Fix: prevent double notification for frame done in external frame usage (#1180)

Skip notify if ext_frame is used and derive is false (input_fmt !=
transport_fmt).
In this case, the frame done notification is not needed since the
notification is already done after convert callback.
This is to avoid double notification(and double free) for the same
frame.
Fixes #1147

Author: tszumski

ecosystem/gstreamer_plugin/gst_mtl_st20p_tx.c

@@ -536,21 +536,10 @@ GST_PLUGIN_DEFINE(GST_VERSION_MAJOR, GST_VERSION_MINOR, mtl_st20p_tx,
                   GST_PACKAGE_ORIGIN)
 
 static int gst_mtl_st20p_tx_frame_done(void* priv, struct st_frame* frame) {
-  /* In case of format conversion (transmit vs input), MTL may call
-   * gst_mtl_st20p_tx_frame_done twice.
-   * To avoid double free, we set (frame->opaque = NULL) in first call so that the second
-   * call can exit gracefully.
-   */
-  if (frame == NULL || frame->opaque == NULL) {
-    return 0;
-  }
-
   GstSt20pTxExternalDataChild* child = frame->opaque;
   GstSt20pTxExternalDataParent* parent = child->parent;
 
   gst_memory_unmap(child->gst_buffer_memory, &child->map_info);
-
-  frame->opaque = NULL;
   free(child);
 
   pthread_mutex_lock(&parent->parent_mutex);

lib/src/st2110/pipeline/st20_pipeline_tx.c

@@ -130,8 +130,10 @@ static int tx_st20p_frame_done(void* priv, uint16_t frame_idx,
   frame->epoch = meta->epoch;
   frame->rtp_timestamp = meta->rtp_timestamp;
 
-  if (ctx->ops.notify_frame_done) { /* notify app which frame done */
+  if (ctx->ops.notify_frame_done &&
+      !framebuff->frame_done_cb_called) { /* notify app which frame done */
     ctx->ops.notify_frame_done(ctx->ops.priv, frame);
+    framebuff->frame_done_cb_called = true;
   }
 
   /* notify app can get frame */
@@ -212,6 +214,11 @@ static int tx_st20p_convert_put_frame(void* priv, struct st20_convert_frame_meta
     framebuff->stat = ST20P_TX_FRAME_CONVERTED;
   }
 
+  if (ctx->ops.notify_frame_done && !framebuff->frame_done_cb_called) {
+    ctx->ops.notify_frame_done(ctx->ops.priv, &framebuff->src);
+    framebuff->frame_done_cb_called = true;
+  }
+
   return 0;
 }
 
@@ -602,6 +609,7 @@ struct st_frame* st20p_tx_get_frame(st20p_tx_handle handle) {
   }
 
   framebuff->stat = ST20P_TX_FRAME_IN_USER;
+  framebuff->frame_done_cb_called = false;
   /* point to next */
   ctx->framebuff_producer_idx = tx_st20p_next_idx(ctx, framebuff->idx);
   mt_pthread_mutex_unlock(&ctx->lock);
@@ -748,8 +756,10 @@ int st20p_tx_put_ext_frame(st20p_tx_handle handle, struct st_frame* frame,
     if (ctx->internal_converter) { /* convert internal */
       ctx->internal_converter->convert_func(&framebuff->src, &framebuff->dst);
       framebuff->stat = ST20P_TX_FRAME_CONVERTED;
-      if (ctx->ops.notify_frame_done)
+      if (ctx->ops.notify_frame_done && !framebuff->frame_done_cb_called) {
         ctx->ops.notify_frame_done(ctx->ops.priv, &framebuff->src);
+        framebuff->frame_done_cb_called = true;
+      }
     } else {
       framebuff->stat = ST20P_TX_FRAME_READY;
       st20_convert_notify_frame_ready(ctx->convert_impl);

lib/src/st2110/pipeline/st20_pipeline_tx.h

@@ -27,6 +27,7 @@ struct st20p_tx_frame {
   void* user_meta; /* the meta data from user */
   size_t user_meta_buffer_size;
   size_t user_meta_data_size;
+  bool frame_done_cb_called; /* frame done callback called */
 };
 
 struct st20p_tx_ctx {