hlsdemux: Extract ID3 tags, strip them from the output and provide them as tags

They often don't only contain the PCR information but also other
metadata, like title. Give this information to the pipeline.

Also strip the tags from the stream as we a) already parsed them now and
b) decoders don't like these tags to happen in the middle of the stream
(i.e. the start of each fragment) and tagdemux only can strip them off
the beginning and end.

ext/hls/gsthlsdemux-util.c

@@ -265,13 +265,15 @@ gst_hlsdemux_tsreader_find_pcrs_mpegts (GstHLSTSReader * r,
 
 static gboolean
 gst_hlsdemux_tsreader_find_pcrs_id3 (GstHLSTSReader * r,
-    GstBuffer * buffer, GstClockTime * first_pcr, GstClockTime * last_pcr)
+    GstBuffer ** buffer_out, GstClockTime * first_pcr, GstClockTime * last_pcr,
+    GstTagList ** tags)
 {
   GstMapInfo info;
   guint32 tag_size;
   gsize size;
   GstTagList *taglist;
   GstSample *priv_data = NULL;
+  GstBuffer *buffer = *buffer_out;
   GstBuffer *tag_buf;
   guint64 pts;
 
@@ -297,10 +299,17 @@ gst_hlsdemux_tsreader_find_pcrs_id3 (GstHLSTSReader * r,
    * not try and read again */
   r->have_id3 = TRUE;
 
+  *buffer_out =
+      gst_buffer_copy_region (buffer, GST_BUFFER_COPY_ALL, tag_size, -1);
+
   /* Parse the tag */
   taglist = gst_tag_list_from_id3v2_tag (buffer);
-  if (taglist == NULL)
+  if (taglist == NULL) {
+    gst_buffer_unref (buffer);
     return TRUE;                /* Invalid tag, stop trying */
+  }
+
+  *tags = taglist;
 
   /* Extract the timestamps */
   if (!gst_tag_list_get_sample (taglist, GST_TAG_PRIVATE_DATA, &priv_data))
@@ -330,19 +339,22 @@ gst_hlsdemux_tsreader_find_pcrs_id3 (GstHLSTSReader * r,
 out:
   if (priv_data)
     gst_sample_unref (priv_data);
-
+  gst_buffer_unref (buffer);
-  gst_tag_list_unref (taglist);
 
   return TRUE;
 }
 
 gboolean
 gst_hlsdemux_tsreader_find_pcrs (GstHLSTSReader * r,
-    GstBuffer * buffer, GstClockTime * first_pcr, GstClockTime * last_pcr)
+    GstBuffer ** buffer, GstClockTime * first_pcr, GstClockTime * last_pcr,
+    GstTagList ** tags)
 {
+  *tags = NULL;
+
   if (r->rtype == GST_HLS_TSREADER_MPEGTS)
-    return gst_hlsdemux_tsreader_find_pcrs_mpegts (r, buffer, first_pcr,
+    return gst_hlsdemux_tsreader_find_pcrs_mpegts (r, *buffer, first_pcr,
         last_pcr);
 
-  return gst_hlsdemux_tsreader_find_pcrs_id3 (r, buffer, first_pcr, last_pcr);
+  return gst_hlsdemux_tsreader_find_pcrs_id3 (r, buffer, first_pcr, last_pcr,
+      tags);
 }

ext/hls/gsthlsdemux.c

@@ -767,6 +767,7 @@ gst_hls_demux_handle_buffer (GstAdaptiveDemux * demux,
   GstHLSDemux *hlsdemux = GST_HLS_DEMUX_CAST (demux);
   GstMapInfo info;
   GstClockTime first_pcr, last_pcr;
+  GstTagList *tags;
 
   if (buffer == NULL)
     return GST_FLOW_OK;
@@ -832,14 +833,18 @@ gst_hls_demux_handle_buffer (GstAdaptiveDemux * demux,
     hls_stream->pending_pcr_buffer = NULL;
   }
 
-  if (!gst_hlsdemux_tsreader_find_pcrs (&hls_stream->tsreader, buffer,
+  if (!gst_hlsdemux_tsreader_find_pcrs (&hls_stream->tsreader, &buffer,
-          &first_pcr, &last_pcr)
+          &first_pcr, &last_pcr, &tags)
       && !at_eos) {
     // Store this buffer for later
     hls_stream->pending_pcr_buffer = buffer;
     return GST_FLOW_OK;
   }
 
+  if (tags) {
+    gst_adaptive_demux_stream_set_tags (stream, tags);
+  }
+
   if (buffer) {
     buffer = gst_buffer_make_writable (buffer);
     GST_BUFFER_OFFSET (buffer) = hls_stream->current_offset;

ext/hls/gsthlsdemux.h

@@ -154,8 +154,8 @@ struct _GstHLSDemuxClass
 void gst_hlsdemux_tsreader_init (GstHLSTSReader *r);
 void gst_hlsdemux_tsreader_set_type (GstHLSTSReader *r, GstHLSTSReaderType rtype);
 
-gboolean gst_hlsdemux_tsreader_find_pcrs (GstHLSTSReader *r, GstBuffer *buffer,
+gboolean gst_hlsdemux_tsreader_find_pcrs (GstHLSTSReader *r, GstBuffer **buffer,
-    GstClockTime *first_pcr, GstClockTime *last_pcr);
+    GstClockTime *first_pcr, GstClockTime *last_pcr, GstTagList **tags);
 
 GType gst_hls_demux_get_type (void);