[FFmpeg-devel] AMR-NB decoder
Colin McQuillan
m.niloc
Mon Aug 10 09:42:53 CEST 2009
2009/8/9 M?ns Rullg?rd <mans at mansr.com>:
> Colin McQuillan <m.niloc at googlemail.com> writes:
>
>> 2009/8/8 Michael Niedermayer <michaelni at gmx.at>:
>>> On Sat, Aug 08, 2009 at 04:09:39PM +0100, Colin McQuillan wrote:
>>>> 2009/8/8 Michael Niedermayer <michaelni at gmx.at>:
>>>> > On Fri, Aug 07, 2009 at 08:23:53PM +0100, Colin McQuillan wrote:
>>>> >> 2009/8/6 Michael Niedermayer <michaelni at gmx.at>:
>>>> >> > On Wed, Aug 05, 2009 at 05:51:36PM +0100, Colin McQuillan wrote:
>>>> >> >> Attached is a patch for an AMR-NB decoder.
>>>>
>>>> [...]
>>>>
>>>> >> > that should e a seperate patch
>>>> >>
>>>> >> I'll leave this one until I investigate a version for sparse vectors. Attached:
>>>> >>
>>>> >> 1. Helper functions for gain control in floating-point codecs
>>>> >> I couldn't find a similar fixed point function to copy the function name.
>>>> >>
>>>> >> 2. Floating-point version of ff_acelp_high_pass_filter
>>>> >
>>>> >> ?acelp_vectors.c | ? 22 ++++++++++++++++++++++
>>>> >> ?acelp_vectors.h | ? 27 +++++++++++++++++++++++++++
>>>> >> ?2 files changed, 49 insertions(+)
>>>> >> f1abbee9b62c1779fd5fb1c634d4ab4294d8611d ?get-set-energyf.patch
>>>> >> Index: libavcodec/acelp_vectors.c
>>>> >> ===================================================================
>>>> >> --- libavcodec/acelp_vectors.c ? ? ? ?(revision 19606)
>>>> >> +++ libavcodec/acelp_vectors.c ? ? ? ?(working copy)
>>>> >> @@ -155,3 +155,25 @@
>>>> >> ? ? ? ? ?out[i] = weight_coeff_a * in_a[i]
>>>> >> ? ? ? ? ? ? ? ? + weight_coeff_b * in_b[i];
>>>> >> ?}
>>>> >> +
>>>> >> +float ff_energyf(const float *v, int length)
>>>> >> +{
>>>> >> + ? ?float sum = 0;
>>>> >> + ? ?int i;
>>>> >> +
>>>> >> + ? ?for (i = 0; i < length; i++)
>>>> >> + ? ? ? ?sum += v[i] * v[i];
>>>> >> +
>>>> >> + ? ?return sum;
>>>> >> +}
>>>> >
>>>> > ff_dot_productf)(
>>>>
>>>> Do you mean that ff_energyf is redundant? I've taken it out.
>>>
>>> hmm well, as you say it that way, ff_energyf() could be faster due to
>>> fewer mem reads, if that is te case in practice it could be kept
>>
>> ff_energyf is reliably 4% faster in my test, so I'll add it back in.
>
> That function has high simdicity so it should be added to dsputil and
> simdified.
I'll try, but I didn't mean to imply that energy calculations are
critical to performance. The slow parts of the AMR decoder are the IIR
and FIR filters, which are already in celp_filters.c.
Attached is "Implement vector energy calculation in dsputil".
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