Add a parser for metadata

Original commit message from CVS:
Add a parser for metadata
(demux_metadata): Given the buffer containing the metadata, look through it and
get the info out of it.
(wav_new_chunk_callback): Change the if statement to a switch statement.
Handle GST_RIFF_TAG_LIST by changing what the type of list it is and parsing out
metadata if it is "INFO".

gst/wavparse/gstwavparse.c

@@ -51,6 +51,7 @@ static void		gst_wavparse_chain		(GstPad *pad, GstData *_data);
 static const GstEventMask*
 			gst_wavparse_get_event_masks 	(GstPad *pad);
 static gboolean 	gst_wavparse_srcpad_event 	(GstPad *pad, GstEvent *event);
+static void             gst_wavparse_get_property       (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
 
 /* elementfactory information */
 static GstElementDetails gst_wavparse_details = {
@@ -136,8 +137,8 @@ enum {
 };
 
 enum {
-  ARG_0,
+  PROP_0,
-  /* FILL ME */
+  PROP_METADATA
 };
 
 static GstElementClass *parent_class = NULL;
@@ -168,12 +169,21 @@ static void
 gst_wavparse_class_init (GstWavParseClass *klass) 
 {
   GstElementClass *gstelement_class;
+  GObjectClass *object_class;
   
   gstelement_class = (GstElementClass*) klass;
+  object_class = (GObjectClass *) klass;
   
   parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
 
+  object_class->get_property = gst_wavparse_get_property;
   gstelement_class->change_state = gst_wavparse_change_state;
+
+  g_object_class_install_property (object_class, PROP_METADATA,
+				   g_param_spec_boxed ("metadata",
+						       "Metadata", "Metadata",
+						       GST_TYPE_CAPS,
+						       G_PARAM_READABLE));
 }
 
 static void 
@@ -213,6 +223,26 @@ gst_wavparse_init (GstWavParse *wavparse)
   wavparse->need_discont = FALSE;
 }
 
+static void
+gst_wavparse_get_property (GObject *object,
+			   guint prop_id,
+			   GValue *value,
+			   GParamSpec *pspec)
+{
+  GstWavParse *wavparse;
+
+  wavparse = GST_WAVPARSE (object);
+
+  switch (prop_id) {
+  case PROP_METADATA:
+    g_value_set_boxed (value, wavparse->metadata);
+    break;
+
+  default:
+    break;
+  }
+}
+
 static GstCaps*
 wav_type_find (GstByteStream *bs, gpointer private)
 {
@@ -237,17 +267,129 @@ wav_type_find (GstByteStream *bs, gpointer private)
   return new;
 }
 
+static void
+demux_metadata (GstWavParse *wavparse,
+		const char *data,
+		int len)
+{
+  gst_riff_chunk *temp_chunk, chunk;
+  char *name, *type;
+  GstPropsEntry *entry;
+  GstProps *props;
+
+  props = gst_props_empty_new ();
+  
+  while (len > 0) {
+    temp_chunk = (gst_riff_chunk *) data;
+    chunk.id = GUINT32_FROM_LE (temp_chunk->id);
+    chunk.size = GUINT32_FROM_LE (temp_chunk->size);
+
+    /* move our pointer on past the header */
+    len -= sizeof (gst_riff_chunk);
+    data += sizeof (gst_riff_chunk);
+    
+    if (chunk.size == 0) {
+      continue;
+    }
+
+    name = g_strndup (data, chunk.size);
+
+    /* move our pointer on past the data ... on an even boundary */
+    len -= ((chunk.size + 1) & ~1);
+    data += ((chunk.size + 1) & ~1);
+
+    /* We now have an info string in 'name' of type chunk.id
+       - find type */
+
+    switch (chunk.id) {
+    case GST_RIFF_INFO_IARL:
+      type = "Location";
+      break;
+      
+    case GST_RIFF_INFO_IART:
+      type = "Artist";
+      break;
+      
+    case GST_RIFF_INFO_ICMS:
+      type = "Commissioner";
+      break;
+      
+    case GST_RIFF_INFO_ICMT:
+      type = "Comment";
+      break;
+      
+    case GST_RIFF_INFO_ICOP:
+      type = "Copyright";
+      break;
+      
+    case GST_RIFF_INFO_ICRD:
+      type = "Creation Date";
+      break;
+      
+    case GST_RIFF_INFO_IENG:
+      type = "Engineer";
+      break;
+      
+    case GST_RIFF_INFO_IGNR:
+      type = "Genre";
+      break;
+      
+    case GST_RIFF_INFO_IKEY:
+      type = "Keywords";
+      break;
+      
+    case GST_RIFF_INFO_INAM:
+      type = "Title"; /* name */
+      break;
+      
+    case GST_RIFF_INFO_IPRD:
+      type = "Product";
+      break;
+      
+    case GST_RIFF_INFO_ISBJ:
+      type = "Subject";
+      break;
+      
+    case GST_RIFF_INFO_ISFT:
+      type = "Software";
+      break;
+      
+    case GST_RIFF_INFO_ITCH:
+      type = "Technician";
+      break;
+      
+    default:
+      type = NULL;
+      break;
+    }
+    
+    if (type) {
+      entry = gst_props_entry_new (type, GST_PROPS_STRING (name));
+      gst_props_add_entry (props, entry);
+    }
+
+    g_free (name);
+  }
+
+  gst_caps_replace_sink (&wavparse->metadata,
+			 gst_caps_new ("wav_metadata",
+				       "application/x-gst-metadata",
+				       props));
+  g_object_notify (G_OBJECT (wavparse), "metadata");
+}
+
 static void wav_new_chunk_callback(GstRiffChunk *chunk, gpointer data)
 {
   GstWavParse *wavparse;
+  GstWavParseFormat *format;
+  GstCaps *caps = NULL;
   
