FFmpeg
pthread_slice.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 /**
20  * @file
21  * Slice multithreading support functions
22  * @see doc/multithreading.txt
23  */
24 
25 #include "config.h"
26 
27 #include "avcodec.h"
28 #include "internal.h"
29 #include "pthread_internal.h"
30 #include "thread.h"
31 
32 #include "libavutil/avassert.h"
33 #include "libavutil/common.h"
34 #include "libavutil/cpu.h"
35 #include "libavutil/mem.h"
36 #include "libavutil/thread.h"
37 #include "libavutil/slicethread.h"
38 
39 typedef int (action_func)(AVCodecContext *c, void *arg);
40 typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);
42 
43 typedef struct SliceThreadContext {
48  void *args;
49  int *rets;
50  int job_size;
51 
52  int *entries;
58 
59 static void main_function(void *priv) {
60  AVCodecContext *avctx = priv;
62  c->mainfunc(avctx);
63 }
64 
65 static void worker_func(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads)
66 {
67  AVCodecContext *avctx = priv;
69  int ret;
70 
71  ret = c->func ? c->func(avctx, (char *)c->args + c->job_size * jobnr)
72  : c->func2(avctx, c->args, jobnr, threadnr);
73  if (c->rets)
74  c->rets[jobnr] = ret;
75 }
76 
78 {
80  int i;
81 
82  avpriv_slicethread_free(&c->thread);
83 
84  for (i = 0; i < c->thread_count; i++) {
85  pthread_mutex_destroy(&c->progress_mutex[i]);
86  pthread_cond_destroy(&c->progress_cond[i]);
87  }
88 
89  av_freep(&c->entries);
90  av_freep(&c->progress_mutex);
91  av_freep(&c->progress_cond);
92  av_freep(&avctx->internal->thread_ctx);
93 }
94 
95 static int thread_execute(AVCodecContext *avctx, action_func* func, void *arg, int *ret, int job_count, int job_size)
96 {
98 
99  if (!(avctx->active_thread_type&FF_THREAD_SLICE) || avctx->thread_count <= 1)
100  return avcodec_default_execute(avctx, func, arg, ret, job_count, job_size);
101 
102  if (job_count <= 0)
103  return 0;
104 
105  c->job_size = job_size;
106  c->args = arg;
107  c->func = func;
108  c->rets = ret;
109 
110  avpriv_slicethread_execute(c->thread, job_count, !!c->mainfunc );
111  return 0;
112 }
113 
114 static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
115 {
117  c->func2 = func2;
118  return thread_execute(avctx, NULL, arg, ret, job_count, 0);
119 }
120 
121 int ff_slice_thread_execute_with_mainfunc(AVCodecContext *avctx, action_func2* func2, main_func *mainfunc, void *arg, int *ret, int job_count)
122 {
124  c->func2 = func2;
125  c->mainfunc = mainfunc;
126  return thread_execute(avctx, NULL, arg, ret, job_count, 0);
127 }
128 
130 {
132  int thread_count = avctx->thread_count;
133  void (*mainfunc)(void *);
134 
135  // We cannot do this in the encoder init as the threads are created before
136  if (av_codec_is_encoder(avctx->codec) &&
137  avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO &&
138  avctx->height > 2800)
139  thread_count = avctx->thread_count = 1;
140 
141  if (!thread_count) {
142  int nb_cpus = av_cpu_count();
143  if (avctx->height)
144  nb_cpus = FFMIN(nb_cpus, (avctx->height+15)/16);
145  // use number of cores + 1 as thread count if there is more than one
146  if (nb_cpus > 1)
147  thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
148  else
149  thread_count = avctx->thread_count = 1;
150  }
151 
152  if (thread_count <= 1) {
153  avctx->active_thread_type = 0;
154  return 0;
155  }
156 
157  avctx->internal->thread_ctx = c = av_mallocz(sizeof(*c));
159  if (!c || (thread_count = avpriv_slicethread_create(&c->thread, avctx, worker_func, mainfunc, thread_count)) <= 1) {
160  if (c)
161  avpriv_slicethread_free(&c->thread);
162  av_freep(&avctx->internal->thread_ctx);
163  avctx->thread_count = 1;
164  avctx->active_thread_type = 0;
165  return 0;
166  }
167  avctx->thread_count = thread_count;
168 
169  avctx->execute = thread_execute;
170  avctx->execute2 = thread_execute2;
171  return 0;
172 }
173 
174 void ff_thread_report_progress2(AVCodecContext *avctx, int field, int thread, int n)
175 {
177  int *entries = p->entries;
178 
179  pthread_mutex_lock(&p->progress_mutex[thread]);
180  entries[field] +=n;
181  pthread_cond_signal(&p->progress_cond[thread]);
183 }
184 
185 void ff_thread_await_progress2(AVCodecContext *avctx, int field, int thread, int shift)
