lavfi: allow user-provided execute() callbacks

1 files changed, 50 insertions, 0 deletions

diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index c5efdb8374..ca11be9bc6 100644
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -899,6 +899,35 @@ const AVClass *avfilter_get_class(void);
 
 typedef struct AVFilterGraphInternal AVFilterGraphInternal;
 
+/**
+ * A function pointer passed to the @ref AVFilterGraph.execute callback to be
+ * executed multiple times, possibly in parallel.
+ *
+ * @param ctx the filter context the job belongs to
+ * @param arg an opaque parameter passed through from @ref
+ *            AVFilterGraph.execute
+ * @param jobnr the index of the job being executed
+ * @param nb_jobs the total number of jobs
+ *
+ * @return 0 on success, a negative AVERROR on error
+ */
+typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
+
+/**
+ * A function executing multiple jobs, possibly in parallel.
+ *
+ * @param ctx the filter context to which the jobs belong
+ * @param func the function to be called multiple times
+ * @param arg the argument to be passed to func
+ * @param ret a nb_jobs-sized array to be filled with return values from each
+ *            invocation of func
+ * @param nb_jobs the number of jobs to execute
+ *
+ * @return 0 on success, a negative AVERROR on error
+ */
+typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
+                                    void *arg, int *ret, int nb_jobs);
+
 typedef struct AVFilterGraph {
     const AVClass *av_class;
 #if FF_API_FOO_COUNT
@@ -941,6 +970,27 @@ typedef struct AVFilterGraph {
      * Opaque object for libavfilter internal use.
      */
     AVFilterGraphInternal *internal;
+
+    /**
+     * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
+     * be used from callbacks like @ref AVFilterGraph.execute.
+     * Libavfilter will not touch this field in any way.
+     */
+    void *opaque;
+
+    /**
+     * This callback may be set by the caller immediately after allocating the
+     * graph and before adding any filters to it, to provide a custom
+     * multithreading implementation.
+     *
+     * If set, filters with slice threading capability will call this callback
+     * to execute multiple jobs in parallel.
+     *
+     * If this field is left unset, libavfilter will use its internal
+     * implementation, which may or may not be multithreaded depending on the
+     * platform and build options.
+     */
+    avfilter_execute_func *execute;
 } AVFilterGraph;
 
 /**