mpegtsmux: Properly add subtitle descriptor for DVb subpicture subtitles

We were adding an empty descriptor for them and it was not possible to
actually use them on muxed streams.

gst/mpegtsmux/Makefile.am

@@ -9,6 +9,7 @@ libgstmpegtsmux_la_SOURCES = \
 
 libgstmpegtsmux_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS)
 libgstmpegtsmux_la_LIBADD = $(top_builddir)/gst/mpegtsmux/tsmux/libtsmux.la \
+	-lgsttag-@GST_API_VERSION@ \
 	$(GST_PLUGINS_BASE_LIBS) -lgstvideo-@GST_API_VERSION@ $(GST_BASE_LIBS) $(GST_LIBS)
 libgstmpegtsmux_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
 libgstmpegtsmux_la_LIBTOOLFLAGS = $(GST_PLUGIN_LIBTOOLFLAGS)

gst/mpegtsmux/mpegtsmux.c

@@ -92,6 +92,7 @@
  * with newer GLib versions (>= 2.31.0) */
 #define GLIB_DISABLE_DEPRECATION_WARNINGS
 
+#include <gst/tag/tag.h>
 #include <gst/video/video.h>
 
 #include "mpegtsmux.h"
@@ -340,6 +341,12 @@ mpegtsmux_pad_reset (MpegTsPadData * pad_data)
   /* reference owned elsewhere */
   pad_data->stream = NULL;
   pad_data->prog = NULL;
+
+  if (pad_data->language) {
+    g_free (pad_data->language);
+    pad_data->language = NULL;
+  }
+
 }
 
 static void
@@ -646,7 +653,8 @@ mpegtsmux_create_stream (MpegTsMux * mux, MpegTsPadData * ts_data)
   }
 
   if (st != TSMUX_ST_RESERVED) {
-    ts_data->stream = tsmux_create_stream (mux->tsmux, st, ts_data->pid);
+    ts_data->stream = tsmux_create_stream (mux->tsmux, st, ts_data->pid,
+        ts_data->language);
   } else {
     GST_DEBUG_OBJECT (pad, "Failed to determine stream type");
   }
@@ -781,6 +789,7 @@ mpegtsmux_sink_event (GstCollectPads * pads, GstCollectData * data,
   gboolean forward = TRUE;
 #ifndef GST_DISABLE_GST_DEBUG
   GstPad *pad;
+  MpegTsPadData *pad_data = (MpegTsPadData *) data;
 
   pad = data->pad;
 #endif
@@ -818,6 +827,32 @@ mpegtsmux_sink_event (GstCollectPads * pads, GstCollectData * data,
       gst_event_replace (&mux->force_key_unit_event, event);
       break;
     }
+    case GST_EVENT_TAG:{
+      GstTagList *list;
+      gchar *lang = NULL;
+
+      GST_DEBUG_OBJECT (mux, "received tag event");
+      gst_event_parse_tag (event, &list);
+
+      /* Matroska wants ISO 639-2B code, taglist most likely contains 639-1 */
+      if (gst_tag_list_get_string (list, GST_TAG_LANGUAGE_CODE, &lang)) {
+        const gchar *lang_code;
+
+        lang_code = gst_tag_get_language_code_iso_639_2B (lang);
+        if (lang_code) {
+          GST_DEBUG_OBJECT (pad, "Setting language to '%s'", lang_code);
+          pad_data->language = g_strdup (lang_code);
+        } else {
+          GST_WARNING_OBJECT (pad, "Did not get language code for '%s'", lang);
+        }
+        g_free (lang);
+      }
+
+      /* handled this, don't want collectpads to forward it downstream */
+      res = TRUE;
+      forward = FALSE;
+      break;
+    }
     default:
       break;
   }

gst/mpegtsmux/mpegtsmux.h

@@ -208,6 +208,8 @@ struct MpegTsPadData {
   gint prog_id;
   /* program this stream belongs to == mux->programs[prog_id] */
   TsMuxProgram *prog;
+
+  gchar *language;
 };
 
