Hello Ronald! Sorry fo bothering you again with this question, I just can't get it to work... :(( You pointed me to the API description, the only documentation I've found however is /usr/linux/Documentation/video4linux/API.html which doesn't help me much :( Well, if anyone has time, please help me out with this (getting a bit frustrated here.. :) The problem is that I want to output a still jpeg image on the video out device. (In the end I want to update that image regulary, but as I can't even get the first one right, I'll start there.) What I get now, is a rolling screen on the tv, you can however (with a litte bit of imagination) see the actual picture behind the noise and rolling. (big breakthrough, yeehaw ;) Any help appreciated! I've included my source files, and the sample picture with this email. sincerely Markus Nilsson (Student at Lund Institute of Technology) -----Original Message----- From: Ronald Bultje [mailto:rbultje@xxxxxxxxxxxxxxxxxxx] Sent: den 23 januari 2003 16:41 To: video4linux-list@xxxxxxxxxx Subject: Re: Output jpeg-frames on DC10+ Hey Markus, On Thu, 2003-01-23 at 09:51, Markus Nilsson wrote: > //Store params > bp.norm = 0; //PAL > bp.quality = 100; > bp.field_per_buff = 1; > bp.img_width = 352; > bp.img_height = 240; > if (ioctl(vid_fd, MJPIOC_S_PARAMS, &bp) < 0) { > cout << "***Error setting video parameters" << endl << "::" << strerror(errno) << endl; > } That's wrong. You need to set the width/height of the *unscaled* frame, so 704/240 (field height!), and then use HorDcm/VerDcm/TmpDcm to scale the frame to full size or double field/frame, in this case bp.decimation=0 (which means 'manual' instead of 'auto'), bp.HorDcm=2, bp.VerDcm=1, bp.TmpDcm=2 (see the API description provided in the kernel package). > /* REQBUFS */ > if(ioctl(vid_fd, MJPIOC_REQBUFS, &vm)<0) { > cout << "***Error requesting buffers" << endl << "::" << strerror(errno) << endl; > } > /* mmap */ > vm.frames = 5; > vm.size = 352*240*3*5; First set the vm.count and vm.size, then request buffers, you're doing it the other way around. Your vm.size is a bit large, by the way (128k is enough for this size), and vm.size is the size *per buffer*, not the total size (again, see the API description provided in the kernel package). > void PS_VideoDriver::update() { Looks good to me. :-). Ronald -- Ronald Bultje <rbultje@xxxxxxxxxxxxxxxxxxx> Linux Video/Multimedia developer -- video4linux-list mailing list Unsubscribe mailto:video4linux-list-request@xxxxxxxxxx?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
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