Re: [Nvrec-open] Optimum build for nvrec on bttv

[Trevor B. <tb...@br...>]

Trevor Boicey wrote:
>   I tried upgrading it to kernel 2.6.11, and it works for one card but 
> if I try to start recording from the second card, it never makes the 
> output file... it just pauses for a few seconds then starts spitting out 
> that "No place to put data - discarding 0" message until stopped.

   Wait, I think I solved this problem as well as a lot of the build 
problems I have been having.

   Slackware created a directory /usr/include/linux that had in it, 
among other things, a videodev.h. This is a copy of the videodev.h from 
2.4.29.

   When I upgraded to 2.6.x, or patched with kraxel-patch, that file was 
still getting referenced by nvrec rather than the proper one in the 
kernel build tree.

   So... it wasn't correctly building for v4l2, and probably had some 
bad constants and #defines that was causing all of the invalid arguments.

   So at least from loose testing, I have it working with 2.6.x, ffmpeg 
0.4.9-pre1, and nvrec CVS latest.

   Something small is happening though that is perhaps worth reporting.

   With 2.4.x and v4l1 I can capture on two cards at once without issue.

   However, with this build, the second one blocks on audio, strace 
shows it blocking on open("/dev/snd/pcmC0D0c", O_RDRW). It will block 
there until the other capture stops.

   A workaround seems to be using -ua oss instead of -ua alsa. Then it 
will work in parallel nicely.

   Many thanks, Antonio.

-- 
Trevor Boicey, P. Eng.
Ottawa, Canada, tb...@br...
ICQ #17432933 http://www.brit.ca/~tboicey/