[FFmpeg-user] Problem with -f video4linux2 thru all versions from stock Ubuntu 0.5.1

Michał Lesiak bler at earthplanet.org
Thu Aug 25 21:57:29 CEST 2011


Hello,

I'm having problems with v4l2 indev on ffmpegs > 0.5.1.

Ubuntu 10.04 LTS (fresh install), stock kernel 2.6.32-33-generic.

cmd line: ffmpeg -f video4linux2 -i /dev/video0 1.avi

v4l device as per dmesg:
[39444.503290] A827 registered V4L2 device video0[video]
[39444.503312] A827 registered V4L2 device vbi0[vbi]
[39444.503329] A827 registered V4L2 device radio0[radio]
[39444.503518] A827 registered ALSA sound card 1
[39444.503531] DVB: registering new adapter (A827[0] DVB-T)
[39444.503533] A827[0] DVB-T registered DVB adapter 0
[39444.503733] DVB: registering adapter 0 frontend 0 (A827[0] DVB-T)...

Everything works fine with ffmpeg found in this Ubuntu version's 
aptitude, which I believe is 0.5.1 (at least it works at all, im using 
it for streaming mpeg4 via ffserwer and it get clogged after a couple of 
hours, that's why im trying newer versions).

I've tried releases 0.6.3, 0.7.3 and 0.8.2, also tried latest (a couple 
of minutes ago) git clone from git://git.videolan.org/ffmpeg.git. All of 
them give more or less the same output:

ffmpeg version N-32098-gabe0b8e, Copyright (c) 2000-2011 the FFmpeg 
developers
   built on Aug 25 2011 21:35:50 with gcc 4.4.3
   configuration:
   libavutil    51. 13. 0 / 51. 13. 0
   libavcodec   53. 12. 0 / 53. 12. 0
   libavformat  53.  9. 0 / 53.  9. 0
   libavdevice  53.  3. 0 / 53.  3. 0
   libavfilter   2. 34. 2 /  2. 34. 2
   libswscale    2.  0. 0 /  2.  0. 0
[video4linux2 @ 0x1888420] ioctl set time per frame(1/30) failed
[video4linux2 @ 0x1888420] Could not find codec parameters (Unknown: none)
[video4linux2 @ 0x1888420] Estimating duration from bitrate, this may be 
inaccurate
/dev/video0: could not find codec parameters

Is there anything I can do about it? I'd rather not go back to 0.5.1 as 
there cleary were some issues with mpeg4 or ffserver which I hope are 
fixed now.

Best regards,
ML


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