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
  36 #include <ctype.h>
  37 #define MAX_LINE 16024
  38
  39 /*****************************************************************************
  40  * Module descriptor
  41  *****************************************************************************/
  42 static int  DemuxOpen  ( vlc_object_t * );
  43 static void DemuxClose ( vlc_object_t * );
  44
  45 vlc_module_begin ()
  46     set_description( N_("Windows Media NSC metademux") )
  47     set_category( CAT_INPUT )
  48     set_subcategory( SUBCAT_INPUT_DEMUX )
  49     set_capability( "demux", 3 )
  50     set_callbacks( DemuxOpen, DemuxClose )
  51 vlc_module_end ()
  52
  53 static int Demux ( demux_t *p_demux );
  54 static int Control( demux_t *p_demux, int i_query, va_list args );
  55
  56 static const unsigned char inverse[ 128 ] =
  57 {
  58     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  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     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0xFF, 0xFF,
  63     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10,
  64     0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C,
  65     0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  66     0xFF, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E,
  67     0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
  68     0x3B, 0x3C, 0x3D, 0x3E, 0xFF, 0x3F, 0xFF, 0xFF
  69 };
  70
  71 static int load_byte( unsigned char encoding_type,
  72                       unsigned char *output, char **input,
  73                       unsigned char *j, unsigned char *k )
  74 {
  75     *output = 0;
  76
  77     if( encoding_type == 1 )
  78     {
  79         if( isxdigit( **input ) == 0 )
  80             return -1;
  81
  82         if( isdigit( **input ) == 0 )
  83             *output = (toupper( **input ) - 7) * 16;
  84         else
  85             *output = **input * 16;
  86
  87         (*input)++;
  88
  89         if( isxdigit( **input ) == 0 )
  90             return -1;
  91
  92         if( isdigit( **input ) == 0 )
  93             *output |= toupper( **input ) - 0x37;
  94         else
  95             *output |= **input - 0x30;
  96
  97         (*input)++;
  98     }
  99     else if( encoding_type == 2 )
 100     {
 101         unsigned char **uinput = (unsigned char **)input;
 102
 103         if( **uinput > 127 || inverse[ **uinput ] == 0xFF )
 104             return -1;
 105
 106         if( *k == 0 )
 107         {
 108             if( (*uinput)[ 1 ] > 127 || inverse[ (*uinput)[ 1 ] ] == 0xFF )
 109                 return -1;
 110
 111             *output = (inverse[ (*uinput)[ 0 ] ] * 4) |
 112                         (inverse[ (*uinput)[ 1 ] ] / 16);
 113
 114             *j = inverse[ (*uinput)[ 1 ] ] * 16;
 115             *k = 4;
 116
 117             (*uinput) += 2;
 118         }
 119         else if( *k == 2 )
 120         {
 121             *output = *j | inverse[ **uinput ];
 122
 123             *j = 0;
 124             *k = 0;
 125
 126             (*uinput)++;
 127         }
 128         else if( *k == 4 )
 129         {
 130             *output = (inverse[ **uinput ] / 4) | *j;
 131
 132             *j = inverse[ **uinput ] * 64;
 133             *k = 2;
 134
 135             (*uinput)++;
 136         }
 137     }
 138
 139     return 0;
 140 }
 141
 142 static char *nscdec( vlc_object_t *p_demux, char* p_encoded )
 143 {
 144     unsigned int i;
 145     unsigned char tmp;
 146     unsigned char j, k;
 147     unsigned int length;
 148     unsigned char encoding_type;
 149
 150     vlc_iconv_t conv;
 151     size_t buf16_size;
 152     unsigned char *buf16;
 153     const char *p_buf16;
 154     size_t buf8_size;
 155     char *buf8;
 156     char *p_buf8;
 157
 158     char *p_input = p_encoded;
 159
 160     if( strlen( p_input ) < 15 )
 161     {
 162         msg_Err( p_demux, "input string less than 15 characters" );
 163         return NULL;
 164     }
 165
 166     if( load_byte( 1, &encoding_type, &p_input, NULL, NULL ) )
 167     {
 168         msg_Err( p_demux, "unable to get NSC encoding type" );
 169         return NULL;
 170     }
 171
 172     if( encoding_type != 1 && encoding_type != 2 )
 173     {
 174         msg_Err( p_demux, "encoding type %d is not supported",
 175                  encoding_type );
 176         return NULL;
 177     }
 178
 179     j = k = 0;
 180
 181     if( load_byte( encoding_type, &tmp, &p_input, &j, &k ) )
 182     {
 183         msg_Err( p_demux, "load_byte failed" );
 184         return NULL;
 185     }
 186
 187     for( i = 0; i < 4; i++ )
 188     {
 189         if( load_byte( encoding_type, &tmp, &p_input, &j, &k ) )
 190         {
 191             msg_Err( p_demux, "load_byte failed" );
 192             return NULL;
 193         }
 194     }
 195
 196     length = 0;
 197     for( i = 4; i; i-- )
 198     {
 199         if( load_byte( encoding_type, &tmp, &p_input, &j, &k ) )
 200         {
 201             msg_Err( p_demux, "load_byte failed" );
 202             return NULL;
