FFmpeg
pthread.c
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1 /*
2  * Copyright (c) 2004 Roman Shaposhnik
3  * Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com)
4  *
5  * Many thanks to Steven M. Schultz for providing clever ideas and
6  * to Michael Niedermayer <michaelni@gmx.at> for writing initial
7  * implementation.
8  *
9  * This file is part of FFmpeg.
10  *
11  * FFmpeg is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU Lesser General Public
13  * License as published by the Free Software Foundation; either
14  * version 2.1 of the License, or (at your option) any later version.
15  *
16  * FFmpeg is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19  * Lesser General Public License for more details.
20  *
21  * You should have received a copy of the GNU Lesser General Public
22  * License along with FFmpeg; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24  */
25 
26 /**
27  * @file
28  * Multithreading support functions
29  * @see doc/multithreading.txt
30  */
31 
32 #include "libavutil/thread.h"
33 
34 #include "avcodec.h"
35 #include "avcodec_internal.h"
36 #include "codec_internal.h"
37 #include "pthread_internal.h"
38 #include "thread.h"
39 
40 /**
41  * Set the threading algorithms used.
42  *
43  * Threading requires more than one thread.
44  * Frame threading requires entire frames to be passed to the codec,
45  * and introduces extra decoding delay, so is incompatible with low_delay.
46  *
47  * @param avctx The context.
48  */
50 {
51  int frame_threading_supported = (avctx->codec->capabilities & AV_CODEC_CAP_FRAME_THREADS)
54  if (avctx->thread_count == 1) {
56  } else if (frame_threading_supported && (avctx->thread_type & FF_THREAD_FRAME)) {
62  avctx->thread_count = 1;
64  }
65 
68  "Application has requested %d threads. Using a thread count greater than %d is not recommended.\n",
70 }
71 
73 {
75 
80 
81  return 0;
82 }
83 
85 {
88  else
90 }
91 
92 av_cold void ff_pthread_free(void *obj, const unsigned offsets[])
93 {
94  unsigned cnt = *(unsigned*)((char*)obj + offsets[0]);
95  const unsigned *cur_offset = offsets;
96 
97  *(unsigned*)((char*)obj + offsets[0]) = 0;
98 
99  for (; *(++cur_offset) != THREAD_SENTINEL && cnt; cnt--)
100  pthread_mutex_destroy((pthread_mutex_t*)((char*)obj + *cur_offset));
101  for (; *(++cur_offset) != THREAD_SENTINEL && cnt; cnt--)
102  pthread_cond_destroy ((pthread_cond_t *)((char*)obj + *cur_offset));
103 }
104 
105 av_cold int ff_pthread_init(void *obj, const unsigned offsets[])
106 {
107  const unsigned *cur_offset = offsets;
108  unsigned cnt = 0;
109  int err;
110 
111 #define PTHREAD_INIT_LOOP(type) \
112  for (; *(++cur_offset) != THREAD_SENTINEL; cnt++) { \
113  pthread_ ## type ## _t *dst = (void*)((char*)obj + *cur_offset); \
114  err = pthread_ ## type ## _init(dst, NULL); \
115  if (err) { \
116  err = AVERROR(err); \
117  goto fail; \
118  } \
119  }
122 
123 fail:
124  *(unsigned*)((char*)obj + offsets[0]) = cnt;
125  return err;
126 }
ff_slice_thread_init
int ff_slice_thread_init(AVCodecContext *avctx)
Definition: pthread_slice.c:134
pthread_mutex_t
_fmutex pthread_mutex_t
Definition: os2threads.h:53
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:215
thread.h
MAX_AUTO_THREADS
#define MAX_AUTO_THREADS
Definition: pthread_internal.h:26
AVCodec::capabilities
int capabilities
Codec capabilities.
