avconv: split creating and (re-)configuring complex filtergraphs

The current code is less than straightforward due to the fact that
output streams can be created based on filtergraph definitions. This
change should make the code simpler and more readable. It will also be
useful in the future commits.

1 files changed, 45 insertions, 24 deletions

diff --git a/avconv_filter.c b/avconv_filter.c
index c3360f1741..18deb1f891 100644
--- a/avconv_filter.c
+++ b/avconv_filter.c
@@ -176,6 +176,45 @@ static void init_input_filter(FilterGraph *fg, AVFilterInOut *in)
     ist->filters[ist->nb_filters - 1] = fg->inputs[fg->nb_inputs - 1];
 }
 
+int init_complex_filtergraph(FilterGraph *fg)
+{
+    AVFilterInOut *inputs, *outputs, *cur;
+    AVFilterGraph *graph;
+    int ret = 0;
+
+    /* this graph is only used for determining the kinds of inputs
+     * and outputs we have, and is discarded on exit from this function */
+    graph = avfilter_graph_alloc();
+    if (!graph)
+        return AVERROR(ENOMEM);
+
+    ret = avfilter_graph_parse2(graph, fg->graph_desc, &inputs, &outputs);
+    if (ret < 0)
+        goto fail;
+
+    for (cur = inputs; cur; cur = cur->next)
+        init_input_filter(fg, cur);
+
+    for (cur = outputs; cur;) {
+        GROW_ARRAY(fg->outputs, fg->nb_outputs);
+        fg->outputs[fg->nb_outputs - 1] = av_mallocz(sizeof(*fg->outputs[0]));
+        if (!fg->outputs[fg->nb_outputs - 1])
+            exit(1);
+
+        fg->outputs[fg->nb_outputs - 1]->graph   = fg;
+        fg->outputs[fg->nb_outputs - 1]->out_tmp = cur;
+        fg->outputs[fg->nb_outputs - 1]->type    = avfilter_pad_get_type(cur->filter_ctx->output_pads,
+                                                                         cur->pad_idx);
+        cur = cur->next;
+        fg->outputs[fg->nb_outputs - 1]->out_tmp->next = NULL;
+    }
+
+fail:
+    avfilter_inout_free(&inputs);
+    avfilter_graph_free(&graph);
+    return ret;
+}
+
 static int insert_trim(int64_t start_time, int64_t duration,
                        AVFilterContext **last_filter, int *pad_idx,
                        const char *filter_name)
@@ -622,7 +661,7 @@ static int configure_input_filter(FilterGraph *fg, InputFilter *ifilter,
 int configure_filtergraph(FilterGraph *fg)
 {
     AVFilterInOut *inputs, *outputs, *cur;
-    int ret, i, init = !fg->graph, simple = !fg->graph_desc;
+    int ret, i, simple = !fg->graph_desc;
     const char *graph_desc = simple ? fg->outputs[0]->ost->avfilter :
                                       fg->graph_desc;
 
@@ -657,35 +696,17 @@ int configure_filtergraph(FilterGraph *fg)
         return AVERROR(EINVAL);
     }
 
-    for (cur = inputs; !simple && init && cur; cur = cur->next)
-        init_input_filter(fg, cur);
-
     for (cur = inputs, i = 0; cur; cur = cur->next, i++)
         if ((ret = configure_input_filter(fg, fg->inputs[i], cur)) < 0)
             return ret;
     avfilter_inout_free(&inputs);
 
-    if (!init || simple) {
-        /* we already know the mappings between lavfi outputs and output streams,
-         * so we can finish the setup */
-        for (cur = outputs, i = 0; cur; cur = cur->next, i++)
-            configure_output_filter(fg, fg->outputs[i], cur);
-        avfilter_inout_free(&outputs);
+    for (cur = outputs, i = 0; cur; cur = cur->next, i++)
+        configure_output_filter(fg, fg->outputs[i], cur);
+    avfilter_inout_free(&outputs);
 
-        if ((ret = avfilter_graph_config(fg->graph, NULL)) < 0)
-            return ret;
-    } else {
-        /* wait until output mappings are processed */
-        for (cur = outputs; cur;) {
-            GROW_ARRAY(fg->outputs, fg->nb_outputs);
-            if (!(fg->outputs[fg->nb_outputs - 1] = av_mallocz(sizeof(*fg->outputs[0]))))
-                exit(1);
-            fg->outputs[fg->nb_outputs - 1]->graph   = fg;
-            fg->outputs[fg->nb_outputs - 1]->out_tmp = cur;
-            cur = cur->next;
-            fg->outputs[fg->nb_outputs - 1]->out_tmp->next = NULL;
-        }
-    }
+    if ((ret = avfilter_graph_config(fg->graph, NULL)) < 0)
+        return ret;
 
     return 0;
 }