Handles strides (needed for Opus transients), does pre-reindexing and folding
without needing a copy.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
This commit replaces the current inefficient non-power-of-two FFT with a
much faster FFT based on the Prime Factor Algorithm.
Although it is already much faster than the old algorithm without SIMD,
the new algorithm makes use of the already very throughouly SIMD'd power
of two FFT, which improves performance even more across all platforms
which we have SIMD support for.
Most of the work was done by Peter Barfuss, who passed the code to me to
implement into the iMDCT and the current codebase. The code for a
5-point and 15-point FFT was derived from the previous implementation,
although it was optimized and simplified, which will make its future
SIMD easier. The 15-point FFT is currently using 6% of the current
overall decoder overhead.
The FFT can now easily be used as a forward transform by simply not
multiplying the 5-point FFT's imaginary component by -1 (which comes
from the fact that changing the complex exponential's angle by -1 also
changes the output by that) and by multiplying the "theta" angle of the
main exptab by -1. Hence the deliberately left multiplication by -1 at
the end.
FATE passes, and performance reports on other platforms/CPUs are
welcome.
Performance comparisons:
iMDCT, PFA:
101127 decicycles in speed, 32765 runs, 3 skips
iMDCT, Old:
211022 decicycles in speed, 32768 runs, 0 skips
Standalone FFT, 300000 transforms of size 960:
PFA Old FFT kiss_fft libfftw3f
3.659695s, 15.726912s, 13.300789s, 1.182222s
Being only 3x slower than libfftw3f is a big achievement by itself.
There appears to be something capping the performance in the iMDCT side
of things, possibly during the pre-stage reindexing. However, it is
certainly fast enough for now.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
Prep work for the next commit, which will add a new FFT algorithm
which makes the iMDCT over 3x faster than it is currently (standalone,
the FFT is with some framesizes over 10x faster).
The new FFT algorithm uses the already thouroughly SIMD'd power of two
FFT which already has SIMD for AArch64, so users of that platform will
still see an improvement.
The previous FFT+SIMD was barely 2.5x faster than the C versions on these
platforms.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
Reference:
commit 41fda91d09
Author: BERO <bero@geocities.co.jp>
Date: Wed May 14 17:46:55 2003 +0000
aligned dsputil (for sh4) patch by (BERO <bero at geocities dot co dot jp>)
Originally committed as revision 1880 to svn://svn.ffmpeg.org/ffmpeg/trunk
commit 8dbe585641
Author: Oskar Arvidsson <oskar@irock.se>
Date: Tue Mar 29 17:48:59 2011 +0200
Adds 8-, 9- and 10-bit versions of some of the functions used by the h264 decoder.
This patch lets e.g. dsputil_init chose dsp functions with respect to
the bit depth to decode. The naming scheme of bit depth dependent
functions is <base name>_<bit depth>[_<prefix>] (i.e. the old
clear_blocks_c is now named clear_blocks_8_c).
Note: Some of the functions for high bit depth is not dependent on the
bit depth, but only on the pixel size. This leaves some room for
optimizing binary size.
Preparatory patch for high bit depth h264 decoding support.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Passing an explicit filename to this command is only necessary if the
documentation in the @file block refers to a file different from the
one the block resides in.
Originally committed as revision 22921 to svn://svn.ffmpeg.org/ffmpeg/trunk
This reduces the number of false dependencies on header files and
speeds up compilation.
Originally committed as revision 22407 to svn://svn.ffmpeg.org/ffmpeg/trunk
Otherwise doxygen complains about ambiguous filenames when files exist
under the same name in different subdirectories.
Originally committed as revision 16912 to svn://svn.ffmpeg.org/ffmpeg/trunk
Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.' to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".
Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk
while playing with some new hardware, I found it's running a forked mplayer
-- and it looks like they're following the GPL.
The maintainer's page is here: http://atty.jp/?Zaurus/mplayer
Unfortunately it's mostly in Japanese, so it's hard to figure out any
details.
Their code looks quite interesting (at least to those of us w/ ARM CPUs).
The patches I've attached are the patches from atty.jp with a couple of
modifications by myself:
- ported to current CVS
- reverted their change of removing SNOW support from ffmpeg
- cleaned up their bswap mess
- removed DOS-style linebreaks from various files
patch by (Bernhard Rosenkraenzer: bero, arklinux org)
Originally committed as revision 4311 to svn://svn.ffmpeg.org/ffmpeg/trunk
Rostislav Pehlivanov
Diego Biurrun
Janne Grunau
Ronald S. Bultje
Michael Niedermayer
Mans Rullgard
Stefano Sabatini
Aurelien Jacobs
Luca Barbato
Bernhard Rosenkränzer
Zdenek Kabelac
Fabrice Bellard