[FFmpeg-devel] [PATCH 03/23] avfilter/avfilter: Allow to free pads generically

[Andreas Rheinhardt]

This can be enabled/disabled on a per-filter basis by setting
the new internal flags FF_FILTER_FLAG_FREE_(IN|OUT)PADS.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
It would be possible to only free the names of non-static pads;
it could then be used with the headphone and afir filters.
But I don't think the additional complexity is worth it.

 libavfilter/avfilter.c | 19 +++++++++++++++----
 libavfilter/internal.h | 10 ++++++++++
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
index de7501c37b..9ac247c251 100644
--- a/libavfilter/avfilter.c
+++ b/libavfilter/avfilter.c
@@ -117,7 +117,7 @@ void ff_command_queue_pop(AVFilterContext *filter)
  */
 static int insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
                       AVFilterPad **pads, AVFilterLink ***links,
-                      AVFilterPad *newpad)
+                      AVFilterPad *newpad, int free_on_failure)
 {
     AVFilterLink **newlinks;
     AVFilterPad *newpads;
@@ -131,8 +131,11 @@ static int insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
         *pads  = newpads;
     if (newlinks)
         *links = newlinks;
-    if (!newpads || !newlinks)
+    if (!newpads || !newlinks) {
+        if (free_on_failure)
+            av_freep(&newpad->name);
         return AVERROR(ENOMEM);
+    }
 
     memmove(*pads  + idx + 1, *pads  + idx, sizeof(AVFilterPad)   * (*count - idx));
     memmove(*links + idx + 1, *links + idx, sizeof(AVFilterLink*) * (*count - idx));
@@ -150,13 +153,15 @@ static int insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
 int ff_insert_inpad(AVFilterContext *f, unsigned index, AVFilterPad *p)
 {
     return insert_pad(index, &f->nb_inputs, offsetof(AVFilterLink, dstpad),
-                  &f->input_pads, &f->inputs, p);
+                      &f->input_pads, &f->inputs, p,
+                      f->filter->flags_internal & FF_FILTER_FLAG_FREE_INPADS);
 }
 
 int ff_insert_outpad(AVFilterContext *f, unsigned index, AVFilterPad *p)
 {
     return insert_pad(index, &f->nb_outputs, offsetof(AVFilterLink, srcpad),
-                  &f->output_pads, &f->outputs, p);
+                      &f->output_pads, &f->outputs, p,
+                      f->filter->flags_internal & FF_FILTER_FLAG_FREE_OUTPADS);
 }
 
 int avfilter_link(AVFilterContext *src, unsigned srcpad,
@@ -767,7 +772,13 @@ void avfilter_free(AVFilterContext *filter)
     av_buffer_unref(&filter->hw_device_ctx);
 
     av_freep(&filter->name);
+    if (filter->filter->flags_internal & FF_FILTER_FLAG_FREE_INPADS)
+        for (unsigned i = 0; i < filter->nb_inputs; i++)
+            av_freep(&filter->input_pads[i].name);
     av_freep(&filter->input_pads);
+    if (filter->filter->flags_internal & FF_FILTER_FLAG_FREE_OUTPADS)
+        for (unsigned i = 0; i < filter->nb_outputs; i++)
+            av_freep(&filter->output_pads[i].name);
     av_freep(&filter->output_pads);
     av_freep(&filter->inputs);
     av_freep(&filter->outputs);
diff --git a/libavfilter/internal.h b/libavfilter/internal.h
index 615b725cab..d9ff997e72 100644
--- a/libavfilter/internal.h
+++ b/libavfilter/internal.h
@@ -306,6 +306,16 @@ void ff_filter_graph_remove_filter(AVFilterGraph *graph, AVFilterContext *filter
  */
 #define FF_FILTER_FLAG_HWFRAME_AWARE (1 << 0)
 
+/**
+ * The names of all input pads are allocated and should be freed generically.
+ */
+ #define FF_FILTER_FLAG_FREE_INPADS  (1 << 1)
+
+/**
+ * The names of all output pads are allocated and should be freed generically.
+ */
+ #define FF_FILTER_FLAG_FREE_OUTPADS (1 << 2)
+
 /**
  * Run one round of processing on a filter graph.
  */
-- 
2.30.2