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avcodec/[e]ac3enc: Make encoders init-threadsafe, fix race

ff_eac3_exponent_init() set values twice when initializing a static
table; ergo the initialization code must not run concurrently with
a running EAC-3 encoder. Yet this code is executed every time an EAC-3
encoder is initialized. So use ff_thread_once() for this and also for a
similar initialization performed for all AC-3 encoders to make them all
init-threadsafe.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This commit is contained in:
Andreas Rheinhardt 2020-12-03 02:57:18 +01:00
parent 69aeba8a19
commit 505d4de064
4 changed files with 12 additions and 11 deletions

View File

@ -36,6 +36,7 @@
#include "libavutil/internal.h"
#include "libavutil/mem_internal.h"
#include "libavutil/opt.h"
#include "libavutil/thread.h"
#include "avcodec.h"
#include "internal.h"
#include "me_cmp.h"
@ -304,7 +305,7 @@ void ff_ac3_apply_rematrixing(AC3EncodeContext *s)
/*
* Initialize exponent tables.
*/
static av_cold void exponent_init(AC3EncodeContext *s)
static av_cold void exponent_init(void)
{
int expstr, i, grpsize;
@ -317,9 +318,6 @@ static av_cold void exponent_init(AC3EncodeContext *s)
}
/* LFE */
exponent_group_tab[0][0][7] = 2;
if (CONFIG_EAC3_ENCODER && s->eac3)
ff_eac3_exponent_init();
}
@ -2409,6 +2407,7 @@ static av_cold int allocate_buffers(AC3EncodeContext *s)
av_cold int ff_ac3_encode_init(AVCodecContext *avctx)
{
static AVOnce init_static_once = AV_ONCE_INIT;
AC3EncodeContext *s = avctx->priv_data;
int ret, frame_size_58;
@ -2448,15 +2447,15 @@ av_cold int ff_ac3_encode_init(AVCodecContext *avctx)
s->mdct_init = ff_ac3_float_mdct_init;
s->allocate_sample_buffers = ff_ac3_float_allocate_sample_buffers;
}
if (CONFIG_EAC3_ENCODER && s->eac3)
if (CONFIG_EAC3_ENCODER && s->eac3) {
static AVOnce init_static_once = AV_ONCE_INIT;
ff_thread_once(&init_static_once, ff_eac3_exponent_init);
s->output_frame_header = ff_eac3_output_frame_header;
else
} else
s->output_frame_header = ac3_output_frame_header;
set_bandwidth(s);
exponent_init(s);
bit_alloc_init(s);
ret = s->mdct_init(s);
@ -2473,5 +2472,7 @@ av_cold int ff_ac3_encode_init(AVCodecContext *avctx)
dprint_options(s);
ff_thread_once(&init_static_once, exponent_init);
return 0;
}

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@ -155,7 +155,7 @@ AVCodec ff_ac3_fixed_encoder = {
.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16P,
AV_SAMPLE_FMT_NONE },
.priv_class = &ac3enc_class,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
.supported_samplerates = ff_ac3_sample_rate_tab,
.channel_layouts = ff_ac3_channel_layouts,
.defaults = ac3_defaults,

View File

@ -153,5 +153,5 @@ AVCodec ff_ac3_encoder = {
.supported_samplerates = ff_ac3_sample_rate_tab,
.channel_layouts = ff_ac3_channel_layouts,
.defaults = ac3_defaults,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
};

View File

@ -266,5 +266,5 @@ AVCodec ff_eac3_encoder = {
.supported_samplerates = ff_ac3_sample_rate_tab,
.channel_layouts = ff_ac3_channel_layouts,
.defaults = ac3_defaults,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
};