/apps/plugins/mpegplayer/

/a> 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399
/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2006-2007 Adam Gashlin (hcs)
 * Copyright (C) 2004-2007 Shay Green (blargg)
 * Copyright (C) 2002 Brad Martin
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

/* lovingly ripped off from Game_Music_Emu 0.5.2. http://www.slack.net/~ant/ */
/* DSP Based on Brad Martin's OpenSPC DSP emulator */
/* tag reading from sexyspc by John Brawn (John_Brawn@yahoo.com) and others */

#ifndef _SPC_CODEC_H_
#define _SPC_CODEC_H_

/* rather than comment out asserts, just define NDEBUG */
#define NDEBUG
#include <assert.h>

/** Basic configuration options **/

/* TGB is the only target fast enough for gaussian and realtime BRR decode */
/* echo is almost fast enough but not quite */
#ifndef TOSHIBA_GIGABEAT_F
    /* Cache BRR waves */
    #define SPC_BRRCACHE 1

    /* Disable gaussian interpolation */
    #define SPC_NOINTERP 1

#ifndef CPU_COLDFIRE
    /* Disable echo processing */
    #define SPC_NOECHO 1
#else
    /* Enable echo processing */
    #define SPC_NOECHO 0
#endif
#else
    /* Don't cache BRR waves */
    #define SPC_BRRCACHE 0 
    
    /* Allow gaussian interpolation */
    #define SPC_NOINTERP 0
    
    /* Allow echo processing */
    #define SPC_NOECHO 0
#endif

/* Samples per channel per iteration */
#ifdef CPU_COLDFIRE
#define WAV_CHUNK_SIZE 1024
#else
#define WAV_CHUNK_SIZE 2048
#endif

#ifdef CPU_ARM
    #undef  ICODE_ATTR
    #define ICODE_ATTR

    #undef  IDATA_ATTR
    #define IDATA_ATTR
#endif

/**************** Little-endian handling ****************/

static inline unsigned get_le16( void const* p )
{
    return  ((unsigned char const*) p) [1] * 0x100u +
            ((unsigned char const*) p) [0];
}

static inline int get_le16s( void const* p )
{
    return  ((signed char const*) p) [1] * 0x100 +
            ((unsigned char const*) p) [0];
}

static inline void set_le16( void* p, unsigned n )
{
    ((unsigned char*) p) [1] = (unsigned char) (n >> 8);
    ((unsigned char*) p) [0] = (unsigned char) n;
}

#define GET_LE16( addr )        get_le16( addr )
#define SET_LE16( addr, data )  set_le16( addr, data )
#define INT16A( addr ) (*(uint16_t*) (addr))
#define INT16SA( addr ) (*(int16_t*) (addr))

#ifdef ROCKBOX_LITTLE_ENDIAN
    #define GET_LE16A( addr )       (*(uint16_t*) (addr))
    #define GET_LE16SA( addr )      (*( int16_t*) (addr))
    #define SET_LE16A( addr, data ) (void) (*(uint16_t*) (addr) = (data))
#else
    #define GET_LE16A( addr )       get_le16 ( addr )
    #define GET_LE16SA( addr )      get_le16s( addr )
    #define SET_LE16A( addr, data ) set_le16 ( addr, data )
#endif

struct Spc_Emu;
#define THIS struct Spc_Emu* const this

/* The CPU portion (shock!) */

struct cpu_regs_t
{
    long pc; /* more than 16 bits to allow overflow detection */
    uint8_t a;
    uint8_t x;
    uint8_t y;
    uint8_t status;
    uint8_t sp;
};

struct cpu_ram_t
{
    union {
        uint8_t padding1 [0x100];
        uint16_t align;
    } padding1 [1];
    uint8_t ram      [0x10000];
    uint8_t padding2 [0x100];
};

#undef RAM
#define RAM ram.ram
extern struct cpu_ram_t ram;

long CPU_run( THIS, long start_time ) ICODE_ATTR;
void CPU_Init( THIS );