 GType mpegtsmux_get_type (void);

gst/mpegtsmux/tsmux/tsmux.c

@@ -419,7 +419,8 @@ tsmux_get_new_pid (TsMux * mux)
  * Returns: a new #TsMuxStream.
  */
 TsMuxStream *
-tsmux_create_stream (TsMux * mux, TsMuxStreamType stream_type, guint16 pid)
+tsmux_create_stream (TsMux * mux, TsMuxStreamType stream_type, guint16 pid,
+    gchar * language)
 {
   TsMuxStream *stream;
   guint16 new_pid;
@@ -441,6 +442,11 @@ tsmux_create_stream (TsMux * mux, TsMuxStreamType stream_type, guint16 pid)
   mux->streams = g_list_prepend (mux->streams, stream);
   mux->nb_streams++;
 
+  if (language)
+    g_strlcat (stream->language, language, 3 * sizeof (gchar));
+  else
+    g_strlcat (stream->language, "eng", 3 * sizeof (gchar));
+
   return stream;
 }
 

gst/mpegtsmux/tsmux/tsmux.h

@@ -189,7 +189,7 @@ void 		tsmux_set_pmt_interval          (TsMuxProgram *program, guint interval);
 guint 		tsmux_get_pmt_interval   	(TsMuxProgram *program);
 
 /* stream management */
-TsMuxStream *	tsmux_create_stream 		(TsMux *mux, TsMuxStreamType stream_type, guint16 pid);
+TsMuxStream *	tsmux_create_stream 		(TsMux *mux, TsMuxStreamType stream_type, guint16 pid, gchar *language);
 TsMuxStream *	tsmux_find_stream 		(TsMux *mux, guint16 pid);
 
 void 		tsmux_program_add_stream 	(TsMuxProgram *program, TsMuxStream *stream);

gst/mpegtsmux/tsmux/tsmuxstream.c

@@ -181,6 +181,7 @@ tsmux_stream_new (guint16 pid, TsMuxStreamType stream_type)
     case TSMUX_ST_PS_DVB_SUBPICTURE:
       /* private stream 1 */
       stream->id = 0xBD;
+      stream->is_dvb_sub = TRUE;
       stream->stream_type = TSMUX_ST_PRIVATE_DATA;
       stream->pi.flags |=
           TSMUX_PACKET_FLAG_PES_FULL_HEADER |
@@ -877,13 +878,6 @@ tsmux_stream_get_es_descrs (TsMuxStream * stream, guint8 * buf, guint16 * len)
     case TSMUX_ST_PS_AUDIO_LPCM:
       /* FIXME */
       break;
-    case TSMUX_ST_PS_DVB_SUBPICTURE:
-      /* tag */
-      *pos++ = 0x59;
-      /* FIXME empty descriptor for now;
-       * should be provided by upstream in event or so ? */
-      *pos = 0;
-      break;
     case TSMUX_ST_PS_TELETEXT:
       /* tag */
       *pos++ = 0x56;
@@ -891,6 +885,26 @@ tsmux_stream_get_es_descrs (TsMuxStream * stream, guint8 * buf, guint16 * len)
        * should be provided by upstream in event or so ? */
       *pos = 0;
       break;
+    case TSMUX_ST_PS_DVB_SUBPICTURE:
+      /* falltrough ...
+       * that should never happen anyway as
+       * dvb subtitles are private data */
+    case TSMUX_ST_PRIVATE_DATA:
+      if (stream->is_dvb_sub) {
+        GST_DEBUG ("Stream language %s", stream->language);
+        *pos++ = 0x59;          /* dvb subtitles */
+        *pos++ = 0x08;          /* descriptor length */
+        *pos++ = stream->language[0];   /* Language */
+        *pos++ = stream->language[1];
+        *pos++ = stream->language[2];
+        *pos++ = 0x10;          /* Simple DVB subtitles with no monitor aspect ratio critical
+                                   FIXME, how do we make it settable? */
+        *pos++ = 0x00;          /* Default composition page ID */
+        *pos++ = 0x01;
+        *pos++ = 0x01;          /* Default ancillary_page_id */
+        *pos++ = 0x52;
+        break;
+      }
     default:
       break;
   }

gst/mpegtsmux/tsmux/tsmuxstream.h

@@ -203,6 +203,9 @@ struct TsMuxStream {
   gint audio_sampling;
   gint audio_channels;
   gint audio_bitrate;
+
+  gboolean is_dvb_sub;
+  gchar language[4];
 };
 
 /* stream management */