diff --git a/ecosystem/gstreamer_plugin/gst_mtl_st20p_tx.c b/ecosystem/gstreamer_plugin/gst_mtl_st20p_tx.c
index b9d091cdd..c036138d2 100644
--- a/ecosystem/gstreamer_plugin/gst_mtl_st20p_tx.c
+++ b/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);
diff --git a/lib/src/st2110/pipeline/st20_pipeline_tx.c b/lib/src/st2110/pipeline/st20_pipeline_tx.c
index 18c880e16..4ecf6a5e4 100644
--- a/lib/src/st2110/pipeline/st20_pipeline_tx.c
+++ b/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);
diff --git a/lib/src/st2110/pipeline/st20_pipeline_tx.h b/lib/src/st2110/pipeline/st20_pipeline_tx.h
index a55ef8497..228a2b97b 100644
--- a/lib/src/st2110/pipeline/st20_pipeline_tx.h
+++ b/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 {