Hi Andrew I hope Hans doesn't mind that we discuss alternative cards on this mailing list. You are correct that I really don't need mpeg encoded streams since basically the first thing I have to do with such a stream is to decode it in order to show it on the operator's (user's) screen. At a very basic level, what my application will do is to capture a video and sound stream and show the video on the screen and at the same time store the video with sound to disc. For this I'll use Gstreamer which have features for muxing/demuxing etc. of video/sound streams.
If you have any recommendation of such a card, i.e. based on bttv or cx88 I'll be glad to hear. The additional 20 - 30 USD doesn't matter if they work better. If I manage to provide my employer with a good solution we probably talking about 50 - 100 units to start with at about 2000 USD a piece. My main requests is apart from a low latency is that they manage a reasonable resolution at a reasonable frame rate, i.e. somewhere along the lines of 600x400 and 20 fps or better. Kind regards, Ola -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andrew Dodd Sent: den 16 mars 2006 00:31 To: [email protected] Subject: Re: [ivtv-users] How to lower the latency (delay)on compositevideowhen capturing (PVR 150)? Quoting Ola Theander <[EMAIL PROTECTED]>: > Hi Hans > > I did find the /dev/video32, just after I mailed you (as usual). I > found a lot of sample code mplayer switches, similar to "mplayer > -demuxer rawvideo -rawvideo pal:yv12" to process raw YUV but so far it > looks terrible. It's certainly something moving on the screen but it > looks more or less like a blur. It's not noise like, it's have more > "structure", i.e. it's more like colored, horizontal, jagged bars. I > suspect that it might have something to do with that ivtv seems to > default to interlaced mode. I tried to change it to progressive using > "ivtvctl --set-yuv-mode=1,576" or "ivtvctl --set-yuv-mode=1". Ivtvctrl > responds with OK but the change doesn't seem to stick because if I do "ioctrl --get-yuv-mode" it's right back to interlaced. Just curious, does your application require the MPEG encoder or will you always be doing encoding of raw video yourself with low latency being your critical need? If you have no need for the MPEG functionality and need reliable low latency video capture, you would probably be better off with a bt8x8 or cx88 based capture card - They work INCREDIBLY well if you don't need hardware MPEG encoding and have very low latency. (Suitable for playing console games, low latency videoconferencing, etc.) The PVR-150 wasn't really designed to provide raw YUV - it happens to do so but it is essentially a design afterthought that has low priority with both Hauppauge's engineers and most of the ivtv people. Cards that use the bttv or cx88 drivers, on the other hand, do nothing but raw video capture. bttv and cx88 cards also happen to be significantly cheaper - I've heard of people getting tunerless cx88-based boards for $20-30 USD. Too late for your current system, but if you are planning multiple systems with capture boards down the line it could make a big difference. _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
