Canon HV20 live capture question

[bryant]

I've got a question regarding the Canon HV20:

I know that the HDV spec doesn't allow for anything above 1440x1080 interlaced. However, since the camera itself can still capture at 1920x1080p, is it possible for it to push that full picture through to the computer if I'm streaming the feed from the camera directly via a firewire cable as opposed to recording it?

Like, let's say I have the camera plugged into my laptop via a firewire cable. I'm using a tool to stream from the camcorder directly without recording to tape (any recommendations for tools which can do this? I've heard horror stories from users of Adobe applications, and I've seen HDVsplit work with this camera though I don't remember if it captured live footage at 1920x1080). Since it's skipping the record-to-tape function, will the result be 1920x1080p, or will it be reduced to 1440x1080i?

I need to know because I'm using this camera to record keynotes and interviews at major Microsoft conferences. Deinterlacing the video is a huge hassle.

If the Canon HV20 can't push 1920x1080p through the firewire cable, can anyone tell me if the HG10 can? I don't mind if the camera can only record 1080i but I'd heavily prefer being able to stream 1080p directly from the CMOS when it is hooked up to my laptop.

[racer-x]

If you don't want to de-interlace, shoot in 24p................

To capture full 1920 x 1080 while hooked up to your PC, you can use one of these:
http://www.blackmagic-design.com/products/intensity/

You''l need to hook up through HDMI, not Firewire.

[bryant]

If you don't want to de-interlace, shoot in 24p................

To capture full 1920 x 1080 while hooked up to your PC, you can use one of these:
http://www.blackmagic-design.com/products/intensity/

You''l need to hook up through HDMI, not Firewire.

Does the 24p mode on the HV20 actually write to the minidv tape without interlacing it? Last I checked, the HDV standard can only do 1440x1080i tops. I'm asking this because you then went on to mention the HDMI capture card if I was to capture in full 1080p.

Some clarification with your post would be appreciated.

[racer-x]

24p mode writes to tape in 1440 x 1080p. it is actually 24 progressive frames that are telecined to 29.97 for NTSC playback. You can shoot 24p then use various methods to inverse telecine the footage back to 24p. Do a google search for HV20 24p and you'll get a wealth of information on it.

If you use the Black Magic cards, your footage will probably still be interlaced, but will be the full 1920 x 1080 that you wanted. I don't know because I don't use one, just an educated guess...................

[edDV]

I've got a question regarding the Canon HV20:

I know that the HDV spec doesn't allow for anything above 1440x1080 interlaced. However, since the camera itself can still capture at 1920x1080p, is it possible for it to push that full picture through to the computer if I'm streaming the feed from the camera directly via a firewire cable as opposed to recording it?

Like, let's say I have the camera plugged into my laptop via a firewire cable. I'm using a tool to stream from the camcorder directly without recording to tape (any recommendations for tools which can do this? I've heard horror stories from users of Adobe applications, and I've seen HDVsplit work with this camera though I don't remember if it captured live footage at 1920x1080). Since it's skipping the record-to-tape function, will the result be 1920x1080p, or will it be reduced to 1440x1080i?

I need to know because I'm using this camera to record keynotes and interviews at major Microsoft conferences. Deinterlacing the video is a huge hassle.

If the Canon HV20 can't push 1920x1080p through the firewire cable, can anyone tell me if the HG10 can? I don't mind if the camera can only record 1080i but I'd heavily prefer being able to stream 1080p directly from the CMOS when it is hooked up to my laptop.

It's not clear to me what you are trying to do. Feed a webcast?

The HDMI port outputs 1920x1080i in order to be standard for TV monitoring input. I haven't noticed a live HDV feed in m2t from camera mode. It does feed live in DV format mode.

[racer-x]

Actually, capturing live HDV 1440 x 1080 via firewire is a breeze. I've done it with HDVSplit. I actually did it with 24p as a test because I didn't feel like writing to tape at the time.

I agree that the OP's posts are confusing. I really don't think he knows what he wants.........

Anyway, I looked for a link to a guide for inverse telecine of HV20 24p, but couldn't find it. I'm going to post a zip file of the guide and tools need it for anyone interested. Hope Baldrick doesn't mind. here it is:


hdv24p.zip

[edDV]

Actually, capturing live HDV 1440 x 1080 via firewire is a breeze. I've done it with HDVSplit. I actually did it with 24p as a test because I didn't feel like writing to tape at the time.

I agree that the OP's posts are confusing. I really don't think he knows what he wants.........

Anyway, I looked for a link to a guide for inverse telecine of HV20 24p, but couldn't find it. I'm going to post a zip file of the guide and tools need it for anyone interested. Hope Baldrick doesn't mind. here it is:


hdv24p.zip

Thanks for confirming the m2t live out over IEEE-1394 in HDV camera mode. I just hadn't tried that mode yet.

[bryant]

Actually, capturing live HDV 1440 x 1080 via firewire is a breeze. I've done it with HDVSplit. I actually did it with 24p as a test because I didn't feel like writing to tape at the time.

I agree that the OP's posts are confusing. I really don't think he knows what he wants.........

Anyway, I looked for a link to a guide for inverse telecine of HV20 24p, but couldn't find it. I'm going to post a zip file of the guide and tools need it for anyone interested. Hope Baldrick doesn't mind. here it is:


hdv24p.zip

Thanks for confirming the m2t live out over IEEE-1394 in HDV camera mode. I just hadn't tried that mode yet.

