decode.c

mpeg layerI II III, support window and linux

        else
        {
           foo = (long)(sum * (double)SCALE -(double)0.5);
        }

     if (foo >= (long) SCALE)      {samples[j] = (OUTPUT_TYPE)(SCALE-1); ++clip;}
     else if (foo < (long) -SCALE) {samples[j] = (OUTPUT_TYPE)(-SCALE);  ++clip;}
     else                           samples[j] =(OUTPUT_TYPE)foo;
 
     //printf("sample[%d] = 0x%x\n",j,samples[j]);
    }
    return(clip);
}

void out_fifo(pcm_sample, num, fr_ps, done, outFile, psampFrames)
OUTPUT_TYPE FAR pcm_sample[2][SSLIMIT][SBLIMIT];
int num;
frame_params *fr_ps;
int done;
FILE *outFile;
unsigned long *psampFrames;
{
    int i,j,l;
    int stereo = fr_ps->stereo;
    int sblimit = fr_ps->sblimit;
    static OUTPUT_TYPE outsamp[1600];
    static long k = 0;

    if (!done)
        for (i=0;i<num;i++) for (j=0;j<SBLIMIT;j++) {
            (*psampFrames)++;
            for (l=0;l<stereo;l++) {
                if (!(k%1600) && k) {
                    /*
                      Samples are big-endian. If this is a little-endian machine
                      we must swap
                      */
                    if ( NativeByteOrder == order_unknown )
                    {
                        NativeByteOrder = DetermineByteOrder();
                        if ( NativeByteOrder == order_unknown )
                        {
                            fprintf( stderr, "byte order not determined\n" );
                            exit( 1 );
                        }
                    }
                    if ( NativeByteOrder == order_littleEndian )
#ifdef  OUT20
                        SwapBytesInLongs( outsamp, 1600 );
#else
                        SwapBytesInWords( outsamp, 1600 );
#endif
                    fwrite(outsamp,sizeof(OUTPUT_TYPE),1600,outFile);
                    k = 0;
                }
                outsamp[k++] = pcm_sample[l][i][j];
            }
        }
    else {
            if ( NativeByteOrder == order_unknown )
            {
                NativeByteOrder = DetermineByteOrder();
                if ( NativeByteOrder == order_unknown )
                {
                    fprintf( stderr, "byte order not determined\n" );
                    exit( 1 );
                }
            }
            if ( NativeByteOrder == order_littleEndian )
#ifdef  OUT20
                SwapBytesInLongs( outsamp, (int)k );
#else
                SwapBytesInWords( outsamp, (int)k );
#endif
        fwrite(outsamp,sizeof(OUTPUT_TYPE),(int)k,outFile);
        k = 0;
    }
}

void  buffer_CRC(bs, old_crc)
Bit_stream_struc  *bs;
unsigned int  *old_crc;
{
    *old_crc = getbits(bs, 16);
}

void  recover_CRC_error(pcm_sample, error_count, fr_ps, outFile, psampFrames)
OUTPUT_TYPE FAR pcm_sample[2][SSLIMIT][SBLIMIT];
int error_count;
frame_params *fr_ps;
FILE *outFile;
unsigned long *psampFrames;
{
    int  stereo = fr_ps->stereo;
    int  num, done, i;
    int  samplesPerFrame, samplesPerSlot;
    layer  *hdr = fr_ps->header;
    long  offset;
    OUTPUT_TYPE  *temp;

    num = 3;
    if (hdr->lay == 1) num = 1;

    samplesPerSlot = SBLIMIT * num * stereo;
    samplesPerFrame = samplesPerSlot * 32;

  #ifndef NO_CRC_RECOVERY
    // MDB 3/19/2003 Don't attempt to predict how decoder will
    // behave on bad CRC, just mute frame
    if (error_count == 1) {     /* replicate previous error_free frame */
        done = 1;
        /* flush out fifo */
        out_fifo(pcm_sample, num, fr_ps, done, outFile, psampFrames);
        /* go back to the beginning of the previous frame */
        offset = sizeof(OUTPUT_TYPE) * samplesPerFrame;
        fseek(outFile, -offset, SEEK_CUR);
        done = 0;
        for (i = 0; i < SCALE_BLOCK; i++) {
            fread(pcm_sample, sizeof(OUTPUT_TYPE), samplesPerSlot, outFile);
            out_fifo(pcm_sample, num, fr_ps, done, outFile, psampFrames);
        }
    }
    else
   #endif
    {                       /* mute the frame */
        temp = (OUTPUT_TYPE*) pcm_sample;
        done = 0;
        for (i = 0; i < 2*3*SBLIMIT; i++)
            *temp++ = MUTE;     /* MUTE value is in decoder.h */
        for (i = 0; i < SCALE_BLOCK; i++)
            out_fifo(pcm_sample, num, fr_ps, done, outFile, psampFrames);
    }
}

