A1 HDV vs. Uncompressed Color

[Elton]

Just out of curiosity I shot a simple test today comparing the color sampling of the A1's HDV codec vs. the uncompressed 4:2:2 output of the live component HD analog signal.

I captured the analog signal through the camera's D4 component cable connected to the KonaLH card/FCP combo, and recorded with the Sheer lossless HD codec. I rolled HDV simultaneously.

Will have grabs soon

[Drew Ott]

Looking forward to those.

[mcgeedigital]

tag for results

[Jay Rodriguez]

nice! Can't wait to see them.

[Elton]

The short of it: differences are much more subtle than you would think.

Edit: DNS issues with the server. Should be up sometime today or tomorrow.

[Jay Stebbins]

Now this I am very excited to see. By chance would you have some footage that is very detailed, complex and contains a lot of movement?


Barlow Rocks...

[Elton]

These are uncorrected btw. There is a slight brightness difference between the two for some reason. You'll especially notice it in the reds.

HDV:

http://www.dvxuser6.com/uploaded/10380/1168189847.jpg

Analog Uncompressed:

http://www.dvxuser6.com/uploaded/10380/1168189950.jpg

[Jay Rodriguez]

that's interseting, seems like the analog uncompressed it richer in color

[Elton]

Richer...yes, but *that much* at least perceptually? To me, it's close enough to not care too much unless you really really need the extra acquisition color.

[Digihead]

Hi Elton,
Are you sure that the anolog component out is pre hdv compression? I was told by a local dealer that it was after hdv compression, and thus if I wanted uncompressed I would have to move up to the XH G1. Is the sales guy trying to sell me up ( or mis-informed), or is he correct--no UC out?

If the component out is pre hdv compression (I thought that the anolog out would be pre compression to avoid latency), then the A1 is the cam for me. I can live with the DA-AD loss if I need UC 4:2:2. I just can't justify the extra cost of the G1 for a feature I expect to rarely use.

[MovieSwede]

The analog seems more noisy.


It would be intresting to se a greenscreen comparision and something like waterfall/stormy weather footage.

This footage is not pushing the HDV codec to its limits.

[Juan Diaz]

It's interesting. This test reminds me of another comparing an F900's native HDCAM recording vs its HDSDI output.

http://hd24.com/hdsdi_vs_hdcam.htm

The HDCAM footage seemed to hold more contrast and I actually preferred it over the HDSDI. But HDCAM is by all technical regards a more robust codec than HDV, so it's nice to see how well Canon's HDV implementation holds up when compared to its component out.

[Elton]

Hi Elton,
Are you sure that the anolog component out is pre hdv compression?

Yes, it's pre-compression and full raster 4:2:2.

[Elton]

The analog seems more noisy.

Perceptually, I think it may actually be more noisy. I've noticed how the HDV compression in a very subtle way softens noisy areas, whereas the uncompressed shows the fine grit in all its glory/infamy. I personally like the pattern of the uncompressed noise better, but they're both acceptable to me.


This footage is not pushing the HDV codec to its limits.

That wasn't my intent; I was simply trying to compare color, not possible motion artifacts.

[Duff]

Links aren't working for me -- 404 error.

[Kholi]

Yes, it's pre-compression and full raster 4:2:2.

Trying to get this answer in the HVX forum: Component out is pre compression for A1. Is it also for the HVX? And by full raster you mean it's not 1440, it's 1920? Same would be for the HVX?

[Elton]

A1 live camera signal through component is pre-compression, (i.e. non VTR mode) and I believe the HVX is too.

Also, I believe both A1 and HVX would be full raster as far as displaying 1920 x 1080. The A1's live output is the full horizontally pixel-shifted pre-HDV 1920 output. Additionally, I believe the HVX's live 1080 signal bypasses DVCPRO HD, but uses pixel shift in both axes to fill in the frame.

[Kholi]

Thanks Elton--.

Do you know of any cables, converters that will convert the RGB ends into HDMI?

