modules/demux/mod.c

   1 /*****************************************************************************
   2  * mod.c: MOD file demuxer (using libmodplug)
   3  *****************************************************************************
   4  * Copyright (C) 2004-2009 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  * Konstanty Bialkowski <konstanty@ieee.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
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_demux.h>
  36 #include <vlc_meta.h>
  37 #include <assert.h>
  38
  39 #include <libmodplug/modplug.h>
  40
  41 /* TODO:
  42  *  - extend demux control to query meta data (demuxer should NEVER touch
  43  *      playlist itself)
  44  *  - FIXME test endian of samples
  45  *  - ...
  46  */
  47
  48 /*****************************************************************************
  49  * Module descriptor
  50  *****************************************************************************/
  51 static int  Open    ( vlc_object_t * );
  52 static void Close  ( vlc_object_t * );
  53
  54 #define NOISE_LONGTEXT N_("Enable noise reduction algorithm.")
  55 #define REVERB_LONGTEXT N_("Enable reverberation" )
  56 #define REVERB_LEVEL_LONGTEXT N_( "Reverberation level (from 0 " \
  57                 "to 100, default value is 0)." )
  58 #define REVERB_DELAY_LONGTEXT N_("Reverberation delay, in ms." \
  59                 " Usual values are from to 40 to 200ms." )
  60 #define MEGABASS_LONGTEXT N_( "Enable megabass mode" )
  61 #define MEGABASS_LEVEL_LONGTEXT N_("Megabass mode level (from 0 to 100, " \
  62                 "default value is 0)." )
  63 #define MEGABASS_RANGE_LONGTEXT N_("Megabass mode cutoff frequency, in Hz. " \
  64                 "This is the maximum frequency for which the megabass " \
  65                 "effect applies. Valid values are from 10 to 100 Hz." )
  66 #define SURROUND_LEVEL_LONGTEXT N_( "Surround effect level (from 0 to 100, " \
  67                 "default value is 0)." )
  68 #define SURROUND_DELAY_LONGTEXT N_("Surround delay, in ms. Usual values are " \
  69                 "from 5 to 40 ms." )
  70
  71 vlc_module_begin ()
  72     set_shortname( "MOD")
  73     set_description( N_("MOD demuxer (libmodplug)" ) )
  74     set_capability( "demux", 10 )
  75     set_category( CAT_INPUT )
  76     set_subcategory( SUBCAT_INPUT_DEMUX )
  77
  78     add_bool( "mod-noisereduction", true, N_("Noise reduction"),
  79               NOISE_LONGTEXT, false )
  80
  81     add_bool( "mod-reverb", false, N_("Reverb"),
  82               REVERB_LONGTEXT, false )
  83     add_integer_with_range( "mod-reverb-level", 0, 0, 100,
  84              N_("Reverberation level"), REVERB_LEVEL_LONGTEXT, true )
  85     add_integer_with_range( "mod-reverb-delay", 40, 0, 1000,
  86              N_("Reverberation delay"), REVERB_DELAY_LONGTEXT, true )
  87
  88     add_bool( "mod-megabass", false, N_("Mega bass"),
  89                     MEGABASS_LONGTEXT, false )
  90     add_integer_with_range( "mod-megabass-level", 0, 0, 100,
  91               N_("Mega bass level"), MEGABASS_LEVEL_LONGTEXT, true )
  92     add_integer_with_range( "mod-megabass-range", 10, 10, 100,
  93               N_("Mega bass cutoff"), MEGABASS_RANGE_LONGTEXT, true )
  94
  95     add_bool( "mod-surround", false, N_("Surround"), N_("Surround"),
  96                false )
  97     add_integer_with_range( "mod-surround-level", 0, 0, 100,
  98               N_("Surround level"), SURROUND_LEVEL_LONGTEXT, true )
  99     add_integer_with_range( "mod-surround-delay", 5, 0, 1000,
 100               N_("Surround delay (ms)"), SURROUND_DELAY_LONGTEXT, true )
 101
