lavfi: make filter_frame non-recursive.

A lot of changes happen at the same time:

- Add a framequeue fifo to AVFilterLink.

- split AVFilterLink.status into status_in and status_out: requires
  changes to the few filters and programs that use it directly
  (f_interleave, split, filtfmts).

- Add a field ready to AVFilterContext, marking when the filter is ready
  and its activation priority.

- Add flags to mark blocked links.

- Change ff_filter_frame() to enqueue the frame.

- Change all filtering functions to update the ready field and the
  blocked flags.

- Update ff_filter_graph_run_once() to use the ready field.

- buffersrc: always push the frame immediately.

1 files changed, 17 insertions, 36 deletions

diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index 3af698d4be..6b5a6f34ec 100644
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -32,6 +32,9 @@
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 
+#define FF_INTERNAL_FIELDS 1
+#include "framequeue.h"
+
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
@@ -87,6 +90,7 @@ AVFilterGraph *avfilter_graph_alloc(void)
 
     ret->av_class = &filtergraph_class;
     av_opt_set_defaults(ret);
+    ff_framequeue_global_init(&ret->internal->frame_queues);
 
     return ret;
 }
@@ -1377,10 +1381,10 @@ void ff_avfilter_graph_update_heap(AVFilterGraph *graph, AVFilterLink *link)
     heap_bubble_down(graph, link, link->age_index);
 }
 
-
 int avfilter_graph_request_oldest(AVFilterGraph *graph)
 {
     AVFilterLink *oldest = graph->sink_links[0];
+    int64_t frame_count;
     int r;
 
     while (graph->sink_links_count) {
@@ -1400,7 +1404,8 @@ int avfilter_graph_request_oldest(AVFilterGraph *graph)
     if (!graph->sink_links_count)
         return AVERROR_EOF;
     av_assert1(oldest->age_index >= 0);
-    while (oldest->frame_wanted_out) {
+    frame_count = oldest->frame_count_out;
+    while (frame_count == oldest->frame_count_out) {
         r = ff_filter_graph_run_once(graph);
         if (r < 0)
             return r;
@@ -1408,41 +1413,17 @@ int avfilter_graph_request_oldest(AVFilterGraph *graph)
     return 0;
 }
 
-static AVFilterLink *graph_run_once_find_filter(AVFilterGraph *graph)
-{
-    unsigned i, j;
-    AVFilterContext *f;
-
-    /* TODO: replace scanning the graph with a priority list */
-    for (i = 0; i < graph->nb_filters; i++) {
-        f = graph->filters[i];
-        for (j = 0; j < f->nb_outputs; j++)
-            if (f->outputs[j]->frame_wanted_in)
-                return f->outputs[j];
-    }
-    for (i = 0; i < graph->nb_filters; i++) {
-        f = graph->filters[i];
-        for (j = 0; j < f->nb_outputs; j++)
-            if (f->outputs[j]->frame_wanted_out)
-                return f->outputs[j];
-    }
-    return NULL;
-}
-
 int ff_filter_graph_run_once(AVFilterGraph *graph)
 {
-    AVFilterLink *link;
-    int ret;
-
-    link = graph_run_once_find_filter(graph);
-    if (!link) {
-        av_log(NULL, AV_LOG_WARNING, "Useless run of a filter graph\n");
+    AVFilterContext *filter;
+    unsigned i;
+
+    av_assert0(graph->nb_filters);
+    filter = graph->filters[0];
+    for (i = 1; i < graph->nb_filters; i++)
+        if (graph->filters[i]->ready > filter->ready)
+            filter = graph->filters[i];
+    if (!filter->ready)
         return AVERROR(EAGAIN);
-    }
-    ret = ff_request_frame_to_filter(link);
-    if (ret == AVERROR_EOF)
-        /* local EOF will be forwarded through request_frame() /
-           set_status() until it reaches the sink */
-        ret = 0;
-    return ret < 0 ? ret : 1;
+    return ff_filter_activate(filter);
 }