[FFmpeg-devel] [PATCH 1/2] lavfi/graphdump: add plain listing output

[Nicolas George]

Signed-off-by: Nicolas George <george at nsup.org>
---
 libavfilter/avfilter.h  |  5 ++-
 libavfilter/graphdump.c | 79 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 80 insertions(+), 4 deletions(-)

diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index 69ecb0186d..2a3c1e79a8 100644
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -1097,7 +1097,10 @@ int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const
  * Dump a graph into a human-readable string representation.
  *
  * @param graph    the graph to dump
- * @param options  formatting options; currently ignored
+ * @param options  formatting options; can be NULL, empty
+ *                 or "f=aa" for clumsy ascii-art drawing,
+ *                 or "f=tech" for plain listing;
+ *                 other values silently ignored
  * @return  a string, or NULL in case of memory allocation failure;
  *          the string must be freed using av_free
  */
diff --git a/libavfilter/graphdump.c b/libavfilter/graphdump.c
index 79ef1a733f..388f80de80 100644
--- a/libavfilter/graphdump.c
+++ b/libavfilter/graphdump.c
@@ -27,6 +27,9 @@
 #include "avfilter.h"
 #include "internal.h"
 
+#define FORMAT_AA 0
+#define FORMAT_TECH 1
+
 static int print_link_prop(AVBPrint *buf, AVFilterLink *link)
 {
     char *format;
@@ -59,7 +62,51 @@ static int print_link_prop(AVBPrint *buf, AVFilterLink *link)
     return buf->len;
 }
 
-static void avfilter_graph_dump_to_buf(AVBPrint *buf, AVFilterGraph *graph)
+static inline const char *fcname(const AVFilterContext *filter)
+{
+    return filter->name ? filter->name : "<unnamed>";
+}
+
+static void dump_tech(AVBPrint *buf, AVFilterGraph *graph)
+{
+    unsigned i, j;
+
+    for (i = 0; i < graph->nb_filters; i++) {
+        AVFilterContext *filter = graph->filters[i];
+
+        if (i)
+            av_bprintf(buf, "\n");
+        av_bprintf(buf, "Filter: %s (%s)\n", fcname(filter), filter->filter->name);
+
+        for (j = 0; j < filter->nb_inputs; j++) {
+            AVFilterPad *pad = &filter->input_pads[j];
+            AVFilterLink *link = filter->inputs[j];
+            AVFilterPad *ppad = link->srcpad;
+            AVFilterContext *peer = link->src;
+
+            av_bprintf(buf, "  in %d: %s ← %s.%d:%s ",
+                       j, pad->name,
+                       fcname(peer), FF_OUTLINK_IDX(link), ppad->name);
+            print_link_prop(buf, link);
+            av_bprintf(buf, "\n");
+        }
+
+        for (j = 0; j < filter->nb_outputs; j++) {
+            AVFilterPad *pad = &filter->output_pads[j];
+            AVFilterLink *link = filter->outputs[j];
+            AVFilterPad *ppad = link->dstpad;
+            AVFilterContext *peer = link->dst;
+
+            av_bprintf(buf, "  out %d: %s → %s.%d:%s ",
+                       j, pad->name,
+                       fcname(peer), FF_INLINK_IDX(link), ppad->name);
+            print_link_prop(buf, link);
+            av_bprintf(buf, "\n");
+        }
+    }
+}
+
+static void dump_ascii_art(AVBPrint *buf, AVFilterGraph *graph)
 {
     unsigned i, j, x, e;
 
@@ -151,15 +198,41 @@ static void avfilter_graph_dump_to_buf(AVBPrint *buf, AVFilterGraph *graph)
     }
 }
 
+static void avfilter_graph_dump_to_buf(AVBPrint *buf, AVFilterGraph *graph, const char *options)
+{
+    unsigned format = FORMAT_AA;
+
+    /* For a very long time, options was ignored.
+       Having a string for that task was a mistake, but it is not important.
+       It is not worth a proper parsing.
+     */
+    if (options && *options) {
+        if (!strcmp("f=aa", options)) {
+            format = FORMAT_AA;
+        } else if (!strcmp("f=tech", options)) {
+            format = FORMAT_TECH;
+        }
+        /* ignore other values */
+    }
+    switch (format) {
+    case FORMAT_AA:
+        dump_ascii_art(buf, graph);
+        break;
+    case FORMAT_TECH:
+        dump_tech(buf, graph);
+        break;
+    }
+}
+
 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options)
 {
     AVBPrint buf;
     char *dump = NULL;
 
     av_bprint_init(&buf, 0, AV_BPRINT_SIZE_COUNT_ONLY);
-    avfilter_graph_dump_to_buf(&buf, graph);
+    avfilter_graph_dump_to_buf(&buf, graph, options);
     av_bprint_init(&buf, buf.len + 1, buf.len + 1);
-    avfilter_graph_dump_to_buf(&buf, graph);
+    avfilter_graph_dump_to_buf(&buf, graph, options);
     av_bprint_finalize(&buf, &dump);
     return dump;
 }
-- 
2.32.0