 102     set_callbacks( Open, Close )
 103     add_shortcut( "mod" )
 104 vlc_module_end ()
 105
 106 /*****************************************************************************
 107  * Local prototypes
 108  *****************************************************************************/
 109 static vlc_mutex_t libmodplug_lock = VLC_STATIC_MUTEX;
 110
 111 struct demux_sys_t
 112 {
 113     es_format_t  fmt;
 114     es_out_id_t *es;
 115
 116     date_t      pts;
 117     int64_t     i_length;
 118
 119     int         i_data;
 120     uint8_t     *p_data;
 121     ModPlugFile *f;
 122 };
 123
 124 static int Demux  ( demux_t *p_demux );
 125 static int Control( demux_t *p_demux, int i_query, va_list args );
 126
 127 static int Validate( demux_t *p_demux, const char *psz_ext );
 128
 129 static const char *ppsz_mod_ext[] =
 130 {
 131     "mod", "s3m", "xm",  "it",  "669", "amf", "ams", "dbm", "dmf", "dsm",
 132     "far", "mdl", "med", "mtm", "okt", "ptm", "stm", "ult", "umx", "mt2",
 133     "psm", "abc", NULL
 134 };
 135
 136
 137 /* We load the complete file in memory, put a higher bound
 138  * of 500 Mo (which is really big anyway) */
 139 #define MOD_MAX_FILE_SIZE (500*1000*1000)
 140
 141 /*****************************************************************************
 142  * Open
 143  *****************************************************************************/
 144 static int Open( vlc_object_t *p_this )
 145 {
 146     demux_t     *p_demux = (demux_t*)p_this;
 147     demux_sys_t *p_sys;
 148     ModPlug_Settings settings;
 149
 150     /* We accept file based on extension match */
 151     if( !p_demux->b_force )
 152     {
 153         if( !p_demux->psz_file )
 154             return VLC_EGENERIC;
 155         const char *psz_ext = strrchr( p_demux->psz_file, '.' );
 156         int i;
 157
 158         if( !psz_ext )
 159             return VLC_EGENERIC;
 160
 161         psz_ext++;  /* skip . */
 162         for( i = 0; ppsz_mod_ext[i] != NULL; i++ )
 163         {
 164             if( !strcasecmp( psz_ext, ppsz_mod_ext[i] ) )
 165                 break;
 166         }
 167         if( ppsz_mod_ext[i] == NULL )
 168             return VLC_EGENERIC;
 169         if( Validate( p_demux, ppsz_mod_ext[i] ) )
 170         {
 171             msg_Warn( p_demux, "MOD validation failed (ext=%s)", ppsz_mod_ext[i]);
 172             return VLC_EGENERIC;
 173         }
 174         msg_Dbg( p_demux, "running MOD demuxer (ext=%s)", ppsz_mod_ext[i] );
 175     }
 176
 177     const int64_t i_size = stream_Size( p_demux->s );
 178     if( i_size <= 0 || i_size >= MOD_MAX_FILE_SIZE )
 179         return VLC_EGENERIC;
 180
 181     /* Fill p_demux field */
 182     p_demux->pf_demux = Demux;
 183     p_demux->pf_control = Control;
 184     p_demux->p_sys = p_sys = malloc( sizeof( *p_sys ) );
 185     if( !p_sys )
 186         return VLC_ENOMEM;
 187
 188     msg_Dbg( p_demux, "loading complete file (could be long)" );
 189     p_sys->i_data = i_size;
 190     p_sys->p_data = malloc( p_sys->i_data );
 191     if( p_sys->p_data )
 192         p_sys->i_data = stream_Read( p_demux->s, p_sys->p_data, p_sys->i_data );
 193     if( p_sys->i_data <= 0 || !p_sys->p_data )
 194     {
 195         msg_Err( p_demux, "failed to read the complete file" );
 196         free( p_sys->p_data );
 197         free( p_sys );
 198         return VLC_EGENERIC;
 199     }
 200
 201     /* Configure modplug before loading the file */
 202     vlc_mutex_lock( &libmodplug_lock );
 203     ModPlug_GetSettings( &settings );
 204     settings.mFlags = MODPLUG_ENABLE_OVERSAMPLING;
 205     settings.mChannels = 2;
 206     settings.mBits = 16;
 207     settings.mFrequency = 44100;