186 {
188  int *entries = p->entries;
189 
190  if (!entries || !field) return;
191 
192  thread = thread ? thread - 1 : p->thread_count - 1;
193 
194  pthread_mutex_lock(&p->progress_mutex[thread]);
195  while ((entries[field - 1] - entries[field]) < shift){
196  pthread_cond_wait(&p->progress_cond[thread], &p->progress_mutex[thread]);
197  }
199 }
200 
201 int ff_alloc_entries(AVCodecContext *avctx, int count)
202 {
203  int i;
204 
205  if (avctx->active_thread_type & FF_THREAD_SLICE) {
207 
208  if (p->entries) {
209  av_assert0(p->thread_count == avctx->thread_count);
210  av_freep(&p->entries);
211  }
212 
213  p->thread_count = avctx->thread_count;
214  p->entries = av_calloc(count, sizeof(*p->entries));
215 
216  if (!p->progress_mutex) {
219  }
220 
221  if (!p->entries || !p->progress_mutex || !p->progress_cond) {
222  av_freep(&p->entries);
224  av_freep(&p->progress_cond);
225  return AVERROR(ENOMEM);
226  }
227  p->entries_count = count;
228 
229  for (i = 0; i < p->thread_count; i++) {
232  }
233  }
234 
235  return 0;
236 }
237 
239 {
241  memset(p->entries, 0, p->entries_count * sizeof(int));
242 }
func
int(* func)(AVBPrint *dst, const char *in, const char *arg)
Definition: jacosubdec.c:68
SliceThreadContext::args
void * args
Definition: pthread_slice.c:48
pthread_mutex_t
_fmutex pthread_mutex_t
Definition: os2threads.h:53
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
thread.h
pthread_mutex_init
static av_always_inline int pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
Definition: os2threads.h:104
MAX_AUTO_THREADS
#define MAX_AUTO_THREADS
Definition: pthread_internal.h:26
avpriv_slicethread_execute
void avpriv_slicethread_execute(AVSliceThread *ctx, int nb_jobs, int execute_main)
Execute slice threading.
Definition: slicethread.c:246
SliceThreadContext::mainfunc
main_func * mainfunc
Definition: pthread_slice.c:47
internal.h
ff_slice_thread_free
void ff_slice_thread_free(AVCodecContext *avctx)
Definition: pthread_slice.c:77
SliceThreadContext::entries_count
int entries_count
Definition: pthread_slice.c:53
AVSliceThread
struct AVSliceThread AVSliceThread
Definition: slicethread.h:22
thread.h
main_function
static void main_function(void *priv)
Definition: pthread_slice.c:59
SliceThreadContext::progress_mutex
pthread_mutex_t * progress_mutex
Definition: pthread_slice.c:56
SliceThreadContext::thread_count
int thread_count
Definition: pthread_slice.c:54
AVCodecContext::codec
const struct AVCodec * codec
Definition: avcodec.h:392
avpriv_slicethread_create
int avpriv_slicethread_create(AVSliceThread **pctx, void *priv, void(*worker_func)(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads), void(*main_func)(void *priv), int nb_threads)
Create slice threading context.
Definition: slicethread.c:237
AVCodecContext::thread_count
int thread_count
thread count is used to decide how many independent tasks should be passed to execute()
Definition: avcodec.h:1440
ff_reset_entries
void ff_reset_entries(AVCodecContext *avctx)
Definition: pthread_slice.c:238
SliceThreadContext::func2
action_func2 * func2
Definition: pthread_slice.c:46
ff_thread_report_progress2
void ff_thread_report_progress2(AVCodecContext *avctx, int field, int thread, int n)
Definition: pthread_slice.c:174
avassert.h
func2
static double(*const func2[])(void *, double, double)
Definition: af_afftfilt.c:102
ff_thread_await_progress2
void ff_thread_await_progress2(AVCodecContext *avctx, int field, int thread, int shift)
Definition: pthread_slice.c:185
SliceThreadContext::job_size
int job_size
Definition: pthread_slice.c:50
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
field
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this field
Definition: writing_filters.txt:78
AVCodecContext::codec_id
enum AVCodecID codec_id
Definition: avcodec.h:393
arg
const char * arg
Definition: jacosubdec.c:67
if
if(ret)
Definition: filter_design.txt:179
SliceThreadContext::progress_cond
pthread_cond_t * progress_cond
Definition: pthread_slice.c:55
NULL
#define NULL
Definition: coverity.c:32
SliceThreadContext::rets
int * rets
Definition: pthread_slice.c:49
AVCodecContext::internal
struct AVCodecInternal * internal
Private context used for internal data.
