#include "config.h"
#include "include/dac_drv.h"
#include "include/aud_drv.h"
#include "include/mp3_drv.h"
#include "include/clock.h"
#include "include/audio.h"
#include "include/mp3_buffer.h"

/* Frame size value for one second  */
__xdata   Uint16  song_frame_size;


static  void    snd_audio_init (void);

code Uint16 song_tab_frame_size_00 [2][16] =
    {/* 44.1 KHz MPEG1 */
      {0, 104, 130, 156, 182, 208, 261, 313, 365, 417, 522, 626, 731, 835, 1044, 0},
     /* 22.05 KHz MPEG2 */
      {0,  26, 52, 78, 104, 130, 156, 182, 208,  261,  313, 365, 417, 470, 522, 0}
    };

code Uint16 song_tab_frame_size_01 [2][16] =
    {
    /* 48 Khz MPEG1 */
      {0, 96, 120, 144, 168, 192, 240, 288, 336, 384, 480, 576, 672, 768, 960, 0},
    /* 24 Khz MPEG2 */
      {0,  24, 48, 72, 96, 120, 144, 168, 192, 240, 288, 336, 384, 432, 480, 0}
    };

code Uint16 song_tab_frame_size_10 [2][16] =

    {/* 32 Khz MPEG1  */
      {0, 144, 180, 216, 252, 288, 360, 432, 504, 576, 720, 864, 1008, 1152, 1440, 0},
     /* 16 Khz MPEG2  */
      {0,  36, 72, 108, 144, 180, 216, 252, 288, 360, 432, 504, 576, 648, 720, 0}
    };


code Uint16 song_tab_seek [2][16]=
{
  {0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0},
  {0,  8, 16, 24, 32, 40, 48, 56,  64,  80,  96, 112, 128, 144, 160, 0}

};

/* initialize sound controls */
void snd_init (void) {
  MP3VOL = VOLUME_MED;
  MP3VOR = VOLUME_MED;
  MP3BAS = BASS_MED;
  MP3MED = MEDIUM_MED;
  MP3TRE = TREBLE_MED;
}

void snd_vol_inc(void) {
  if (MP3VOL != VOLUME_MAX) {
    MP3VOL++;
    MP3VOR = MP3VOL;
  }
}

void snd_bas_inc(void) {
  if (MP3BAS != BASS_MAX) {
    MP3BAS++;
  }
}

void snd_med_inc(void) {
  if (MP3MED != MEDIUM_MAX) {
    MP3MED++;

  }
}

void snd_tre_inc(void) {
  if (MP3TRE != TREBLE_MAX) {
    MP3TRE++;
  }
}

void snd_vol_dec(void) {
  if (MP3VOL != VOLUME_MIN) {
    MP3VOL--;
    MP3VOR = MP3VOL;
  }
}

void snd_bas_dec(void) {
  if (MP3BAS != BASS_MIN) {
    MP3BAS--;
  }
}

void snd_med_dec(void) {
  if (MP3MED != MEDIUM_MIN) {
    MP3MED--;
  }
}

void snd_tre_dec(void) {
  if (MP3TRE != TREBLE_MIN) {
    MP3TRE--;
  }
}

/* this searches a frame header and initializes audio playing accordingly.
   it returns
   header status:  SONG_NO_ERR:    header ok
                   SONG_LAYER_ERR: not a layer 3 file
                   SONG_BR_ERR:    bit rate not supported
                   SONG_FS_ERR:    bad frequency sampling
                   SONG_SYNC_ERR:  no header found
*/
Byte audio_init (void) {
 Byte    b, c;
  while (!mp3_buffer_eof()) {
    /* continue searching synchro */
    if (mp3_buffer_getc() == MP3_SYNC_H) {

      /* high order sync found */
      b = mp3_buffer_getc();
      if ((b & MP3_MSK_SYNC) == MP3_SYNC_L) {
	
	/* low order sync found */
	c = mp3_buffer_getc();
	
	/* keep MPEG Version B3 -> B2 */
	b = (b & MP3_MSK_VER) >> 1;

	/* read FS B3:2 -> B1:0 */
	b |= (c & MP3_MSK_FS) >> 2;
	c &= MP3_MSK_BR;
        /* init audio interface */
        snd_audio_init();
	/* program the song clocks */
	clock_song_init(b);
	return SONG_NO_ERR;
      }
    }
  }
  return SONG_SYNC_ERR;
}

void snd_audio_init (void)
{
  Aud_set_pcm_32(DAC_NB_BIT);
  Aud_set_song();
  Aud_enable();

  /* disable audio interrupt */
  Aud_disable_int();
}

void snd_start (void)
{
  /* maestro please! */
  Dac_unmute();

  /* start sample request */
  Aud_song_play();

  /* enable mp3 decoder */
  mp3_init();

}

void snd_pause (void)
{

  /* disable audio */
  Aud_song_pause();

  /* disable mp3 macrocell */
  mp3_stop();
}

void snd_stop (void)
{

  /* silence please! */
  Dac_mute();

  /* disable audio */
  aud_stop();

  /* disable mp3 macrocell */
  mp3_stop();

}