Georgios Kapetanakis wrote: > > Hi all, > > I know this is getting slightly away from the core interest of the list, but > I need your help once more. I am convinced now that getting a frame grabber > with a bt8x8 chipset is the best way to go, as far as driver support is > concerned (bttv). > > I know of only two frame grabbers with this chipset: > - Imagenation PXC200AL > - Sensoray 611 > > Are there any more? Please note that I am interested in frame grabbers for > computer vision, not TV/Tuner cards.... But what's the difference between a computer vision grabber and a TV card with the channel set to the raw video input? Following for example is the output of a test program I wrote using the functions in linux/videodev.h to query the bttv driver. You can set the channel to 1 to receive video. I'm pretty sure that the video quality is mostly limited by the video format itself, and that any grabber will produce similar output for a given NTSC or PAL signal. The only other issue is progressive scan, where you grab only a part of an image, but there you might be better off getting a dedicated camera with image processing built into it. Hello world. Today we are going to look at the video grabber at /dev/video name of /dev/video: BT878(Hauppauge (bt878)) VID_TYPE_CAPTURE Can capture to memory VID_TYPE_TUNER Has a tuner of some form VID_TYPE_OVERLAY Can overlay its image onto the frame buffer VID_TYPE_CLIPPING Overlay clipping is supported VID_TYPE_FRAMERAM Overlay overwrites frame buffer memory VID_TYPE_SCALES The hardware supports image scaling Type 0xEB 4 channels 1 audio device Max width: 768 Max height: 480 Min width: 48 Min height: 32 Video frame buffer base 0xe8000000 height 768 width 1024 depth 16 bytes per line 2048 * * * Channel 0: Television has 1 tuner Flags: 0x3: has tuner; has audio Type: 0x1: TV; not camera Norm: 0x1: NTSC brightness 0x7FFF hue 0x7FFF colour 0x7D70 contrast 0x6B84 whiteness 0x0 depth 0x10 VIDEO_PALETTE_RGB565 565 16 bit RGB * * * Channel 1: Composite1 has 0 tuners Flags: 0x2: no tuner; has audio Type: 0x2: not TV; camera Norm: 0x1: NTSC brightness 0x7FFF hue 0x7FFF colour 0x7D70 contrast 0x6B84 whiteness 0x0 depth 0x10 VIDEO_PALETTE_RGB565 565 16 bit RGB * * * Channel 2: S-Video has 0 tuners Flags: 0x2: no tuner; has audio Type: 0x2: not TV; camera Norm: 0x1: NTSC brightness 0x7FFF hue 0x7FFF colour 0x7D70 contrast 0x6B84 whiteness 0x0 depth 0x10 VIDEO_PALETTE_RGB565 565 16 bit RGB * * * Channel 3: Composite3 has 0 tuners Flags: 0x2: no tuner; has audio Type: 0x2: not TV; camera Norm: 0x1: NTSC brightness 0x7FFF hue 0x7FFF colour 0x7D70 contrast 0x6B84 whiteness 0x0 depth 0x10 VIDEO_PALETTE_RGB565 565 16 bit RGB /\/\/\/*=Martin
