From 8ca66f336e23ff85d3ff22a03950fdfc25cb1a0f Mon Sep 17 00:00:00 2001
From: Arun Raghavan <arun.raghavan@collabora.co.uk>
Date: Wed, 18 Aug 2010 02:00:10 +0530
Subject: [PATCH] jpegformat: Push tags after setting srcpad caps

This patch defers emission of tag events till caps are set on the source
pad of jpegparse, so that these tags can be seen downstream.

https://bugzilla.gnome.org/show_bug.cgi?id=627211
---
 gst/jpegformat/gstjpegparse.c | 58 +++++++++++++++++++++++++++++++++++--------
 1 file changed, 47 insertions(+), 11 deletions(-)

diff --git a/gst/jpegformat/gstjpegparse.c b/gst/jpegformat/gstjpegparse.c
index 9de54e2..012c77f 100644
--- a/gst/jpegformat/gstjpegparse.c
+++ b/gst/jpegformat/gstjpegparse.c
@@ -114,6 +114,9 @@ struct _GstJpegParsePrivate
   /* video state */
   gint framerate_numerator;
   gint framerate_denominator;
+
+  /* tags */
+  GstTagList *tags;
 };
 
 static void gst_jpeg_parse_dispose (GObject * object);
@@ -549,7 +552,6 @@ gst_jpeg_parse_read_header (GstJpegParse * parse, GstBuffer * buffer)
         break;
 
       case COM:{               /* read comment and post as tag */
-        GstTagList *tags;
         const guint8 *comment = NULL;
 
         if (!gst_byte_reader_get_uint16_be (&reader, &size))
@@ -557,11 +559,10 @@ gst_jpeg_parse_read_header (GstJpegParse * parse, GstBuffer * buffer)
         if (!gst_byte_reader_get_data (&reader, size - 2, &comment))
           goto error;
 
-        tags = gst_tag_list_new ();
-        gst_tag_list_add (tags, GST_TAG_MERGE_REPLACE,
+        if (!parse->priv->tags)
+          parse->priv->tags = gst_tag_list_new ();
+        gst_tag_list_add (parse->priv->tags, GST_TAG_MERGE_REPLACE,
             GST_TAG_COMMENT, comment, NULL);
-        gst_element_found_tags_for_pad (GST_ELEMENT_CAST (parse),
-            parse->priv->srcpad, tags);
         break;
       }
 
@@ -590,11 +591,16 @@ gst_jpeg_parse_read_header (GstJpegParse * parse, GstBuffer * buffer)
           GST_BUFFER_SIZE (buf) = exif_size;
           tags = gst_tag_list_from_exif_buffer_with_tiff_header (buf);
           gst_buffer_unref (buf);
+
           if (tags) {
-            GST_INFO_OBJECT (parse, "post exif metadata");
-            gst_element_found_tags_for_pad (GST_ELEMENT_CAST (parse),
-                parse->priv->srcpad, tags);
+            GST_INFO_OBJECT (parse, "got exif metadata");
+            if (!parse->priv->tags)
+              parse->priv->tags = gst_tag_list_new ();
+            gst_tag_list_insert (parse->priv->tags, tags,
+                GST_TAG_MERGE_REPLACE);
+            gst_tag_list_free (tags);
           }
+
           GST_LOG_OBJECT (parse, "parsed marker %x: '%s' %u bytes",
               marker, id_str, size - 2);
         } else if (!strcmp (id_str, "http://ns.adobe.com/xap/1.0/")) {
@@ -612,11 +618,16 @@ gst_jpeg_parse_read_header (GstJpegParse * parse, GstBuffer * buffer)
           GST_BUFFER_SIZE (buf) = xmp_size;
           tags = gst_tag_list_from_xmp_buffer (buf);
           gst_buffer_unref (buf);
+
           if (tags) {
-            GST_INFO_OBJECT (parse, "post xmp metadata");
-            gst_element_found_tags_for_pad (GST_ELEMENT_CAST (parse),
-                parse->priv->srcpad, tags);
+            GST_INFO_OBJECT (parse, "got xmp metadata");
+            if (!parse->priv->tags)
+              parse->priv->tags = gst_tag_list_new ();
+            gst_tag_list_insert (parse->priv->tags, tags,
+                GST_TAG_MERGE_REPLACE);
+            gst_tag_list_free (tags);
           }
+
           GST_LOG_OBJECT (parse, "parsed marker %x: '%s' %u bytes",
               marker, id_str, size - 2);
         } else {
@@ -788,12 +799,20 @@ gst_jpeg_parse_push_buffer (GstJpegParse * parse, guint len)
       return GST_FLOW_ERROR;
     }
 
+    if (parse->priv->tags) {
+      GST_DEBUG_OBJECT (parse, "Pushing tags");
+      gst_element_found_tags_for_pad (GST_ELEMENT_CAST (parse),
+          parse->priv->srcpad, parse->priv->tags);
+      parse->priv->tags = NULL;
+    }
+
     parse->priv->new_segment = FALSE;
     parse->priv->caps_width = parse->priv->width;
     parse->priv->caps_height = parse->priv->height;
     parse->priv->caps_framerate_numerator = parse->priv->framerate_numerator;
     parse->priv->caps_framerate_denominator =
         parse->priv->framerate_denominator;
+    parse->priv->tags = NULL;
   }
 
   GST_BUFFER_TIMESTAMP (outbuf) = parse->priv->next_ts;
@@ -887,6 +906,19 @@ gst_jpeg_parse_sink_event (GstPad * pad, GstEvent * event)
       res = gst_pad_push_event (parse->priv->srcpad, event);
       parse->priv->new_segment = TRUE;
       break;
+    case GST_EVENT_TAG:{
+      GstTagList *taglist = NULL;
+      gst_event_parse_tag (event, &taglist);
+      if (!parse->priv->new_segment)
+        res = gst_pad_event_default (pad, event);
+      else {
+        /* Hold on to the tags till the srcpad caps are definitely set */
+        if (!parse->priv->tags)
+          parse->priv->tags = gst_tag_list_new ();
+        gst_tag_list_insert (parse->priv->tags, taglist, GST_TAG_MERGE_REPLACE);
+      }
+      break;
+    }
     default:
       res = gst_pad_event_default (pad, event);
       break;
@@ -924,6 +956,8 @@ gst_jpeg_parse_change_state (GstElement * element, GstStateChange transition)
       parse->priv->last_offset = 0;
       parse->priv->last_entropy_len = 0;
       parse->priv->last_resync = FALSE;
+
+      parse->priv->tags = NULL;
     default:
       break;
   }
@@ -935,6 +969,8 @@ gst_jpeg_parse_change_state (GstElement * element, GstStateChange transition)
   switch (transition) {
     case GST_STATE_CHANGE_PAUSED_TO_READY:
       gst_adapter_clear (parse->priv->adapter);
+      if (parse->priv->tags)
+        gst_tag_list_free (parse->priv->tags);
       break;
     default:
       break;
-- 
2.7.4