[Ffmpeg-devel] [PATCH] Vorbis decoder
Thu May 12 17:10:11 CEST 2005
Rich Felker wrote:
> I don't believe float is ever faster than a _proper_ int
The issue, per my understanding, is that these perceptual audio
decoders need to work with numbers that are larger than 32 bits in
precision. You either use a float/double and use the CPU's FPU
instructions or you break the 64-bit number up into 2 32-bit numbers and
do a little more work to perform, e.g., a multiplication (vs. a single
FMUL instruction for the floating point data type).
CPUs without FPU benefit from pure integer implementation since it is
faster than having to do FP ops in software with integers.
> implementation, except maybe on broken intel crap (i.e. P4).
What on Earth makes you call the P4 "broken", smart guy? I remember
that whole Pentium 1 FDIV bug fiasco, but I can not find similar bugs
>>3.) lavc's fft based imdct is floating point
> Volunteers to fix? :(
I heard that you were the math major...
More information about the ffmpeg-devel