[Ffmpeg-devel] [PATCH] ac3enc mdct data type

Dave Dodge dododge
Tue Apr 11 13:44:56 CEST 2006

On Mon, Apr 10, 2006 at 11:59:09PM -0400, Justin Ruggles wrote:
> Michael Niedermayer wrote:
> > int16_t is not optimal, use int or int_fast16_t IMHO
> I'm not too familiar with int_fastXX_t types.  Does this just choose the
> fastest int type depending the platform?

Right, it picks the "fastest" integer type at least XX bits in width.
There's int_fastXX_t and uint_fastXX_t, depending on whether you want
a signed or unsigned type.  XX values of 8, 16, 32, and 64 are
required to be defined by <stdint.h> for C99.

Note that the Standard leaves it up to the implementation to decide
what "fastest" really means and which operations/purposes it should
optimize for when it selects these types.

> And if so, why is it not used more often?

They're relatively new, and people aren't familiar with them or used
to using them.  I suspect MSVC is missing them, which wouldn't help.

                                                  -Dave Dodge

More information about the ffmpeg-devel mailing list