graphparser: add avfilter_graph_parse2().

Unlike avfilter_graph_parse(), it returns unlinked inputs and outputs to the caller, which allows parsing of graphs where inputs/outputs are not known in advance.

Anton Khirnov committed 14 years ago

Commit d7bcc711 parent 7ae7c412 files · +141 −39Browse files

Unified · Split

2 files

libavfilter/avfiltergraph.h +39 −5
libavfilter/graphparser.c +102 −34

libavfilter/avfiltergraph.h+39−5

@@ -91,11 +91,11 @@ void avfilter_graph_free(AVFilterGraph **graph); · 90 unmodified lines
91	/**	91	/**
92	* A linked-list of the inputs/outputs of the filter chain.	92	* A linked-list of the inputs/outputs of the filter chain.
93	*	93	*
94	* This is mainly useful for avfilter_graph_parse(), since this	94	* This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
95	* function may accept a description of a graph with not connected	95	* where it is used to communicate open (unlinked) inputs and outputs from and
96	* input/output pads. This struct specifies, per each not connected	96	* to the caller.
97	* pad contained in the graph, the filter context and the pad index	97	* This struct specifies, per each not connected pad contained in the graph, the
98	* required for establishing a link.	98	* filter context and the pad index required for establishing a link.
99	*/	99	*/
100	typedef struct AVFilterInOut {	100	typedef struct AVFilterInOut {
101	/** unique name for this input/output in the list */	101	/** unique name for this input/output in the list */
@@ -124,4 +124,38 @@ int avfilter_graph_parse(AVFilterGraph graph, const char filters, · 22 unmodified lines
124	AVFilterInOut inputs, AVFilterInOut outputs,	124	AVFilterInOut inputs, AVFilterInOut outputs,
125	void *log_ctx);	125	void *log_ctx);
126		126
		127	/**
		128	* Add a graph described by a string to a graph.
		129	*
		130	* @param[in] graph the filter graph where to link the parsed graph context
		131	* @param[in] filters string to be parsed
		132	* @param[out] inputs a linked list of all free (unlinked) inputs of the
		133	* parsed graph will be returned here. It is to be freed
		134	* by the caller using avfilter_inout_free().
		135	* @param[out] outputs a linked list of all free (unlinked) outputs of the
		136	* parsed graph will be returned here. It is to be freed by the
		137	* caller using avfilter_inout_free().
		138	* @return zero on success, a negative AVERROR code on error
		139	*
		140	* @note the difference between avfilter_graph_parse2() and
		141	* avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
		142	* the lists of inputs and outputs, which therefore must be known before calling
		143	* the function. On the other hand, avfilter_graph_parse2() \em returns the
		144	* inputs and outputs that are left unlinked after parsing the graph and the
		145	* caller then deals with them. Another difference is that in
		146	* avfilter_graph_parse(), the inputs parameter describes inputs of the
		147	* <em>already existing</em> part of the graph; i.e. from the point of view of
		148	* the newly created part, they are outputs. Similarly the outputs parameter
		149	* describes outputs of the already existing filters, which are provided as
		150	* inputs to the parsed filters.
		151	* avfilter_graph_parse2() takes the opposite approach -- it makes no reference
		152	* whatsoever to already existing parts of the graph and the inputs parameter
		153	* will on return contain inputs of the newly parsed part of the graph.
		154	* Analogously the outputs parameter will contain outputs of the newly created
		155	* filters.
		156	*/
		157	int avfilter_graph_parse2(AVFilterGraph graph, const char filters,
		158	AVFilterInOut **inputs,
		159	AVFilterInOut **outputs);
		160
127	#endif /* AVFILTER_AVFILTERGRAPH_H */	161	#endif /* AVFILTER_AVFILTERGRAPH_H */

