Some questions regarding XHA1 / HDV

[Steve Lewis]

Hello,
I have been shooting with the A1 for a while now, mostly 60i footage with a little 24F sprinkled in for good measure. My first question is, have you guys been able to color-grade your 60i footage from the A1 with relative success? I ask because whenever I grade(MBL), the end result looks okay in my NLE, however the picture simply falls apart (crazy banding, blurriness, muted colors, noise, pixelation) when I export out to MP4 compressed for the web (720, 5Mbps). My second question is: what is the definitive method for de-interlacing HDV footage? Should I apply deinterlace filters onto each clip in the timeline or leave the timeline alone and check-off "De-Interlace" in the export window? (FCP)

Thanks,
-Steve

[Chris Hurd]

Steve, this isn't answering any of your questions, but I wanted to point out that the issues you're stating here are the primary reason why folks use XH Custom Presets in order to grade in-camera.

[Joel Peregrine]

Hi Steve,

Do you have an example online of the artifacts you're seeing? Footage from the A1 should hold up to color balancing and output beautifully pretty much regardless of how you process it. I have a feeling it has something to do with you export settings.

[Steve Lewis]

Originally Posted by Joel Peregrine

Hi Steve,

Do you have an example online of the artifacts you're seeing?

Chase Palm Park on Vimeo

the last shot fade out especially (about 1:20) (on video below)

The Crossing - Trailer #2 on Vimeo

[Bill Pryor]

That 5bps is a really low data rate, isn't it?

[Steve Lewis]

Originally Posted by Bill Pryor

That 5bps is a really low data rate, isn't it?

5Mbps = 5000kbps (i think), which is pretty good for 720 HD.

[Bill Pryor]

Oops, overlooked the M.

[Michael Wisniewski]

Have you tried grading with ProRes422 or uncompressed to see if that's any better?

[Bill Grant]

Hey Steve,
I'm really am moron, and I understand that, but I saw no problems with either clip. The park thing had a good bit of shakiness but no image issues that I could see. The only thing with the trailer was that the night shots were a bit grainy but holy smokes your on the ocean AT NIGHT. This stuff looks fine to me. But, as aformentioned, I am a moron.
Bil

[Dave Stern]

Steve do you have any jpegs that would show the before (from your NLE) and after (first from the mpeg4 then from the flash?) is vimeo taking your mpeg4 and converting it to flash? I see (possibly) the color issue, but not any other artifacts (although as pointed out already the night shot on the water). if you burn to a DVD do you see the problems still? would be worth posting in the FCP or web delivery forum to see how to best tune your output from FCP for web delivery (my 1 cent).

[Joel Peregrine]

Hi Steve,

I've got a screen capture here that I think shows what you're seeing. The fade that is right after it also shows some compression artifacts

http://www.dvinfo.net/conf/attachmen...1&d=1226460882

What codec are you using for your renders? The contour lines in the sky are a sign of a codec that is taxed and isn't up to what its being asked to do. I'm no expert in this area, but if you're really looking to improve the image quality it seems like you may want to bump all your source footage up to ProRes HQ and render in 10 bit. The noise and blockiness at the fade are compression artifacts that are also caused by a codec being asked to do too much within the restraints of the data rate it has to work with, i.e. DV/HDV, ProRes, ProRes HQ, Uncompressed etc. (I'm assuming you're on FCP.)

[Steve Lewis]

Originally Posted by Joel Peregrine

What codec are you using for your renders? The contour lines in the sky are a sign of a codec that is taxed and isn't up to what its being asked to do. I'm no expert in this area, but if you're really looking to improve the image quality it seems like you may want to bump all your source footage up to ProRes HQ and render in 10 bit.

For this, I have just simply been capturing as 1080i60 HDV and rendering in HDV as well. I have found that simply just changing the Render codec in the Sequence options menu will mess up my timelines after I try to export: (My "Green Render Status Bar" will revert to being RED: unrendered) That is neither here nor there, because I guess I could just convert ALL the footage to ProRes422... I don't how I would do that at this late stage in the editing process (I already have about 30% of a 35 minute film edited in HDV).

Originally Posted by Bill Grant

I'm really am moron, and I understand that, but I saw no problems with either clip.

If anyone here is a moron, it is me. :)

[Steve Lewis]

Originally Posted by Dave Stern

Steve do you have any jpegs that would show the before (from your NLE) and after (first from the mpeg4 then from the flash?) is vimeo taking your mpeg4 and converting it to flash?

I will try to upload some jpegs tomorrow. Yes, vimeo converts to FLASH...
-Steve

[Steve Lewis]

Here are a couple of pics comparing the MP4 to the Vimeo Flash encode... clearly, the flash is adding some additional artifacts (the stills aren't from the exact same frame, but close) In a couple days (when I get back to my editing workstation) I'll upload a pristine JPEG from FCP...