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@xxxxxxxxxxxxxxx [mailto:linux-media-owner@xxxxxxxxxxxxxxx] On Behalf Of Bjørn Mork Sent: Wednesday, June 19, 2013 7:10 AM To: James Board Cc: Daniel Glöckner; Steve Cookson; linux-media@xxxxxxxxxxxxxxx Subject: Re: HD Capture Card (HDMI and Component) output raw pixels James Board <jpboard2@xxxxxxxxx> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
