Adobe After Effects - HD Bluescreen Problems

Author

HD Bluescreen Problems

Andy_Davenport@adobeforums.com

2006-12-06, 8:14 pm

Hi Guys.

I've been given one of those ever-lovable jobs from Hell. I've been given some blue (Hah, more like grey!) screen footage provided as HDV, 1440 x 1080 mpeg format and asked to provide the keyed footage with alpha and audio.

I've exported the final movies as Quicktime Animation + from the timeline, but the movie is jerky and the audio is out of phase and intermittent.

Would I be better off exporting to TGA's first? Or perhaps two Photo Jpeg Quicktimes, one of the footage and one of the Alpha?

As you may have guessed, this is my first experience of keying HD, so please be gentle with me :-)

Any help much appreciated.

All the best,

Andy

Rick_Gerard@adobeforums.com

2006-12-06, 8:14 pm

The data rate for your animation codec QT is probably way beyond the capabilities of your system to playback smoothly. Many systems can handle SD Animation Codec movies, I've never run across one that could handle HD size material.

You've picked a great delivery format, but in order to check the playback you may have to render a different version using another codec. My usual procedure is to add an additional output module to the render queue and render a test movie to check playbac
k. The other option is to drop the render in FCP or Premiere and run a preview.

Andy_Davenport@adobeforums.com

2006-12-06, 8:14 pm

Hi Rick, thanks for your reply.

I took the final Quicktimes into Premiere Pro and rendered a video preview but the results were the same - Jerky and/or skipped frames and mis-matched audio. The audio I can deal with (I've just rendered it out as a separate file) but I'm still stuck with
the video problem. It must be happening in AE at render time.

I'm going to try rendering to TGA's and see if I get the same problem.

Thanks again,

Andy

Andy_Davenport@adobeforums.com

2006-12-06, 8:14 pm

Alas, no luck. Same problem with the TGA's :(

If it's any help, my system specs are:

Windows XP Pro
Dual AMD Opteron 246 processors
2GB RAMNVIDIA Quadro FX 540 graphics card

What next I wonder?

Andy

Rick_Gerard@adobeforums.com

2006-12-06, 8:14 pm

First, check your comp settings, frame rates, and all of that in your AE projects.
Second, double the frame rate in the AE comps and step through one field at a time to make sure that fields are separating properly.
Third, step through a render one frame at a time, then by doubling the frame rate, then one field at a time using the double frame rate of a comp technique and look for problems.

If everything looks OK try rendering a 1/2 size test file without fields and check for

There's no reason that AE would be dropping frames on render unless something is wrong with the frame rate or field interpretation settings. HDV is upper field first and could be any number of frame rates. HDV could also be progressive or some odd version
of progressive with 3,2 pulldown.

Andy_Davenport@adobeforums.com

2006-12-06, 8:14 pm

Thank You Rick, I'll try that.

As a test, I exported the MPEG as a Quicktime Photo JPEG, did my keying and masking on that and exported that as Animation + - Worked fine. So, must be the way AE is interpreting the MPEG. I was told it was Progressive but I guess that 'aint so!