1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-02 03:06:28 +02:00
Commit Graph

6 Commits

Author SHA1 Message Date
Andreas Rheinhardt
b9c1ab8907 avcodec/fft_template, fft_init_table: Make ff_fft_init() thread-safe
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>
2020-11-24 11:35:03 +01:00
Michael Niedermayer
ae76b84221 avcodec: Extend fft to size 2^17
Asked-for-by: durandal_1707

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2016-03-04 13:51:42 +01:00
Reimar Döffinger
1654514ab0 fft: add ff_ prefix to some global arrays.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
2014-08-31 10:25:36 +02:00
Reimar Döffinger
e2cd28c926 fft: add missing const.
This table was the largest object in FFmpeg's .data,
and really should be in .rodata.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
2014-08-30 16:33:00 +02:00
Reimar Döffinger
8cbf0827e1 Various small spelling fixes.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
2014-04-22 20:44:31 +02:00
Nedeljko Babic
18d7074b4e libavcodec: Implementation of 32 bit fixed point FFT
Iterative implementation of 32 bit fixed point split-radix FFT.
Max FFT that can be calculated currently is 2^12.

Signed-off-by: Nedeljko Babic <nbabic@mips.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
2013-08-04 14:01:41 +02:00