 208     settings.mResamplingMode = MODPLUG_RESAMPLE_FIR;
 209
 210     if( var_InheritBool( p_demux, "mod-noisereduction" ) )
 211         settings.mFlags |= MODPLUG_ENABLE_NOISE_REDUCTION;
 212
 213     if( var_InheritBool( p_demux, "mod-reverb" ) )
 214         settings.mFlags |= MODPLUG_ENABLE_REVERB;
 215     settings.mReverbDepth = var_InheritInteger( p_demux, "mod-reverb-level" );
 216     settings.mReverbDelay = var_InheritInteger( p_demux, "mod-reverb-delay" );
 217
 218     if( var_InheritBool( p_demux, "mod-megabass" ) )
 219         settings.mFlags |= MODPLUG_ENABLE_MEGABASS;
 220     settings.mBassAmount = var_InheritInteger( p_demux, "mod-megabass-level" );
 221     settings.mBassRange = var_InheritInteger( p_demux, "mod-megabass-range" );
 222
 223     if( var_InheritBool( p_demux, "mod-surround" ) )
 224         settings.mFlags |= MODPLUG_ENABLE_SURROUND;
 225     settings.mSurroundDepth = var_InheritInteger( p_demux, "mod-surround-level" );
 226     settings.mSurroundDelay = var_InheritInteger( p_demux, "mod-surround-delay" );
 227
 228     ModPlug_SetSettings( &settings );
 229
 230     p_sys->f = ModPlug_Load( p_sys->p_data, p_sys->i_data );
 231     vlc_mutex_unlock( &libmodplug_lock );
 232
 233     if( !p_sys->f )
 234     {
 235         msg_Err( p_demux, "failed to understand the file" );
 236         /* we try to seek to recover for other plugin */
 237         stream_Seek( p_demux->s, 0 );
 238         free( p_sys->p_data );
 239         free( p_sys );
 240         return VLC_EGENERIC;
 241     }
 242
 243     /* init time */
 244     date_Init( &p_sys->pts, settings.mFrequency, 1 );
 245     date_Set( &p_sys->pts, 0 );
 246     p_sys->i_length = ModPlug_GetLength( p_sys->f ) * INT64_C(1000);
 247
 248     msg_Dbg( p_demux, "MOD loaded name=%s lenght=%"PRId64"ms",
 249              ModPlug_GetName( p_sys->f ),
 250              p_sys->i_length );
 251
 252 #ifdef WORDS_BIGENDIAN
 253     es_format_Init( &p_sys->fmt, AUDIO_ES, VLC_FOURCC( 't', 'w', 'o', 's' ) );
 254 #else
 255     es_format_Init( &p_sys->fmt, AUDIO_ES, VLC_FOURCC( 'a', 'r', 'a', 'w' ) );
 256 #endif
 257     p_sys->fmt.audio.i_rate = settings.mFrequency;
 258     p_sys->fmt.audio.i_channels = settings.mChannels;
 259     p_sys->fmt.audio.i_bitspersample = settings.mBits;
 260     p_sys->es = es_out_Add( p_demux->out, &p_sys->fmt );
 261
 262     return VLC_SUCCESS;
 263 }
 264
 265 /*****************************************************************************
 266  * Close
 267  *****************************************************************************/
 268 static void Close( vlc_object_t *p_this )
 269 {
 270     demux_t     *p_demux = (demux_t*)p_this;
 271     demux_sys_t *p_sys = p_demux->p_sys;
 272
 273     ModPlug_Unload( p_sys->f );
 274     free( p_sys->p_data );
 275     free( p_sys );
 276 }
 277
 278
 279 /*****************************************************************************
 280  * Demux:
 281  *****************************************************************************/
 282 static int Demux( demux_t *p_demux )
 283 {
 284     demux_sys_t *p_sys = p_demux->p_sys;
 285     block_t     *p_frame;
 286     const int i_bk = ( p_sys->fmt.audio.i_bitspersample / 8 ) *
 287                        p_sys->fmt.audio.i_channels;
 288
 289     p_frame = block_New( p_demux, p_sys->fmt.audio.i_rate / 10 * i_bk );
 290     if( !p_frame )
 291         return -1;
 292
 293     const int i_read = ModPlug_Read( p_sys->f, p_frame->p_buffer, p_frame->i_buffer );
 294     if( i_read <= 0 )
 295     {
 296         /* EOF */
 297         block_Release( p_frame );
 298         return 0;
 299     }
 300     p_frame->i_buffer = i_read;