Definition: codec.h:206
ff_thread_init
int ff_thread_init(AVCodecContext *avctx)
Definition: pthread.c:72
thread.h
ff_pthread_free
av_cold void ff_pthread_free(void *obj, const unsigned offsets[])
Definition: pthread.c:92
ff_frame_thread_free
void ff_frame_thread_free(AVCodecContext *avctx, int thread_count)
Definition: pthread_frame.c:749
AVCodecContext::codec
const struct AVCodec * codec
Definition: avcodec.h:460
fail
#define fail()
Definition: checkasm.h:188
AVCodecContext::thread_count
int thread_count
thread count is used to decide how many independent tasks should be passed to execute()
Definition: avcodec.h:1593
AVCodecContext::flags
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:508
AV_CODEC_FLAG_LOW_DELAY
#define AV_CODEC_FLAG_LOW_DELAY
Force low delay.
Definition: avcodec.h:334
av_cold
#define av_cold
Definition: attributes.h:90
offsets
static const int offsets[]
Definition: hevc_pel.c:34
AVCodecContext::thread_type
int thread_type
Which multithreading methods to use.
Definition: avcodec.h:1603
validate_thread_parameters
static void validate_thread_parameters(AVCodecContext *avctx)
Set the threading algorithms used.
Definition: pthread.c:49
ff_thread_free
void ff_thread_free(AVCodecContext *avctx)
Definition: pthread.c:84
AV_CODEC_CAP_FRAME_THREADS
#define AV_CODEC_CAP_FRAME_THREADS
Codec supports frame-level multithreading.
Definition: codec.h:110
pthread_internal.h
FFPsyPreprocessContext::avctx
AVCodecContext * avctx
Definition: psymodel.c:94
AVCodecContext::flags2
int flags2
AV_CODEC_FLAG2_*.
Definition: avcodec.h:515
codec_internal.h
ffcodec
static const av_always_inline FFCodec * ffcodec(const AVCodec *codec)
Definition: codec_internal.h:330
FF_THREAD_SLICE
#define FF_THREAD_SLICE
Decode more than one part of a single frame at once.
Definition: avcodec.h:1605
AV_CODEC_CAP_SLICE_THREADS
#define AV_CODEC_CAP_SLICE_THREADS
Codec supports slice-based (or partition-based) multithreading.
Definition: codec.h:114
pthread_cond_destroy
static av_always_inline int pthread_cond_destroy(pthread_cond_t *cond)
Definition: os2threads.h:144
FF_THREAD_FRAME
#define FF_THREAD_FRAME
Decode more than one frame at once.
Definition: avcodec.h:1604
pthread_mutex_destroy
static av_always_inline int pthread_mutex_destroy(pthread_mutex_t *mutex)
Definition: os2threads.h:112
FFCodec::caps_internal
unsigned caps_internal
Internal codec capabilities FF_CODEC_CAP_*.
Definition: codec_internal.h:136
pthread_cond_t
Definition: os2threads.h:58
THREAD_SENTINEL
#define THREAD_SENTINEL
Definition: pthread_internal.h:34
avcodec.h
ff_frame_thread_init
int ff_frame_thread_init(AVCodecContext *avctx)
Definition: pthread_frame.c:921
AV_CODEC_FLAG2_CHUNKS
#define AV_CODEC_FLAG2_CHUNKS
Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
Definition: avcodec.h:371
AVCodecContext
main external API structure.
Definition: avcodec.h:451
AVCodecContext::active_thread_type
int active_thread_type
Which multithreading methods are in use by the codec.
Definition: avcodec.h:1612
avcodec_internal.h
ff_slice_thread_free
void ff_slice_thread_free(AVCodecContext *avctx)
Definition: pthread_slice.c:82
PTHREAD_INIT_LOOP
#define PTHREAD_INIT_LOOP(type)
ff_pthread_init
av_cold int ff_pthread_init(void *obj, const unsigned offsets[])
Initialize/destroy a list of mutexes/conditions contained in a structure.
Definition: pthread.c:105
FF_CODEC_CAP_AUTO_THREADS
#define FF_CODEC_CAP_AUTO_THREADS
Codec handles avctx->thread_count == 0 (auto) internally.
Definition: codec_internal.h:73
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
cond
int(* cond)(enum AVPixelFormat pix_fmt)
Definition: pixdesc_query.c:28
mutex
static AVMutex mutex
Definition: log.c:46