rawvideoparse: Fix missing VideoMeta

The base class is trying to align the processed data, but it endup
removing the GstVideoMeta. That caused wrong result. Instead, just copy
from the process function with the appropriate alignment.

https://bugzilla.gnome.org/show_bug.cgi?id=781204

gst/rawparse/gstrawvideoparse.c

@@ -172,9 +172,6 @@ static GstRawVideoParseConfig
     * gst_raw_video_parse_get_config_ptr (GstRawVideoParse * raw_video_parse,
     GstRawBaseParseConfig config);
 
-static gint gst_raw_video_parse_get_alignment (GstRawBaseParse * raw_base_parse,
-    GstRawBaseParseConfig config);
-
 static void gst_raw_video_parse_init_config (GstRawVideoParseConfig * config);
 static void gst_raw_video_parse_update_info (GstRawVideoParseConfig * config);
 
@@ -227,8 +224,6 @@ gst_raw_video_parse_class_init (GstRawVideoParseClass * klass)
       GST_DEBUG_FUNCPTR (gst_raw_video_parse_get_units_per_second);
   rawbaseparse_class->get_overhead_size =
       GST_DEBUG_FUNCPTR (gst_raw_video_parse_get_overhead_size);
-  rawbaseparse_class->get_alignment =
-      GST_DEBUG_FUNCPTR (gst_raw_video_parse_get_alignment);
 
   g_object_class_install_property (object_class,
       PROP_WIDTH,
@@ -890,39 +885,38 @@ gst_raw_video_parse_is_config_ready (GstRawBaseParse * raw_base_parse,
   return gst_raw_video_parse_get_config_ptr (raw_video_parse, config)->ready;
 }
 
-static gint
-gst_raw_video_parse_get_alignment (GstRawBaseParse * raw_base_parse,
-    GstRawBaseParseConfig config)
-{
-  return 32;
-}
-
 static gboolean
 gst_raw_video_parse_process (GstRawBaseParse * raw_base_parse,
     GstRawBaseParseConfig config, GstBuffer * in_data,
     G_GNUC_UNUSED gsize total_num_in_bytes,
     G_GNUC_UNUSED gsize num_valid_in_bytes, GstBuffer ** processed_data)
 {
+  GstAllocationParams alloc_params = { 0, 31, 0, 0 };
+  GstMapInfo map_info;
   GstRawVideoParse *raw_video_parse = GST_RAW_VIDEO_PARSE (raw_base_parse);
   GstRawVideoParseConfig *config_ptr =
       gst_raw_video_parse_get_config_ptr (raw_video_parse, config);
   guint frame_flags = 0;
   GstVideoInfo *video_info = &(config_ptr->info);
-  GstVideoMeta *videometa;
   GstBuffer *out_data;
 
-  /* In case of extra padding bytes, get a subbuffer without the padding bytes.
+  if (!gst_buffer_map (in_data, &map_info, GST_MAP_READ)) {
-   * Otherwise, just add the video meta. */
+    GST_WARNING_OBJECT (raw_video_parse, "Failed to map input data");
-  if (GST_VIDEO_INFO_SIZE (video_info) < config_ptr->frame_size) {
+    return FALSE;
-    *processed_data = out_data =
-        gst_buffer_copy_region (in_data,
-        GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS |
-        GST_BUFFER_COPY_MEMORY, 0, GST_VIDEO_INFO_SIZE (video_info));
-  } else {
-    out_data = in_data;
-    *processed_data = NULL;
   }
 
+  /* Allocate the output memory our required alignment */
+  *processed_data = out_data = gst_buffer_new_allocate (NULL,
+      GST_VIDEO_INFO_SIZE (video_info), &alloc_params);
+  gst_buffer_fill (*processed_data, 0, map_info.data,
+      GST_VIDEO_INFO_SIZE (video_info));
+  gst_buffer_unmap (in_data, &map_info);
+
+  /* And copy the metadata */
+  gst_buffer_copy_into (*processed_data, in_data,
+      GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0,
+      GST_VIDEO_INFO_SIZE (video_info));
+
   if (config_ptr->interlaced) {
     GST_BUFFER_FLAG_SET (out_data, GST_VIDEO_BUFFER_FLAG_INTERLACED);
     frame_flags |= GST_VIDEO_FRAME_FLAG_INTERLACED;
@@ -934,13 +928,6 @@ gst_raw_video_parse_process (GstRawBaseParse * raw_base_parse,
       GST_BUFFER_FLAG_UNSET (out_data, GST_VIDEO_BUFFER_FLAG_TFF);
   }
 
-  /* Remove any existing videometa - it will be replaced by the new videometa
-   * from here */
-  while ((videometa = gst_buffer_get_video_meta (out_data))) {
-    GST_LOG_OBJECT (raw_base_parse, "removing existing videometa from buffer");
-    gst_buffer_remove_meta (out_data, (GstMeta *) videometa);
-  }
-
   gst_buffer_add_video_meta_full (out_data,
       frame_flags,
       config_ptr->format,