[Ffmpeg-devel] Re: new grab interface breaks bktr grabing

Nikns Siankin nikns
Wed Apr 4 20:59:15 CEST 2007

On Wed, Apr 04, 2007 at 03:46:04PM -0300, Ramiro Ribeiro Polla wrote:
>Nikns Siankin wrote:
>>On Tue, Apr 03, 2007 at 02:56:09PM -0700, Piero Bugoni wrote:
>>>--- Nikns Siankin <nikns at secure.lv> wrote:
>>>>First I tried:
>>>>ffmpeg -y -f bktr -i /dev/bktr0 -an -vcodec wmv2
>>>>-tvstd pal /root/test.wmv
>>>>/dev/bktr0: Error while opening file
>>>>Then I remembered that even with old ffmpeg there
>>>>was such error if no frame
>>>>size specified, but running:
>>>>ffmpeg -y -f bktr -i /dev/bktr0 -an -vcodec wmv2
>>>>-tvstd pal -s cif /root/test.wmv
>>>>didn't help either.
>>>>Hovewer, specifying "-s" in front of args finnaly
>>>>started capturing:
>>>>ffmpeg -y -s cif -f bktr -i /dev/bktr0 -an -vcodec
>>>>wmv2 -tvstd pal /root/test.wmv
>>>>Anyone have success grabing from bktr with new grab
>>>Thanks for this. I have been using ffmpeg for a while
>>>on Slackware Linux, but just set it up today on
>>>FreeBSD 6.2. I referred back to your info to get
>>>grabbing to work. (The command line is different from
>>>Linux. I might have fucked around for hours trying to
>>>get it to work without this info.)
>>>The kernel was rebuilt to remove all unnecessary
>>>drivers, and bktr built in statically. (The box was an
>>>old  450MHz PIII with 128M RAM, so it was pared down
>>>to minimum, just to be sure. The bktr driver
>>>complained about unable to allocate memory when loaded
>>>with kldload, but seemed to load ok when loaded at
>>>boot with  loader.conf. The card was a LW-104 --aka
>>>Pico2000 ebay special).
>>>I used SVN-r8618, downloaded today.
>>>This command worked:
>>>./ffmpeg -y -s cif -f bktr -i /dev/bktr0 -an  -tvstd
>>>ntsc test.mpg
>>>(Although I got this repeating error message that I
>>>think has to do with the bktr driver):
>>>SLEPT NO signals - xxxx microseconds late
>>>Generally speaking, the video looked OK.
>>>I do not know if this is an issue for ffmpeg-user, or
>>>not, so I mention it here.
>>So you say video played smoothly?
>>Then, perhaps there are another openbsd
>>specific issues with code that went in from
>>january till april.
>>Want to try on openbsd? Just pick 4.0 install,
>>bktr is in by default.
>Did you read [1]?
>Please try the -isync option and report back. Set the verbose options to 
>see how many dupes/drops there are, like:
>./ffmpeg -v 9 -isync -y -s cif -f bktr -i /dev/bktr0 -an -tvstd ntsc 

-isync doesn't change anything.

Full output of:
# ffmpeg -v 9 -isync -y -s cif -f bktr -i /dev/bktr0 -an -tvstd ntsc bu.mpg
FFmpeg version SVN-r8564, Copyright (c) 2000-2007 Fabrice Bellard, et al.
  configuration: --enable-shared --cc=cc --disable-opts --enable-pp --enable-gpl --enable-pthreads --enable-liba52 --enable-libfaac 
--enable-libfaad --enable-libmp3lame --enable-libogg --enable-libvorbis --extra-libs=-L/usr/local/lib --extra-cflags=-I/usr/local/include
  libavutil version: 49.4.0
  libavcodec version: 51.40.2
  libavformat version: 51.11.0
  built on Apr  3 2007 08:57:39, gcc: 3.3.5 (propolice)
Input #0, bktr, from '/dev/bktr0':
  Duration: N/A, bitrate: N/A
  Stream #0.0, 1/1000000: Video: rawvideo, yuv420p, 352x288, 1/25, 25.00 fps(r)
Output #0, mpeg, to 'bu.mpg':
  Stream #0.0, 1/90000: Video: mpeg1video, yuv420p, 352x288, 1/25, q=2-31, 200 kb/s, 25.00 fps(c)
Stream mapping:
  Stream #0.0 -> #0.0
Press [q] to stop encoding
[no more output, doesnt even show bitspersecond]
timestamp discontinuity 1175712909700679, new offset= -1175712909700679
frame=    1 fps=  0 q=5.3 Lsize=      22kB time=10000000000.0 bitrate=   0.0kbits/s dup=0 drop=0    
video:21kB audio:0kB global headers:0kB muxing overhead 5.241521%
Received signal 2: terminating.

File after ~ minute of capturing:

>Try that with and without -isync.
>Ramiro Polla
>[1] http://article.gmane.org/gmane.comp.video.ffmpeg.devel/47852
>ffmpeg-devel mailing list
>ffmpeg-devel at mplayerhq.hu

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