/* The DSP portion (awe!) */
enum { VOICE_COUNT = 8 };
enum { REGISTER_COUNT = 128 };

struct raw_voice_t
{
    int8_t  volume [2];
    uint8_t rate [2];
    uint8_t waveform;
    uint8_t adsr [2];   /* envelope rates for attack, decay, and sustain */
    uint8_t gain;       /* envelope gain (if not using ADSR) */
    int8_t  envx;       /* current envelope level */
    int8_t  outx;       /* current sample */
    int8_t  unused [6];
};
    
struct globals_t
{
    int8_t  unused1 [12];
    int8_t  volume_0;         /* 0C   Main Volume Left (-.7) */
    int8_t  echo_feedback;    /* 0D   Echo Feedback (-.7) */
    int8_t  unused2 [14];
    int8_t  volume_1;         /* 1C   Main Volume Right (-.7) */
    int8_t  unused3 [15];
    int8_t  echo_volume_0;    /* 2C   Echo Volume Left (-.7) */
    uint8_t pitch_mods;       /* 2D   Pitch Modulation on/off for each voice */
    int8_t  unused4 [14];
    int8_t  echo_volume_1;    /* 3C   Echo Volume Right (-.7) */
    uint8_t noise_enables;    /* 3D   Noise output on/off for each voice */
    int8_t  unused5 [14];
    uint8_t key_ons;          /* 4C   Key On for each voice */
    uint8_t echo_ons;         /* 4D   Echo on/off for each voice */
    int8_t  unused6 [14];
    uint8_t key_offs;         /* 5C   key off for each voice
                                      (instantiates release mode) */
    uint8_t wave_page;        /* 5D   source directory (wave table offsets) */
    int8_t  unused7 [14];
    uint8_t flags;            /* 6C   flags and noise freq */
    uint8_t echo_page;        /* 6D */
    int8_t  unused8 [14];
    uint8_t wave_ended;       /* 7C */
    uint8_t echo_delay;       /* 7D   ms >> 4 */
    char    unused9 [2];
};

enum state_t
{  /* -1, 0, +1 allows more efficient if statements */
    state_decay   = -1,
    state_sustain = 0,
    state_attack  = +1,
    state_release = 2
};

struct cache_entry_t
{
    int16_t const* samples;
    unsigned end; /* past-the-end position */
    unsigned loop; /* number of samples in loop */
    unsigned start_addr;
};

enum { BRR_BLOCK_SIZE = 16 };
enum { BRR_CACHE_SIZE = 0x20000 + 32} ;

struct voice_t
{
#if SPC_BRRCACHE
    int16_t const* samples;
    long wave_end;
    int wave_loop;
#else
    int16_t samples [3 + BRR_BLOCK_SIZE + 1];
    int block_header; /* header byte from current block */
#endif
    uint8_t const* addr;
    short volume [2];
    long position;/* position in samples buffer, with 12-bit fraction */
    short envx;
    short env_mode;
    short env_timer;
    short key_on_delay;
};

#if SPC_BRRCACHE
/* a little extra for samples that go past end */
extern int16_t BRRcache [BRR_CACHE_SIZE];
#endif

enum { FIR_BUF_HALF = 8 };

#ifdef CPU_COLDFIRE
/* global because of the large aligment requirement for hardware masking -
 * L-R interleaved 16-bit samples for easy loading and mac.w use.
 */
enum
{
    FIR_BUF_SIZE = FIR_BUF_HALF * sizeof ( int32_t ),
    FIR_BUF_MASK = ~FIR_BUF_SIZE
};
#endif /* CPU_COLDFIRE */

struct Spc_Dsp
{
    union
    {
        struct raw_voice_t voice [VOICE_COUNT];
        uint8_t reg [REGISTER_COUNT];
        struct globals_t g;
        int16_t align;
    } r;
    
    unsigned echo_pos;
    int keys_down;
    int noise_count;
    uint16_t noise; /* also read as int16_t */
    
