Hey Johannes,
I've read through the v4l code in Gem and realized an important issue:
1. My previous post about resolution and problems with "VIDIOCMCAPTURE1: Invalid argument" messages was due to me using v4l1 not 2!
2. As best as I can tell, while using v4l2, my UYVY card does not work at all.
In the PD window I get:
video driver 0: video4linux2 video driver 1: ieee1394 for linux v4l2: wanted 6408, got 'RGB4' v4l2: GEM: pix_video: Opened video connection 0x12
STDERR gives me:
VIDIOC_DQBUF: stopping capture thread!: Resource temporarily unavailable
Resulting in an all black image.
I could not understand the reqFormat vs format stuff but I do know the card produces V4L2_PIX_FMT_UYVY video.
I inserted a few statements at line 450 of videoV4L2.cpp (attached)
These statements result in:
bbogart: fmt.fmt.pix.pixelformat = 876758866 bbogart: m_reqFormat = 6408 bbogart: GL_YCBCR_422_GEM = 34233 bbogart: GL_LUMINANCE = 6409 bbogart: GL_RGB= 6407 bbogart: V4L2_PIX_FMT_UYVY = 1498831189 bbogart: V4L2_PIX_FMT_SBGGR8 = 825770306 bbogart: V4L2_PIX_FMT_GREY = 1497715271 bbogart: V4L2_PIX_FMT_YUYV = 1448695129 bbogart: V4L2_PIX_FMT_Y41P = 1345401945 bbogart: V4L2_PIX_FMT_YVU420 = 842094169 bbogart: V4L2_PIX_FMT_YVU410 = 961893977 bbogart: V4L2_PIX_FMT_YUV422P = 1345466932 bbogart: V4L2_PIX_FMT_YUV411P = 1345401140 bbogart: V4L2_PIX_FMT_NV12 = 842094158
Ok, so 6408 is RGBA.
So I send the "colorspace YUV" message to pix_video.
Now I see:
bbogart: fmt.fmt.pix.pixelformat = 1498831189 bbogart: m_reqFormat = 34233 bbogart: GL_YCBCR_422_GEM = 34233 bbogart: V4L2_PIX_FMT_UYVY = 1498831189
so that all looks correct fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_UYVY and m_reqFormat = GL_YCBCR_422_GEM
BUT the PD console still prints:
v4l2: wanted 34233, got 'UYVY' v4l2: GEM: pix_video: Opened video connection 0xE
But 34233 is a YUV format...
I still get the VIDIOC_DQBUF: stopping capture thread!: Resource temporarily unavailable error.
So I'm stuck here, but I hope this helps enough that you can give me more hints on what else to try.
Thanks, B. Bogart