Move simple filter chain loading code over to the filter graph.

Commited in SoC by Bobby Bingham on 2007-07-14 22:26:37

Originally committed as revision 12688 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/avfiltergraph.c

@@ -19,6 +19,9 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <string.h>
+#include <stddef.h>
+
 #include "avfilter.h"
 #include "avfiltergraph.h"
 
@@ -54,3 +57,62 @@ void avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
     graph->filters[graph->filter_count - 1] = filter;
 }
 
+static AVFilterContext *create_filter_with_args(char *filter)
+{
+    AVFilterContext *ret;
+    char *name, *args;
+
+    name = filter;
+    if((args = strchr(filter, '='))) {
+        /* ensure we at least have a name */
+        if(args == filter)
+            return NULL;
+
+        *args ++ = 0;
+    }
+
+    av_log(NULL, AV_LOG_INFO, "creating filter \"%s\" with args \"%s\"\n",
+           name, args ? args : "(none)");
+
+    if((ret = avfilter_create_by_name(name, NULL))) {
+        if(avfilter_init_filter(ret, args)) {
+            av_log(NULL, AV_LOG_ERROR, "error initializing filter!\n");
+            avfilter_destroy(ret);
+            ret = NULL;
+        }
+    } else av_log(NULL, AV_LOG_ERROR, "error creating filter!\n");
+
+    return ret;
+}
+
+int avfilter_graph_load_chain(AVFilterGraph *graph,
+                              unsigned count, char **filter_list,
+                              AVFilterContext **first, AVFilterContext **last)
+{
+    unsigned i;
+    AVFilterContext *filters[2] = {NULL,NULL};
+
+    for(i = 0; i < count; i ++) {
+        if(!(filters[1] = create_filter_with_args(filter_list[i])))
+            goto fail;
+        if(i == 0) {
+            if(first) *first = filters[1];
+        } else {
+            if(avfilter_link(filters[0], 0, filters[1], 0)) {
+                av_log(NULL, AV_LOG_ERROR, "error linking filters!\n");
+                goto fail;
+            }
+        }
+        avfilter_graph_add_filter(graph, filters[1]);
+        filters[0] = filters[1];
+    }
+
+    if(last) *last = filters[1];
+    return 0;
+
+fail:
+    destroy_graph_filters(graph);
+    *first = *last = NULL;
+    return -1;
+}
+

libavfilter/avfiltergraph.h

@@ -44,4 +44,17 @@ void avfilter_destroy_graph(AVFilterGraph *graph);
  */
 void avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter);
 
+/**
+ * Loads the filter graph with a simple chain described by filters.
+ * @param graph   The filter graph to load filters into
+ * @param count   The number of filters to be created
+ * @param filters_list An array of strings describing the filters to be created.
+ *                The format of each string is "name=params".
+ * @param first   If non-NULL, will be set to the first filter in the chain.
+ * @param last    If non-NULL, will be set to the last filter in the chain.
+ * @return 0 on success.  -1 on error.
+ */
+int avfilter_graph_load_chain(AVFilterGraph *graph,
+                              unsigned count, char **filter_list,
+                              AVFilterContext **first, AVFilterContext **last);
 #endif  /* FFMPEG_AVFILTER_H */