libavfilter/graphparser.c+102−34

 {
     AVFilterInOut *ret;
-    while (*links && strcmp((*links)->name, label))
+    while (*links && (!(*links)->name || strcmp((*links)->name, label)))
         links = &((*links)->next);
     ret = *links;
-    if (ret)
+    if (ret) {
         *links = ret->next;
+        ret->next = NULL;
+    }
     return ret;
 }
     *inouts = element;
 }
+static void append_inout(AVFilterInOut **inouts, AVFilterInOut **element)
+{
+    while (*inouts && (*inouts)->next)
+        inouts = &((*inouts)->next);
+    if (!*inouts)
+        *inouts = *element;
+    else
+        (*inouts)->next = *element;
+    *element = NULL;
+}
 static int link_filter_inouts(AVFilterContext *filt_ctx,
                               AVFilterInOut **curr_inputs,
                               AVFilterInOut **open_inputs, void *log_ctx)
     while (pad--) {
         AVFilterInOut *p = *curr_inputs;
-        if (!p) {
-            av_log(log_ctx, AV_LOG_ERROR,
-                   "Not enough inputs specified for the \"%s\" filter.\n",
-                   filt_ctx->filter->name);
-            return AVERROR(EINVAL);
-        }
-        *curr_inputs = (*curr_inputs)->next;
+        if (p)
+            *curr_inputs = (*curr_inputs)->next;
+        else if (!(p = av_mallocz(sizeof(*p))))
+            return AVERROR(ENOMEM);
         if (p->filter_ctx) {
             if ((ret = link_filter(p->filter_ctx, p->pad_idx, filt_ctx, pad, log_ctx)) < 0)
     return pad;
 }
-int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
+#if FF_API_GRAPH_AVCLASS
-                         AVFilterInOut *open_inputs,
+#define log_ctx graph
-                         AVFilterInOut *open_outputs, void *log_ctx)
+#else
+#define log_ctx NULL
+#endif
+int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
+                          AVFilterInOut **inputs,
+                          AVFilterInOut **outputs)
 {
     int index = 0, ret;
     char chr = 0;
-    AVFilterInOut *curr_inputs = NULL;
+    AVFilterInOut *curr_inputs = NULL, *open_inputs = NULL, *open_outputs = NULL;
     do {
         AVFilterContext *filter;
-        const char *filterchain = filters;
         filters += strspn(filters, WHITESPACES);
         if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx)) < 0)
         if ((ret = parse_filter(&filter, &filters, graph, index, log_ctx)) < 0)
             goto fail;
-        if (filter->input_count == 1 && !curr_inputs && !index) {
-            /* First input can be omitted if it is "[in]" */
-            const char *tmp = "[in]";
-            if ((ret = parse_inputs(&tmp, &curr_inputs, &open_outputs, log_ctx)) < 0)
-                goto fail;
-        }
         if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, log_ctx)) < 0)
             goto fail;
         filters += strspn(filters, WHITESPACES);
         chr = *filters++;
-        if (chr == ';' && curr_inputs) {
+        if (chr == ';' && curr_inputs)
-            av_log(log_ctx, AV_LOG_ERROR,
+            append_inout(&open_outputs, &curr_inputs);
-                   "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
-                   filterchain);
-            ret = AVERROR(EINVAL);
-            goto fail;
-        }
         index++;
     } while (chr == ',' || chr == ';');
         goto fail;
     }
-    if (open_inputs && !strcmp(open_inputs->name, "out") && curr_inputs) {
+    append_inout(&open_outputs, &curr_inputs);
-        /* Last output can be omitted if it is "[out]" */
-        const char *tmp = "[out]";
-        if ((ret = parse_outputs(&tmp, &curr_inputs, &open_inputs, &open_outputs,
-                                 log_ctx)) < 0)
-            goto fail;
-    }
+    *inputs  = open_inputs;
+    *outputs = open_outputs;
     return 0;
  fail:
     free_inout(open_inputs);
     free_inout(open_outputs);
     free_inout(curr_inputs);
+    *inputs  = NULL;
+    *outputs = NULL;
+    return ret;
+}
+#undef log_ctx
+int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
+                         AVFilterInOut *open_inputs,
+                         AVFilterInOut *open_outputs, void *log_ctx)
+{
+    int ret;
+    AVFilterInOut *cur, *match, *inputs = NULL, *outputs = NULL;
+    if ((ret = avfilter_graph_parse2(graph, filters, &inputs, &outputs)) < 0)
+        goto fail;
+    /* First input can be omitted if it is "[in]" */
+    if (inputs && !inputs->name)
+        inputs->name = av_strdup("in");
+    for (cur = inputs; cur; cur = cur->next) {
+        if (!cur->name) {
+              av_log(log_ctx, AV_LOG_ERROR,
+                     "Not enough inputs specified for the \"%s\" filter.\n",
+                     cur->filter_ctx->filter->name);
+              ret = AVERROR(EINVAL);
+              goto fail;
+        }
+        if (!(match = extract_inout(cur->name, &open_outputs)))
+            continue;
+        ret = avfilter_link(match->filter_ctx, match->pad_idx,
+                            cur->filter_ctx,   cur->pad_idx);
+        free_inout(match);
+        if (ret < 0)
+            goto fail;
+    }
+    /* Last output can be omitted if it is "[out]" */
+    if (outputs && !outputs->name)
+        outputs->name = av_strdup("out");
+    for (cur = outputs; cur; cur = cur->next) {
+        if (!cur->name) {
+            av_log(log_ctx, AV_LOG_ERROR,
+                   "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
+                   filters);
+            ret = AVERROR(EINVAL);
+            goto fail;
+        }
+        if (!(match = extract_inout(cur->name, &open_inputs)))
+            continue;
+        ret = avfilter_link(cur->filter_ctx,   cur->pad_idx,
+                            match->filter_ctx, match->pad_idx);
+        free_inout(match);
+        if (ret < 0)
+            goto fail;
+    }
+ fail:
+    if (ret < 0) {
+        for (; graph->filter_count > 0; graph->filter_count--)
+            avfilter_free(graph->filters[graph->filter_count - 1]);
+        av_freep(&graph->filters);
+    }
+    free_inout(inputs);
+    free_inout(outputs);
+    free_inout(open_inputs);
+    free_inout(open_outputs);
     return ret;
 }

graphparser: add avfilter_graph_parse2().

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