[PD] pdp and webcams (was: Re: Still trying to get pdp to run)

[Tom Schouten]

hi jim,

try to send a 'captureformat RGB24' or 'captureformat RGB32' the the
pdp_v4l object. if that doesn't help, it means your camera is either too
new (and has only a video4linux2 driver), or it doesn't support double
buffered capturing, which is implicitly assumed in pdp_v4l, or has a
broken driver.

if it's the double buffering, it means you're stuck. maybe i will support
it later, but that's no priority for me now.

consider buying a camera with a philips chipset. they are a little more
expensive, but it's worth it. it's decent hardware, but more importantly,
there's a good driver that supports its special features. this driver is
explicitly supported in pdp. the driver is called 'pwc' and is in the
kernel. the proprietary codec is supported in the 'pwcx' module.

they have built-in compression which makes it possible to have a
relatively high framerate for a webcam: 27fps at 320x240 compared to 10
for the cheap ones. i don't know if there are any other driver/camera
combinations that can do this.

and no, i'm not payed by philips, but as far as i can see, it's the only
thing that really works well, despite the fact that there's non-open
source part that makes it go that extra mile..

see http://www.smcc.demon.nl/webcam/ for a list of cameras supported by
the pwc/pwcx driver.

cheers,

tom


On Sun, 25 Jul 2004, jim ruxton wrote:

> I'm still trying to figure out why nothing is in the video window. Any
> thoughts where I should start to look.
> Jim
>
> I thought I had succeeded but when I try to look for an image in an
> example patch (input_output.pd) I don't see it. Below is what I get in
> the terminal window after creating a window opening pdp_v4l and banging
> it once. I tried pdp_xv and pdp_glx with no luck. I can see the video
> with Gem and xawtv so I think video4linux is ok. Any thought where I
> should start to look for problems. I'm using a logitech usb based
> webcam.
> Jim
> Sample width set to 2 bytes
> PDP: pure data packet
> PDP: version 0.12.3
> pdp_xvideo: grabbed port 61 on adaptor 0
> pdp_v4l: opening /dev/video0
> pdp_v4l: cap: name Logitech USB Camera type 513 channels 1 maxw 352 maxh
> 292 minw 32 minh 32
> pdp_v4l: picture: brightness 32767 depth 24 palette 4
> pdp_v4l: channel 0 name Camera type 2 flags 0
> pdp_v4l: switched to channel 0
> pdp_v4l: set norm to 0
> pdp_v4l: buffer size 426240, frames 1, offset 0 0
> pdp_v4l: using VIDEO_PALETTE_YUV422
> pdp_v4l: frame 0 0, format 7, width 320, height 240
> pdp_v4l: Opened video connection (320x240)
> pdp_v4l: VIDIOCMCAPTURE: Invalid argument
> pdp_v4l: VIDIOCMCAPTURE2: Invalid argument
> pdp_v4l: frame 1 1, format 7, width 320, height 240
> pdp_v4l: VIDIOCSYNC: Bad file descriptor
> pdp_v4l: no device opened
> pdp_v4l: attempting auto open
> pdp_v4l: opening /dev/video0
> pdp_v4l: cap: name Logitech USB Camera type 513 channels 1 maxw 352 maxh
> 292 minw 32 minh 32
> pdp_v4l: picture: brightness 32767 depth 24 palette 4
> pdp_v4l: channel 0 name Camera type 2 flags 0
> pdp_v4l: switched to channel 0
> pdp_v4l: set norm to 0
> pdp_v4l: buffer size 426240, frames 1, offset 0 0
> pdp_v4l: using VIDEO_PALETTE_YUV422
> pdp_v4l: frame 0 0, format 7, width 320, height 240
> pdp_v4l: Opened video connection (320x240)
> pdp_v4l: VIDIOCMCAPTURE: Invalid argument
> pdp_v4l: VIDIOCMCAPTURE2: Invalid argument
> pdp_v4l: frame 1 1, format 7, width 320, height 240
> pdp_v4l: VIDIOCSYNC: Bad file descriptor
> pdp_v4l: auto open failed
>