Re: HD Capture Card (HDMI and Component) output raw pixels

Bjørn Mork
2013-06-19T14:10:30Z

James Board <jpboard2@yahoo.com> writes:

> You are right.  According to your numbers, this card can't work.  So
> why would BlackMagic design an HDMI capture card with only one PCIe
> lane if it can't possibly work?   It must work somehow.  I must be
> missing some crucial piece of information.
>
> The card doesn't support hardware encoding, right?  If so, raw pixels
> are the only output.  Maybe the card uses more than one PCIe lane?
> What makes you think the card only uses a single lane?

http://www.blackmagicdesign.com/products/intensity/techspecs/ says so.
It also says

HD Format Support: 1080i50, 1080i59.94, 1080i60, 1080p23.98, 1080p24,
1080p25, 1080p29.97, 1080p30, 720p50, 720p59.94 and
720p60.

which makes the 1080p50 calculation a bit irrelevant.

> Are they using lossless compression to get the raw pixels data rate
> under 200-250 MB/sec, which is the PCIe speed?

None of the supported formats need more than ~180 MB/sec.

Bjørn