 301     p_frame->i_dts =
 302     p_frame->i_pts = VLC_TS_0 + date_Get( &p_sys->pts );
 303
 304     /* Set PCR */
 305     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_frame->i_pts );
 306
 307     /* Send data */
 308     es_out_Send( p_demux->out, p_sys->es, p_frame );
 309
 310     date_Increment( &p_sys->pts, i_read / i_bk );
 311
 312     return 1;
 313 }
 314
 315 /*****************************************************************************
 316  * Control:
 317  *****************************************************************************/
 318 static int Control( demux_t *p_demux, int i_query, va_list args )
 319 {
 320     demux_sys_t *p_sys = p_demux->p_sys;
 321     double f, *pf;
 322     int64_t i64, *pi64;
 323
 324     switch( i_query )
 325     {
 326     case DEMUX_GET_POSITION:
 327         pf = (double*) va_arg( args, double* );
 328         if( p_sys->i_length > 0 )
 329         {
 330             double current = date_Get( &p_sys->pts );
 331             double length = p_sys->i_length;
 332             *pf = current / length;
 333             return VLC_SUCCESS;
 334         }
 335         return VLC_EGENERIC;
 336
 337     case DEMUX_SET_POSITION:
 338         f = (double) va_arg( args, double );
 339
 340         i64 = f * p_sys->i_length;
 341         if( i64 >= 0 && i64 <= p_sys->i_length )
 342         {
 343             ModPlug_Seek( p_sys->f, i64 / 1000 );
 344             date_Set( &p_sys->pts, i64 );
 345
 346             return VLC_SUCCESS;
 347         }
 348         return VLC_EGENERIC;
 349
 350     case DEMUX_GET_TIME:
 351         pi64 = (int64_t*)va_arg( args, int64_t * );
 352         *pi64 = date_Get( &p_sys->pts );
 353         return VLC_SUCCESS;
 354
 355     case DEMUX_GET_LENGTH:
 356         pi64 = (int64_t*)va_arg( args, int64_t * );
 357         *pi64 = p_sys->i_length;
 358         return VLC_SUCCESS;
 359
 360     case DEMUX_SET_TIME:
 361         i64 = (int64_t)va_arg( args, int64_t );
 362
 363         if( i64 >= 0 && i64 <= p_sys->i_length )
 364         {
 365             ModPlug_Seek( p_sys->f, i64 / 1000 );
 366             date_Set( &p_sys->pts, i64 );
 367
 368             return VLC_SUCCESS;
 369         }
 370         return VLC_EGENERIC;
 371
 372     case DEMUX_HAS_UNSUPPORTED_META:
 373     {
 374         bool *pb_bool = (bool*)va_arg( args, bool* );
 375         *pb_bool = false; /* FIXME I am not sure of this one */
 376         return VLC_SUCCESS;
 377     }
 378     case DEMUX_GET_META:
 379     {
 380         vlc_meta_t *p_meta = (vlc_meta_t *)va_arg( args, vlc_meta_t* );
 381         unsigned i_num_samples = ModPlug_NumSamples( p_sys->f ),
 382                  i_num_instruments = ModPlug_NumInstruments( p_sys->f );
 383         unsigned i_num_patterns = ModPlug_NumPatterns( p_sys->f ),
 384                  i_num_channels = ModPlug_NumChannels( p_sys->f );
 385         //      unsigned modType = ModPlug_GetModuleType( p_sys->f );
 386
 387         char psz_temp[2048]; /* 32 * 240 max, but only need start  */
 388         char *psz_module_info, *psz_instrument_info;
 389         unsigned i_temp_index = 0;
 390         const char *psz_name = ModPlug_GetName( p_sys->f );
 391         if( psz_name && *psz_name )
 392             vlc_meta_SetTitle( p_meta, psz_name );
 393
 394         /* Comment field from artist - not in every type of MOD */
 395         psz_name = ModPlug_GetMessage( p_sys->f );
 396         if( psz_name && *psz_name )
 397             vlc_meta_SetDescription( p_meta, psz_name );
 398
 399         /* Instruments only in newer MODs - so don't show if 0 */
 400         if( asprintf( &psz_instrument_info, ", %i Instruments",
