[opendtv] Re: Format Independence

MPEG-2 encoders and
 > decoders know how to recognize 24P material that is doubled (3/5) to 
fit in
 > 60P, so very little bandwidth is actually wasted.

Maybe some encoders do, and maybe more today, but when I checked back in 
Detroit 2-3 years ago none of the OTA broadcasters were using any 
telecine flags.  I think here in Jax I may have seen one (NBC?) that 
does but I have not systematically checked them all recently.

- Tom


Stephen W. Long wrote:
> Dan,
> 
> An engineer at a major network explained it to me this way - do you want to
> risk losing eyeballs (customer changes the channel) every time you go to a
> commercial or come back to a program?  Since there is no guarantee
> whatsoever that consumer equipment will properly behave when different
> formats are received (my CRT HDTV goes blank every time the format changes
> BTW), the broadcaster can only control his end - thus upconvert or cross
> convert every signal to your base "master" signal.  MPEG-2 encoders and
> decoders know how to recognize 24P material that is doubled (3/5) to fit in
> 60P, so very little bandwidth is actually wasted.
> 
> Stephen
> 
> At 06:21 PM 11/9/2005 -0800, you wrote:
> 
>>In response to some of the discussion about formats, I have another
>>question.  Why do broadcasters put out a fixed format stream when at the
>>production level the format is different.  For instance, if Fox puts out
>>720@60P all the time, and the original production content is 24P, why would
>>the broadcaster waste bits by sending several frames of the same picture?
>>Why not send out 720@24P and use the 19Mb/s to send a less compressed
>>picture?  Or how about when a 640x480@30i is sent out 720@60P?  Is it a
>>problem with the master control switcher only switching one format, or the
>>server, or is the problem on the customer's end (like the monitor won't
>>naturally switch)?  Is it simply easier that way?  I would think a lot of
>>efficiency could be gained there.
>>
>>Dan
>>
>>
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