This is more spec-compliant because it does not rely
on dead-code elimination by the compiler. Especially
MSVC has problems with this, as can be seen in
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/296373.html
or
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/297022.html
This commit does not eliminate every instance where we rely
on dead code elimination: It only tackles branching to
the initialization of arch-specific dsp code, not e.g. all
uses of CONFIG_ and HAVE_ checks. But maybe it is already
enough to compile FFmpeg with MSVC with whole-programm-optimizations
enabled (if one does not disable too many components).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Since the removal of the 16-bit FFT said define is unnecessary as
FFT_FIXED_32 is always !FFT_FLOAT. But one wouldn't believe it when
looking at the code.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
ff_init_ff_cos_tabs is only used for the floating point FFT and only
if hardcoded tables are disabled.
Reviewed-by: Lynne <dev@lynne.ee>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
No longer used by anything.
Unfortunately the old FFT_FLOAT/FFT_FIXED_32 is left as-is. It's
simply too much work for code meant to be all removed anyway.
Also do it for FFT_FLOAT only, as this is the only combination for which
it can be set.
Reviewed-by: Lynne <dev@lynne.ee>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Commit 1af615683e put initializing
the ff_fft_offsets_lut (which is typically used if FFT_FIXED_32)
behind an ff_thread_once() to make ff_fft_init() thread-safe; yet
there is a second place where said table may be initialized which
is not guarded by this AVOnce: ff_fft_init_mips(). MIPS uses this LUT
even for ordinary floating point FFTs, so that ff_fft_init() is not
thread-safe (on MIPS) for both 32bit fixed-point as well as
floating-point FFTs; e.g. ff_mdct_init() inherits this flaw and
therefore initializing e.g. the AAC decoders is not thread-safe (on
MIPS) despite them having FF_CODEC_CAP_INIT_CLEANUP set.
This commit fixes this by moving the AVOnce to fft_init_table.c and
using it to guard all initializations of ff_fft_offsets_lut.
(It is not that bad in practice, because every entry of
ff_fft_offsets_lut is never read during initialization and is only once
ever written to (namely to its final value); but even these are
conflicting actions which are (by definition) data races and lead to
undefined behaviour.)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Before patch:
init nbits = 17, get 10000 samples, average cost: 16175 us
After patch:
init nbits = 17, get 10000 samples, average cost: 14989 us
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>
Fixes the following warnings:
In file included from libavcodec/fft_fixed.c:21:0:
libavcodec/fft_template.c:528:6: warning: ‘pass_big’ defined but not used [-Wunused-function]
PASS(pass_big)
^
libavcodec/fft_template.c:505:13: note: in definition of macro ‘PASS’
static void name(FFTComplex *z, const FFTSample *wre, unsigned int n)\
^~~~
CC libavcodec/ffv1.o
In file included from libavcodec/fft_float.c:21:0:
libavcodec/fft_template.c:528:6: warning: ‘pass_big’ defined but not used [-Wunused-function]
PASS(pass_big)
^
libavcodec/fft_template.c:505:13: note: in definition of macro ‘PASS’
static void name(FFTComplex *z, const FFTSample *wre, unsigned int n)\
^~~~
Make it thread-safe and avoid redundant initialization.
Reviewed-by: Rostislav Pehlivanov <atomnuker@gmail.com>
Reviewed-by: wm4 <nfxjfg@googlemail.com>
Signed-off-by: Muhammad Faiz <mfcc64@gmail.com>
Fixes: 1735/clusterfuzz-testcase-minimized-5350472347025408
This uses unsigned instead of SUINT because the later was rejected by multiple developers
See: [FFmpeg-devel] [PATCH] avcodec/fft_template: Fix multiple runtime error: signed integer overflow: -1943918714 - 1935113003 cannot be represented in type 'int'
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
