[pvrusb2] Intermittent video stream damage

[Carsten Meier]

Yes, I noticed this issue here, too. It regularly happened when I used
the af9015-tree from linuxtv.org, because I also have such a device.
After switching to the current v4l-main-tree a few weeks ago, my pvrusb2
hadn't produced such a buggy stream. Don't know if it is because that
error only occures very seldom or if it is because of a fixed bug. I
would suggest that you compile and install the latest stable v4l-tree.

Regards,
Carsten


 Am Sat, 13 Dec 2008 20:04:09 +0100
schrieb Bjorn Danielsson <pvr-usb2 at dax.nu>:

> Once in a while I get an unusable video stream, and I want to ask
> here if anyone else has seen the same symptoms. I start streaming
> and get both video and sound, but the video is extremely "jerky"
> with mplayer, as if everyone in the picture has severe chronic
> spasms, including the furniture sometimes...
> 
> I have seen this happen a couple of times per month, and usually I
> just stop the streaming and restart (re-open /dev/video0) and then
> the problem goes away. But I am worried that this might happen while
> recording something. This has fortunately not happened yet, or perhaps
> unfortunately because a saved broken MPEG would really make it easier
> to debug this. But I did manage to catch the output from an affected
> mplayer process recently:
> 
> AO: [alsa] 48000Hz 2ch s16le (2 bytes per sample)
> Starting playback...
> VDec: vo config request - 720 x 576 (preferred colorspace: Planar
> YV12) VDec: using Planar YV12 as output csp (no 0)
> Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
> VO: [xv] 720x576 => 768x576 Planar YV12 
> [mpeg2video @ 0xb90c60]ac-tex damaged at 7 0
> [mpeg2video @ 0xb90c60]00 motion_type at 8 1
> [mpeg2video @ 0xb90c60]00 motion_type at 4 2
> [mpeg2video @ 0xb90c60]mb incr damaged
> [mpeg2video @ 0xb90c60]00 motion_type at 5 4
> [mpeg2video @ 0xb90c60]slice mismatch
> [mpeg2video @ 0xb90c60]00 motion_type at 25 6
> [mpeg2video @ 0xb90c60]ac-tex damaged at 0 7
> [mpeg2video @ 0xb90c60]invalid cbp at 2 8
> [mpeg2video @ 0xb90c60]00 motion_type at 2 9
> 
> and it kept going on like that. The pvrusb2 driver in this case is
> the one bundled with linux-2.6.26.2.
> 
> I can't be sure of course that these broken video streams have
> anything to do with the pvrusb2 driver, but I think I have already
> excluded some of the more "obvious" failure modes, because I know
> that:
> 
>  + The problem has occurred on two different pvrusb2 hardware devices
>  + This never happened when I used the old libusb userspace driver
>  + This never happens when I stream DVB-T to mplayer via the same
> software
> 
> Don't we all love intermittent failures? :-)
>