AJA IO compression - why no results?

Posted by jeffleiser 
AJA IO compression - why no results?
November 16, 2007 11:42PM
Our feature "Imagination" secured international distribution through Vanguard International Cinema recently.

We are very excited about this. We brought our hard drive with the Final Cut sequence to them, and they exported from Final Cut, using Quicktime Conversion, to the AJA IO software, which is similar to Apple's compressor (Although it's assisted by a hardware box) to ake the master MPEG-2.

The problem is that the results don't seem significantly better than Apple's Compressor (version 2). This was a shock, as I would've come to expect something better from a dedicated company like AJA (even though they don't have the best model).

My question is, I asked him what settings he used, and he said 4-7 kbps(?). I asked him to set the lowest at 5, highest at 7. But WOULD this make a difference in quality? I set Compressor 2 to 6.1, with a 7.2 highest, as recommended here.

Also there is the problem in REDS. I might've read something of this awhile back, but is the color RED affect most by compression? (We shot "Imagination" on 16mm film) In a scene, a woman wears a red sweater. The sweater is obviously compressed, but the rest of the frame seems less or unaffected.

And lastly - would it be worthwhile on selected scenes that suffer from compression to add a bunch of compression markers? I never seem to notice the difference on the other scenes I put compression markers on. And I don't know if AJA software carries these over from Final Cut, or if they use their own system.

It's just really a pain to have something shot on beautiful 16mm, then look like this. I wonder if hollywood studios use million-dollar machines to compress film to DVD...

- jeff

p.s. They are not making dual-layer disks, only 4.7 gig limit disks.

Using
Final Cut 5.0
Compressor 2
Re: AJA IO compression - why no results?
November 17, 2007 07:07PM
Or maybe could someone just please explain to me about REDS in compression? I couldn't find anything on it.

Why does the color RED compress so badly and how can we work around this?
Re: AJA IO compression - why no results?
November 17, 2007 07:40PM
Reds are notoriously bad once they get too saturated. If you have a look in your scopes, you will see that the legal level that the reds can go to - it's the small box with an 'r' in it at the top left of your vectorscope. If you have lines that go outside this area, you are in illegal saturation territory.

If you lower the saturation of the reds, the compression problems will improve. This is a big part of the colourists job - keeping everything legal.

And yes, Hollywood studios do use million dollar machines to do compression. And experts who look at every single frame. But even they have to obey the boundaries of what is possible with broadcast.

Re: AJA IO compression - why no results?
November 17, 2007 10:01PM
Thanks! I appreciate it. Will adjust oversaturated reds accordingly.

I hope others know about this..
Re: AJA IO compression - why no results?
November 17, 2007 10:26PM
Anyone who has to deliver for broadcast should know. It's been this way pretty much since the dawn of time. smiling smiley Try exporting the oversaturated red stuff to VHS and see what happens.

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