applemedia: implement copying of meta

Before this, buffers would lose their Core Video / Core Media meta
over intervideo* boundary.

https://bugzilla.gnome.org/show_bug.cgi?id=747216

sys/applemedia/coremediabuffer.c

@@ -23,12 +23,38 @@
 #include "coremediabuffer.h"
 #include "corevideomemory.h"
 
+static const GstMetaInfo *gst_core_media_meta_get_info (void);
+
+static void
+gst_core_media_meta_add (GstBuffer * buffer, CMSampleBufferRef sample_buf,
+    CVImageBufferRef image_buf, CMBlockBufferRef block_buf)
+{
+  GstCoreMediaMeta *meta;
+
+  meta =
+      (GstCoreMediaMeta *) gst_buffer_add_meta (buffer,
+      gst_core_media_meta_get_info (), NULL);
+  CFRetain (sample_buf);
+  if (image_buf)
+    CVBufferRetain (image_buf);
+  if (block_buf)
+    CFRetain (block_buf);
+  meta->sample_buf = sample_buf;
+  meta->image_buf = image_buf;
+  meta->block_buf = block_buf;
+  if (image_buf != NULL && CFGetTypeID (image_buf) == CVPixelBufferGetTypeID ())
+    meta->pixel_buf = (CVPixelBufferRef) image_buf;
+  else
+    meta->pixel_buf = NULL;
+}
+
 static void
 gst_core_media_meta_free (GstCoreMediaMeta * meta, GstBuffer * buf)
 {
   if (meta->image_buf != NULL) {
     CVBufferRelease (meta->image_buf);
   }
+
   if (meta->block_buf != NULL) {
     CFRelease (meta->block_buf);
   }
@@ -36,6 +62,22 @@ gst_core_media_meta_free (GstCoreMediaMeta * meta, GstBuffer * buf)
   CFRelease (meta->sample_buf);
 }
 
+static gboolean
+gst_core_media_meta_transform (GstBuffer * transbuf, GstCoreMediaMeta * meta,
+    GstBuffer * buffer, GQuark type, GstMetaTransformCopy * data)
+{
+  if (!data->region) {
+    /* only copy if the complete data is copied as well */
+    gst_core_media_meta_add (transbuf, meta->sample_buf, meta->image_buf,
+        meta->block_buf);
+  } else {
+    GST_WARNING_OBJECT (transbuf,
+        "dropping Core Media metadata due to partial buffer");
+  }
+
+  return TRUE;                  /* retval unused */
+}
+
 GType
 gst_core_media_meta_api_get_type (void)
 {
@@ -59,7 +101,7 @@ gst_core_media_meta_get_info (void)
         "GstCoreMediaMeta", sizeof (GstCoreMediaMeta),
         (GstMetaInitFunction) NULL,
         (GstMetaFreeFunction) gst_core_media_meta_free,
-        (GstMetaTransformFunction) NULL);
+        (GstMetaTransformFunction) gst_core_media_meta_transform);
     g_once_init_leave (&core_media_meta_info, meta);
   }
   return core_media_meta_info;
@@ -190,7 +232,6 @@ gst_core_media_buffer_new (CMSampleBufferRef sample_buf,
 {
   CVImageBufferRef image_buf;
   CMBlockBufferRef block_buf;
-  GstCoreMediaMeta *meta;
   GstBuffer *buf;
 
   image_buf = CMSampleBufferGetImageBuffer (sample_buf);
@@ -198,29 +239,18 @@ gst_core_media_buffer_new (CMSampleBufferRef sample_buf,
 
   buf = gst_buffer_new ();
 
-  meta = (GstCoreMediaMeta *) gst_buffer_add_meta (buf,
+  gst_core_media_meta_add (buf, sample_buf, image_buf, block_buf);
-      gst_core_media_meta_get_info (), NULL);
-  CFRetain (sample_buf);
-  if (image_buf)
-    CVBufferRetain (image_buf);
-  if (block_buf)
-    CFRetain (block_buf);
-  meta->sample_buf = sample_buf;
-  meta->image_buf = image_buf;
-  meta->pixel_buf = NULL;
-  meta->block_buf = block_buf;
 
   if (image_buf != NULL && CFGetTypeID (image_buf) == CVPixelBufferGetTypeID ()) {
     GstVideoInfo info;
     gboolean has_padding = FALSE;
+    CVPixelBufferRef pixel_buf = (CVPixelBufferRef) image_buf;
 
-    meta->pixel_buf = (CVPixelBufferRef) image_buf;
+    if (!gst_video_info_init_from_pixel_buffer (&info, pixel_buf)) {
-    if (!gst_video_info_init_from_pixel_buffer (&info, meta->pixel_buf)) {
       goto error;
     }
 
-    gst_core_video_wrap_pixel_buffer (buf, &info, meta->pixel_buf, &has_padding,
+    gst_core_video_wrap_pixel_buffer (buf, &info, pixel_buf, &has_padding, map);
-        map);
 
     /* If the video meta API is not supported, remove padding by
      * copying the core media buffer to a system memory buffer */

sys/applemedia/corevideobuffer.c

@@ -20,12 +20,40 @@
 #include "corevideobuffer.h"
 #include "corevideomemory.h"
 
+static const GstMetaInfo *gst_core_video_meta_get_info (void);
+
+static void
+gst_core_video_meta_add (GstBuffer * buffer, CVBufferRef cvbuf)
+{
+  GstCoreVideoMeta *meta;
+
+  meta = (GstCoreVideoMeta *) gst_buffer_add_meta (buffer,
+      gst_core_video_meta_get_info (), NULL);
+  meta->cvbuf = CVBufferRetain (cvbuf);
+  meta->pixbuf = (CVPixelBufferRef) cvbuf;
+}
+
 static void
 gst_core_video_meta_free (GstCoreVideoMeta * meta, GstBuffer * buf)
 {
   CVBufferRelease (meta->cvbuf);
 }
 
+static gboolean
+gst_core_video_meta_transform (GstBuffer * transbuf, GstCoreVideoMeta * meta,
+    GstBuffer * buffer, GQuark type, GstMetaTransformCopy * data)
+{
+  if (!data->region) {
+    /* only copy if the complete data is copied as well */
+    gst_core_video_meta_add (transbuf, meta->cvbuf);
+  } else {
+    GST_WARNING_OBJECT (transbuf,
+        "dropping Core Video metadata due to partial buffer");
+  }
+
+  return TRUE;                  /* retval unused */
+}
+
 GType
 gst_core_video_meta_api_get_type (void)
 {
@@ -49,7 +77,7 @@ gst_core_video_meta_get_info (void)
         "GstCoreVideoMeta", sizeof (GstCoreVideoMeta),
         (GstMetaInitFunction) NULL,
         (GstMetaFreeFunction) gst_core_video_meta_free,
-        (GstMetaTransformFunction) NULL);
+        (GstMetaTransformFunction) gst_core_video_meta_transform);
     g_once_init_leave (&core_video_meta_info, meta);
   }
   return core_video_meta_info;
@@ -140,7 +168,7 @@ gst_core_video_buffer_new (CVBufferRef cvbuf, GstVideoInfo * vinfo,
 
   buf = gst_buffer_new ();
 
-  /* add the corevideo meta to free the underlying corevideo buffer */
+  /* add the corevideo meta to pass the underlying corevideo buffer */
   meta = (GstCoreVideoMeta *) gst_buffer_add_meta (buf,
       gst_core_video_meta_get_info (), NULL);
   meta->cvbuf = CVBufferRetain (cvbuf);