On Thu, 2008-11-20 at 08:31 +0100, Hans Verkuil wrote: > On Wednesday 19 November 2008 11:27:05 Alexander Pipelka wrote: > > Hans, > > > > I reinstalled the old system. > > It was Ubuntu Feisty with the ivtv driver version 0.10.0 > > > > Here the dmesg snippet: > > > > [ 19.404000] ivtv: ==================== START INIT IVTV > > ==================== > > [ 19.404000] ivtv: version 0.10.1 (tagged release) loading > > [ 19.404000] ivtv: Linux version: 2.6.20-15-generic SMP mod_unload > > 586 [ 19.404000] ivtv: In case of problems please include the debug > > info between > > [ 19.404000] ivtv: the START INIT IVTV and END INIT IVTV lines, along > > with > > [ 19.404000] ivtv: any module options, when mailing the ivtv-users > > mailinglist. > > [ 19.404000] ivtv0: Autodetected Yuan MPC622 card (cx23416 based) > > [ 19.404000] ivtv0: Unreasonably low latency timer, setting to 64 > > (was 32) > > [ 20.876000] ivtv0: loaded v4l-cx2341x-enc.fw firmware (262144 > > bytes) [ 21.104000] ivtv0: Encoder revision: 0x02050032 > > [ 21.104000] ivtv0: Recommended firmware version is 0x02060039. > > [ 21.188000] cx25840 0-0044: cx25843-23 found @ 0x88 (ivtv i2c driver > > #0) > > [ 26.188000] ivtv0: Registered device video0 for encoder MPEG (4 > > MB) [ 26.188000] ivtv0: Registered device video32 for encoder YUV > > (2 MB) [ 26.188000] ivtv0: Registered device vbi0 for encoder VBI > > (1 MB) [ 26.188000] ivtv0: Registered device video24 for encoder PCM > > audio (1 MB) > > [ 26.568000] ivtv0: Initialized Yuan MPC622, card #0 > > [ 26.568000] ivtv: ==================== END INIT IVTV > > ==================== > > > > > > You may believe it or not this driver produces a correct stream > > without any B-Frames. > > > > To prove my words here are two links to captured streams. One with 2 > > B-Frames one with 0 B-Frames. > > > > http://www.bms-austria.com/~pipelka/2bframes.mpeg > > http://www.bms-austria.com/~pipelka/0bframes.mpeg > > > > Open them with e.g. avidemux and check the frame types. > > > > The following commands where used to create the streams: > > > > v4l2-ctl -i 1 > > v4l2-ctl -s pal > > > > v4l2-ctl -c video_b_frames=2 > > cat /dev/video0 > 2bframes.mpeg > > > > v4l2-ctl -c video_b_frames=0 > > cat /dev/video0 > 0bframes.mpeg > > I'm going to take a look at this during the weekend. Sorry for having > you go through all this trouble, but it really surprises me that it > ever worked at all.
Might I suggest that perhaps changes to the cx25840 module may be the cause, and not the ivtv driver nor firmware, especially since you noted a dependency with the AV decoder chip used. Perhaps a change modified the way SAV and EAV codes get emitted in the stream by the CX2584x (especially when the V & F bit change) which induced the change. Just a guess. Feel free to ignore. :) Regards, Andy > Regards, > > Hans > > > > > > > Regards, > > > > Alex > > > > Am Di 18.11.2008 20:57 schrieb Hans Verkuil <[EMAIL PROTECTED]>: > > > On Tuesday 18 November 2008 18:13:04 Alexander Pipelka wrote: > > > > Hans, > > > > > > > > The older version of the driver supported 0 B-Frames (I'm 100% > > > > sure). > > > > > > > > I need this for very fast frame navigation in a MPEG stream. > > > > It worked with the driver included in Ubuntu Edgy (I think it > > > > was version 0.7.4 of the driver). > > > > > > > > Unfortunately I updated that machine to Ubuntu Hardy and the > > > > problem appeared. > > > > > > > > Well, I could reinstall an other machine with Ubuntu Edgy to > > > > *verify* that the 0 B-Frame thing works, but I already know this, > > > > ... > > > > > > > > Please help ! > > > > > > I am not convinced. The only difference I've found between 0.7.4 > > > and the > > > latest driver when it comes to B-frames was corrected by my patch. > > > As far as I can tell 0.7.4 used the same firmware as well. > > > > > > I vaguely remember that someone tried it with an old ivtv version > > > as well in the past and got a similar results. However, I can't > > > find the specifics so I might be wrong. > > > > > > The upshot is that I *really* need to see proof that this ever > > > worked (and worked with the same firmware as well!) before I go and > > > spend a lot of time figuring out what changed. The fact that you > > > could set B-frames to 0 using ivtvctl doesn't mean at all that it > > > actually worked. Actually the value 0 that was passed to the > > > firmware in 0.7.4 was not according to the fw docs since they > > > specific that you have to pass '#bframes + 1' to the firmware, so > > > '0' should be an illegal value. > > > > > > Regards, > > > > > > Hans > > > > > > > Alex > > > > > > > > Hans Verkuil schrieb: > > > > On Tuesday 18 November 2008 08:26:16 Levente Novák wrote: > > > > > > > > Hi, > > > > > > > > Is there any advance on the topic of B-frames problem on PVR-150s > > > > and > > > > PVR-250s? A few days ago I tested Hans' patch and while my > > > > PVR-150 MCE does now save a non-zero length stream if th number > > > > of B-frames is set to 0, this stream has not 0 but 1 B-frames per > > > > P-frames. Beside this, even if it seems to work OK with 1 or 2 > > > > B-frames, the stream is choppy and unusable with 3 or 4. > > > > > > > > > > > > My patch fixes the zero-length stream issue, but that's all. I > > > > don't believe it ever gave you a stream with 0 B-frames. I > > > > suspect that the > > > > firmware forces a minimum of 1 B-frame. > > > > > > > > If you can prove that the older driver actually gave you 0 > > > > B-frames, then I'll take another look. But I believe that the > > > > conclusion simply > > > > is that you need a minimum of 1 B-frame. > > > > > > > > Regards, > > > > > > > > Hans > > > > > > > > _______________________________________________ > > > > ivtv-users mailing list > > > > [email protected] > > > > http://ivtvdriver.org/mailman/listinfo/ivtv-users > > > > _______________________________________________ > ivtv-users mailing list > [email protected] > http://ivtvdriver.org/mailman/listinfo/ivtv-users > _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
