HV20 HDMI Out = 8bit.. chance of 10bit? - Page 4 at DVinfo.net

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Canon VIXIA Series AVCHD and HDV Camcorders
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Old February 11th, 2008, 02:05 PM   #46
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hi chris,

no. what is happening is the hdmi is streaming content out, but you need a dedicated PC/laptop w/software installed to capture that stream. think of it as a digital "rca cable" pretty much. that's all the digital outputs on camcorders do.

the reason why firestore is incredibly expensive is because they loaded the software right onto a memory chip inside of the hard drive enclosure to capture the stream itself.

my idea is to have the camcorder as the "PC" so to speak with the software built-in right into the camcorders. the hdmi basically becomes a glorified port to attach to external/portable SSD/raid enclosures. that way, when you press record, the external disks goto to capture things and that's it =P.
-yfy




Quote:
Originally Posted by Christopher Ruffell View Post
Isn't that what HDMI and FireWire outputs on the camera is already for? The Focus Enhancements FireStore exists for FireWire (HDV), and now, portable HDMI recording options are coming from Convergent Design (with HDMI-to HD-SDI convertor) and Cineform. It's great we have HDMI out :D Just a matter of time for portable support hardware to be made avaliable.

We just need a 50mb/sec HDMI 4:2:2 FireStore for HD! I'd prefer to record to hard drive too - cheap cheap $-per GB! I saw that a 250GB SATA hard disk sells for $80 now. Apple ProRes 422 is efficient enough that it'll capture to a single drive :)
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Old February 11th, 2008, 04:56 PM   #47
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Yi Fong Yu, I understand how HDMI works - there is no 'speaking' on behalf of the recording device to the camera, it's just raw (or played back recorded) video & audio data presented digitally.

I think a FireStore with HDMI in (much like Cineform's proposed product, or a something that we may have seen come from Convergent Design) would be ideal for the future of capturing high-res data - for now, max 8bit 422 video camera independent, keeping the price of the camera down, and allowing for flexibility on the part of the capture unit.

I think I hear what you're saying.. a port that'll connect to external devices, that the camera itself controls. I think the future of cameras are computer-controlled high-res sensors - think glorified, computerized industrial camera heads with small PCs with lots of portable storage - but that's a whole different discussion best saved for the Alternate Imaging Methods thread.

As it stands, the HV20 is a 8 bit camera.
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Old February 13th, 2008, 01:23 PM   #48
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yes exactly, cameras function this way. all the software is inside the still camera, but the storage is just that, storage. it doesn't have any software inside to capture anything.
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Old March 29th, 2008, 12:32 AM   #49
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Quote:
Originally Posted by Christopher Ruffell View Post
P.S. there's an interesting thread that parallel's this one going on in the Sony EX 1 camera thread - debate over 10bit. Some users are swearing it's a 10-bit camera. Adam Wilt made no mention of it, though he did import HD-SDI footage for his review I believe. If it's true, that'd make the EX 1 the first sub $10k camera with 10-bit out.
The single problem with live capture from the EX1 HD-SDI is that there is no way to capture full 1920x1080p30. If it weren't for that limitation I would have bought the EX1 so I'll still be playing with the HV20 until something else better comes out that can provide true 1920x1080p30 live out.
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Old March 29th, 2008, 06:44 PM   #50
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By the way, Adam Wilt has confirmed for me that the EX1 is 10bit! Which is kind of big deal as that means it's the first in a price this low and hopefully will start a new trend.
http://provideocoalition.com/index.p..._ex1_update_2/

If i'm not mistaken, on the EX1, 30P will display fine in a 60i stream, just like the HV30 does. The image you're watching would be ture 30P. In the 60i playback/recording, each half of the progressive frame from the sensor is shown at the same time; the visible result is the true, fully progressive frame. If you were playing this video clip in QuickTime, you'd only be able to tell it was in a 60i timeline by looking at video clip's 'get info' window!

You'd be able to get 30P out over 60i via HD-SDI LIVE with the EX1 and it'll just require a rerender if you want to get it down to 30 frames instead of 60 per second. HV30 is no different in how it treats 30P.

The EX1 is not at fault in it's treatment of progressive video as many professional cameras treat progressive video in this way as a delivery method over 60i. And, it's 10bit!
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Old March 29th, 2008, 07:04 PM   #51
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I've been hoping I'm wrong on this for a while now but I don't see how it's possible to squeeze the full 1080p30 raw data into a 1080i data stream without loss. The difference in data is around 30%. Look at the section title "Standards" at:

http://en.wikipedia.org/wiki/Serial_Digital_Interface

1080p requires SMPTE 372M dual-link HD-SDI. I've speculated that 1080p30 is transmitted through the EX1 HD-SDI as 1440x1080p30 wrapped into 1080i, but that's not true 1080p30. Or maybe it just sends out 1080i30 and it still looks so good that it's believed to have been 1080p30?

1080p 4:2:2 10 bit requires a set "x" amount of data. Nothing can change that no matter how it's wrapped.
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Old March 29th, 2008, 07:56 PM   #52
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Mike, I'm not saying it is true 1080p 30fps 4:2:2, but hypothetically there should be enough bandwidth to carry the stream. 30fps takes about 1 Gibts/sec. While 59.94 fps takes upward of 2.5 Gbits/sec.

