> > VIDIOCSPICT and VIDIOCSWIN are only used for setting up an overlay > > window, not for memory capture. Or for capture using the read() system call. With bttv 0.8.x capture with read() does actually work (unlike older versions)... > > For doing memory capture the size/format > > are passed to each VIDIOMCAPTURE call. > > This is a point I am not sure of. The v4l API specification explicitly > requires that GMBUF is isued AFTER setting the size and format, while > MCAPTURE is only allowed after GMBUF and mmap. As you can see, this > prevents using MCAPTURE to set the size/format, and the only other ioctl > that sets size is SWIN, so this must be the one. Sure? For v4l1? I can't remember having this seen in Alan's specs (havn't checked it for some time throuth...). v4l2 _is_ specified that way (i.e. first set format, then ask buffer size + map stuff), but IIRC v4l1 is not. As size+format are specified on frame by frame bases in struct video_mmap I can't see the point of setting the video format first... Gerd -- Get back there in front of the computer NOW. Christmas can wait. -- Linus "the Grinch" Torvalds, 24 Dec 2000 on linux-kernel
