Author Topic: Best current working Capture Card for a core  (Read 2372 times)

tzinternet

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Best current working Capture Card for a core
« on: December 06, 2007, 07:33:00 pm »
I am looking for the best known working Capture Card for my core box.  I looked thru the Hardware WIKI but
some seem to be a bit old.  Any current suggestions?  thanks!


Hagen

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Re: Best current working Capture Card for a core
« Reply #2 on: December 07, 2007, 12:11:19 pm »
and for Europe?  ;)

Matthew

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HDMI Input?
« Reply #3 on: December 07, 2007, 06:18:33 pm »
Is there any device that takes HDMI input from a digital cablebox that would otherwise go directly to a TV, but makes the incoming signal and directs it to MythTV (and then to PVR/MDs)?

Or is that the entire point of HDMI (DVI+HDCP): prevent anything but a "write only" TV from receiving HD content, so HD content can only be displayed immediately, and never any other use?

colinjones

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Re: Best current working Capture Card for a core
« Reply #4 on: December 07, 2007, 09:13:40 pm »
That's right, the point of HDCP is to prevent copying - theoretically it could be cracked, and I think I have seen something out there that claims this, but the stream is uncompressed and requires a huge bandwidth. If you couldn't compress it real time (would require BIG hardware!) it would very quickly fill a hard drive! BTW - HDMI is more than DVI plus copy protection - in the later revisions it has a much higher bandwidth, digital audio, equipment control (CEC), etc.

Matthew

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Re: Best current working Capture Card for a core
« Reply #5 on: December 07, 2007, 11:29:57 pm »
That's right, the point of HDCP is to prevent copying - theoretically it could be cracked, and I think I have seen something out there that claims this, but the stream is uncompressed and requires a huge bandwidth. If you couldn't compress it real time (would require BIG hardware!) it would very quickly fill a hard drive! BTW - HDMI is more than DVI plus copy protection - in the later revisions it has a much higher bandwidth, digital audio, equipment control (CEC), etc.

That's what I thought. But what about something like this HDMI splitter, which seems to offer HDMI in, and DVI+TOSlink (+ parallel HDMI simultaneously) out, which would seem to "open" the HDMI stream? FWIW, I don't know how "big" the HW needs to be to compress HDMI realtime, when there are fairly cheap (<$500) HDTVs that process HDMI into a picture in realtime,  and therefore include all the display and other electronics which could instead be a Pentium or DSP.

tschak909

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Re: Best current working Capture Card for a core
« Reply #6 on: December 08, 2007, 05:24:28 am »
it is well outside the realm of current general purpose CPUs (which would need to be roughly 4 times faster than what they are now).. there ARE devices based on special purpose ASICs and DSPs, but these devices (which are used for broadcast transcoding) are in the range of $5,000 to $10,000, and are way above the range of the average consumer.

The best bet currently (and this is a stretch!), would be to create a device that captured high bandwidth YbPbPr component signals, this would take some of the beefiest FPGAs currently on the market.

-Thom

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Re: Best current working Capture Card for a core
« Reply #7 on: December 08, 2007, 08:12:48 am »
it is well outside the realm of current general purpose CPUs (which would need to be roughly 4 times faster than what they are now).. there ARE devices based on special purpose ASICs and DSPs, but these devices (which are used for broadcast transcoding) are in the range of $5,000 to $10,000, and are way above the range of the average consumer.

The best bet currently (and this is a stretch!), would be to create a device that captured high bandwidth YbPbPr component signals, this would take some of the beefiest FPGAs currently on the market.

I believe you, but I don't understand how a $500 TV does it, and includes a 22" LCD and the rest, too.

tschak909

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Re: Best current working Capture Card for a core
« Reply #8 on: December 08, 2007, 08:16:22 am »
you can get the technical operation details of DVI transcievers, but basically, the data channel is incredibly fast, and there is a tight buffer just enough to process and render the display. There is not sufficient processing power on a general purpose CPU to decode the stream, and recompress it in real time, which is what is needed. If you don't believe me, I suggest doing some research.

-Thom

Matthew

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Re: Best current working Capture Card for a core
« Reply #9 on: December 08, 2007, 05:05:46 pm »
you can get the technical operation details of DVI transcievers, but basically, the data channel is incredibly fast, and there is a tight buffer just enough to process and render the display. There is not sufficient processing power on a general purpose CPU to decode the stream, and recompress it in real time, which is what is needed. If you don't believe me, I suggest doing some research.

Do you think that a Sony PS3, which has HDMI output, could handle the processing, if the code ran on the Cell's SPUs? The device has no HDMI input, but there might be a way to get the data compressed and into the machine through its other inputs, if it's fast enough to bother trying.

tschak909

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Re: Best current working Capture Card for a core
« Reply #10 on: December 08, 2007, 05:38:09 pm »
no, it wouldn't.

-Thom

Matthew

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Re: Best current working Capture Card for a core
« Reply #11 on: December 08, 2007, 06:12:50 pm »
no, it wouldn't.

Again, I'm just trying to understand this. How come a PS3 Blu-Ray drive and its Cell can decode the Blu-Ray and encode it to HDMI, but isn't fast enough to do that compression to HD? 204GFLOPS isn't fast enough?

tschak909

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Re: Best current working Capture Card for a core
« Reply #12 on: December 08, 2007, 06:28:12 pm »
it's because the CPU isn't encoding to HDMI! The HDMI part is being done by an application specific IC, and it is designed in a very tight locked loop.

bro

DO SOME RESEARCH!

-Thom

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Re: Best current working Capture Card for a core
« Reply #13 on: December 09, 2007, 02:12:43 am »
no, it wouldn't.

-Thom


Hmmm... the issue is the encryption not the processing power. Of course there are already components that can do the processing and they cost a few 10's of dollars.
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Matthew

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Re: Best current working Capture Card for a core
« Reply #14 on: December 09, 2007, 07:30:46 pm »
it's because the CPU isn't encoding to HDMI! The HDMI part is being done by an application specific IC, and it is designed in a very tight locked loop.

bro

DO SOME RESEARCH!

DON'T TAZE ME, BRO!

You started out saying that HDMI de/coding would cost $5K+, and that's clearly not the case. But it's clear that researching by having a discussion here just pisses you off, and no one else seems to know, so I'm giving up on this venue.