yocto-poky/meta/recipes-multimedia/gstreamer/gstreamer1.0-plugins-base/0001-basetextoverlay-make-memory-copy-when-video-buffer-s.patch

From 3781d40940d46d7e6a502092d24aac7997f6da5b Mon Sep 17 00:00:00 2001
From: Mingke Wang <mingke.wang@freescale.com>
Date: Thu, 5 Mar 2015 12:06:23 +0800
Subject: [PATCH 1/4] basetextoverlay: make memory copy when video buffer's
 memory is ready only

1. since gst_buffer_make_writable just lookup the refcount to determine if
   a buffer is writable, and it will use _gst_buffer_copy() which don't
   perform a deep memory copy even if the flag of a memory is set to
   GST_MEMORY_FLAG_READONLY. So, we detect the memory flag and use
   gst_buffer_copy_region with GST_BUFFER_COPY_DEEP parameter to perform
   deep memory copy. if the allocator of a memory don't support mem_copy
   interface, the it will return NULL, if this case, we can use
   gst_buffer_make_writable() to get a shared memory buffer or the orignal
   buffer if the buffer's refcount is 1.
2.  new feature is no added if caps has no feature during caps negotiation

Upstream-Status: Submitted [https://bugzilla.gnome.org/show_bug.cgi?id=747495]

Signed-off-by: Mingke Wang <mingke.wang@freescale.com>

diff --git a/ext/pango/gstbasetextoverlay.c b/ext/pango/gstbasetextoverlay.c
index c919861..3c0a1d7 100755
--- a/ext/pango/gstbasetextoverlay.c
+++ b/ext/pango/gstbasetextoverlay.c
@@ -747,6 +747,7 @@ gst_base_text_overlay_negotiate (GstBaseTextOverlay * overlay, GstCaps * caps)
     if (f == NULL) {
       f = gst_caps_features_new
           (GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION, NULL);
+      gst_caps_set_features(overlay_caps, 0, f);
     } else {
       gst_caps_features_add (f,
           GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION);
@@ -1890,16 +1891,71 @@ gst_base_text_overlay_push_frame (GstBaseTextOverlay * overlay,
   if (gst_pad_check_reconfigure (overlay->srcpad))
     gst_base_text_overlay_negotiate (overlay, NULL);
 
-  video_frame = gst_buffer_make_writable (video_frame);
-
   if (overlay->attach_compo_to_buffer) {
     GST_DEBUG_OBJECT (overlay, "Attaching text overlay image to video buffer");
+    video_frame = gst_buffer_make_writable (video_frame);
     gst_buffer_add_video_overlay_composition_meta (video_frame,
         overlay->composition);
     /* FIXME: emulate shaded background box if want_shading=true */
     goto done;
   }
 
+  gint m = gst_buffer_n_memory(video_frame);
+  gboolean mem_rdonly = FALSE;
+  GstMemory *mem;
+  GstBuffer *orig = video_frame;
+
+  while (--m>=0) {
+    mem = gst_buffer_get_memory(video_frame, m);
+    if (GST_MEMORY_IS_READONLY(mem)) {
+      mem_rdonly = TRUE;
+      gst_memory_unref (mem);
+      break;
+    }
+    gst_memory_unref (mem);
+  }
+
+  if (mem_rdonly) {
+    // since gst_buffer_make_writable just lookup the refcount to determine if
+    // a buffer is writable, and it will use _gst_buffer_copy() which don't
+    // perform a deep memory copy even if the flag of a memory is set to
+    // GST_MEMORY_FLAG_READONLY. So, we detect the memory flag and use
+    // gst_buffer_copy_region with GST_BUFFER_COPY_DEEP parameter to perform
+    // deep memory copy. if the allocator of a memory don't support mem_copy
+    // interface, the it will return NULL, if this case, we can use
+    // gst_buffer_make_writable() to get a shared memory buffer or the orignal
+    // buffer if the buffer's refcount is 1.
+    GstBuffer *new_buf = gst_buffer_copy_region (video_frame,
+        GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP, 0, -1);
+
+    GST_DEBUG_OBJECT (overlay, "copy %s video frame buffer %p -> %p",
+        g_type_name (GST_MINI_OBJECT_TYPE (video_frame)), video_frame, new_buf);
+
+    if (!new_buf) {
+      //maybe the allocator don't support mem_copy interface, the we just use
+      //gst_buffer_make_writable() to get a writable buffer.
+      video_frame = gst_buffer_make_writable (video_frame);
+    } else {
+      gst_mini_object_unref (video_frame);
+      GST_BUFFER_FLAG_UNSET (new_buf, GST_BUFFER_FLAG_TAG_MEMORY);
+      video_frame = new_buf;
+    }
+
+    if (!video_frame) {
+      GST_WARNING_OBJECT (overlay, "make writable buffer failed");
+      return GST_FLOW_OK;
+    }
+
+    m = gst_buffer_n_memory(video_frame);
+    while (--m>=0) {
+      mem = gst_buffer_get_memory(video_frame, m);
+      GST_MEMORY_FLAG_UNSET (mem, GST_MEMORY_FLAG_READONLY);
+      gst_memory_unref (mem);
+    }
+  } else {
+    video_frame = gst_buffer_make_writable (video_frame);
+  }
+
   if (!gst_video_frame_map (&frame, &overlay->info, video_frame,
           GST_MAP_READWRITE))
     goto invalid_frame;
@@ -1918,6 +1974,18 @@ gst_base_text_overlay_push_frame (GstBaseTextOverlay * overlay,
 
   gst_video_frame_unmap (&frame);
 
+  if (mem_rdonly && orig == video_frame) {
+    //if we used the original buffer and it's mem is set to read only,
+    //recover the memory ready only flag since we unset it before
+    // gst_video_frame_map ()
+    m = gst_buffer_n_memory(video_frame);
+    while (--m>=0) {
+      mem = gst_buffer_get_memory(video_frame, m);
+      GST_MEMORY_FLAGS(mem) |= (GST_MEMORY_FLAG_READONLY);
+      gst_memory_unref (mem);
+    }
+  }
+
 done:
 
   return gst_pad_push (overlay->srcpad, video_frame);
-- 
1.7.9.5