Hello Paulo Thank you for your quick response. Unfortunately if I select YUYV or any other format that is not MJPG data flow stops and I see timeouts appear in the console. Does this represent a bug in either the webcam's UVC support or the UVC driver? If so I presume there is no likely quick workaround. Phil ________________________________ From: Paulo Assis <pj.assis@xxxxxxxxx> To: phil rosenberg <philip_rosenberg@xxxxxxxxx> Cc: "linux-media@xxxxxxxxxxxxxxx" <linux-media@xxxxxxxxxxxxxxx> Sent: Tuesday, 11 June 2013, 10:11 Subject: Re: Hi, make sure you are streaming in YUYV format and not in MJPG or any of the libv4l formats since these are decoded from MJPG. If you are using guvcview for the stream preview you should also set the bayer pattern accordindly since it will depend on whathever resolution you are using. Regards, Paulo 2013/6/11 phil rosenberg <philip_rosenberg@xxxxxxxxx> Hi this is my first email to the list, I'm hoping someone can help >I have a logitech C300 webcam with the option of raw/bayer output. This works fine on windows where the RGB output consists of zeros in the r and b bytes and pixel intensitey in the g byte. However on linux when I activate the webcam using uvcdynctrl and/or the options in guvcview the out put seems to be corrupted. I get something that looks like multiple images interlaces and displaced horizontally, generally pink. I've put an example of an extracted avi frame at http://homepages.see.leeds.ac.uk/~earpros/test0.png, which is a close up of one of my daughters hair clips and shows an (upside down) picture of a disney character. >I'm wondering if the UVC/V4L2 driver is interpretting the data as mjpeg and incorrectly decoding it giving the corruption. When I use guvcview I can choose the input format, but the only one that works in mjpeg, all others cause timeouts and no data. The image also has the tell-tale 8x8 jpeg block effect. Is there any way I can stop this decoding happening and get to the raw data? Presumably if my theory is correct then the decompression is lossy so cannot be undone. >Any help or suggestions welcome. > >Phil >-- >To unsubscribe from this list: send the line "unsubscribe linux-media" in >the body of a message to majordomo@xxxxxxxxxxxxxxx >More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
