On Mon, 28 Oct 2002 16:01:48 -0800 (PST) Ankur Mahajan <ank81ur@xxxxxxxxx> wrote: Hello Ankur. I'd suggest studying the webcam code that comes with xawtv. That's a simple example of how to capture single images. John > Hi, > I have a Linux 2.4 machine with a video capture card > and a pan/tilt camera attached to it. I have > installed the bttv module and it works. I would like > to capture just one frame at a time in order to > analyze the pixel values. > I can communicate with the capture card and it does > seem to give me back a table of pixel values. > However, I am not sure if the values shown are > correct. > I would like to know the basic steps needed to > capture an image. A link to a web page explaining the > steps would be fine too. > So far, here's what I am doing: > > 1. initialize the video_mmap structure > 2. ioctl() on VIDIOCGMBUF to get the frame size. > 3. use mmap() to map capture card memory to user > process memory > 4. capture a frame to the user process memory with > ioctl on VIDIOCMCAPTUREC > 5. ioctl on VIDIOCSYNC > 6. print out the contents of frame as hex numbers. > > Am I doing this right? Is there any documentation > explaining the basic steps to grabbing an image? > Thanks. > > Ankur > > > > __________________________________________________ > Do you Yahoo!? > Y! Web Hosting - Let the expert host your web site > http://webhosting.yahoo.com/ > > > > -- > video4linux-list mailing list > Unsubscribe mailto:video4linux-list-request@xxxxxxxxxx?subject=unsubscribe > https://listman.redhat.com/mailman/listinfo/video4linux-list