 401                       i_num_instruments ) >= 0 )
 402         {
 403             if( asprintf( &psz_module_info,
 404                           "%i Channels, %i Patterns\n"
 405                           "%i Samples%s\n",
 406                           i_num_channels, i_num_patterns, i_num_samples,
 407                           ( i_num_instruments ? psz_instrument_info : "" ) ) >= 0 )
 408             {
 409                 vlc_meta_AddExtra( p_meta, "Module Information",
 410                                    psz_module_info );
 411                 free( psz_module_info );
 412             }
 413
 414             free( psz_instrument_info );
 415         }
 416
 417         /* Make list of instruments (XM, IT, etc) */
 418         if( i_num_instruments )
 419         {
 420             i_temp_index = 0;
 421             for( unsigned i = 0; i < i_num_instruments && i_temp_index < sizeof(psz_temp); i++ )
 422             {
 423                 char lBuffer[33];
 424                 ModPlug_InstrumentName( p_sys->f, i, lBuffer );
 425                 if ( !lBuffer[0] ) continue; // don't add empty fields.
 426                 i_temp_index += snprintf( &psz_temp[i_temp_index], sizeof(psz_temp) - i_temp_index, "%s\n", lBuffer );
 427             }
 428
 429             vlc_meta_AddExtra( p_meta, "Instruments", psz_temp );
 430         }
 431
 432         /* Make list of samples */
 433         for( unsigned int i = 0; i < i_num_samples && i_temp_index < sizeof(psz_temp); i++ )
 434         {
 435             char psz_buffer[33];
 436             ModPlug_SampleName( p_sys->f, i, psz_buffer );
 437             if ( !psz_buffer[0] ) continue; // don't add empty fields.
 438             i_temp_index += snprintf( &psz_temp[i_temp_index], sizeof(psz_temp) - i_temp_index, "%s\n", psz_buffer );
 439         }
 440
 441         vlc_meta_AddExtra( p_meta, "Samples", psz_temp );
 442
 443         return VLC_SUCCESS;
 444     }
 445
 446     case DEMUX_GET_FPS: /* meaningless */
 447     default:
 448         return VLC_EGENERIC;
 449     }
 450 }
 451
 452 /*****************************************************************************
 453  * Validate: try to ensure it is really a mod file.
 454  * The tests are not robust enough to replace extension checks in the general
 455  * cases.
 456  * TODO: maybe it should return a score, which will be used to bypass the
 457  * extension checks when high enough.
 458  *****************************************************************************/
 459 static int Validate( demux_t *p_demux, const char *psz_ext )
 460 {
 461     static const struct
 462     {
 463         int i_offset;
 464         const char *psz_marker;
 465     } p_marker[] = {
 466         {  0, "ziRCONia" },             /* MMCMP files */
 467         {  0, "Extended Module" },      /* XM */
 468         { 44, "SCRM" },                 /* S3M */
 469         {  0, "IMPM" },                 /* IT */
 470         {  0, "MThd" },                 /* MID */
 471         {  0, "GF1PATCH110" },          /* PAT */
 472         { 20, "!SCREAM!" },             /* STM */
 473         { 20, "!Scream!" },             /* STM */
 474         { 20, "BMOD2STM" },             /* STM */
 475         {  0, "MMD0" },                 /* MED v0 */
 476         {  0, "MMD1" },                 /* MED v1 */
 477         {  0, "MMD2" },                 /* MED v2 */
 478         {  0, "MMD3" },                 /* MED v3 */
 479         {  0, "MTM" },                  /* MTM */
 480         {  0, "DMDL" },                 /* MDL */
 481         {  0, "DBM0" },                 /* DBM */
 482         {  0, "if" },                   /* 669 */
