Re: [Motion-user] can't start motion with 2 UVC devices

[Angel C. <ac...@te...>]

El vie, 18-07-2008 a las 09:50 +0200, Louis-David Mitterrand escribió:
> Hi,

Salut Louis-David,

> Using kernel 2.6.26 on a debian/unstable box and motion 3.2.9-4 I find
> it impossible to start motion with two UVC cameras in the following
> configuration:
> 
> - UBV camera @ 640x480 YUYV + UVC camera @ 640x480 YUYV
> 
> The error:
> 
>         Jul 17 18:11:00 sylla kernel: uvcvideo: Failed to submit URB 0 (-28).
>         Jul 17 18:11:00 sylla motion: [1] Error starting stream.
>         Jul 17 18:11:00 sylla motion: [1] VIDIOC_STREAMON: No space left on
> +device
>         Jul 17 18:11:00 sylla motion: [1] ioctl(VIDIOCGMBUF) - Error device does
> +not support memory map


UBV ? , i think you meant UVC , anyway your issue looks at first sight a
problem with kernel module or usb host bandwidth ... but to get more
clues , i'll some debian advices :

1-. Current package of debian is out of date , i'm agree with his policy
of have a stable packages but sometimes this makes use a really old
packages that have bugs/problems already fixed in "upstreams" version.
Right now motion stable is 3.2.10.1 but for some distros i needed to
apply :

http://www.lavrsen.dk/twiki/pub/Motion/ReleaseNoteMotion3x2x10x1/ffmpeg-changed-API_ffmpeg-encoding.diff

As release notes says :

http://www.lavrsen.dk/twiki/bin/view/Motion/ReleaseNoteMotion3x2x10x1


On more warning about debian : 

ffmpeg package they deploy has not mpeg encoders so unless you use a
ffmpeg built by yourself and motion tarball motion will only support not
mpeg codecs.


2-. Motion allow to be run with debug level , so any "bug" or issue
should be reported using at least :

./motion -n -d 7 

otherwise is hard to guess what's the problem and nobody will answer.



> However this configuration works:
> 
> - PWC camera @ 640x480 YUYV + UVC camera @ 960x720 YUYV
> 
> So it doesn't seem to be a USB bandwidth limitation problem (as someone
> on the linux-uvc mailing list suggested).


I'm following video4linux mailing list and uvcvideo is known that has
some issue that are being fixed in 2.6.27 , but when someone report a
problem will help to know what version of module is using ( no only
kernel but also webcam module svn revision, git revision , etc... ).

last think i have some UVC and PWC webcams and as far as i know PWC
doesn't supply YUYV format , only YV12 (V4L2)  | YUV420P (V4L1) , so
maybe you did a typo that makes hard to guess your problem.

For futures issues with usb webcams some information could help a lot :

lsusb -v
host usb or hub usb description

although probably that is beyond of motion support could help us to get
some clues.

> Thanks,
> 

Salut !

Cheers,
-- 
Angel Carpintero
ack ( at ) telefonica ( dot ) net

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