From: "Charlie X. Liu" <charlie@sensoray.com>
To: "'Bjørn Mork'" <bjorn@mork.no>, "'James Board'" <jpboard2@yahoo.com>
Cc: "'Daniel Glöckner'" <daniel-gl@gmx.net>,
"'Steve Cookson'" <it@sca-uk.com>,
linux-media@vger.kernel.org
Subject: RE: HD Capture Card (HDMI and Component) output raw pixels
Date: Wed, 19 Jun 2013 16:46:02 -0700 [thread overview]
Message-ID: <005201ce6d47$28a79520$79f6bf60$@com> (raw)
In-Reply-To: <87ip1a42fa.fsf@nemi.mork.no>
If 1080i60 or 1080p30 as max supported, the bandwidth requirement would be 124.416MB/s (1920*1080*2*30, in YUV422 format). Make sense and it can pass through over a PCIe lane x1.
-----Original Message-----
From: linux-media-owner@vger.kernel.org [mailto:linux-media-owner@vger.kernel.org] On Behalf Of Bjørn Mork
Sent: Wednesday, June 19, 2013 7:10 AM
To: James Board
Cc: Daniel Glöckner; Steve Cookson; linux-media@vger.kernel.org
Subject: Re: HD Capture Card (HDMI and Component) output raw pixels
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
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next prev parent reply other threads:[~2013-06-20 0:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-16 14:32 HD Capture Card (HDMI and Component) output raw pixels James Board
2013-06-16 19:15 ` Steve Cookson
[not found] ` <1371572315.65617.YahooMailNeo@web163901.mail.gq1.yahoo.com>
2013-06-18 19:38 ` Steve Cookson
[not found] ` <1371587831.30761.YahooMailNeo@web163905.mail.gq1.yahoo.com>
2013-06-18 20:55 ` Steve Cookson
2013-06-18 23:06 ` Daniel Glöckner
2013-06-19 0:38 ` Charlie X. Liu
2013-06-19 13:35 ` James Board
2013-06-19 14:10 ` Bjørn Mork
2013-06-19 23:46 ` Charlie X. Liu [this message]
2013-06-19 14:21 ` Steven Toth
2013-06-19 14:52 ` Daniel Glöckner
2013-06-19 23:35 ` Charlie X. Liu
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