[opendtv] Re: Half Truths - Was More 1080p@60

Craig Birkmaier wrote:

> As the frame rate increases, you can use shorted shutter periods,
> and thus acquire sharper images.

There is no reason why shortened shutter speeds can't also be used at
lower frame rates, however. If you want to capture fast motion with
little blur, you can use 1/1000 shutter speed, then transmit at 60 fps.
In principle.

I would expect this to create the need for higher frequency MPEG
components, which should work against a high compression ratio, but
maybe the improvement in speed vector computations more than compensates
for this.

> This helps the motion compensated prediction component of the MPEG
> algorithms, as it is easier to find block matches in the areas of
> motion. But FAR MORE IMPORTANT, you can increase the number of
> B-frames in a GOP, and B-frames are where the MPEG algorithms gain
> most of their coding efficiency.

I can see that if the frame rate becomes higher than you really need for
judder elimination, then the MPEG algorithm will compress the extra
frames very efficiently, because these extra frames could consist mostly
of B frames. But this is not the same as saying that the bit rate is not
increased at the higher frame rates.

Would be nice to have actual test results.

Whatever the answer is, you are (were) still developing a new standard
that has to coexist with existing standards. I know you have a problem
with this concept.

Bert
 
 
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