Recording uncompressed HD via HDMI to hardrives or SSD media at DVinfo.net

Jon Braeley · February 21st, 2011, 10:11 AM

So the Ninja is shipping this week and I am told that it will work with the HDMI of the GH2 - if it does this is a game changer for uncompressed video? I still doubt this. At $995 its a dream come true and you get an extra LCD monitor!

I know it does not work with my 7D as Canon crippled that, but Atomos sources say it should work on my GH2. Fingers are crossed!

Go here The Ninja - HDMI ProRes HDD or SSD Recorder

Brian Luce · February 21st, 2011, 12:08 PM

Out of the box, hooking a Ninja up to a GH2 won't work well. But a fix is either done or nearly done using the AVsynth software. For some reason Panasonic tossed in a glich, an extra field I think on the hdmi out, but the whiz kids have got it worked out I think. And I don't believe it's uncompressed either, it's still going to be a 4:2:0 signal. But some of the test footage looks absolutely amazing. Like something you'd see from a Genesis.

William Hohauser · February 22nd, 2011, 10:57 AM

Certainly an interesting product. Terrible web site, every other link restarts the annoying video promo.

I am curious about the HDMI out on the GH2. How is there an extra field? Is the progressive output split into fields on the HDMI? And when you say the signal is 4:2:0, would that indicate that the HDMI output is post compression to AVCHD?

Brian Luce · February 22nd, 2011, 02:44 PM

William, I'm a little out my depth understanding/explaining stuff at this level, my posts are never mistaken for Jon Fairhurst's, but I'll try.

The GH2 scans at 23.976P and embeds the picture in a 59.94i stream by adding pulldown. But, when it sends this signal out the HDMI port, it adds in extra fields to make the signal 60i. The duplicate fields create chaos when attempting to remove the 3:2 pulldown. Some of the test footage I've seen from uncompressed hdmi is impressive in its superiority to the AVCHD, it's something most people would pay for. Depending on which codec you capture with, you'll get about 10x the data rate of AVCHD. For example, Blackmagic's MJPEG codec runs around 13.5 MB/sec. UT lossless 4.2.0 runs around 30 MB/sec. AVCHD is normally 3 MB/sec.

Other issues. hdmi doesn't have on audio signal on the GH2. No problem as long as your HDMI device has an audio in. But wait, there's a latency issue which throws the video stream and audio out of sync. Again, the whiz kids (a secretive, subversive and hyper intelligent underground of hyper intelligent programmers and engineers in love with video) have a script that fixes the sync issue.

So how good is the uncompressed HDMI footage Avsynth script? Here's a frame grab shot with 20mm pancake, through a window. See for yourself. Let your eyes judge.
Download Dawn - GH2 HDMI.png from Sendspace.com - send big files the easy way

William Hohauser · February 23rd, 2011, 05:07 PM

The camera is putting out non-drop frame when everything else is expecting drop frame. That is a problem for pull-down removers that are not expecting an extra frame in the interlace signal. Historically, drop frame is essentially a time code issue going way back to when a color subcarrier signal was imposed unto a black and white broadcast signal, not a field or frame issue.

James Campbell · February 23rd, 2011, 06:34 PM

Brian,
you stated above, "The GH2 scans at 23.976P and embeds the picture in a 59.94i stream by adding pulldown."

Are you certain about that? I've recorded 24p footage with the GH2, and when I import it into Vegas and check the frame rate properties, it states "23.976."

This contrasts with the Panasonic TM700 footage I've captured that is definitely known to be 24P in a 60i stream. When I initially copy this footage onto my PC and pull into Vegas, the frame rate shows as 29.970. Then, when I convert the TM700 footage via Cineform and remove the pulldown, it then shows as 23.976, whereas the GH2 footage shows as this without any conversion.

Brian Luce · February 23rd, 2011, 06:45 PM

Quote:

Originally Posted by James Campbell

Brian,
you stated above, "The GH2 scans at 23.976P and embeds the picture in a 59.94i stream by adding pulldown."

Are you certain about that? I've recorded 24p footage with the GH2, and when I import it into Vegas and check the frame rate properties, it states "23.976."

This contrasts with the Panasonic TM700 footage I've captured that is definitely known to be 24P in a 60i stream. When I initially copy this footage onto my PC and pull into Vegas, the frame rate shows as 29.970. Then, when I convert the TM700 footage via Cineform and remove the pulldown, it then shows as 23.976, whereas the GH2 footage shows as this without any conversion.

James, no, not sure at all :/ but I believe the 59.94i stream is what you're getting via an HDMI capture device such as a Black Magic board or a Ninja recorder, not what is recorded on your sd memory card. I think what you're getting on the card is closer to a native 24p.