So depending on how HD-SDI handles the slower frame rate, it is techinically feasable, FWIU.

But more likely, the EX-1's HD-SDI stream is limited to 1080i and 720P. I imagine this is a pretty "easy" question for Sony or some EX-1 owners to answer.
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Old March 29th, 2008, 08:17 PM   #53
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This is definitely something needed to know. Well, so we don't hijack this thread, this is being discussed here on the EX1 forum...

http://www.dvinfo.net/conf/showthread.php?t=118054
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Old March 29th, 2008, 08:41 PM   #54
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Quote:
Originally Posted by Mike Thomann View Post
I've been hoping I'm wrong on this for a while now but I don't see how it's possible to squeeze the full 1080p30 raw data into a 1080i data stream without loss. The difference in data is around 30%. Look at the section title "Standards" at:

http://en.wikipedia.org/wiki/Serial_Digital_Interface

1080p requires SMPTE 372M dual-link HD-SDI. I've speculated that 1080p30 is transmitted through the EX1 HD-SDI as 1440x1080p30 wrapped into 1080i, but that's not true 1080p30. Or maybe it just sends out 1080i30 and it still looks so good that it's believed to have been 1080p30?

1080p 4:2:2 10 bit requires a set "x" amount of data. Nothing can change that no matter how it's wrapped.
1080p isn't any larger in terms of bandwidth then 1080i. Dual link is used on the high end Cinealta equipment to pump out RGB 4:4:4 data. That is why the bandwidth is higher. 1080i and 1080p contain the exact same amount of pixels. One is just made up of two moments woven together. That same number of pixels is still there. A single SDI is capable of sending any form of 4:2:2 video no matter what the resolution or framerate. Dual link again is only used for 4:4:4 RGB output and only from the F9## series cameras and like decks.

Cinealta uses PSf frames where they put progressive frames inside of an interlaced stream. From a viewers point of view there is no difference at all in doing this. It is only so the signal makes sense to interlaced equipment because interlaced equipment expects the alternating fields.

The only time psf is an issue is with cameras such as the V1 or pal DV cameras that shoot progressive scan because they put progressive data into a interlaced encoded video file. The reason why this is an issue is because mpeg2 uses two different forms of chroma pixel layout for interlaced and progressive video. Pal DV always uses the interlaced form of 4:2:0. Progressive of course is what you want with progressive footage but since the stream is an interlaced mpeg2 file it has to use the interlaced method of arranging the chroma blocks. With an uncompressed live feed this is not an issue at all since you never go down to 4:2:0 anyway. For 4:2:2 or 4:4:4 material is doesn't matter how the data is dumped into a format.
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Old March 29th, 2008, 09:09 PM   #55
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Thanks a lot for the clarification. On post #29 at http://www.dvinfo.net/conf/showthread.php?t=118054 I outlined how the max bandwidth of 1080p30 4:4:2 10 bit is calculated to fit precisely within SMPTE 292M HD-SDI at 1.485 Gbit/s. But in that post I ask how sound would then fit. Anyone know?
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Old March 29th, 2008, 11:08 PM   #56
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Quote:
Originally Posted by Thomas Smet View Post
1080p isn't any larger in terms of bandwidth then 1080i. Dual link is used on the high end Cinealta equipment to pump out RGB 4:4:4 data. That is why the bandwidth is higher. 1080i and 1080p contain the exact same amount of pixels. One is just made up of two moments woven together. That same number of pixels is still there. A single SDI is capable of sending any form of 4:2:2 video no matter what the resolution or framerate. Dual link again is only used for 4:4:4 RGB output and only from the F9## series cameras and like decks...
Thomas, I really don't believe that this is entirely correct. 1920 X 1080 59.94 10-bit 4:2:2 is approximately 2.5 Gbits/sec. This IS too much bandwidth for single HD-SDI. Now if you are comparing embedding 1080P into a 1080i timeline using a pulldown, then yes they are the same bandwidth b/c by definition, you are using a 1080i stream. But you can't do that with any frame rate. I believe I am correct with this.
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Old March 30th, 2008, 02:28 AM   #57
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I think he's saying 1080i60 bandwidth = 1080p30 bandwidth which sounds right
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Old March 30th, 2008, 04:03 PM   #58
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Correct. 1080p 60p doesn't really exhist yet except for with Red. Single link SDI handles up to 720p 60p or 1080i 60i or 1080 30p which the last two are the same. No camera including the Cinealta F900 or even the F950 can output 1080p 60p so there is no need at all to even think about it. Dual link SDI is strictly for 1080 i/p RGB 4:4:4.

When anybody talks about 1080p they are talking about 24p 25p or 30p.
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Old March 31st, 2008, 01:26 AM   #59
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I see where you are coming from, but not to be too picky, but it is a tad bit different from: "A single SDI is capable of sending any form of 4:2:2 video no matter what the resolution or framerate." In the context you've outlined, yes it makes sense. But as a general statement, which is how I first took it, it doesn't.
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