#ifdef CPU_COLDFIRE
    /* circularly hardware masked address */
    int32_t *fir_ptr;
    /* wrapped address just behind current position -
       allows mac.w to increment and mask fir_ptr */
    int32_t *last_fir_ptr;
    /* copy of echo FIR constants as int16_t for use with mac.w */
    int16_t fir_coeff[VOICE_COUNT];
#else
    /* fir_buf [i + 8] == fir_buf [i], to avoid wrap checking in FIR code */
    int fir_pos; /* (0 to 7) */
    int fir_buf [FIR_BUF_HALF * 2] [2];
    /* copy of echo FIR constants as int, for faster access */
    int fir_coeff [VOICE_COUNT]; 
#endif
    
    struct voice_t voice_state [VOICE_COUNT];
    
#if SPC_BRRCACHE
    uint8_t oldsize;
    struct cache_entry_t wave_entry     [256];
    struct cache_entry_t wave_entry_old [256];
#endif
};

struct src_dir
{
    char start [2];
    char loop  [2];
};

void DSP_run_( struct Spc_Dsp* this, long count, int32_t* out_buf ) ICODE_ATTR;
void DSP_reset( struct Spc_Dsp* this );

static inline void DSP_run( struct Spc_Dsp* this, long count, int32_t* out )
{
    /* Should we just fill the buffer with silence? Flags won't be cleared */
    /* during this run so it seems it should keep resetting every sample. */
    if ( this->r.g.flags & 0x80 )
        DSP_reset( this );
    
    DSP_run_( this, count, out );
}

/**************** SPC emulator ****************/
/* 1.024 MHz clock / 32000 samples per second */
enum { CLOCKS_PER_SAMPLE = 32 }; 

enum { EXTRA_CLOCKS = CLOCKS_PER_SAMPLE / 2 };

/* using this disables timer (since this will always be in the future) */
enum { TIMER_DISABLED_TIME = 127 };

enum { ROM_SIZE = 64 };
enum { ROM_ADDR = 0xFFC0 };

enum { TIMER_COUNT = 3 };

struct Timer
{
    long next_tick;
    int period;
    int count;
    int shift;
    int enabled;
    int counter;
};

void Timer_run_( struct Timer* t, long time ) ICODE_ATTR;

static inline void Timer_run( struct Timer* t, long time )
{
    if ( time >= t->next_tick )
        Timer_run_( t, time );
}

struct Spc_Emu
{
    uint8_t cycle_table [0x100];
    struct cpu_regs_t r;
    
    int32_t* sample_buf;
    long next_dsp;
    int rom_enabled;
    int extra_cycles;
    
    struct Timer timer [TIMER_COUNT];
    
    /* large objects at end */
    struct Spc_Dsp dsp;
    uint8_t extra_ram [ROM_SIZE];
    uint8_t boot_rom  [ROM_SIZE];
};

enum { SPC_FILE_SIZE = 0x10180 };

struct spc_file_t
{
    char    signature [27];
    char    unused [10];
    uint8_t pc [2];
    uint8_t a;
    uint8_t x;
    uint8_t y;
    uint8_t status;
    uint8_t sp;
    char    unused2 [212];
    uint8_t ram [0x10000];
    uint8_t dsp [128];
    uint8_t ipl_rom [128];
};

void SPC_Init( THIS );

int SPC_load_spc( THIS, const void* data, long size );

/**************** DSP interaction ****************/
void DSP_write( struct Spc_Dsp* this, int i, int data ) ICODE_ATTR;

static inline int DSP_read( struct Spc_Dsp* this, int i )
{
    assert( (unsigned) i < REGISTER_COUNT );
    return this->r.reg [i];
}

void SPC_run_dsp_( THIS, long time ) ICODE_ATTR;

static inline void SPC_run_dsp( THIS, long time )
{
    if ( time >= this->next_dsp )
        SPC_run_dsp_( this, time );
}

int SPC_read( THIS, unsigned addr, long const time ) ICODE_ATTR;
void SPC_write( THIS, unsigned addr, int data, long const time ) ICODE_ATTR;

/**************** Sample generation ****************/
int SPC_play( THIS, long count, int32_t* out ) ICODE_ATTR;

#endif /* _SPC_CODEC_H_ */