mpegsub.c

Application (fix point) for playing MP3 data on embedded systems. mp3play is designed to be able to

   SUB_TYPE           *buf0, *buf1;
   SUB_TYPE           *buf_ptr;
   INT16               b_offset = mpegsub->b_offset[ channel ];
   MPEGAUD_FRACT_TYPE *bb = &mpegsub->bb[ channel ][ 0 ];

   if( b_offset & 1 ) { // Odd
      buf0 = &bb[ MPA_HANNING_SIZE + b_offset ];
      buf1 = &bb[ b_offset ];
      buf_ptr = &bb[ MPA_HANNING_SIZE ];
   }
   else { // Even
      buf0 = &bb[ b_offset ];
      buf1 = &bb[ MPA_HANNING_SIZE + b_offset ];
      buf_ptr = &bb[ 0 ];
   }

#if defined(ASM_OPTIMIZE) || defined(COLDFIRE_ASM_2)
#ifdef MPEGAUD_INT
//   MPEGSUBB_filter_band( bandPtr, buf0, buf1 );
   MPEGSUBB_filter_band( bandPtr, buf0, buf1, mpegsub->freq_div ); // #6
#else
//   MPEGSUBF_filter_band( bandPtr, buf0, buf1 );
   MPEGSUBF_filter_band( bandPtr, buf0, buf1, mpegsub->freq_div ); // #6
#endif
#else
   fast_dct( bandPtr, buf0, buf1, mpegsub->freq_div );
#endif

#if defined(ASM_OPTIMIZE) || defined(COLDFIRE_ASM_2)
#ifdef MPEGAUD_INT
//   MPEGSUBB_window_band( buf_ptr, samples, b_offset );
   MPEGSUBB_window_band( buf_ptr, samples, mpegsub->scaled_dewindow /* #7 */, b_offset,
                         mpegsub->w_begin, mpegsub->w_width, mpegsub->freq_div,
                         mpegsub->scaled_shift /* #7 */ ); // #6
#else
//   MPEGSUBF_window_band( buf_ptr, samples, b_offset );
   MPEGSUBF_window_band( buf_ptr, samples, mpegsub->scaled_dewindow /* #7 */, b_offset,
                         mpegsub->w_begin, mpegsub->w_width, mpegsub->freq_div ); // #6
#endif
#else
   {
      INT16 start, top, cnt0, cnt1, off0, off1, offd;
      INT16 *samp;
      register SUB_DCT_TYPE sum;
      register const SUB_TYPE *dewindow;
      register INT16 j;
// #7 Begin
#ifdef MPEGAUD_INT
      INT32 dew_shift = mpegsub->scaled_shift + SUB_BAND_BITS - 16 + SUB_OUT_BITS - 15;
#endif
// #7 End

      samp = samples;

      start = (mpegsub->w_begin + b_offset) & 15;
      top = start + mpegsub->w_width;
      if( top > 16 ) top = 16;
      cnt1 = top - start;    // From start to ...
      cnt0 = mpegsub->w_width - cnt1; // From 0 to ...
      off1 = mpegsub->freq_div*16 - cnt1;
      off0 = mpegsub->freq_div*16 - cnt0;
      offd = mpegsub->freq_div*16 - mpegsub->w_width;
      buf1 = &buf_ptr[ start ];
      buf0 = &buf_ptr[ 0 ];
//      dewindow = &MPT_dewindow[ mpegsub->w_begin ]; // #7 Removed
      dewindow = &(mpegsub->scaled_dewindow[ mpegsub->w_begin ]); // #7 Scaled dewindow
      j = mpegsub->pcm_count;

      // #3 Begin: NEW_WIN

#define MULTS sum = MULT_DEW( *dewindow++, *buf1++ )
#define MULT0 sum += MULT_DEW( *dewindow++, *buf1++ )
#define MULT1 sum += MULT_DEW( *dewindow++, *buf0++ )

#ifdef DETECT_CLIP
#define STORE buf1 += off1; buf0 += off0; dewindow += offd;\
              sum = SCALE_DEW( sum );\
              if( sum > (SUB_TYPE)32767 ) sum = (SUB_TYPE)32767;\
              else if( sum < (SUB_TYPE)-32768 ) sum = (SUB_TYPE)-32768;\
              *samp++ = (INT16)sum;
#else
#define STORE buf1 += off1; buf0 += off0; dewindow += offd;\
              sum = SCALE_DEW( sum );\
              *samp++ = (INT16)sum;
#endif

