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View Full Version : AVI Files Answer to Haze or Low Contrast Problem with SP?


Don R.
22nd November 2003, 15:02
I have been testing Cinema Craft SP for months and was about to quit using it and Basic because the MPEG-2 encoded results showed a haze, fog, or lack of contrast. I was using the Quick Time Reference method of exporting the timeline. I had just about decided it would be necessary to go the hardware encoder route because the Optibase and Sonic reps took my 3 1/2 minute test tape and returned beautiful MPEG-2 files that, in turn, made beautiful DVD's while the Quick Time Reference file/CCE-SP encoded MPEG-2 files made very "flat and hazy" DVD's.

Yesterday, out of exasperation and after talking to the Cinema Craft reps about the problem, I exported a 48 seconds (2GB) of the same test sequence using AVI "Full Uncompressed" setting in Avid Xpress Pro export window. Then, I used SP to encode that clip.

Bingo! In the poster part of the sequence, the colors almost jumped off the TV screen rather than just lying there, and the blacks on the French Angel fish were black not a dark gray, the dark shadows in the crevices were dark rather than smokey, and the blue ocean water was blue not a hazy gray.

To me at least, it is becoming clear that the true key to MPEG-2 quality lies with the underlying files, and the problem is the Quick Time Reference files rather than CCE-SP. As someone here has noted in this forum in regard to encoded MPEG-2 files, "garbage in, garbage out."

So now, the quest will be for me to figure out how to break up 830 minutes of sequence into at least 1120 or so AVI files that in my editing system can be no larger than 2 GB. I am getting about 48 seconds of video on one 2 GB file. My math may be faulty but 48 seconds of video requires 1,952,136 KB or just under 2GB, 83 minutes X 60 = 4980 seconds. 4980 seconds divided by 48 seconds = 104 2 GB AVI files. Again, if my math is correct, 104 2GB AVI uncompressed files will be necessary to handle the load.

It does appear I will have to dig into Avisynth to see if that utility will provide a means of dividing the 83 minute sequence into 104 2GB AVI files so the sequence may be exported from Xpress Pro into a file or files that Cinema Craft SP is able to encode.

If anyone has a recommendation how to split up the sequence into about 104 files, I would very much appreciate it.

DDogg
22nd November 2003, 15:43
So now, the quest will be for me to figure out how to break up 830 minutes of sequence into at least 1120 or so AVI files that in my editing system can be no larger than 2 GB. I am getting about 48 seconds of video on one 2 GB file. My math may be faulty but 48 seconds of video requires 1,952,136 KB or just under 2GB, 83 minutes X 60 = 4980 seconds. 4980 seconds divided by 48 seconds = 104 2 GB AVI files. Again, if my math is correct, 104 2GB AVI uncompressed files will be necessary to handle the load.
Yes, this is what we thought might be the problem. Maybe you see where I was trying to go now in my unclear way :). As far as the segment of your post quoted above, please try to clarify. Maybe I have not had enough coffee this morning, but I can't seem to understand whether you are talking in or out. Just treat us all as ignorant of Avid Express and take us through the process (detailed) of: original source (what, where, how) > Avid (you doing any color correction in Avid?) > Out to CCE (what, where, how), or out to other format (what, where how). Then I think people can better help.

It may be that frame-serving raw source to Avid, using MakeAVIS, might help. I don't know of a frame-serving out tool for Avid Express. Also, instead of raw, try exporting to Huffy which will compress more than raw but will be non lossy. Huffy is the preferred intermediate format most used for this type of thing.

Another thing, Avid users tend to stay with Avid because of the learning time invested. It may be that another NLE can read your finished edit and that NLE can be used as the delivery vehicle to CCE via Satish's frameserver plugin ( www.debugmode.com ) Do you have a demo of Premier or Vegas? A full demo of Vegas is easily available at Sony/Sonic Foundry.

Btw, it is very easy to load multiple avi segment into VirtualDub and then frameserve the resulting signpost.VDR to most applications via Makeavis/Avisynth, Link2 ( www.videotools.net ), or VFAPI (rgb24 only).

In the end I think it may well be just a simple color conversion problem, or as sh0dan suggested a luma problem - both of which could be fixed within Avisynth probably.

I wish we did have a small segment of the QT ref file. I assume the colors in it look fine?