[MPlayer-users] video buffer full

[James Lancaster]

On Monday 06 October 2003 19:11, you wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> I'd like to record a broadcast signal to a file. So I have been reading
> and looking about and have come up with the following command line:
>
> mencoder -tv on:driver=v4l:width=640:height=480:norm=ntsc -ovc lavc
> -lavcopts vcodec=mpeg4:vbitrate=350 -oac mp3lame -lameopts cbr:br=48
> -sws 1 -o output.avi
>

You are using an older mencoder, I would suggest upgrading it to main or the 
new 1.0 beta

then do (to get the exact same fuctionality):
mencoder tv:// -tv driver=v4l:width=640:height=480:norm=ntsc -ovc lavc
 -lavcopts vcodec=mpeg4:vbitrate=350 -oac mp3lame -lameopts cbr:br=48
 -sws 1 -o output.avi



> This works great for about 40 seconds and then the following message
> scrolls repeatedly up my screen.
>
> video buffer full - dropping frame
>

This means your cpu is just not fast enough to do the 640x480 capture direct 
to lavc mpeg4 (but oh so close). I have a similar problem (p3-800 dual w/2 
tuners) What I do (and it won't playback corectly according to the docs with 
anything other than mplayer) is use the aspect option, and encode 640x240 
(NTSC is interlaced) (change height to 240, and add to lavcopts aspect=1.333) 
mplayer will automatically scale this to the correct 640x480 on playing.

OR you could add "-vf scale=640:480" to have mencoder scale the whole file. 
This takes less time, and works on my p3-800s. 

> At this point I interrupt the mencoder. The output file is about 2GB and
> looks fine. I see that my disk activity is not very high during the
> process, so I doubt it is my disk write rate that is the bottleneck. I
> cannot do multiple passes as I am recording live TV broadcasts.
>
2GB for 40sec?! with vbitrate=350 .... 
something is wrong, using much higher (default, vbitrate=800) bitrates I have 
somewhere around 400MB/hour.

> So what can i do to up the frame/audio processing rate? Being a novice,
> I am not sure what dials to tweak to reduce the load on my cpu and
> eliminate the bottleneck. Lower quality is just fine. I just want to
> recognize enough to get the storyline.
>
> I have a 800MHz athalon with 256MB ram (the max). I know this is not
> much (these days) but that is all I have right now.
>

cheat :) record at a lower resolution.

luck, and I should really write up a better (and upto date) 
mencoder-tv-HOWTO...
James L.

> Thanks
>
> Phil
>
>
>
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