Add support for DivX XSUB subtitle streams.

This close #2383
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/codec/avcodec/subtitle.c

@@ -66,6 +66,7 @@ int InitSubtitleDec(decoder_t *dec, AVCodecContext *context,
     /* */
     switch (codec_id) {
     case CODEC_ID_HDMV_PGS_SUBTITLE:
+    case CODEC_ID_XSUB:
         break;
     default:
         msg_Warn(dec, "refusing to decode non validated subtitle codec");

modules/demux/avi/avi.c

@@ -450,6 +450,7 @@ static int Open( vlc_object_t * p_this )
                 {
                    msg_Dbg( p_demux, "stream[%d] subtitles", i );
                    es_format_Init( &fmt, SPU_ES, p_vids->p_bih->biCompression );
+                   tk->i_cat = SPU_ES;
                    break;
                 }
                 else if( p_vids->p_bih->biCompression == 0x00 )
@@ -1921,6 +1922,7 @@ static void AVI_ParseStreamHeader( vlc_fourcc_t i_id,
                 SET_PTR( pi_type, VIDEO_ES );
                 break;
             case AVITWOCC_tx:
+            case AVITWOCC_sb:
                 SET_PTR( pi_type, SPU_ES );
                 break;
             default:

modules/demux/avi/libavi.h

@@ -300,6 +300,8 @@ void    AVI_ChunkFreeRoot( stream_t *, avi_chunk_t  *p_chk );
 #define AVITWOCC_pc            VLC_TWOCC('p','c')
 #define AVITWOCC_AC            VLC_TWOCC('A','C')
 #define AVITWOCC_tx            VLC_TWOCC('t','x')
+#define AVITWOCC_sb            VLC_TWOCC('s','b')
+
     /* *** codex stuff ***  */
 
     /* DV */