No but see I dont want 1440x1080.

The Canon HV20 actually captures a full 1920x1080 picture. It scales it to fit 1440x1080 and interlaces it to fit the constraints of the HDV format. I want to be able to stream 1920x1080 into my computer without it being squeezed and interlaced.

I don't mind the camcorder being tethered to the laptop. I just want to be able to capture the full 1920x1080p image from the camera. The camera only interlaces and squeezes the image to fit the constraints of the HDV format. The chip itself supports 1920x1080p.

[Soopafresh]

Then it's the black magic card via HDMI, but 1080p isn't supported by it It's 1920x1080i

And your laptop would have to support PCI express

Besides, the disk space and CPU power you'd need to capture uncompressed 1920x1080p would be unlikely in a laptop.

But look here for an example:

http://www.hv20.com/showthread.php?t=3913

[bryant]

Then it's the black magic card via HDMI, but 1080p isn't supported by it It's 1920x1080i

And your laptop would have to support PCI express

Besides, the disk space and CPU power you'd need to capture uncompressed 1920x1080p would be unlikely in a laptop.

Alright, looks like I'm stuck with the Blackmagic card (I'll have to wait til they come out with an expresscard version)

But wait a second, that means I've been misinformed. I've read just about everywhere that the CMOS on the HV20 captures the video at 1920x1080 progressive. It doesn't interlace them until it's headed for the chipset which compresses the footage for the HDV format.

My whole goal is just to avoid deinterlacing and having a full 1080p image.

Clarification would be nice here too. Does the HDMI port on the camcorder output at a full 1920x1080p (not interlaced) when it's a live feed?

[Soopafresh]

I would venture the answer is "no", otherwise Black Magic would be touting it as the miracle of miracles in their tech and marketing literature. While your camera can output 1080p, the black magic card seems to be limited to 1080i.

[bryant]

I would venture the answer is "no", otherwise Black Magic would be touting it as the miracle of miracles in their tech and marketing literature. While your camera can output 1080p, the black magic card seems to be limited to 1080i.

Yep, you're right. The tech specs note it as supporting 1080i on the upper end.

[edDV]

I would venture the answer is "no", otherwise Black Magic would be touting it as the miracle of miracles in their tech and marketing literature. While your camera can output 1080p, the black magic card seems to be limited to 1080i.

Yep, you're right. The tech specs note it as supporting 1080i on the upper end.

You are missing an important point here. Uncompressed 1920x1080i comes over the HDMI port at a rate of ~960 Mb/s (120MB/s) or 421 GB per Hour ! Be careful what you ask for . To capture that you would need a RAID 0 of about 3-4 fast SATA drives or a Core2/quad level CPU chip performing realtime compression to MJPeg or Cineform (digital intermediate format) which could be progressive if you could handle real time deinterlacing (twin CPU?), but you still haven't said what this is for?

As for the HV20, don't expect a pristine 1920x1080p out of it. CMOS sensor chips are round and resolution is always biased against H and to V. 1440x1080 is enough for HDV (or XDCAM/HDCAM for that matter). You need a much higher end 3 sensor camera to get usable 1920x1080p (i.e. enough to see a difference vs 1440x1080).

HDMI is a intended for short range feeds to monitors in a consumer environment. If you want to do broadcasting, you should step up to at least a Canon XH-G1 or XL H1 with serial digital output (SMPTE-292M) which handles 1920x1080i/p over long coax cable runs. This is the standard interface for live pro recording, telco or uplink feeds.

HDV over IEEE-1394 is the prosumer/lowpro equivalent for real time 1440x1080i and can be extended to 100 feet with IEEE-1394 repeater/extenders. 30Mb/s makes a big diffference vs 1485Mb/s max SDI bit rate and can be handled by a laptop PC.

[bryant]

Got it. Thanks for your help.

[2Bdecided]

There are plenty of people using the HV20 for 1080p24 via HDMI - see www.hv20.com

If 24p is wrapped up in 60i, getting 24p back again is not "deinterlacing" - it's removing the pulldown. It's a (near) lossless process.

Real deinterlacing of real interlaced content cannot be done perfectly, and doing it well is challenging. Converting 24p-in-60i back to 24p is trivial in comparison.

If you want a camera that is truly pixel sharp at 1920x1080, you are going to have to spend serious money on the camera and the lens. If you are even thinking about the HV20, then you do not have that budget. The HV20 is remarkable for the price.

Cheers,
David.

[edDV]

There are plenty of people using the HV20 for 1080p24 via HDMI - see www.hv20.com

If 24p is wrapped up in 60i, getting 24p back again is not "deinterlacing" - it's removing the pulldown. It's a (near) lossless process.

Real deinterlacing of real interlaced content cannot be done perfectly, and doing it well is challenging. Converting 24p-in-60i back to 24p is trivial in comparison.

If you want a camera that is truly pixel sharp at 1920x1080, you are going to have to spend serious money on the camera and the lens. If you are even thinking about the HV20, then you do not have that budget. The HV20 is remarkable for the price.

Cheers,
David.

Agreed 24p can be inverse telecined without loss. Conversion of normal 1080i/29.97 to progressive requires deinterlacing.

This can be done from normal HDV tape or from an HDMI capture. The main advantage to using HDMI capture for the HV20 is avoidance of HDV compression, not necessarily getting higher resolution.