rawparse: Properly align raw audio/video output buffers

That is, aligned to the basic type for audio and to 32 bytes for video.
Fixes crashes if the raw buffers are passed to SIMD processing functions.

https://bugzilla.gnome.org/show_bug.cgi?id=774428

gst/rawparse/gstrawaudioparse.c

@@ -161,6 +161,8 @@ static gboolean gst_raw_audio_parse_is_unit_format_supported (GstRawBaseParse *
 static void gst_raw_audio_parse_get_units_per_second (GstRawBaseParse *
     raw_base_parse, GstFormat format, GstRawBaseParseConfig config,
     gsize * units_per_sec_n, gsize * units_per_sec_d);
+static gint gst_raw_audio_parse_get_alignment (GstRawBaseParse * raw_base_parse,
+    GstRawBaseParseConfig config);
 
 static gboolean gst_raw_audio_parse_is_using_sink_caps (GstRawAudioParse *
     raw_audio_parse);
@@ -228,6 +230,8 @@ gst_raw_audio_parse_class_init (GstRawAudioParseClass * klass)
       GST_DEBUG_FUNCPTR (gst_raw_audio_parse_is_unit_format_supported);
   rawbaseparse_class->get_units_per_second =
       GST_DEBUG_FUNCPTR (gst_raw_audio_parse_get_units_per_second);
+  rawbaseparse_class->get_alignment =
+      GST_DEBUG_FUNCPTR (gst_raw_audio_parse_get_alignment);
 
   g_object_class_install_property (object_class,
       PROP_FORMAT,
@@ -669,6 +673,38 @@ gst_raw_audio_parse_is_config_ready (GstRawBaseParse * raw_base_parse,
   return gst_raw_audio_parse_get_config_ptr (raw_audio_parse, config)->ready;
 }
 
+static guint
+round_up_pow2 (guint n)
+{
+  n = n - 1;
+  n = n | (n >> 1);
+  n = n | (n >> 2);
+  n = n | (n >> 4);
+  n = n | (n >> 8);
+  n = n | (n >> 16);
+  return n + 1;
+}
+
+static gint
+gst_raw_audio_parse_get_alignment (GstRawBaseParse * raw_base_parse,
+    GstRawBaseParseConfig config)
+{
+  GstRawAudioParse *raw_audio_parse = GST_RAW_AUDIO_PARSE (raw_base_parse);
+  GstRawAudioParseConfig *config_ptr =
+      gst_raw_audio_parse_get_config_ptr (raw_audio_parse, config);
+  gint width;
+
+  if (config_ptr->format != GST_RAW_AUDIO_PARSE_FORMAT_PCM)
+    return 1;
+
+  width =
+      GST_AUDIO_FORMAT_INFO_WIDTH (gst_audio_format_get_info
+      (config_ptr->pcm_format)) / 8;
+  width = GST_ROUND_UP_8 (width);
+  width = round_up_pow2 (width);
+
+  return width;
+}
 
 static gboolean
 gst_raw_audio_parse_process (GstRawBaseParse * raw_base_parse,

gst/rawparse/gstrawbaseparse.c

@@ -430,6 +430,43 @@ done:
   return ret;
 }
 
+static GstBuffer *
+gst_raw_base_parse_align_buffer (GstRawBaseParse * raw_base_parse,
+    gsize alignment, GstBuffer * buffer)
+{
+  GstMapInfo map;
+
+  gst_buffer_map (buffer, &map, GST_MAP_READ);
+
+  if (map.size < sizeof (guintptr)) {
+    gst_buffer_unmap (buffer, &map);
+    return buffer;
+  }
+
+  if (((guintptr) map.data) & (alignment - 1)) {
+    GstBuffer *new_buffer;
+    GstAllocationParams params = { 0, alignment - 1, 0, 0, };
+
+    new_buffer = gst_buffer_new_allocate (NULL,
+        gst_buffer_get_size (buffer), &params);
+
+    /* Copy data "by hand", so ensure alignment is kept: */
+    gst_buffer_fill (new_buffer, 0, map.data, map.size);
+
+    gst_buffer_copy_into (new_buffer, buffer, GST_BUFFER_COPY_METADATA, 0, -1);
+    GST_DEBUG_OBJECT (raw_base_parse,
+        "We want output aligned on %" G_GSIZE_FORMAT ", reallocated",
+        alignment);
+
+    gst_buffer_unmap (buffer, &map);
+    gst_buffer_unref (buffer);
+
+    return new_buffer;
+  }
+
+  gst_buffer_unmap (buffer, &map);
+  return buffer;
+}
 
 static GstFlowReturn
 gst_raw_base_parse_handle_frame (GstBaseParse * parse,
@@ -442,6 +479,7 @@ gst_raw_base_parse_handle_frame (GstBaseParse * parse,
   guint64 buffer_duration;
   GstFlowReturn flow_ret = GST_FLOW_OK;
   GstEvent *new_caps_event = NULL;
+  gint alignment;
   GstRawBaseParse *raw_base_parse = GST_RAW_BASE_PARSE (parse);
   GstRawBaseParseClass *klass = GST_RAW_BASE_PARSE_GET_CLASS (parse);
 
@@ -567,6 +605,15 @@ gst_raw_base_parse_handle_frame (GstBaseParse * parse,
     frame->out_buffer = NULL;
   }
 
+  if (klass->get_alignment
+      && (alignment =
+          klass->get_alignment (raw_base_parse,
+              GST_RAW_BASE_PARSE_CONFIG_CURRENT)) != 1) {
+    frame->out_buffer =
+        gst_raw_base_parse_align_buffer (raw_base_parse, alignment,
+        gst_buffer_ref (frame->buffer));
+  }
+
   /* Set the duration of the output buffer, or if none exists, of
    * the input buffer. Do this after the process() call, since in
    * case out_buffer is set, the subclass has created a new buffer.

gst/rawparse/gstrawbaseparse.h

@@ -193,6 +193,9 @@ struct _GstRawBaseParseClass
 
   gint                  (*get_overhead_size)         (GstRawBaseParse * raw_base_parse,
                                                       GstRawBaseParseConfig config);
+
+  gint                  (*get_alignment)             (GstRawBaseParse * raw_base_parse,
+                                                      GstRawBaseParseConfig config);
 };
 
 

gst/rawparse/gstrawvideoparse.c

@@ -182,11 +182,12 @@ 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);
 
-
-
 static void
 gst_raw_video_parse_class_init (GstRawVideoParseClass * klass)
 {
@@ -236,6 +237,8 @@ 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,
@@ -929,6 +932,12 @@ 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,