Add an execute2 function that is more flexible and allows to use parallel

processing with jobs > threads without wasting too much memory.
It also avoids needing a separate int array when the only additional data
the jobs needs is a single int running from 0 to count-1.

Originally committed as revision 20210 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/avcodec.h

@@ -30,7 +30,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 52
-#define LIBAVCODEC_VERSION_MINOR 36
+#define LIBAVCODEC_VERSION_MINOR 37
 #define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
@@ -2526,6 +2526,26 @@ typedef struct AVCodecContext {
      * - decoding: Set by libavcodec
      */
     enum AVChromaLocation chroma_sample_location;
+
+    /**
+     * The codec may call this to execute several independent things.
+     * It will return only after finishing all tasks.
+     * The user may replace this with some multithreaded implementation,
+     * the default implementation will execute the parts serially.
+     * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
+     * @param c context passed also to func
+     * @param count the number of things to execute
+     * @param arg2 argument passed unchanged to func
+     * @param ret return values of executed functions, must have space for "count" values. May be NULL.
+     * @param func function that will be called count times, with jobnr from 0 to count-1.
+     *             threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
+     *             two instances of func executing at the same time will have the same threadnr.
+     * @return always 0 currently, but code should handle a future improvement where when any call to func
+     *         returns < 0 no further calls to func may be done and < 0 is returned.
+     * - encoding: Set by libavcodec, user can override.
+     * - decoding: Set by libavcodec, user can override.
+     */
+    int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
 } AVCodecContext;
 
 /**
@@ -3154,6 +3174,7 @@ int avcodec_thread_init(AVCodecContext *s, int thread_count);
 void avcodec_thread_free(AVCodecContext *s);
 int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
+int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
 //FIXME func typedef
 
 /**

libavcodec/options.c

@@ -433,6 +433,7 @@ void avcodec_get_context_defaults2(AVCodecContext *s, enum CodecType codec_type)
     s->release_buffer= avcodec_default_release_buffer;
     s->get_format= avcodec_default_get_format;
     s->execute= avcodec_default_execute;
+    s->execute2= avcodec_default_execute2;
     s->sample_aspect_ratio= (AVRational){0,1};
     s->pix_fmt= PIX_FMT_NONE;
     s->sample_fmt= SAMPLE_FMT_S16; // FIXME: set to NONE

libavcodec/pthread.c

@@ -26,10 +26,12 @@
 #include "avcodec.h"
 
 typedef int (action_func)(AVCodecContext *c, void *arg);
+typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);
 
 typedef struct ThreadContext {
     pthread_t *workers;
     action_func *func;
+    action_func2 *func2;
     void *args;
     int *rets;
     int rets_count;
@@ -68,7 +70,8 @@ static void* attribute_align_arg worker(void *v)
         }
         pthread_mutex_unlock(&c->current_job_lock);
 
-        c->rets[our_job%c->rets_count] = c->func(avctx, (char*)c->args + our_job*c->job_size);
+        c->rets[our_job%c->rets_count] = c->func ? c->func(avctx, (char*)c->args + our_job*c->job_size):
+                                                   c->func2(avctx, c->args, our_job, self_id);
 
         pthread_mutex_lock(&c->current_job_lock);
         our_job = c->current_job++;
@@ -130,6 +133,13 @@ int avcodec_thread_execute(AVCodecContext *avctx, action_func* func, void *arg,
     return 0;
 }
 
+int avcodec_thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
+{
+    ThreadContext *c= avctx->thread_opaque;
+    c->func2 = func2;
+    return avcodec_thread_execute(avctx, NULL, arg, ret, job_count, 0);
+}
+
 int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
 {
     int i;
@@ -167,5 +177,6 @@ int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
     avcodec_thread_park_workers(c, thread_count);
 
     avctx->execute = avcodec_thread_execute;
+    avctx->execute2 = avcodec_thread_execute2;
     return 0;
 }

libavcodec/utils.c

@@ -414,6 +414,16 @@ int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, v
     return 0;
 }
 
+int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int jobnr, int threadnr),void *arg, int *ret, int count){
+    int i;
+
+    for(i=0; i<count; i++){
+        int r= func(c, arg, i, 0);
+        if(ret) ret[i]= r;
+    }
+    return 0;
+}
+
 enum PixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum PixelFormat *fmt){
     while (*fmt != PIX_FMT_NONE && ff_is_hwaccel_pix_fmt(*fmt))
         ++fmt;