   wavparse = GST_WAVPARSE (data);
 
   GST_DEBUG("new tag " GST_FOURCC_FORMAT "\n", GST_FOURCC_ARGS(chunk->id));
 
-  if(chunk->id == GST_RIFF_TAG_fmt){
+  switch (chunk->id) {
-    GstWavParseFormat *format;
+  case GST_RIFF_TAG_fmt:
-    GstCaps *caps = NULL;
     
     /* we can gather format information now */
     format = (GstWavParseFormat *)((guchar *) GST_BUFFER_DATA (wavparse->buf) + chunk->offset);
@@ -260,8 +402,7 @@ static void wav_new_chunk_callback(GstRiffChunk *chunk, gpointer data)
     
     /* set the caps on the src pad */
     /* FIXME: handle all of the other formats as well */
-    switch (wavparse->format)
+    switch (wavparse->format) {
-    {
     case GST_RIFF_WAVE_FORMAT_ALAW:
     case GST_RIFF_WAVE_FORMAT_MULAW: {
       gchar *mime = (wavparse->format == GST_RIFF_WAVE_FORMAT_ALAW) ?
@@ -279,6 +420,7 @@ static void wav_new_chunk_callback(GstRiffChunk *chunk, gpointer data)
 	);
     }
       break;
+      
     case GST_RIFF_WAVE_FORMAT_PCM:
       caps = GST_CAPS_NEW (
 	"parsewav_src",
@@ -319,8 +461,18 @@ static void wav_new_chunk_callback(GstRiffChunk *chunk, gpointer data)
     
     /* we're now looking for the data chunk */
     wavparse->state = GST_WAVPARSE_CHUNK_DATA;
-  }
+    break;
 
+  case GST_RIFF_TAG_LIST:
+    if (strncmp (chunk->data, "INFO", 4) == 0) {
+      /* We got metadata */
+      demux_metadata (wavparse, chunk->data + 4, chunk->size - 4);
+    }
+    break;
+
+  default:
+    break;
+  }
 }
 
 static void
@@ -405,11 +557,11 @@ gst_wavparse_chain (GstPad *pad, GstData *_data)
 
   if (wavparse->state == GST_WAVPARSE_OTHER) {
     GST_DEBUG ("we're in unknown territory here, not passing on");
+
     gst_buffer_unref(buf);
     return;
   }
 
-
   /* here we deal with parsing out the primary state */
   /* these are sequenced such that in the normal case each (RIFF/WAVE,
      fmt, data) will fire in sequence, as they should */

gst/wavparse/gstwavparse.h

@@ -83,6 +83,8 @@ struct _GstWavParse {
   gboolean need_discont;
 
   GstBuffer *buf;
+
+  GstCaps *metadata;
 };
 
 struct _GstWavParseClass {
@@ -102,6 +104,7 @@ struct _GstWavParseFormat {
   guint16 wBitsPerSample;
 };
   
+  
 /**** from public Microsoft RIFF docs ******/
 #define GST_RIFF_WAVE_FORMAT_UNKNOWN        (0x0000)
 #define GST_RIFF_WAVE_FORMAT_PCM            (0x0001)