      if( mpegsub->w_width <= 4 ) {
         switch( cnt0 ) {
            case 0:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0;
                  STORE;
               }
               break;
            case 1:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT1;
                  STORE;
               }
               break;
            case 2:
               while( j-- ) {
                  MULTS; MULT0; MULT1; MULT1;
                  STORE;
               }
               break;
            case 3:
               while( j-- ) {
                  MULTS; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
         }
      }
      else if( mpegsub->w_width <= 8 ) {
         switch( cnt0 ) {
            case 0:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  STORE;
               }
               break;
            case 1:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT1;
                  STORE;
               }
               break;
            case 2:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT1; MULT1;
                  STORE;
               }
               break;
            case 3:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 4:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 5:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 6:
               while( j-- ) {
                  MULTS; MULT0; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 7:
               while( j-- ) {
                  MULTS; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
         }
      }
      else {
         switch( cnt0 ) {
            case 0:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  STORE;
               }
               break;
            case 1:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT1;
                  STORE;
               }
               break;
            case 2:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT1; MULT1;
                  STORE;
               }
               break;
            case 3:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  MULT0; MULT0; MULT0; MULT0; MULT0; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 4:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  MULT0; MULT0; MULT0; MULT0; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 5:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  MULT0; MULT0; MULT0; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 6:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  MULT0; MULT0; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 7:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  MULT0; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 8:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0;
                  MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 9:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT0; MULT1;
                  MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 10:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT0; MULT1; MULT1;
                  MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 11:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT0; MULT1; MULT1; MULT1;
                  MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 12:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT0; MULT1; MULT1; MULT1; MULT1;
                  MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 13:
               while( j-- ) {
                  MULTS; MULT0; MULT0; MULT1; MULT1; MULT1; MULT1; MULT1;
                  MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 14:
               while( j-- ) {
                  MULTS; MULT0; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
            case 15:
               while( j-- ) {
                  MULTS; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1; MULT1;
                  STORE;
               }
               break;
         }
      }
      // #3 End

   }
#endif // ASM_OPTIMIZE
     mpegsub->b_offset[ channel ] = (b_offset - 1) & 15;

   return mpegsub->pcm_count;
}

int MPEGSUB_reset( MPEGSUB *mpegsub )
/*-----------------------------------
   Reset the MPEGSUB module
*/
{
   INT16 ch;

   if( !mpegsub ) return -1;
   // Reset sub band buffer
   memset( mpegsub->bb, 0, MPA_MAX_CHANNELS * 2 * MPA_HANNING_SIZE * sizeof( MPEGAUD_FRACT_TYPE ) );
   // Reset offsets
   for( ch=0; ch<MPA_MAX_CHANNELS; ch++ ) {
      mpegsub->b_offset[ ch ] = 0;
   }

   return 0;

} /* MPEGSUB_reset */

// #7 Begin
int MPEGSUB_scale( MPEGSUB *mpegsub, INT32 scale_percent ) {
/*--------------------------------------------------------
   Set the scale of the output of synthesis filter
   input: scale_percent = scale in % (100 is nominal value)
   return 0 if Ok
*/
   INT16 i;

   if( mpegsub->scale_percent == scale_percent ) return 0;

   if( scale_percent <= 0 ) return -1;
   if( scale_percent > 10000 ) return -2;

#ifdef MPEGAUD_INT
   {
      INT32 s, c;

      s = MPEGTAB_DEW_BITS;
      c = scale_percent;
      while( (c <= 50) && (s < 17) ) {
         c <<= 1;
         s++;
      }
      while( (c > 100) && (s > 2) ) {
         c >>= 1;
         s--;
      }
      if( s == 2 ) c = 100; // Limit max scale
      mpegsub->scaled_shift = s;
      c <<= 14;
      c /= 100;
      for( i=0; i<MPA_HANNING_SIZE; i++ ) {
         mpegsub->scaled_dewindow[ i ] = (MPEGTAB_DEW_TYPE)(((INT32)MPT_dewindow[ i ] * c)>>14);
      }
   }
#else
   {
      REAL coeff;

      coeff = (REAL)(scale_percent) * (MPA_SCALE * 0.01);
      for( i=0; i<MPA_HANNING_SIZE; i++ ) {
         mpegsub->scaled_dewindow[ i ] = MPT_dewindow[ i ] * coeff;
      }
   }
#endif
   mpegsub->scale_percent = scale_percent;
   return 0;
}
// #7 End

void MPEGSUB_close( MPEGSUB *mpegsub )
/*------------------------------------
   Close the MPEGSUB module
*/
{
   if( !mpegsub ) return;
   free( mpegsub );

} /* MPEGSUB_close */

MPEGSUB *MPEGSUB_open( INT16 freq_div, INT16 quality )
/*----------------------------------------------------
   Open the MPEGSUB module
*/
{
   MPEGSUB *mpegsub;

   mpegsub = (MPEGSUB *)malloc( sizeof(MPEGSUB) );
   if( !mpegsub ) return NULL;
   (void)MPEGSUB_reset( mpegsub );
   mpegsub->scale_percent = 0; // #7
   MPEGSUB_scale( mpegsub, 100 ); // #7

   switch( freq_div ) {
      case 2:  mpegsub->pcm_count = MPA_SBLIMIT>>1; break;
      case 4:  mpegsub->pcm_count = MPA_SBLIMIT>>2; break;
      default: mpegsub->pcm_count = MPA_SBLIMIT; freq_div = 1; break;
   }
   switch( quality ) {
      case 0:  mpegsub->w_begin = 6; mpegsub->w_width = 4; break;
      case 1:  mpegsub->w_begin = 4; mpegsub->w_width = 8; break;
      default: mpegsub->w_begin = 0; mpegsub->w_width = 16; quality = 2; break;
   }

   mpegsub->freq_div = freq_div;
   mpegsub->quality = quality;

#if defined(ASM_OPTIMIZE) || defined(COLDFIRE_ASM_2)
#ifdef MPEGAUD_INT
//   MPEGSUBB_config( freq_div, quality, 0 ); #6
#else
//   MPEGSUBF_config( freq_div, quality, 0 ); #6
#endif
#endif

   return mpegsub;

} /* MPEGSUB_open */