song_drv.c

ATMEL全套MP3设计资料

/*C**************************************************************************
* $RCSfile: song_drv.c,v $
*----------------------------------------------------------------------------
* Copyright (c) 2002 Atmel.
*----------------------------------------------------------------------------
* RELEASE:      $Name: DEMO_FAT_1_9_9 $      
* REVISION:     $Revision: 1.9 $     
* FILE_CVSID:   $Id: song_drv.c,v 1.9 2002/09/06 12:59:11 njourdan Exp $       
*----------------------------------------------------------------------------
* PURPOSE:
* This file contains the song driver routines
*****************************************************************************/

/*_____ I N C L U D E S ____________________________________________________*/

#include "config.h"                         /* system configuration */
#include "..\..\..\..\lib\aud\aud_drv.h"    /* audio driver definition */
#include "..\..\..\..\lib\mp3\mp3_drv.h"    /* mp3 driver definition */
#include "..\..\..\..\lib_demob\dac\dac_drv.h"/* dac driver definition */
#include "..\file\file.h"                   /* file definition */
#include "..\clock\clock.h"                 /* clock definition */
#include "song_drv.h"                       /* song driver definition */


/*_____ M A C R O S ________________________________________________________*/


/*_____ D E F I N I T I O N ________________________________________________*/

static  Byte    song_sound;                 /* save the selected sound */


/*_____ D E C L A R A T I O N ______________________________________________*/

static  void    song_audio_init (void);


/*F**************************************************************************
* NAME: song_snd_init
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Sound control initialization
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   Initializes the sound controls to their medium value
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void song_snd_init (void)
{
  MP3VOL = VOLUME_MED;
  MP3VOR = VOLUME_MED;
  MP3BAS = BASS_MED;
  MP3MED = MEDIUM_MED;
  MP3TRE = TREBLE_MED;

  song_sound = SND_VOLUME;          /* volume control selected by default */
}



/*F**************************************************************************
* NAME: song_snd_inc
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   Increment the selected sound control
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   The number of the current selected sound control is stored in the
*   variable snd_select (0.Volume; 1.Bass; 2.Medium; 3. Trebble)
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void song_snd_inc (void)
{
  switch (song_sound)
  {
    case SND_VOLUME:
    {
      if (MP3VOL != VOLUME_MAX)
      {
        MP3VOL++;
        MP3VOR = MP3VOL;
      }
      break;
    }

    case SND_BASS:
    {
      if (MP3BAS != BASS_MAX)
        MP3BAS++;
      break;
    }

    case SND_MEDIUM:
    {
      if (MP3MED != MEDIUM_MAX)
        MP3MED++;
      break;
    }

    case SND_TREBLE:
    {
      if (MP3TRE != TREBLE_MAX)
        MP3TRE++;
      break;
    }
  }
}


/*F**************************************************************************
* NAME: song_snd_dec
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   Decrement the selected sound control
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   The number of the current selected sound control is stored in the
*   variable snd_select (0.Volume; 1.Bass; 2.Medium; 3. Trebble)
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void song_snd_dec (void)
{
  switch (song_sound)
  {
    case SND_VOLUME:
    {
      if (MP3VOL != VOLUME_MIN)
      {
        MP3VOL--;
        MP3VOR = MP3VOL;
      }
      break;
    }

    case SND_BASS:
    {
      if (MP3BAS != BASS_MIN)
        MP3BAS--;
      break;
    }

    case SND_MEDIUM:
    {
      if (MP3MED != MEDIUM_MIN)
        MP3MED--;
      break;
    }

    case SND_TREBLE:
    {
      if (MP3TRE != TREBLE_MIN)
        MP3TRE--;
      break;
    }
  }
}


/*F**************************************************************************
* NAME: song_snd_select
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   Select next sound control
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void song_snd_select (void)
{
  song_sound = (song_sound + 1) % NB_SOUND;
}


/*F**************************************************************************
* NAME: song_get_sound
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*   sound selected: SND_VOLUME, SND_BASS, SND_MEDIUM, SND_TREBLE
*----------------------------------------------------------------------------
* PURPOSE: 
*   Returns selected sound control
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
Byte song_get_sound (void)
{
  return (song_sound);
}


