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.
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
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