[FFmpeg-devel] [RFC] ac3dec: use dsputil.clear_block

Måns Rullgård mans
Thu Jan 14 00:34:49 CET 2010

Justin Ruggles <justin.ruggles at gmail.com> writes:

> Reimar D?ffinger wrote:
>> On Wed, Jan 13, 2010 at 11:42:27PM +0100, Michael Niedermayer wrote:
>>> On Wed, Jan 13, 2010 at 09:46:17PM +0100, Reimar D?ffinger wrote:
>>>> Hello,
>>>> this gives an overall speedup of about 1.1 % on Intel Atom with my sample.
>>>> Testing with other CPUs and samples heavily welcome, I suspect a
>>>> slowdown may be possible, beside it being a bit ugly.
>>> what happens with these coeffs afterwards?
>>> is it
>>> s->dsp.int32_to_float_fmul_scalar(s->transform_coeffs[ch], s->fixed_coeffs[ch], gain, 256);
>>> ?
>>> if so maybe that could be changed to not touch the supposed to be zero
>>> coeffs?
>> I had that idea as well, but I have to admit I do not know, nor if
>> I will have the time to understand the code well enough to know :-)
> Yes the only time they're used is when they're converted to float.

What about doing the float conversion on the fly instead of as a
separate pass?

M?ns Rullg?rd
mans at mansr.com

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