February 21st, 2011, 10:11 AM	#1
Jon Braeley Major Player Join Date: Oct 2007 Location: Miami, FL Posts: 528	Recording uncompressed HD via HDMI to hardrives or SSD media So the Ninja is shipping this week and I am told that it will work with the HDMI of the GH2 - if it does this is a game changer for uncompressed video? I still doubt this. At $995 its a dream come true and you get an extra LCD monitor! I know it does not work with my 7D as Canon crippled that, but Atomos sources say it should work on my GH2. Fingers are crossed! Go here The Ninja - HDMI ProRes HDD or SSD Recorder

February 21st, 2011, 12:08 PM	#2
Brian Luce Inner Circle Join Date: Jan 2006 Posts: 2,290	Re: Recording uncompressed HD via HDMI to hardrives or SSD media Out of the box, hooking a Ninja up to a GH2 won't work well. But a fix is either done or nearly done using the AVsynth software. For some reason Panasonic tossed in a glich, an extra field I think on the hdmi out, but the whiz kids have got it worked out I think. And I don't believe it's uncompressed either, it's still going to be a 4:2:0 signal. But some of the test footage looks absolutely amazing. Like something you'd see from a Genesis.

February 22nd, 2011, 10:57 AM	#3
William Hohauser Inner Circle Join Date: Dec 2005 Location: New York City Posts: 2,650	Re: Recording uncompressed HD via HDMI to hardrives or SSD media Certainly an interesting product. Terrible web site, every other link restarts the annoying video promo. I am curious about the HDMI out on the GH2. How is there an extra field? Is the progressive output split into fields on the HDMI? And when you say the signal is 4:2:0, would that indicate that the HDMI output is post compression to AVCHD? __________________ William Hohauser - New York City Producer/Edit/Camera/Animation

February 22nd, 2011, 02:44 PM	#4
Brian Luce Inner Circle Join Date: Jan 2006 Posts: 2,290	Re: Recording uncompressed HD via HDMI to hardrives or SSD media William, I'm a little out my depth understanding/explaining stuff at this level, my posts are never mistaken for Jon Fairhurst's, but I'll try. The GH2 scans at 23.976P and embeds the picture in a 59.94i stream by adding pulldown. But, when it sends this signal out the HDMI port, it adds in extra fields to make the signal 60i. The duplicate fields create chaos when attempting to remove the 3:2 pulldown. Some of the test footage I've seen from uncompressed hdmi is impressive in its superiority to the AVCHD, it's something most people would pay for. Depending on which codec you capture with, you'll get about 10x the data rate of AVCHD. For example, Blackmagic's MJPEG codec runs around 13.5 MB/sec. UT lossless 4.2.0 runs around 30 MB/sec. AVCHD is normally 3 MB/sec. Other issues. hdmi doesn't have on audio signal on the GH2. No problem as long as your HDMI device has an audio in. But wait, there's a latency issue which throws the video stream and audio out of sync. Again, the whiz kids (a secretive, subversive and hyper intelligent underground of hyper intelligent programmers and engineers in love with video) have a script that fixes the sync issue. So how good is the uncompressed HDMI footage Avsynth script? Here's a frame grab shot with 20mm pancake, through a window. See for yourself. Let your eyes judge. Download Dawn - GH2 HDMI.png from Sendspace.com - send big files the easy way

February 23rd, 2011, 05:07 PM	#5
William Hohauser Inner Circle Join Date: Dec 2005 Location: New York City Posts: 2,650	Re: Recording uncompressed HD via HDMI to hardrives or SSD media The camera is putting out non-drop frame when everything else is expecting drop frame. That is a problem for pull-down removers that are not expecting an extra frame in the interlace signal. Historically, drop frame is essentially a time code issue going way back to when a color subcarrier signal was imposed unto a black and white broadcast signal, not a field or frame issue. __________________ William Hohauser - New York City Producer/Edit/Camera/Animation

February 23rd, 2011, 06:34 PM	#6
James Campbell Regular Crew Join Date: Apr 2007 Location: Cheshire, CT Posts: 110	Re: Recording uncompressed HD via HDMI to hardrives or SSD media Brian, you stated above, "The GH2 scans at 23.976P and embeds the picture in a 59.94i stream by adding pulldown." Are you certain about that? I've recorded 24p footage with the GH2, and when I import it into Vegas and check the frame rate properties, it states "23.976." This contrasts with the Panasonic TM700 footage I've captured that is definitely known to be 24P in a 60i stream. When I initially copy this footage onto my PC and pull into Vegas, the frame rate shows as 29.970. Then, when I convert the TM700 footage via Cineform and remove the pulldown, it then shows as 23.976, whereas the GH2 footage shows as this without any conversion.