[FFmpeg-devel] [PATCH 01/10] dcadsp: remove scaling in LFE FIR

Michael Niedermayer michaelni at gmx.at
Fri Feb 14 23:19:10 CET 2014


On Fri, Feb 14, 2014 at 04:00:45PM +0000, Christophe Gisquet wrote:
> This scale is constant so it is simpler to just scale the
> FIR coefficients in the tables instead.
> ---
>  libavcodec/dcadata.h | 384 +++++++++++++++++++++++++--------------------------
>  libavcodec/dcadec.c  |   7 +-
>  libavcodec/dcadsp.c  |  16 +--
>  libavcodec/dcadsp.h  |   3 +-
>  4 files changed, 203 insertions(+), 207 deletions(-)

I suggest instead of replacing the numeric values to instead use
a macro like
DECLARE_ALIGNED(16, static const float, lfe_fir_64)[] =
{
    LFE_FIR_SCALE(2.658434386830777e-4), LFE_FIR_SCALE(9.029330685734748e-3),
    ...

to do the scaling
this way different scales can be used without the need to replace
the whole table in the source

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Democracy is the form of government in which you can choose your dictator
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