On Wed, 2011-11-02 at 17:38 +0100, Laurent Pinchart wrote: > Hi, > > On Saturday 29 October 2011 09:30:04 Alexey Fisher wrote: > > Am 28.10.2011 18:01, schrieb cheshirekow: > > > On Sun, 2011-10-23 at 13:50 -0400, cheshirekow wrote: > > >> On 10/22/2011 03:16 AM, Alexey Fisher wrote: > > >>> Can you please attach the output of this command: > > >>> lsusb -vd 10f1:1a26> lsusb_dump > > >> > > >> Sure. The dump file is attached. > > >> > > >> Thanks! > > > > > > Has anyone by chance managed to take a look at this lsusb dump? > > > > > > To recap: > > > the HP Slate has two integrated we cams: One forward facing for video > > > calls, and one higher-resolution rear-facing for snapping photos. There > > > appears to be a single controller for both cameras. In linux, lsusb only > > > shows one webcam device. In windows, the device manager also shows only > > > one device for the webcam. However, in windows applications that use the > > > webcam (i.e. HP's webcam application, and in skype) I'm able to select > > > which one to use as an option. In linux, there is only one video > > > device, /dev/video0. > > > > > > There does not appear to be any control available from uvcdynctrl or > > > within vlc to select which physical camera to use. I've tried setting > > > the resolution in vlc when I use the "open capture device" menu item. I > > > know that the forward facing camera is VGA so I tried specifying > > > 640x480, but the result is that it shows the rear-camera stream at a low > > > resolution, rather then showing the forward-camera stream. > > > > > > I'd appreciate any suggestions on how to get the forward-facing camera > > > to work in linux (for skype/google video calls). Also, if it is clear > > > that this facility is not available in UVC and that there is no way this > > > is possilble, that would also be useful information. > > > > > > Thanks again > > > > Hi, > > > > suddenly i do not see any control to switch the sensor. I assume there > > can be two variants how it may work: > > 1. vendor specific extension unit for uvc > > 2. or usb mode switcher > > > > if both sensors have same capabilities, the 1. make sense. If not then > > second. Because this usb dump report settings only for one sensor. > > > > For 1. it will be probably possible to control it with libwebcam. For 2. > > it should be possible to control it with some kind of usb_modeswitch > > (i'm not up to date). > > > > To find what it is actually, there can be fallowing options: > > 1. sniff usb traffic > > 2. see if the windows driver has some advise for us > > 3. unscrew your laptop and find what control use your webcam. > > My guess is that the camera uses either an extension unit (XU) control or a > vendor-specific request to select between the two sensors (which is very > unfortunate, given that the UVC specification has explicit support for dual- > sensor cameras, and I would have liked to test that code :-)).
Thanks for the information. It is unfortunate that the camera doesn't take advantage of what is already in the spec. > Let's start with the XU control. I've attached a patch for the yavta test > application (http://git.ideasonboard.org/?p=yavta.git;a=summary) to this e- > mail. Could you please apply it, compile the application with Ok sure. I downloaded the test, applied the patch, and ran it with the following output: Device /dev/video0 opened. Device `HP Webcam' on `usb-0000:00:1d.7-8' is a video capture device. XU control 0: info GET SET (0x03) 2 bytes XU control 1: info GET SET (0x03) 64 bytes XU control 2: info GET SET (0x03) 64 bytes XU control 3: info GET SET (0x03) 2 bytes XU control 4: info GET SET (0x03) 2 bytes XU control 5: info GET SET (0x03) 2 bytes XU control 6: info GET SET (0x03) 2 bytes XU control 7: info GET SET (0x03) 2 bytes Video format: YUYV (56595559) 640x480 buffer size 614400 _______________________________________________ Linux-uvc-devel mailing list Linux-uvc-devel@lists.berlios.de https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