 483         {  0, "JN" },                   /* 669 */
 484         {  0, "FAR\xfe" },              /* FAR */
 485         {  0, "Extreme" },              /* AMS */
 486         {  0, "OKTASONGCMOD" },         /* OKT */
 487         { 44, "PTMF" },                 /* PTM */
 488         {  0, "MAS_UTrack_V00" },       /* Ult */
 489         {  0, "DDMF" },                 /* DMF */
 490         {  8, "DSMFSONG" },             /* DSM */
 491         {  0, "\xc1\x83\x2a\x9e" },     /* UMX */
 492         {  0, "ASYLUM Music Format V1.0" }, /* AMF Type 0 */
 493         {  0, "AMF" },                  /* AMF */
 494         {  0, "PSM\xfe" },              /* PSM */
 495         {  0, "PSM " },                 /* PSM */
 496         {  0, "MT20" },                 /* MT2 */
 497
 498         { 1080, "M.K." },               /* MOD */
 499         { 1080, "M!K!" },
 500         { 1080, "M&K!" },
 501         { 1080, "N.T." },
 502         { 1080, "CD81" },
 503         { 1080, "OKTA" },
 504         { 1080, "16CN" },
 505         { 1080, "32CN" },
 506         { 1080, "FLT" },
 507         { 1080, "TDZ" },
 508         { 1081, "CHN" },
 509         { 1082, "CH" },
 510
 511         {  -1, NULL }
 512     };
 513
 514     const uint8_t *p_peek;
 515     const int i_peek = stream_Peek( p_demux->s, &p_peek, 2048 );
 516     if( i_peek < 4 )
 517         return VLC_EGENERIC;
 518
 519     for( int i = 0; p_marker[i].i_offset >= 0; i++ )
 520     {
 521         const char *psz_marker = p_marker[i].psz_marker;
 522         const int i_size = strlen( psz_marker );
 523         const int i_offset = p_marker[i].i_offset;
 524
 525         if( i_peek < i_offset + i_size )
 526             continue;
 527
 528         if( !memcmp( &p_peek[i_offset], psz_marker, i_size ) )
 529             return VLC_SUCCESS;
 530     }
 531
 532     /* The only two format left untested are ABC and MOD(old version)
 533      * ant they are difficult to test :( */
 534
 535     /* Check for ABC
 536      * TODO i_peek = 2048 is too big for such files */
 537     if( !strcasecmp( psz_ext, "abc" ) )
 538     {
 539         bool b_k = false;
 540         bool b_tx = false;
 541
 542         for( int i = 0; i < i_peek-1; i++ )
 543         {
 544             b_k |= p_peek[i+0] == 'K' && p_peek[i+1] == ':';
 545             b_tx |= ( p_peek[i+0] == 'X' || p_peek[i+0] == 'T') && p_peek[i+1] == ':';
 546         }
 547         if( !b_k || !b_tx )
 548             return VLC_EGENERIC;
 549         return VLC_SUCCESS;
 550     }
 551
 552     /* Check for MOD */
 553     if( !strcasecmp( psz_ext, "mod" ) && i_peek >= 20 + 15 * 30 )
 554     {
 555         /* Check that the name is correctly null padded */
 556         const uint8_t *p = memchr( p_peek, '\0', 20 );
 557         if( p )
 558         {
 559             for( ; p < &p_peek[20]; p++ )
 560             {
 561                 if( *p )
 562                     return VLC_EGENERIC;
 563             }
 564         }
 565
 566         for( int i = 0; i < 15; i++ )
 567         {
 568             const uint8_t *p_sample = &p_peek[20 + i*30];
 569
 570             /* Check correct null padding */
 571             const uint8_t *p = memchr( &p_sample[0], '\0', 22 );
 572             if( p )
 573             {
 574                 for( ; p < &p_sample[22]; p++ )
 575                 {
 576                     if( *p )
 577                         return VLC_EGENERIC;
 578                 }
 579             }
 580
 581             if( p_sample[25] > 64 ) /* Volume value */
 582                 return VLC_EGENERIC;
 583         }
 584         return VLC_SUCCESS;
 585     }
 586     return VLC_EGENERIC;
 587 }