HV20 HDMI vs HDV picture quality at DVinfo.net

Mario Jesmanowicz · May 3rd, 2007, 02:30 PM

Sine the only true way to get 1920x1080 and then 24Progressive is through HDMI since HDV no matter what, it is 1440x1080 60i. did someone try to compare a captured m2t played back on TV and directly from Camera through HDMI to see if there are real noticable difference or is it almost the same?

I just wonder if we lose a lot because of HDV downgrade

Pieter Jongerius · May 3rd, 2007, 03:29 PM

I second that question! Of course, theoretically HDMI should have more horizontal luma resolution, more chroma resolution, no compression artifacts (?) but has anyone actually put this to the test? And--while we're at it, some samples anyone? ;)

Bruce Allen · May 3rd, 2007, 03:41 PM

I think this is contingent on Blackmagic's Intensity HDMI input card working with the HV20. At the moment it doesn't

Bruce Allen
www.boacinema.com

Dave Halliday · May 3rd, 2007, 05:52 PM

Bruce, any clue as to why not? Are all flavors of HDMI not the same?

Daymon Hoffman · May 3rd, 2007, 06:03 PM

I can't be specific but as i understand it there's just some kindof issue that stops it recording full resolution. There is a thread that has a bit more info but i can't remember the tittle at this moment. But worth looking for guys.

Bruce Allen · May 3rd, 2007, 06:31 PM

Yes. I was on that thread too. I am pretty sure that the signal chain is:
capture at 1920x1080 -> do white balance, processing, etc -> 1440x1080 -> scale back up to 1920x1080 for HDMI output.

So, you wouldn't get true 1920 resolution. Not that that's much of an issue.

I offered to send beers or chocolates to the first person to post comparison HDMI vs HDV tests.

Bruce Allen
www.boacinema.com

Ian G. Thompson · May 3rd, 2007, 07:53 PM

Quote:

Originally Posted by Bruce Allen

Yes. I was on that thread too. I am pretty sure that the signal chain is:
capture at 1920x1080 -> do white balance, processing, etc -> 1440x1080 -> scale back up to 1920x1080 for HDMI output.

So, you wouldn't get true 1920 resolution. Not that that's much of an issue.

I offered to send beers or chocolates to the first person to post comparison HDMI vs HDV tests.

Bruce Allen
www.boacinema.com

What you describe here i believe is just coming off an already recoded tape. The question still remains about live capture.

Heinz Bihlmeir · May 3rd, 2007, 07:57 PM

I recently compared HDMI and HDV captured scenes. There is not much difference visible in static scenes, except the slightly increased vertical color resolution (422 instead of 420).

See http://www.dvinfo.net/conf/showpost....4&postcount=15

Heinz Bihlmeir

Bruce Allen · May 4th, 2007, 11:39 AM

Thanks! Heinz, send me your address and beer / chocolate choice!

Although you're in Germany so I'm sure you have access to much better stuff than me here in LA...

You used a HDMI -> HD-SDI converter and then captured from the HD-SDI, right?

Bruce Allen
www.boacinema.com

Bruce Allen · May 4th, 2007, 12:06 PM

Actually, Heinz, would mind posting some actual frames please? You posted some kind of cool waveform monitor graph thing but I couldn't find the real frames.

Thanks

Bruce

Solomon Chase · May 4th, 2007, 01:37 PM

Yeah, if you could post actual HDMI / HDV frames (preferably very colorful scenes so that 4:2:0 / 4:2:2 diference is noticable.

Or heck, maybe a green screen grab ;)

Ian G. Thompson · May 4th, 2007, 01:51 PM

Quote:

Originally Posted by Heinz Bihlmeir

I recently compared HDMI and HDV captured scenes. There is not much difference visible in static scenes, except the slightly increased vertical color resolution (422 instead of 420).

See http://www.dvinfo.net/conf/showpost....4&postcount=15

Heinz Bihlmeir

I didn't think there would be with static shots...only slightly.

I'm sure though there would be a great deal of difference with motion in the video as opposed to the HDV compression.

Heinz Bihlmeir · May 5th, 2007, 09:03 AM

Quote:

Originally Posted by Bruce Allen

Thanks! Heinz, send me your address and beer / chocolate choice!

Although you're in Germany so I'm sure you have access to much better stuff than me here in LA...

You used a HDMI -> HD-SDI converter and then captured from the HD-SDI, right?

Bruce Allen
www.boacinema.com

Thanks, but I don't need any beer. With the "Hofbräuhaus" only a half mile away here in Munich, I think we have enough supply.

Yes, I use a HDMI to SDI converter.

I have uploaded frame captures (psd format) from a still scene and a pan sequence (car in motion). Images are captured from the HDMI port to compare realtime and tape playback (HDV) quality. The supplied vector diagram shows that the vertical color resolution is reduced in the HDV capture.

Link: http://rapidshare.com/files/29630650/HV20HDMI.zip.html

Heinz Bihlmeir

John Robertson · June 9th, 2007, 02:44 PM

I tested a bit in photoshop with your stills, and the only difference would be when you do some heavy color correction you see minimal jpg like artifacts in the hdv version

Ray Bell · June 9th, 2007, 04:45 PM

I don't think most folks will see the difference of non comressed HDMI VS compressed Tape output... its just not a lot of difference...

