Added CD+G file support:

 - as a standalone file
 - as a kind of subtitle (even if it is a video track).
CD-G disk are not supported.

Please, report any file incorrectly decoded. (I have 0 sample with
circular scrolling)

In subtitle_Detect, do not add as a subtitle the file for which we
are doing the detection.
 (subtitle_Detect("file.sub") returned "file.sub")

modules/demux/cdg.c

+/*****************************************************************************
+ * cdg.c : cdg file demux module for vlc
+ *****************************************************************************
+ * Copyright (C) 2007 Laurent Aimar
+ * $Id: $
+ *
+ * Authors: Laurent Aimar <fenrir # via.ecp.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+
+#include <vlc/vlc.h>
+#include <vlc_demux.h>
+
+#include <vlc_codecs.h>
+
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+static int  Open ( vlc_object_t * );
+static void Close( vlc_object_t * );
+
+vlc_module_begin();
+    set_description( _("CDG demuxer") );
+    set_category( CAT_INPUT );
+    set_subcategory( SUBCAT_INPUT_DEMUX );
+    set_capability( "demux2", 2 );
+    set_callbacks( Open, Close );
+    add_shortcut( "cdg" );
+    add_shortcut( "subtitle" );
+vlc_module_end();
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static int Demux  ( demux_t * );
+static int Control( demux_t *, int i_query, va_list args );
+
+struct demux_sys_t
+{
+    es_format_t     fmt;
+    es_out_id_t     *p_es;
+
+    date_t          pts;
+};
+
+#define CDG_FRAME_SIZE (96)
+#define CDG_FRAME_RATE (75)
+
+/*****************************************************************************
+ * Open: check file and initializes structures
+ *****************************************************************************/
+static int Open( vlc_object_t * p_this )
+{
+    demux_t     *p_demux = (demux_t*)p_this;
+    demux_sys_t *p_sys;
+
+    /* Identify cdg file by extension, as there is no simple way to
+     * detect it */
+    if( !demux2_IsPathExtension( p_demux, ".cdg" ) &&
+        !demux2_IsPathExtension( p_demux, ".CDG" ) &&
+        !demux2_IsForced( p_demux, "cdg" ) )
+        return VLC_EGENERIC;
+
+    /* CDG file size has to be multiple of CDG_FRAME_SIZE (it works even
+     * if size is unknown ie 0) */
+//    if( (stream_Size( p_demux->s ) % CDG_FRAME_SIZE) != 0 )
+//    {
+//        msg_Err( p_demux, "Reject CDG file based on its size" );
+//        return VLC_EGENERIC;
+//    }
+
+    p_demux->pf_demux   = Demux;
+    p_demux->pf_control = Control;
+    p_demux->p_sys      = p_sys = malloc( sizeof( demux_sys_t ) );
+
+    /* */
+    es_format_Init( &p_sys->fmt, VIDEO_ES, VLC_FOURCC('C','D','G', ' ' ) );
+    p_sys->fmt.video.i_width  = 300-2*6;
+    p_sys->fmt.video.i_height = 216-2*12 ;
+
+    p_sys->p_es = es_out_Add( p_demux->out, &p_sys->fmt );
+
+    /* There is CDG_FRAME_RATE frames per second */
+    date_Init( &p_sys->pts, CDG_FRAME_RATE, 1 );
+    date_Set( &p_sys->pts, 1 );
+
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * Demux: read packet and send them to decoders
+ *****************************************************************************
+ * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
+ *****************************************************************************/
+static int Demux( demux_t *p_demux )
+{
+    demux_sys_t *p_sys = p_demux->p_sys;
+    block_t     *p_block;
+
+    p_block = stream_Block( p_demux->s, CDG_FRAME_SIZE );
+    if( p_block == NULL )
+    {
+        msg_Dbg( p_demux, "cannot read data, eof" );
+        return 0;
+    }
+
+    p_block->i_dts =
+    p_block->i_pts = date_Increment( &p_sys->pts, 1 );
+
+    es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block->i_pts );
+
+    es_out_Send( p_demux->out, p_sys->p_es, p_block );
+    return 1;
+}
+
+/*****************************************************************************
+ * Close: frees unused data
+ *****************************************************************************/
+static void Close ( vlc_object_t * p_this )
+{
+    demux_t *p_demux = (demux_t *)p_this;
+    demux_sys_t *p_sys = p_demux->p_sys;
+
+    free( p_sys );
+}
+
+/*****************************************************************************
+ * Control:
+ *****************************************************************************/
+static int Control( demux_t *p_demux, int i_query, va_list args )
+{
+    demux_sys_t *p_sys  = p_demux->p_sys;
+    int64_t *pi64;
+
+    switch( i_query )
+    {
+#if 0
+    case DEMUX_GET_TIME:
+        pi64 = (int64_t*)va_arg( args, int64_t * );
+        *pi64 = date_Get( &p_sys->pts );
+        return VLC_SUCCESS;
+#endif
+    default:
+        return demux2_vaControlHelper( p_demux->s, 0, -1,
+                                       8*CDG_FRAME_SIZE*CDG_FRAME_RATE, CDG_FRAME_SIZE, i_query, args );
+    }
+}
+

src/input/subtitles.c

@@ -59,7 +59,11 @@
 static const char const sub_exts[][6] = {
     "utf", "utf8", "utf-8",
     "sub", "srt", "smi",
-    "txt", "ssa", "idx", ""
+    "txt", "ssa", "idx",
+
+    "cdg",
+
+    ""
 };
 
 /* extensions from unsupported types */
@@ -400,6 +404,9 @@ char **subtitles_Detect( input_thread_t *p_this, char *psz_path,
                     struct stat st;
 
                     sprintf( psz_path, "%s%s", psz_dir, psz_name );
+                    if( !strcmp( psz_path, psz_fname ) )
+                        continue;
+
                     msg_Dbg( p_this,
                                 "autodetected subtitle: %s with priority %d",
                                 psz_path, i_prio );
@@ -460,6 +467,14 @@ char **subtitles_Detect( input_thread_t *p_this, char *psz_path,
                 i_result2++;
             }
         }
+        else if( result[j].psz_ext && !strcasecmp( result[j].psz_ext, "cdg" ) )
+        {
+            if( result[j].priority == 4 )
+            {
+                result2[i_result2] = result[j].psz_fname;
+                i_result2++;
+            }
+        }
         else
         {
             result2[i_result2] = result[j].psz_fname;