Merge remote-tracking branch 'qatar/master'

* qatar/master:
  vsrc_buffer: allow buffering arbitrary number of frames.
  vf_scale: avoid a pointless memcpy in no-op conversion.
  avfiltergraph: try to reduce format conversions in filters.
  avfiltergraph: add an AVClass to AVFilterGraph on next major bump.
  id3v2: fix skipping extended header in id3v2.4

Conflicts:
	libavfilter/vf_scale.c
	libavfilter/vsrc_buffer.c
	libavformat/id3v2.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 62 insertions, 2 deletions

diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index 50ba8fbcf8..af06a9172f 100644
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -28,9 +28,23 @@
 #include "avfiltergraph.h"
 #include "internal.h"
 
+#include "libavutil/log.h"
+
+static const AVClass filtergraph_class = {
+    .class_name = "AVFilterGraph",
+    .item_name  = av_default_item_name,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
 AVFilterGraph *avfilter_graph_alloc(void)
 {
-    return av_mallocz(sizeof(AVFilterGraph));
+    AVFilterGraph *ret = av_mallocz(sizeof(AVFilterGraph));
+    if (!ret)
+        return NULL;
+#if FF_API_GRAPH_AVCLASS
+    ret->av_class = &filtergraph_class;
+#endif
+    return ret;
 }
 
 void avfilter_graph_free(AVFilterGraph **graph)
@@ -261,6 +275,49 @@ static void pick_format(AVFilterLink *link)
     }
 }
 
+static int reduce_formats_on_filter(AVFilterContext *filter)
+{
+    int i, j, k, ret = 0;
+
+    for (i = 0; i < filter->input_count; i++) {
+        AVFilterLink *link = filter->inputs[i];
+        int         format = link->out_formats->formats[0];
+
+        if (link->out_formats->format_count != 1)
+            continue;
+
+        for (j = 0; j < filter->output_count; j++) {
+            AVFilterLink *out_link = filter->outputs[j];
+            AVFilterFormats  *fmts = out_link->in_formats;
+
+            if (link->type != out_link->type ||
+                out_link->in_formats->format_count == 1)
+                continue;
+
+            for (k = 0; k < out_link->in_formats->format_count; k++)
+                if (fmts->formats[k] == format) {
+                    fmts->formats[0]   = format;
+                    fmts->format_count = 1;
+                    ret = 1;
+                    break;
+                }
+        }
+    }
+    return ret;
+}
+
+static void reduce_formats(AVFilterGraph *graph)
+{
+    int i, reduced;
+
+    do {
+        reduced = 0;
+
+        for (i = 0; i < graph->filter_count; i++)
+            reduced |= reduce_formats_on_filter(graph->filters[i]);
+    } while (reduced);
+}
+
 static void pick_formats(AVFilterGraph *graph)
 {
     int i, j;
@@ -284,7 +341,10 @@ int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
         return ret;
 
     /* Once everything is merged, it's possible that we'll still have
-     * multiple valid media format choices. We pick the first one. */
+     * multiple valid media format choices. We try to minimize the amount
+     * of format conversion inside filters */
+    reduce_formats(graph);
+
     pick_formats(graph);
 
     return 0;