There will be the discussion that you wont see compression artifacts and that argument is true.. but for most of us, it just does not matter that much.

but if your using a real time capture device like the black magic board then you have the capability to use a reference display, a monitor or projector,
that will allow you to view the footage on the display, non compressed, and be able to dial in your shot... adjust your settings, adjust your lighting, adjust your angles.. and so forth...
not just based on the cam' small display...
your not going to see zebra on a non compressed HDMI capture... you better be hooked up to the monitor display and using it as the gospel... cause thats all your going to get... so use it, thats what its for :-)

Then when you hit the record button you know exactly what you are capturing, real time... no farting around about did I get that shot the way I wanted it or do I need to shoot it over and over again with different settings.

you look at the reference display and you dial in the shot and when its what you want you hit the record button....

May 3rd, 2007, 02:30 PM	#1
Mario Jesmanowicz Regular Crew Join Date: Apr 2007 Location: Milwaukee WI USA Posts: 55	HV20 HDMI vs HDV picture quality Sine the only true way to get 1920x1080 and then 24Progressive is through HDMI since HDV no matter what, it is 1440x1080 60i. did someone try to compare a captured m2t played back on TV and directly from Camera through HDMI to see if there are real noticable difference or is it almost the same? I just wonder if we lose a lot because of HDV downgrade

May 3rd, 2007, 06:03 PM	#5
Daymon Hoffman Major Player Join Date: Jun 2003 Location: Australia Posts: 267	I can't be specific but as i understand it there's just some kindof issue that stops it recording full resolution. There is a thread that has a bit more info but i can't remember the tittle at this moment. But worth looking for guys. __________________ Welcome... to the real world!

May 3rd, 2007, 03:29 PM	#2
Pieter Jongerius Regular Crew Join Date: Jan 2007 Location: Netherlands Posts: 101	I second that question! Of course, theoretically HDMI should have more horizontal luma resolution, more chroma resolution, no compression artifacts (?) but has anyone actually put this to the test? And--while we're at it, some samples anyone? ;)

May 3rd, 2007, 03:41 PM	#3
Bruce Allen Regular Crew Join Date: Jun 2006 Location: Los Angeles, CA Posts: 43	I think this is contingent on Blackmagic's Intensity HDMI input card working with the HV20. At the moment it doesn't Bruce Allen www.boacinema.com

May 3rd, 2007, 05:52 PM	#4
Dave Halliday Regular Crew Join Date: Feb 2006 Location: Washington DC Posts: 116	Bruce, any clue as to why not? Are all flavors of HDMI not the same?

May 3rd, 2007, 06:31 PM	#6
Bruce Allen Regular Crew Join Date: Jun 2006 Location: Los Angeles, CA Posts: 43	Yes. I was on that thread too. I am pretty sure that the signal chain is: capture at 1920x1080 -> do white balance, processing, etc -> 1440x1080 -> scale back up to 1920x1080 for HDMI output. So, you wouldn't get true 1920 resolution. Not that that's much of an issue. I offered to send beers or chocolates to the first person to post comparison HDMI vs HDV tests. Bruce Allen www.boacinema.com

May 3rd, 2007, 07:57 PM	#8
Heinz Bihlmeir Regular Crew Join Date: Oct 2004 Location: Munich Germany Posts: 34	I recently compared HDMI and HDV captured scenes. There is not much difference visible in static scenes, except the slightly increased vertical color resolution (422 instead of 420). See http://www.dvinfo.net/conf/showpost....4&postcount=15 Heinz Bihlmeir

May 4th, 2007, 11:39 AM	#9
Bruce Allen Regular Crew Join Date: Jun 2006 Location: Los Angeles, CA Posts: 43	Thanks! Heinz, send me your address and beer / chocolate choice! Although you're in Germany so I'm sure you have access to much better stuff than me here in LA... You used a HDMI -> HD-SDI converter and then captured from the HD-SDI, right? Bruce Allen www.boacinema.com

May 4th, 2007, 12:06 PM	#10
Bruce Allen Regular Crew Join Date: Jun 2006 Location: Los Angeles, CA Posts: 43	Actually, Heinz, would mind posting some actual frames please? You posted some kind of cool waveform monitor graph thing but I couldn't find the real frames. Thanks Bruce

May 4th, 2007, 01:37 PM	#11
Solomon Chase Regular Crew Join Date: Jan 2006 Location: Woodstock, Georgia Posts: 154	Yeah, if you could post actual HDMI / HDV frames (preferably very colorful scenes so that 4:2:0 / 4:2:2 diference is noticable. Or heck, maybe a green screen grab ;)

June 9th, 2007, 02:44 PM	#14
John Robertson New Boot Join Date: Dec 2006 Location: Mar del plata Bs As Argentina Posts: 5	I tested a bit in photoshop with your stills, and the only difference would be when you do some heavy color correction you see minimal jpg like artifacts in the hdv version

June 9th, 2007, 04:45 PM	#15
Ray Bell Regular Crew Join Date: Nov 2004 Posts: 1,414	I don't think most folks will see the difference of non comressed HDMI VS compressed Tape output... its just not a lot of difference... There will be the discussion that you wont see compression artifacts and that argument is true.. but for most of us, it just does not matter that much. but if your using a real time capture device like the black magic board then you have the capability to use a reference display, a monitor or projector, that will allow you to view the footage on the display, non compressed, and be able to dial in your shot... adjust your settings, adjust your lighting, adjust your angles.. and so forth... not just based on the cam' small display... your not going to see zebra on a non compressed HDMI capture... you better be hooked up to the monitor display and using it as the gospel... cause thats all your going to get... so use it, thats what its for :-) Then when you hit the record button you know exactly what you are capturing, real time... no farting around about did I get that shot the way I wanted it or do I need to shoot it over and over again with different settings. you look at the reference display and you dial in the shot and when its what you want you hit the record button....