Using an mpeg encoder card seems like overkill to me. The only advantage
this card may have over a 'normal' TV card is that you don't need an
audio card as the audio is available directly from the mpeg card.
Normal TV cards require an audio line-in.
Hans
On Thursday 16 March 2006 00:47, Ola Theander wrote:
> 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.
>
>
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>
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