libavcodec/pthread_slice.c

   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 "codec_internal.h"
  29 #include "internal.h"
  30 #include "pthread_internal.h"
  31 #include "thread.h"
  32
  33 #include "libavutil/avassert.h"
  34 #include "libavutil/common.h"
  35 #include "libavutil/cpu.h"
  36 #include "libavutil/mem.h"
  37 #include "libavutil/thread.h"
  38 #include "libavutil/slicethread.h"
  39
  40 typedef int (action_func)(AVCodecContext *c, void *arg);
  41 typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);
  42 typedef int (main_func)(AVCodecContext *c);
  43
  44 typedef struct SliceThreadContext {
  45     AVSliceThread *thread;
  46     action_func *func;
  47     action_func2 *func2;
  48     main_func *mainfunc;
  49     void *args;
  50     int *rets;
  51     int job_size;
  52 } SliceThreadContext;
  53
  54 static void main_function(void *priv) {
  55     AVCodecContext *avctx = priv;
  56     SliceThreadContext *c = avctx->internal->thread_ctx;
  57     c->mainfunc(avctx);
  58 }
  59
  60 static void worker_func(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads)
  61 {
  62     AVCodecContext *avctx = priv;
  63     SliceThreadContext *c = avctx->internal->thread_ctx;
  64     int ret;
  65
  66     ret = c->func ? c->func(avctx, (char *)c->args + c->job_size * jobnr)
  67                   : c->func2(avctx, c->args, jobnr, threadnr);
  68     if (c->rets)
  69         c->rets[jobnr] = ret;
  70 }
  71
  72 void ff_slice_thread_free(AVCodecContext *avctx)
  73 {
  74     SliceThreadContext *c = avctx->internal->thread_ctx;
  75
  76     avpriv_slicethread_free(&c->thread);
  77
  78     av_freep(&avctx->internal->thread_ctx);
  79 }
  80
  81 static int thread_execute(AVCodecContext *avctx, action_func* func, void *arg, int *ret, int job_count, int job_size)
  82 {
  83     SliceThreadContext *c = avctx->internal->thread_ctx;
  84
  85     if (!(avctx->active_thread_type&FF_THREAD_SLICE) || avctx->thread_count <= 1)
  86         return avcodec_default_execute(avctx, func, arg, ret, job_count, job_size);
  87
  88     if (job_count <= 0)
  89         return 0;
  90
  91     c->job_size = job_size;
  92     c->args = arg;
  93     c->func = func;
  94     c->rets = ret;
  95
  96     avpriv_slicethread_execute(c->thread, job_count, !!c->mainfunc  );
  97     return 0;
  98 }
  99
 100 static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
 101 {
 102     SliceThreadContext *c = avctx->internal->thread_ctx;
 103     c->func2 = func2;
 104     return thread_execute(avctx, NULL, arg, ret, job_count, 0);
 105 }
 106
 107 int ff_slice_thread_execute_with_mainfunc(AVCodecContext *avctx, action_func2* func2, main_func *mainfunc, void *arg, int *ret, int job_count)
 108 {
 109     SliceThreadContext *c = avctx->internal->thread_ctx;
 110     c->func2 = func2;
 111     c->mainfunc = mainfunc;
 112     return thread_execute(avctx, NULL, arg, ret, job_count, 0);
 113 }
 114
 115 int ff_slice_thread_init(AVCodecContext *avctx)
 116 {
 117     SliceThreadContext *c;
 118     int thread_count = avctx->thread_count;
 119     void (*mainfunc)(void *);
 120
 121     // We cannot do this in the encoder init as the threads are created before
 122     if (av_codec_is_encoder(avctx->codec) &&
 123         avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO &&
 124         avctx->height > 2800)
 125         thread_count = avctx->thread_count = 1;
 126
 127     if (!thread_count) {
 128         int nb_cpus = av_cpu_count();
 129         if  (avctx->height)
 130             nb_cpus = FFMIN(nb_cpus, (avctx->height+15)/16);
 131         // use number of cores + 1 as thread count if there is more than one
 132         if (nb_cpus > 1)
 133             thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
 134         else
 135             thread_count = avctx->thread_count = 1;
 136     }
 137
 138     if (thread_count <= 1) {
 139         avctx->active_thread_type = 0;
 140         return 0;
 141     }
 142
 143     avctx->internal->thread_ctx = c = av_mallocz(sizeof(*c));
 144     mainfunc = ffcodec(avctx->codec)->caps_internal & FF_CODEC_CAP_SLICE_THREAD_HAS_MF ? &main_function : NULL;
 145     if (!c || (thread_count = avpriv_slicethread_create(&c->thread, avctx, worker_func, mainfunc, thread_count)) <= 1) {
 146         if (c)
 147             avpriv_slicethread_free(&c->thread);
 148         av_freep(&avctx->internal->thread_ctx);
 149         avctx->thread_count = 1;
 150         avctx->active_thread_type = 0;
 151         return 0;
 152     }
 153     avctx->thread_count = thread_count;
 154
 155     avctx->execute = thread_execute;
 156     avctx->execute2 = thread_execute2;
 157     return 0;
 158 }