/*F**************************************************************************
* NAME: song_get_level
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*   level of sound selected
*----------------------------------------------------------------------------
* PURPOSE:
*   Returns selected sound level
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
Byte song_get_level (void)
{
  switch (song_sound)
  {
    case SND_VOLUME:
    {
      return (MP3VOL);
    }

    case SND_BASS:
    {
      return (MP3BAS);
    }

    case SND_MEDIUM:
    {
      return (MP3MED);
      break;
    }

    case SND_TREBLE:
    {
      return (MP3TRE);
    }
  }
}


/*F**************************************************************************
* NAME: song_init
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*   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
*----------------------------------------------------------------------------
* PURPOSE: 
*   Search frame header and initialize song playing according to this header
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   Header search is stopped when errors number exceeds 
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
Byte song_init (void)
{
Byte    b, c;
Byte    head_status;                        /* return error byte */
Byte    err_count;                          /* error counter */
bit     err_set;                            /* error flag */

  err_set = FALSE;
  head_status = SONG_NO_ERR;
  err_count = SONG_MAX_ERR;
  while (!Feof())
  {
    if (err_count != 0)
    { /* continue searching synchro */
      if (Fgetc() == MP3_SYNC_H)
      { /* high order sync found */
        b = Fgetc();
        if ((b & MP3_MSK_SYNC) == MP3_SYNC_L)
        { /* low order sync found */
          if ((b & MP3_MSK_LAYER) != MP3_LAYER_III)
          {
            head_status |= SONG_LAYER_ERR;  /* bad layer */
            err_count--;
          }
          else
          {
            c = Fgetc();
            b = (b & MP3_MSK_VER) >> 1;       /* keep MPEG Version B3 -> B2 */
            b |= (c & MP3_MSK_FS) >> 2;       /* read FS B3:2 -> B1:0 */
            c &= MP3_MSK_BR;

            switch (b)
            {
#if (0)
              case MP3_FS_44:
              {
                if ((c == MP3_BR_FREE) || (c > MP3_BR_256))
                {
                  head_status |= SONG_BR_ERR; /* bad bit-rate */
                  err_count--;
                  err_set = TRUE;
                }
                break;
              }
              case MP3_FS_48:
              {
                if ((c == MP3_BR_FREE) || (c > MP3_BR_320))
                {
                  head_status |= SONG_BR_ERR; /* bad bit-rate */
                  err_count--;
                  err_set = TRUE;
                }
                break;
              }
              case MP3_FS_32:
              {
                if ((c == MP3_BR_FREE) || (c > MP3_BR_224))
                {
                  head_status |= SONG_BR_ERR; /* bad bit-rate */
                  err_count--;
                  err_set = TRUE;
                }
                break;
              }
#endif
              case MP3_FS_44:
              case MP3_FS_48:
              case MP3_FS_32:
              case MP3_FS_22:
              case MP3_FS_24:
              case MP3_FS_16:
              {
                if (c == MP3_BR_FREE)
                {
                  head_status |= SONG_BR_ERR; /* bad bit-rate */
                  err_count--;
                  err_set = TRUE;
                }
                break;
              }
              default:
              {
                head_status |= SONG_FS_ERR;   /* bad sampling frequency */
                err_count--;
                err_set = TRUE;
                break;
              }
            }
            if (!err_set)
            {
              err_set = FALSE;
              song_audio_init();                /* init audio interface */
              clock_song_init(b);               /* program the song clocks */
//              Dac_emphasis(Fgetc() & MP3_MSK_EMP);/* config DAC emphasis */
              Dac_unmute();                     /* maestro please! */
//              Fseek(-4);                        /* return to beginning of stream */
              Fseek(-3);
              return SONG_NO_ERR;
            }
          }
        }
      }
    }
    else
    { /* too much error */
      return head_status;
    }
  }
  return (head_status | SONG_SYNC_ERR);
}


/*F**************************************************************************
* NAME: song_audio_init
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Audio interface initialization in song mode
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   DAC_NB_BIT defined in config.h
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void song_audio_init (void)
{
  Aud_set_pcm_32(DAC_NB_BIT);
  Aud_set_song();
  Aud_enable();
  Aud_disable_int();                      /* disable audio interrupt */
}


/*F**************************************************************************
* NAME: song_start
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Start song playing
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void song_start (void)
{
  Aud_song_play();                          /* start sample request */
  mp3_init();                               /* enable mp3 decoder */
}


/*F**************************************************************************
* NAME: song_stop
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Stop song playing
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void song_stop (void)
{
  Dac_mute();                               /* silence please! */
  aud_stop();                               /* disable audio */
  mp3_stop();                               /* disable mp3 macrocell */
  clock_disable();                          /* disable clocks */
}