Implement in AVFilterGraph the scale_sws_opts field, and pass its

value in the args for the auto-inserted scale filters.

Originally committed as revision 17547 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/avfilter.h

@@ -23,7 +23,7 @@
 #define AVFILTER_AVFILTER_H
 
 #define LIBAVFILTER_VERSION_MAJOR  0
-#define LIBAVFILTER_VERSION_MINOR  3
+#define LIBAVFILTER_VERSION_MINOR  4
 #define LIBAVFILTER_VERSION_MICRO  0
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

libavfilter/avfiltergraph.c

@@ -30,6 +30,7 @@ void avfilter_destroy_graph(AVFilterGraph *graph)
 {
     for(; graph->filter_count > 0; graph->filter_count --)
         avfilter_destroy(graph->filters[graph->filter_count - 1]);
+    av_freep(&graph->scale_sws_opts);
     av_freep(&graph->filters);
 }
 
@@ -111,13 +112,15 @@ static int query_formats(AVFilterGraph *graph)
                 if(!avfilter_merge_formats(link->in_formats,
                                            link->out_formats)) {
                     AVFilterContext *scale;
+                    char scale_args[256];
                     /* couldn't merge format lists. auto-insert scale filter */
                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
                              scaler_count);
                     scale =
                         avfilter_open(avfilter_get_by_name("scale"),inst_name);
 
-                    if(!scale || scale->filter->init(scale, NULL, NULL) ||
+                    snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
+                    if(!scale || scale->filter->init(scale, scale_args, NULL) ||
                                  avfilter_insert_filter(link, scale, 0, 0)) {
                         avfilter_destroy(scale);
                         return -1;

libavfilter/avfiltergraph.h

@@ -27,6 +27,8 @@
 typedef struct AVFilterGraph {
     unsigned filter_count;
     AVFilterContext **filters;
+
+    char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
 } AVFilterGraph;
 
 /**