[opendtv] Re: Production Codecs
- From: Craig Birkmaier <craig@xxxxxxxxx>
- To: opendtv@xxxxxxxxxxxxx
- Date: Wed, 16 Jul 2008 12:44:12 -0400
At 8:20 AM -0700 7/16/08, dan.grimes@xxxxxxxx wrote:
When you say drop four frames, I assume you are talking about the
time code and not actually dropping essence. Am I correct?
I wish we didn't have to deal with 29.97 and just use 30. Is there
any reason to work in a non-integer format as of Feb. 19, 2009? I
suppose I'll still need to work with other systems out there.
Yes. Everything will still be 59.94 in the U.S.
Not to worry though. As i mentioned earlier, virtually ALL
acquisition gear supports 59.94 - some offer the ability to shoot at
60 as well.
Are there any insights you can provide to helping get MXF to work
properly? Or is this something that must be worked out at the
manufacturer's level? We are hiring a broadcast systems integrator
so hopefully they will know and be able to work out the issues. But
I would also like to know for servicing issues.
Discuss this situation with the vendors supplying your acquisition
gear and the vendors supplying your production gear (i.e. Avid). They
will tell you what features are supported, and what they expect to
support in the future. And remember, TV happened for many decades
before anyone knew what metadata was. Think of it as "potentially"
useful information.; it really depends on what you are doing with it.
It seems like there would be problems treating a frame as a field.
But I imagine the software deals with each differently so long as
it knows which one it is working with. Mixing a progressive frame
and an interlace field would need some special processing, although
I am not sure what that process would be. Perhaps deinterlacing
with predictive fields plus down scaling to match the 720 raster?
The field frame analogy is a bit misleading. Let's assume you are
going to acquire video using 720@xxxxxxx That's all you need to worry
about as long as this is your mastering format. IF you need to
convert to 1080@xxxxxx, the conversion device (or software) will take
a 1280 x 720 FRAME and create a 1920 x 540 field using simple scaling
techniques. Going the other way is more problematic as you must
de-interlace to create the progressive frame.
The 3:2 pulldown issue is also irrelevant if you are mastering in
720@xxxxxxx it only comes into play if you are shooting at 23.96p or
transferring 24P film to video. OR if you are trying to emulate the
film look in software by manipulating 720@xxxxx source to look like
film (i.e. removing information and simulating film flicker).
Regards
Craig
----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:
- Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
unsubscribe in the subject line.
Other related posts:
