[FFmpeg-devel] [RFC] avcodec: Add native DCA decoder based on libdcadec.
christophe.gisquet at gmail.com
Thu Jan 7 12:57:56 CET 2016
2016-01-07 12:48 GMT+01:00 foo86 <foobaz86 at gmail.com>:
> bench dca pcm_f32le
> bench dca2 pcm_f32le
> bench libdcadec pcm_s32le
OK, that was mostly out of curiosity, as "dca2" has benefits
surpassing such issues anyway. And the improvement is 10% for where it
> synth_filter integrates just nicely without any changes, there is no need for
> rewrite. There is 64 subband version of it needed though, as well as fixed
> point versions for 32 and 64 subbands.
In my recollection, the code was weirdly shaped, so I could have
imagined needs for change (e.g., your libdcadec may not be able to
> Other parts can't be directly reused unfortunately. They need to be converted
> to operate on integer input and process entire frame at once (not just one
The gap between dca and dca2 will probably increase, as these
"constrains" should actually help make the operation faster.
> Temporary converting the input to floating point before calling them (what
> current dca code does) seems to negate any performance gain from using these
> assembly optimized routines in the first place...
I think it is ok to change the code and remove the arch-specific dsp
implementations. Whether to put that specific removal in a separate
patch is up to you.
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