Hi Laurent,
Am 06.09.2011 17:24, schrieb Laurent Pinchart:
Hi Alexey,
On Monday 05 September 2011 17:48:42 Alexey Fisher wrote:
Am 31.08.2011 00:32, schrieb Laurent Pinchart:
On Thursday 25 August 2011 09:44:10 Alexey Fisher wrote:
Hi Laurent,
are there any reason why uvc_video_decode_start do not do precise header
size checks? Are there many cameras with broken header size too?
How precise do you mean ? The driver currently doesn't use much of the
header, so it just makes sure that the header size is smaller than or
equal to the packet size, and that it's at least 2 bytes long.
I send you patch on what i work now to catch streams with fragmented
packets.. what do you think about it? Will you apply some thing like
this?
I'm not sure about that. Webcams that would require something like that
are so broken that I'm tempted to consider them as not UVC-compliant.
They should be returned to vendors with a loud complaint.
Your patch might help, but the sad story is that it can't completely fix
the streams. There's always a chance that fragmented packets that
contains no header will start with data that looks like a header. You
won't be able to find a buller-proof solution.
You are right,
the idea is not to show definitely broken frames. If there is some thing
what we can't filter, is ok. we did our best.
I understand. I'm not sure if this should be included in the mainline uvcvideo
driver though. It makes the code more complex to support a couple of
completely broken devices, and doesn't guarantee that those devices will work
correctly.
ok, i give up.
I just thinking about build in uvc compliance tester insight of the module.
Some thing what users can use right in shop or at home before 14 day return
guarantee.
You enables compliance test and it print results in in dmesg. One of
test should be header check, error/drop rate, and so on.
That's an interesting idea. It should probably come with a userspace stress
test software as well.
you mean luvcview or some thing other?
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