Re: [libdv-dev] Quality

[Charles 'B. K. <kr...@ac...>]

Arne Schirmacher <ar...@sc...> writes:

> Applications using libdv, such as my Kino program, would need both
> speed and best quality (not necessarily at the same time though).

Agreed.

> During editing the user want speed and during conversion to other
> formats the user wants best quality images as an input, so this
> should be user defineable in my opinion (a parameter).

Agreed.

> I'm not even close to conversion things with Kino right now, so
> currently I'm most interested in speed. I tried the quality
> parameter in playdv.c a while ago but it did not improve the speed
> more than some ten percent (I was expecting powers of ten :-).

I just did a quick check and I see much more than 10% speedups.
For setting DV_QUALITY_AC_1, I see about %30 reduction.  Setting
DV_QUALITY_DC gives about %50.

> What about half or quarter size image areas? The 720 * 576 player
> area in Kino is way too big anyway. Many Windows programs use only
> half the size.

I'll add this to the TODO list.   Given the numbers above, I'd guess
an overall speedup on the order of 40%.

Another option is 90x{60|72}, based on the DC only setting.  This would
probably require %30 of realtime.

> Arne

-- Buck