[Duct Tape Films]

Would seem that there would have to be a way to take the component out and send it direct to something like a Firestore like device, recording the uncompressed 1920x1080 signal, and if there isn't, there perhaps should be for all you DIYer's looking to make a chunk 'o' change selling something gear related.

[Elton]

Thanks Elton--.

Do you know of any cables, converters that will convert the RGB ends into HDMI?

You'd have to go to SDI and then HDMI, I believe.

http://www.aja.com/html/products_converters_HD10A.html
http://www.aja.com/html/products_converters_HI5.html

[xray]

I think its D3 signal. That is 1440x1080 on the analog component, the XHG1 gives 1920x1080 on the SDI.

[conrad_johnson]

The difference in color contrast is alot better in the uncompressed one. Notice the difference between the girls face and the red toy, both have alot of red, but the uncompressed one looks like two totally different shades of red. Whereas the hdv one looks kinda mushy-the-same.

[Elton]

I've noticed improved reproduction of reds, in particular, with uncompressed capture. What you're looking at is a photojpeg 4:2:2 frame from a Sheer capture. (uncompressed quality)

But I gotta say, the HDV is pretty dang good for how compressed it actually is.

[Artscroll]

Thanks for posting this. I do agree, the HDV is really good. I do think the analog is a little more film-like but only because I'm analyzing a still frame. If I wasn't watching a "still", the differences would be unnoticeable.

[Elton]

You can definitely push the analog footage in CC to more extremes, but again, the HDV holds up well enough for most situations that extreme adjustments aren't necessary.

I will say that you can certainly pull a clean greenscreen key more easily with a true 4:2:2 capture, but even the HDV keys well if you know what you're doing.

[xray]

So.. its not 1440, its pixelshifted and then send -streched- to the analog component as 1920? It probably is.
I need to take another look at it. Page 93 user manual shows a picture with the component terminal out that is D3 1440x1080. Letterbox off. An anamorphic signal that is streched by the device, that was my thirst reaction.

Canon uses a 1440 *1080i CCD clocked at 48hz scanned progressive = 1440*540 24hz. Pixelshifted up to 1920*810 processed 1920*1080 (and stored 1440*1080)

I watched today a live shoot over the analog component on a 42" Tatung LCD tv and it looks stunning. But its 1080i, its not progressive on the analog component. That is what the monitor says. So it looks like the component out digital or analog is 1080i and yes it passed the pixelshift processing. It is streched by the device, the cam itself.

[xray]

Tatung specs: http://avforum.no/avnytt/showproduct.php/product/1322

[agwah]

These are uncorrected btw. There is a slight brightness difference between the two for some reason. You'll especially notice it in the reds.

HDV:

http://www.dvxuser6.com/uploaded/10380/1168189847.jpg

Analog Uncompressed:

http://www.dvxuser6.com/uploaded/10380/1168189950.jpg

elton my man,

you are the only one that has done the magic test of component and hdv comparison with the canon A1 that i can find on this forum

but the links to the images are old and broken

i am thinking of going down that route on a project that will take place all indoors and mostly with a lot of dark areas that will need to be pushed in post color

please if the images are still around, could you post them again

thanks

[Loren Simons]

i too am intrested

[agwah]

here is another trooper doing it with a macbook pro and the hv20,

http://www.dvinfo.net//conf/showthread.php?t=126256
http://panocamera.com/blog/?p=4

of course with the A1 component out one would need to use the intensity pro
but as he says here, it is only 350 bucks for the entire capture solution
who will be the first to try with a Canon A1

[Elton]

That solution is very interesting. You could probably record Blackmagic MJPEG 422 or DVCPRO HD to an internal 7200 rpm laptop drive. Much cheaper than a AJA I/O HD and less burdensome...although I would definitely find a way to house the card externally.

[Drcoffee]

Are the comparison videos anywhere? link is broken...?

[Elton]

They were just frame grabs, and I don't have them on my system anymore. I do have XL-H1 SDI 4:2:2 clips on my iDisk which is basically the same imaging as the A1's analog uncompressed.