Am Montag, den 13.06.2011, 22:48 -0700 schrieb Carl Michal:
> >>
> > Hi,
> >
> > I think you nailed it. Every frame looks perfect now. The trace shows a
> > few
> > of these:
> >
> > Jun 13 09:24:24 uvcvideo: Dropping payload (error bit set)
> >
> > but I don't see corrupt frames any more in either MJPG or YUYV (at 640x480
> > anyway) - in MJPG all the frames have the right size.
> >
> > There is a some weirdness with frame rates depending on the exposure
> > setting:
> > 1) Exposure, auto gives 4 options: auto priority mode, manual mode, shutter
> > priority mode, and aperture priority mode. Auto and shutter don't seem to
> > be
> > settable (errors from guvcview when chosen). There is also an "Exposure,
> > auto
> > priority" checkbox.
> >
> > Frame rates drop dramatically in manual mode (to 10-15fps from 30).
> >
> > But I can't really complain at this point - the corrupt frames are gone.
> > Will that quirk be added to the driver (usb id is: 0408:2fb1)?
> >
> > Thanks,
> >
>
> Hi,
>
> it seems like I am much better off by fully disabling FID (with your
> patch) than before. With the patch, YUYV frames are _always_ the right
> size. There are still some problems:
>
> 1) corrupt frames - with part of the image missing or the image displaced.
> Sometimes (but definitely not always) these occur at the same time as a
> trace message saying the error bit is set.
>
> 2) sometimes the camera just won't start. when guvcview (or luvcview) is
> started, no frames come back from the camera. There is a light next to
> the camera that comes on to indicate it should be active, but no frames
> arrive. There seems to be a fairly strong correlation with using luvcview
> (which from the traces seems to use some different mechanism to get frames
> from
> the driver from guvcview. guvcview polls, luvcview doesn't). Sometimes
> just restarting guvcview several times will work and the camera eventually
> starts. Sometimes just changing resolution or frame rates succeeds in
> starting the camera. I haven't found anything reproducible. I do not
> think this is related to your patch, as it did happen once before your
> patch was applied. Unloading and reloading the uvcvideo and ehci_hcd
> modules does not consistently solve it. guvcview just lists:
>
> Could not grab image (select timeout): Resource temporarily unavailable
>
> and the trace shows guvcview polling, but nothing else going on.
>
> I have tried adding the other quirks to the FID quirk, but haven't seen
> any improvement with any others.
>
> Thanks for you help -
>
> Carl
Webcam returns error in the middle of some frame, theoretically we
should drop complete frame. But current uvcvideo just gather data and
assume the cam will resend previous parts to complete the frame.
Try attached patch additionally to my previous one.
--
Regards,
Alexey
diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index d0b59ca..0dd3d33 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -423,6 +423,8 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
if (data[1] & UVC_STREAM_ERR) {
uvc_trace(UVC_TRACE_FRAME, "Dropping payload (error bit "
"set).\n");
+ if (buf != NULL)
+ buf->error = 1;
return -ENODATA;
}
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