakey. the windows driver crashed very often,
> > > making the card painful to use (one of the reasons why i forgot about
> > > the card).
> > >
> > > anyway, i want to put some of my old VCR tapes onto hard drive and
> > > perhaps eventually burn them to DVD.
> > >
> > >
> > > has anybody ever done this? i can use xawtv to watch my tapes, but for
> > > some reason, it doesn't want to record. it refuses to record the movie
> > > to disk (although i can get screenshots).
> > >
> > > i'm about to go to freshmeat, but if anybody does this kind of thing,
> > > i'd like to hear what you use and about your experiences with this kind
> > > of software. i'm a TOTAL newbie with video on linux, but i'd like to
> > > get acquainted with it.
> > >
> > > thanks!
> > > pete
>
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Mark K. Kim
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