[FFmpeg-devel] [PATCH] WMA Voice decoder

[Michael Niedermayer]

On Sun, Jan 31, 2010 at 09:53:47PM -0500, Ronald S. Bultje wrote:
> Hi,
> 
> same as Reimar - all comments taken care of unless otherwise stated:
> 
> On Sat, Jan 30, 2010 at 8:06 PM, Vitor Sessak <vitor1001 at gmail.com> wrote:
> > Ronald S. Bultje wrote:
> >> + ? ?idx = get_bits(gb, 7);
> >> + ? ?fcb_gain = ff_wmavoice_gain_codebook_fcb[idx] *
> >> + ? ? ? ? ? ? ? expf(ff_dot_productf(s->gain_pred_err, gain_coeff, 6) -
> >> + ? ? ? ? ? ? ? ? ? ?5.2409161640);
> >> + ? ?acb_gain = ff_wmavoice_gain_codebook_acb[idx];
> >> + ? ?pred_err = logf(av_clipf(ff_wmavoice_gain_codebook_fcb[idx], 0.05,
> >> 5.0));
> >
> > You can avoid the logf() if you replace the table by its logarithm and
> >
> > ? ?fcb_gain = expf(ff_dot_productf(s->gain_pred_err, gain_coeff, 6) -
> > ? ? ? ? ? ? ? ? ? ?5.2409161640 + ff_wmavoice_gain_codebook_fcb[idx]);
> > ? ?pred_err = av_clipf(ff_wmavoice_gain_codebook_fcb[idx], log(0.05),
> > log(5.0)));
> 
> Oddly, I had the feeling this change made the code slower.

does gcc replace log(0.05) and 5.0 by constants or does t call log() ?

[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I am the wisest man alive, for I know one thing, and that is that I know
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