modules/demux/nsc.c

   1 /*****************************************************************************
   2  * nsc.c: NSC file demux and encoding decoder
   3  *****************************************************************************
   4  * Copyright (C) 2005 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Jon Lech Johansen <jon@nanocrew.net>
   8  *          Derk-Jan Hartman <hartman at videolan dot org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_demux.h>
  35 #include <vlc_charset.h>
  36
  37 #include <ctype.h>
  38 #define MAX_LINE 16024
  39
  40 /*****************************************************************************
  41  * Module descriptor
  42  *****************************************************************************/
  43 static int  DemuxOpen  ( vlc_object_t * );
  44 static void DemuxClose ( vlc_object_t * );
  45
  46 vlc_module_begin ()
  47     set_description( N_("Windows Media NSC metademux") )
  48     set_category( CAT_INPUT )
  49     set_subcategory( SUBCAT_INPUT_DEMUX )
  50     set_capability( "demux", 3 )
  51     set_callbacks( DemuxOpen, DemuxClose )
  52 vlc_module_end ()
  53
  54 static int Demux ( demux_t *p_demux );
  55 static int Control( demux_t *p_demux, int i_query, va_list args );
  56
  57 static const unsigned char inverse[ 128 ] =
  58 {
  59     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  60     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  61     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  62     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  63     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0xFF, 0xFF,
  64     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10,
  65     0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C,
  66     0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  67     0xFF, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E,
  68     0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
  69     0x3B, 0x3C, 0x3D, 0x3E, 0xFF, 0x3F, 0xFF, 0xFF
  70 };
  71
  72 static int load_byte( unsigned char encoding_type,
  73                       unsigned char *output, char **input,
  74                       unsigned char *j, unsigned char *k )
  75 {
  76     *output = 0;
  77
  78     if( encoding_type == 1 )
  79     {
  80         if( isxdigit( (unsigned char)**input ) == 0 )
  81             return -1;
  82
  83         if( isdigit( (unsigned char)**input ) == 0 )
  84             *output = (toupper( (unsigned char)**input ) - 7) * 16;
  85         else
  86             *output = **input * 16;
  87
  88         (*input)++;
  89
  90         if( isxdigit( (unsigned char)**input ) == 0 )
  91             return -1;
  92
  93         if( isdigit( (unsigned char)**input ) == 0 )
  94             *output |= toupper( (unsigned char)**input ) - 0x37;
  95         else
  96             *output |= **input - 0x30;
  97
  98         (*input)++;
  99     }
 100     else if( encoding_type == 2 )
 101     {
 102         unsigned char **uinput = (unsigned char **)input;
 103
 104         if( **uinput > 127 || inverse[ **uinput ] == 0xFF )
 105             return -1;
 106
 107         if( *k == 0 )
 108         {
 109             if( (*uinput)[ 1 ] > 127 || inverse[ (*uinput)[ 1 ] ] == 0xFF )
 110                 return -1;
 111
 112             *output = (inverse[ (*uinput)[ 0 ] ] * 4) |
 113                         (inverse[ (*uinput)[ 1 ] ] / 16);
 114
 115             *j = inverse[ (*uinput)[ 1 ] ] * 16;
 116             *k = 4;
 117
 118             (*uinput) += 2;
 119         }
 120         else if( *k == 2 )
 121         {
 122             *output = *j | inverse[ **uinput ];
 123
 124             *j = 0;
 125             *k = 0;
 126
 127             (*uinput)++;
 128         }
 129         else if( *k == 4 )
 130         {
 131             *output = (inverse[ **uinput ] / 4) | *j;
 132
 133             *j = inverse[ **uinput ] * 64;
 134             *k = 2;
 135
 136             (*uinput)++;
 137         }
 138     }
 139
 140     return 0;
 141 }
 142
 143 static char *nscdec( vlc_object_t *p_demux, char* p_encoded )
 144 {
 145     unsigned int i;
 146     unsigned char tmp;
 147     unsigned char j, k;
 148     unsigned int length;
 149     unsigned char encoding_type;
 150
 151     unsigned char *buf16;
 152     char *buf8;
 153
 154     char *p_input = p_encoded;
 155
 156     if( strlen( p_input ) < 15 )
 157     {
 158         msg_Err( p_demux, "input string less than 15 characters" );
 159         return NULL;
 160     }
 161
 162     if( load_byte( 1, &encoding_type, &p_input, NULL, NULL ) )
 163     {
 164         msg_Err( p_demux, "unable to get NSC encoding type" );
 165         return NULL;
 166     }
 167
 168     if( encoding_type != 1 && encoding_type != 2 )
 169     {
 170         msg_Err( p_demux, "encoding type %d is not supported",
 171                  encoding_type );
 172         return NULL;
 173     }
 174
 175     j = k = 0;
 176
 177     if( load_byte( encoding_type, &tmp, &p_input, &j, &k ) )