Definition: avcodec.h:418
SliceThreadContext::thread
AVSliceThread * thread
Definition: pthread_slice.c:44
pthread_internal.h
SliceThreadContext::entries
int * entries
Definition: pthread_slice.c:52
worker_func
static void worker_func(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads)
Definition: pthread_slice.c:65
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
pthread_mutex_unlock
#define pthread_mutex_unlock(a)
Definition: ffprobe.c:68
AV_CODEC_ID_MPEG1VIDEO
@ AV_CODEC_ID_MPEG1VIDEO
Definition: codec_id.h:51
av_cpu_count
int av_cpu_count(void)
Definition: cpu.c:185
SliceThreadContext
Definition: pthread_slice.c:43
thread_execute2
static int thread_execute2(AVCodecContext *avctx, action_func2 *func2, void *arg, int *ret, int job_count)
Definition: pthread_slice.c:114
cpu.h
thread_execute
static int thread_execute(AVCodecContext *avctx, action_func *func, void *arg, int *ret, int job_count, int job_size)
Definition: pthread_slice.c:95
SliceThreadContext::func
action_func * func
Definition: pthread_slice.c:45
FF_THREAD_SLICE
#define FF_THREAD_SLICE
Decode more than one part of a single frame at once.
Definition: avcodec.h:1452
avcodec_default_execute
int avcodec_default_execute(AVCodecContext *c, int(*func)(AVCodecContext *c2, void *arg2), void *arg, int *ret, int count, int size)
Definition: avcodec.c:67
pthread_cond_destroy
static av_always_inline int pthread_cond_destroy(pthread_cond_t *cond)
Definition: os2threads.h:144
slicethread.h
ff_slice_thread_init
int ff_slice_thread_init(AVCodecContext *avctx)
Definition: pthread_slice.c:129
FF_CODEC_CAP_SLICE_THREAD_HAS_MF
#define FF_CODEC_CAP_SLICE_THREAD_HAS_MF
Codec initializes slice-based threading with a main function.
Definition: internal.h:72
av_codec_is_encoder
int av_codec_is_encoder(const AVCodec *codec)
Definition: utils.c:76
pthread_mutex_destroy
static av_always_inline int pthread_mutex_destroy(pthread_mutex_t *mutex)
Definition: os2threads.h:112
ff_slice_thread_execute_with_mainfunc
int ff_slice_thread_execute_with_mainfunc(AVCodecContext *avctx, action_func2 *func2, main_func *mainfunc, void *arg, int *ret, int job_count)
Definition: pthread_slice.c:121
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
av_malloc_array
#define av_malloc_array(a, b)
Definition: tableprint_vlc.h:32
common.h
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
main_func
int() main_func(AVCodecContext *c)
Definition: pthread_slice.c:41
av_mallocz
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:263
pthread_cond_t
Definition: os2threads.h:58
AVCodecContext::height
int height
Definition: avcodec.h:556
av_calloc
void * av_calloc(size_t nmemb, size_t size)
Definition: mem.c:271
avcodec.h
ret
ret
Definition: filter_design.txt:187
AVCodec::caps_internal
int caps_internal
Internal codec capabilities.
Definition: codec.h:254
action_func2
int() action_func2(AVCodecContext *c, void *arg, int jobnr, int threadnr)
Definition: pthread_slice.c:40
pthread_cond_signal
static av_always_inline int pthread_cond_signal(pthread_cond_t *cond)
Definition: os2threads.h:152
AVCodecContext
main external API structure.
Definition: avcodec.h:383
AVCodecContext::active_thread_type
int active_thread_type
Which multithreading methods are in use by the codec.
Definition: avcodec.h:1459
AVCodecContext::execute
int(* execute)(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size)
The codec may call this to execute several independent things.
Definition: avcodec.h:1491
pthread_cond_wait
static av_always_inline int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
Definition: os2threads.h:192
shift
static int shift(int a, int b)
Definition: sonic.c:83
mem.h
action_func
int() action_func(AVCodecContext *c, void *arg)
Definition: pthread_slice.c:39
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
AVCodecInternal::thread_ctx
void * thread_ctx
Definition: internal.h:138
avpriv_slicethread_free
void avpriv_slicethread_free(AVSliceThread **pctx)
Destroy slice threading context.
Definition: slicethread.c:251
pthread_cond_init
static av_always_inline int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr)
Definition: os2threads.h:133
int
int
Definition: ffmpeg_filter.c:156
AVCodecContext::execute2
int(* execute2)(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count)
The codec may call this to execute several independent things.
Definition: avcodec.h:1511
ff_alloc_entries
int ff_alloc_entries(AVCodecContext *avctx, int count)
Definition: pthread_slice.c:201
pthread_mutex_lock
#define pthread_mutex_lock(a)
Definition: ffprobe.c:64