Am Dienstag, den 25.01.2011, 14:38 +0100 schrieb Laurent Pinchart:
> Hi Alexey,
>
> On Sunday 16 January 2011 09:57:53 Alexey Fisher wrote:
> > Hi,
> > i helping my friend to install linux on his new laptop "fujisu lifebook
> > a340". It is cheap one (350€) but seems to work good with linux. But web
> > cam has some issues, which i will discuss with you.
> >
> > It is uvc webcam (0408:1fc3 Quanta Computer, Inc.).
> > For most frame sizes it aims to support 10, 15,25, 30 fps. In real life it
> > stream only with 30fps, if i try to set 10fps, it will silently ignore it.
> > The real problem - there is no exposure control and autoexposure do not
> > working with 30fps too. So with normal light the image will be dark and
> > noisy.
> >
> > With frame sizes 1280x960 and 1280x1024, it has max frame rate 9fps
> > (aims to support 9 and 5 fps). Interesting thing is, autoexposure seems
> > to work here. If i close the cam, frame rate will drop to ~4fps, and if
> > i add extra light it will go to ~9fps. The image with this framerate is
> > better than with 30fps.
> >
> > By tracing i also found "uvcvideo: Dropping payload (out of sync)."
> > messages. So i added two quirks for this cam: UVC_QUIRK_STREAM_NO_FID
> > for out of sync;
>
> Did UVC_QUIRK_STREAM_NO_FID make any difference ?
It remove all "out of sync" errors from trace. But i didn't noticed any
stability or quality difference.
> > UVC_QUIRK_RESTRICT_FRAME_RATE for dummy frame rates.
> >
> > Now my question: is it possible to pull/force some registers to test if
> > auto exposure can work with 30fps too?
>
> The camera doesn't report exposure/auto exposure controls in its descriptors.
> You could hack the driver to make it think the camera supports those
> controls.
> You should then be able to set them from userspace to see if they make any
> difference.
>
> The easiest way would be to modify uvc_ctrl_init_device() in uvc_ctrl.c. Add
>
> static const u8 camera_controls[3] = { 0x0e, 0x00, 0x00 };
>
> at the beginning of the function, and replace
>
> } else if (UVC_ENTITY_TYPE(entity) == UVC_ITT_CAMERA) {
> bmControls = entity->camera.bmControls;
> bControlSize = entity->camera.bControlSize;
> }
>
> with
>
> } else if (UVC_ENTITY_TYPE(entity) == UVC_ITT_CAMERA) {
> bmControls = camera_controls;
> bControlSize = entity->camera.bControlSize;
> }
This is not working. I did other hack, i just allowed only high
resolution. This is my last diff:
> diff --git a/drivers/media/video/uvc/uvc_driver.c
> b/drivers/media/video/uvc/uvc_
> index a1e9dfb..e771530 100644
> --- a/drivers/media/video/uvc/uvc_driver.c
> +++ b/drivers/media/video/uvc/uvc_driver.c
> @@ -495,7 +495,9 @@ static int uvc_parse_format(struct uvc_device *dev,
> 10000000/frame->dwDefaultFrameInterval,
> (100000000/frame->dwDefaultFrameInterval)%10);
> - format->nframes++;
> + if (get_unaligned_le16(&buffer[5]) == 1280)
> + format->nframes++;
> +
> buflen -= buffer[0];
> buffer += buffer[0];
> }
> @@ -1957,6 +1959,16 @@ MODULE_PARM_DESC(timeout, "Streaming control requests
> tim
> * though they are compliant.
> */
> static struct usb_device_id uvc_ids[] = {
> + /* (Quanta Computer, Inc.) Build in webcam found on Lifebook A530 */
> + { .match_flags = USB_DEVICE_ID_MATCH_DEVICE
> + | USB_DEVICE_ID_MATCH_INT_INFO,
> + .idVendor = 0x0408,
> + .idProduct = 0x1fc3,
> + .bInterfaceClass = USB_CLASS_VIDEO,
> + .bInterfaceSubClass = 1,
> + .bInterfaceProtocol = 0,
> + .driver_info = UVC_QUIRK_STREAM_NO_FID
> + | UVC_QUIRK_RESTRICT_FRAME_RATE },
> /* Genius eFace 2025 */
> { .match_flags = USB_DEVICE_ID_MATCH_DEVICE
> | USB_DEVICE_ID_MATCH_INT_INFO,
This i get before patch:
uvcdynctrl -f
Listing available frame formats for device video0:
Pixel format: YUYV (YUV 4:2:2 (YUYV); MIME type: video/x-raw-yuv)
Frame size: 640x480
Frame rates: 30, 25, 15, 10
Frame size: 352x288
Frame rates: 30, 25, 15, 10
Frame size: 320x240
Frame rates: 30, 25, 15, 10
Frame size: 176x144
Frame rates: 30, 25, 15, 10
Frame size: 160x120
Frame rates: 30, 25, 15, 10
Frame size: 1280x960
Frame rates: 9, 5
Frame size: 1280x1024
Frame rates: 9, 5
This is after patch:
....
Pixel format: YUYV (YUV 4:2:2 (YUYV); MIME type: video/x-raw-yuv)
Frame size: 1280x960
Frame rates: 9
Frame size: 1280x1024
Frame rates: 9
--
Regards,
Alexey
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