Capture Card Resolution -- was: Re: [mythtv-users] 2 Capturecard questions
ken at bizrace.com
Sun Mar 23 23:23:46 UTC 2003
OK, much better now. I increased the value of VMALLOC_RESERVE from 128 to 256.
Now I can add gbuffers=64 without a problem. Now, the quality is pretty good
at 480x480 and can't do any higher. I do notice a little frame loss and will
try your test later on. It is almost as good as my digital cable box now.
Almost ready to use it full time. :-)
Thanks for all the help.
Quoting Edward Wildgoose <edward.wildgoose at frmhedge.com>:
> > Thanks, adding gbuffers=16 helps considerably. But, gbuffers=32 just
> > mythfrontend. It still appears as if it is dropping frames in both
> > mpeg4, but it is much better than before. If the height for capture is
> set to
> > 240 it doesn't appear to drop any frames. CPU load is fine, always at
> least 25%
> > idle. I am using DMA for hd access and get ~30MB/s. I did find some
> > to gbuffers=32 on the web and people seem to have success. Not me. Any
> > ideas? Would it help to go to the v4l2 stuff and the lastest bttv
> I am
> > willing to try anything. One thing I have observed is the CPU usage of
> If I
> > capture at 720x240 X uses about 6-8% cpu. Capturing at 352x480 X uses
> about 22%
> > cpu. I don't think this is the issue, but might be something wrong. I
> > pretty sure the dropped frames are on the capture side, I always of idle
> of 10+.
> I can use gbuffers=64 without a problem, so it sounds like a memory buffer
> problem somewhere. I am using a vanilla 2.4.20 kernel (under gentoo), and
> settings in the BIOS seem quite normal, but fairly optimised. AGP Window
> 64MB I think.
> What I would suggest is that you try recording without using myth, try
> lavrec (part of mjpegtools) and play with settings to see what works. For
> instructions on using lavrec see the sourceforge site under the documents
> section - there is a howto there with a command line which works (you need
> the --software-encoding switch basically). Lavrec shows clearly when
> are being dropped.
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> mythtv-users at snowman.net
kvandine at biZrace.com
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