[MPlayer-dev-eng] [PATCH] Ogg demuxer & subtitle handling

[Moritz Bunkus]

Hi.

The attached patch changes/fixes the subtitle clearing for
subtitles-in-OGMs.

1) Upon seeking the subtitles currently displayed will be erased.

2) The demuxer now evaluates the 'length' header field present on each
subtitle packet and erases the subtitles after the length specified in
this field. Before it would rely on the fact that there are empty
subtitle packets whenever the current subtitles should be erased.
Unfortunately there are broken files that do NOT contain these empty
packets - and subtitles would be displayed until the next subtitle
appeared. Using the 'length' header is also the correct way to do
things.

If no 'length' header is available (hdrlen == 0) then no clearing is
done.

Ok to commit?

-- 
 ==> Ciao, Mosu (Moritz Bunkus)
-------------- next part --------------
Index: demux_ogg.c
===================================================================
RCS file: /cvsroot/mplayer/main/libmpdemux/demux_ogg.c,v
retrieving revision 1.23
diff -u -r1.23 demux_ogg.c
--- demux_ogg.c	30 Dec 2002 08:59:33 -0000	1.23
+++ demux_ogg.c	4 Jan 2003 12:24:00 -0000
@@ -128,6 +128,7 @@
 
 static subtitle ogg_sub;
 extern subtitle* vo_sub;
+static float clear_sub;
 //FILE* subout;
 
 static
@@ -188,10 +189,11 @@
   }
 }
 
-void demux_ogg_add_sub (char* packet) {
+void demux_ogg_add_sub (ogg_stream_t* os,ogg_packet* pack) {
   int lcv;
   int line_pos = 0;
   int ignoring = 0;
+  char *packet = pack->packet;
 
   mp_msg(MSGT_DEMUX,MSGL_DBG2,"\ndemux_ogg_add_sub %02X %02X %02X '%s'\n",
       (unsigned char)packet[0],
@@ -201,7 +203,22 @@
 
   ogg_sub.lines = 0;
   if (((unsigned char)packet[0]) == 0x88) { // some subtitle text
-    lcv = 3;
+    // Find data start
+    int32_t duration = 0;
+    int16_t hdrlen = (*packet & PACKET_LEN_BITS01)>>6, i;
+    hdrlen |= (*packet & PACKET_LEN_BITS2) <<1;
+    lcv = 1 + hdrlen;
+    for (i = hdrlen; i > 0; i--) {
+      duration <<= 8;
+      duration |= (unsigned char)packet[i];
+    }
+    if ((hdrlen > 0) && (duration > 0)) {
+      float pts;
+      if(pack->granulepos == -1)
+        pack->granulepos = os->lastpos + os->lastsize;
+      pts = (float)pack->granulepos/(float)os->samplerate;
+      clear_sub = pts + (float)duration/1000.0;
+    }
     while (1) {
       int c = packet[lcv++];
       if(c=='\n' || c==0 || line_pos >= OGG_SUB_MAX_LINE-1){
@@ -319,7 +336,7 @@
   int flags = 0;
 
   if (ds == d->sub) { // don't want to add subtitles to the demuxer for now
-    demux_ogg_add_sub(pack->packet);
+    demux_ogg_add_sub(os,pack);
     return 0;
   }
   // If packet is an header we jump it except for vorbis
@@ -334,7 +351,13 @@
   else
     data = demux_ogg_read_packet(os,pack,NULL,&pts,&flags);
 
-
+  /// Clear subtitles if necessary (for broken files)
+  if ((clear_sub > 0) && (pts >= clear_sub)) {
+    ogg_sub.lines = 0;
+    vo_sub = &ogg_sub;
+    vo_osd_changed(OSDTYPE_SUBTITLE);
+    clear_sub = -1;
+  }
   /// Send the packet
   dp = new_demux_packet(pack->bytes-(data-pack->packet));
   memcpy(dp->buffer,data,pack->bytes-(data-pack->packet));
@@ -472,6 +495,7 @@
   subcp_open();
 #endif
 
+  clear_sub = -1;
   s = demuxer->stream;
 
   ogg_d = (ogg_demuxer_t*)calloc(1,sizeof(ogg_demuxer_t));
@@ -640,6 +664,7 @@
       } else if (strncmp(st->streamtype, "text", 4) == 0) {
           mp_msg(MSGT_DEMUX, MSGL_V, "OGG stream %d is text\n", ogg_d->num_sub);
           if(demuxer->sub->id==-1) demuxer->sub->id = ogg_d->num_sub;
+	  ogg_d->subs[ogg_d->num_sub].samplerate= get_uint64(&st->time_unit)/10;
           n_text++;
           demux_ogg_init_sub();
 	//// Unknow header type
@@ -1002,6 +1027,10 @@
       
       if( ((*op.packet & PACKET_IS_SYNCPOINT)  || os->vorbis )  &&
 	  (!ogg_d->syncpoints || op.granulepos >= gp) ) {
+        ogg_sub.lines = 0;
+        vo_sub = &ogg_sub;
+        vo_osd_changed(OSDTYPE_SUBTITLE);
+        clear_sub = -1;
 	demux_ogg_add_packet(ds,os,&op);
 	if(sh_audio)
 	  resync_audio_stream(sh_audio);