Dear subscribers I'm right now trying out the Hauppauge PVR 150 card for use in a project where I need to capture composite video basically in real time. The video signal is received by the computer from a manually operated camera. The camera is mounted on a long cable which the computer operator guides in narrow pipes by the view on the computer screen. To make the operation as easy as possible for the operator I want as short delay as possible between actually moving the camera and until the movement is reflected on the computer screen.
I realize that this isn't important if you e.g. capture a video from an analogue video camera since the delay when the video stream passes through the hardware/software until it's stored on the hard disk isn't noticeable when you later playback the video. I know that the Hauppauge card is capable of virtually no latency since I started out by trying it using Windows and on Windows the screen update when moving the camera was more or less instantaneous, at least the delay wasn't noticeable. The basic tests I've performed I just did "mplayer /dev/video0" and moved the camera. The delay seems to be in the order of 0.5 - 1.0 seconds before the picture is updated. If I look in the output of dmesg I notice one line stating "ivtv0: Unreasonably low latency timer, setting to 64 (was 32)" and I wonder if that might have something to do with this? Eventually I'll use GStreamer instead and I know that the latency in the 0.8 code branch is much worse that it is in the latter 0.9 and 0.10. I've tried my solution with GStreamer 0.10 and an external composite 2 firewire-dv converter so I know that it's possible to have quite a low delay. Now I just hope that I can do the same using the PVR 150. Any help on this matter would be greatly appreciated. Kind regards, Ola Theander _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