 203         }
 204         length |= tmp << ((i - 1) * 8);
 205     }
 206
 207     if( length == 0 )
 208     {
 209         msg_Err( p_demux, "Length is 0" );
 210         return NULL;
 211     }
 212
 213     buf16_size = length;
 214     buf16 = malloc( buf16_size );
 215     if( buf16 == NULL )
 216         return NULL;
 217
 218     for( i = 0; i < length; i++ )
 219     {
 220         if( load_byte( encoding_type, &buf16[ i ], &p_input, &j, &k ) )
 221         {
 222             msg_Err( p_demux, "load_byte failed" );
 223             free( buf16 );
 224             return NULL;
 225         }
 226     }
 227
 228     buf8_size = length;
 229     buf8 = malloc( buf8_size + 1 );
 230     if( buf8 == NULL )
 231     {
 232         free( buf16 );
 233         return NULL;
 234     }
 235
 236     conv = vlc_iconv_open( "UTF-8", "UTF-16LE" );
 237     if( conv == (vlc_iconv_t)(-1) )
 238     {
 239         msg_Err( p_demux, "iconv_open failed" );
 240         free( buf16 );
 241         free( buf8 );
 242         return NULL;
 243     }
 244
 245     p_buf8 = buf8;
 246     p_buf16 = (const char *)buf16;
 247
 248     if( vlc_iconv( conv, &p_buf16, &buf16_size, &p_buf8, &buf8_size ) == (size_t)(-1) )
 249     {
 250         msg_Err( p_demux, "iconv failed" );
 251         return NULL;
 252     }
 253     else
 254     {
 255         buf8[ length - buf8_size ] = '\0';
 256     }
 257
 258     vlc_iconv_close( conv );
 259
 260     free( buf16 );
 261     return buf8;
 262 }
 263
 264 static int DemuxOpen( vlc_object_t * p_this )
 265 {
 266     demux_t *p_demux = (demux_t *)p_this;
 267     const uint8_t *p_peek;
 268     int i_size;
 269
 270     /* Lets check the content to see if this is a NSC file */
 271     i_size = stream_Peek( p_demux->s, &p_peek, MAX_LINE );
 272     i_size -= sizeof("NSC Format Version=") - 1;
 273
 274     if ( i_size > 0 )
 275     {
 276         while ( i_size && strncasecmp( (char *)p_peek, "NSC Format Version=",
 277                                        (int) sizeof("NSC Format Version=") - 1 ) )
 278         {
 279             p_peek++;
 280             i_size--;
 281         }
 282         if ( !strncasecmp( (char *)p_peek, "NSC Format Version=",
 283                            (int) sizeof("NSC Format Version=") -1 ) )
 284         {
 285             p_demux->pf_demux = Demux;
 286             p_demux->pf_control = Control;
 287             return VLC_SUCCESS;
 288         }
 289     }
 290     return VLC_EGENERIC;
 291 }
 292
 293
 294 /*****************************************************************************
 295  * Deactivate: frees unused data
 296  *****************************************************************************/
 297 static void DemuxClose( vlc_object_t *p_this )
 298 {
 299     VLC_UNUSED( p_this );
 300     return;
 301 }
 302
 303 static int ParseLine ( demux_t *p_demux, char *psz_line )
 304 {
 305     char        *psz_bol;
 306     char        *psz_value;
 307
 308     psz_bol = psz_line;
 309     /* Remove unnecessary tabs or spaces at the beginning of line */
 310     while( *psz_bol == ' ' || *psz_bol == '\t' ||
 311            *psz_bol == '\n' || *psz_bol == '\r' )
 312     {
 313         psz_bol++;
 314     }
 315     psz_value = strchr( psz_bol, '=' );
 316     if( psz_value == NULL )
 317     {
 318         return 0; /* a [Address] or [Formats] line or something else we will ignore */
 319     }
 320     *psz_value = '\0';
 321     psz_value++;
 322
 323     if( !strncasecmp( psz_value, "0x", 2 ) )
 324     {
 325         int i_value;
 326         sscanf( psz_value, "%x", &i_value );
 327         msg_Dbg( p_demux, "%s = %d", psz_bol, i_value );
 328     }
 329     else if( !strncasecmp( psz_bol, "Format", 6 ) )
 330     {
 331         msg_Dbg( p_demux, "%s = asf header", psz_bol );
 332     }
 333     else
 334     {
 335         /* This should be NSC encoded strings in the values */
 336         char *psz_out;
 337         psz_out = nscdec( (vlc_object_t *)p_demux, psz_value );
 338         if( psz_out )
 339         {
 340             msg_Dbg( p_demux, "%s = %s", psz_bol, psz_out );
 341             free( psz_out );
 342         }
 343     }
 344     return VLC_SUCCESS;
 345 }
 346
 347 /*****************************************************************************
 348  * Demux: reads and demuxes data packets
 349  *****************************************************************************
 350  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 351  *****************************************************************************/
 352 static int Demux ( demux_t *p_demux )
 353 {
 354     char            *psz_line;
 355
 356     while( ( psz_line = stream_ReadLine( p_demux->s ) ) )
 357     {
 358         ParseLine( p_demux, psz_line );
 359         free( psz_line );
 360     }
 361     return VLC_SUCCESS;
 362 }
 363
 364 static int Control( demux_t *p_demux, int i_query, va_list args )
 365 {
 366     VLC_UNUSED( p_demux ); VLC_UNUSED( i_query ); VLC_UNUSED( args );
 367     //FIXME
 368     return VLC_EGENERIC;
 369 }