 178     {
 179         msg_Err( p_demux, "load_byte failed" );
 180         return NULL;
 181     }
 182
 183     for( i = 0; i < 4; i++ )
 184     {
 185         if( load_byte( encoding_type, &tmp, &p_input, &j, &k ) )
 186         {
 187             msg_Err( p_demux, "load_byte failed" );
 188             return NULL;
 189         }
 190     }
 191
 192     length = 0;
 193     for( i = 4; i; i-- )
 194     {
 195         if( load_byte( encoding_type, &tmp, &p_input, &j, &k ) )
 196         {
 197             msg_Err( p_demux, "load_byte failed" );
 198             return NULL;
 199         }
 200         length |= tmp << ((i - 1) * 8);
 201     }
 202
 203     if( length == 0 )
 204     {
 205         msg_Err( p_demux, "Length is 0" );
 206         return NULL;
 207     }
 208
 209     buf16 = malloc( length );
 210     if( buf16 == NULL )
 211         return NULL;
 212
 213     for( i = 0; i < length; i++ )
 214     {
 215         if( load_byte( encoding_type, &buf16[ i ], &p_input, &j, &k ) )
 216         {
 217             msg_Err( p_demux, "load_byte failed" );
 218             free( buf16 );
 219             return NULL;
 220         }
 221     }
 222
 223     buf8 = FromCharset( "UTF-16LE", buf16, length );
 224     free( buf16 );
 225     if( buf8 == NULL )
 226     {
 227         msg_Err( p_demux, "iconv failed" );
 228         return NULL;
 229     }
 230     return buf8;
 231 }
 232
 233 static int DemuxOpen( vlc_object_t * p_this )
 234 {
 235     demux_t *p_demux = (demux_t *)p_this;
 236     const uint8_t *p_peek;
 237     int i_size;
 238
 239     /* Lets check the content to see if this is a NSC file */
 240     i_size = stream_Peek( p_demux->s, &p_peek, MAX_LINE );
 241     i_size -= sizeof("NSC Format Version=") - 1;
 242
 243     if ( i_size > 0 )
 244     {
 245         while ( i_size && strncasecmp( (char *)p_peek, "NSC Format Version=",
 246                                        (int) sizeof("NSC Format Version=") - 1 ) )
 247         {
 248             p_peek++;
 249             i_size--;
 250         }
 251         if ( !strncasecmp( (char *)p_peek, "NSC Format Version=",
 252                            (int) sizeof("NSC Format Version=") -1 ) )
 253         {
 254             p_demux->pf_demux = Demux;
 255             p_demux->pf_control = Control;
 256             return VLC_SUCCESS;
 257         }
 258     }
 259     return VLC_EGENERIC;
 260 }
 261
 262
 263 /*****************************************************************************
 264  * Deactivate: frees unused data
 265  *****************************************************************************/
 266 static void DemuxClose( vlc_object_t *p_this )
 267 {
 268     VLC_UNUSED( p_this );
 269     return;
 270 }
 271
 272 static int ParseLine ( demux_t *p_demux, char *psz_line )
 273 {
 274     char        *psz_bol;
 275     char        *psz_value;
 276
 277     psz_bol = psz_line;
 278     /* Remove unnecessary tabs or spaces at the beginning of line */
 279     while( *psz_bol == ' ' || *psz_bol == '\t' ||
 280            *psz_bol == '\n' || *psz_bol == '\r' )
 281     {
 282         psz_bol++;
 283     }
 284     psz_value = strchr( psz_bol, '=' );
 285     if( psz_value == NULL )
 286     {
 287         return 0; /* a [Address] or [Formats] line or something else we will ignore */
 288     }
 289     *psz_value = '\0';
 290     psz_value++;
 291
 292     if( !strncasecmp( psz_value, "0x", 2 ) )
 293     {
 294         int i_value;
 295         sscanf( psz_value, "%x", &i_value );
 296         msg_Dbg( p_demux, "%s = %d", psz_bol, i_value );
 297     }
 298     else if( !strncasecmp( psz_bol, "Format", 6 ) )
 299     {
 300         msg_Dbg( p_demux, "%s = asf header", psz_bol );
 301     }
 302     else
 303     {
 304         /* This should be NSC encoded strings in the values */
 305         char *psz_out;
 306         psz_out = nscdec( (vlc_object_t *)p_demux, psz_value );
 307         if( psz_out )
 308         {
 309             msg_Dbg( p_demux, "%s = %s", psz_bol, psz_out );
 310             free( psz_out );
 311         }
 312     }
 313     return VLC_SUCCESS;
 314 }
 315
 316 /*****************************************************************************
 317  * Demux: reads and demuxes data packets
 318  *****************************************************************************
 319  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 320  *****************************************************************************/
 321 static int Demux ( demux_t *p_demux )
 322 {
 323     char            *psz_line;
 324
 325     while( ( psz_line = stream_ReadLine( p_demux->s ) ) )
 326     {
 327         ParseLine( p_demux, psz_line );
 328         free( psz_line );
 329     }
 330     return VLC_SUCCESS;
 331 }
 332
 333 static int Control( demux_t *p_demux, int i_query, va_list args )
 334 {
 335     VLC_UNUSED( p_demux ); VLC_UNUSED( i_query ); VLC_UNUSED( args );
 336     //FIXME
 337     return VLC_EGENERIC;
 338 }