/************************* Layer III routines **********************/

void III_get_side_info(bs, si, fr_ps)
Bit_stream_struc *bs;
III_side_info_t *si;
frame_params *fr_ps;
{
   int ch, gr, i;
   int stereo = fr_ps->stereo;

   if(fr_ps->header->version != MPEG_PHASE2_LSF)
   {
      si->main_data_begin = getbits(bs, 9);
      if (stereo == 1)
         si->private_bits = getbits(bs,5);
         else si->private_bits = getbits(bs,3);

       for (ch=0; ch<stereo; ch++)
           for (i=0; i<4; i++)
           si->ch[ch].scfsi[i] = get1bit(bs);
#ifdef DEBUG_SIDE_INFO
         printf("side_info->main_data_begin = %d\n",si->main_data_begin);
         printf("side_info->private_bits    = %d\n",si->private_bits);
         for (ch=0; ch<stereo; ch++)
           for (i=0; i<4; i++)
           printf("side_info->ch[%d].scfsi[%d] = %d\n",ch,i,si->ch[ch].scfsi[i]); 
#endif 

        for (gr=0; gr< 2 ; gr++) {
           for (ch=0; ch<stereo; ch++) {
              si->ch[ch].gr[gr].part2_3_length = getbits(bs, 12);
              si->ch[ch].gr[gr].big_values = getbits(bs, 9);
              si->ch[ch].gr[gr].global_gain = getbits(bs, 8);
              si->ch[ch].gr[gr].scalefac_compress = getbits(bs, 4);
              si->ch[ch].gr[gr].window_switching_flag = get1bit(bs);
#ifdef DEBUG_SIDE_INFO 
                 printf("side_info->ch[%d].gr[%d].part2_3_length        = %d\n",ch,gr,si->ch[ch].gr[gr].part2_3_length       );
                 printf("side_info->ch[%d].gr[%d].big_values            = %d\n",ch,gr,si->ch[ch].gr[gr].big_values           );
                 printf("side_info->ch[%d].gr[%d].global_gain           = %d\n",ch,gr,si->ch[ch].gr[gr].global_gain          );
                 printf("side_info->ch[%d].gr[%d].scalefac_compress     = %d\n",ch,gr,si->ch[ch].gr[gr].scalefac_compress    );
                 printf("side_info->ch[%d].gr[%d].window_switching_flag = %d\n",ch,gr,si->ch[ch].gr[gr].window_switching_flag);
                 
#endif 
              if (si->ch[ch].gr[gr].window_switching_flag) {
                 si->ch[ch].gr[gr].block_type = getbits(bs, 2);
                 si->ch[ch].gr[gr].mixed_block_flag = get1bit(bs);
                 for (i=0; i<2; i++)
                    si->ch[ch].gr[gr].table_select[i] = getbits(bs, 5);
                 for (i=0; i<3; i++)
                    si->ch[ch].gr[gr].subblock_gain[i] = getbits(bs, 3);

            /* Set region_count parameters since they are implicit in this case. */

                 if (si->ch[ch].gr[gr].block_type == 0) {
                   printf("Side info bad: block_type == 0 in split block.\n");
                   exit(0);
                 }
                 else if (si->ch[ch].gr[gr].block_type == 2
                      && si->ch[ch].gr[gr].mixed_block_flag == 0)
                             si->ch[ch].gr[gr].region0_count = 8; /* MI 9; */
                 else si->ch[ch].gr[gr].region0_count = 7; /* MI 8; */
                      si->ch[ch].gr[gr].region1_count = 20 -
                                                si->ch[ch].gr[gr].region0_count;
#ifdef DEBUG_SIDE_INFO
                     printf("side_info->ch[%d].gr[%d].block_type       = %d\n",ch,gr,si->ch[ch].gr[gr].block_type);
                     printf("side_info->ch[%d].gr[%d].mixed_block_flag = %d\n",ch,gr,si->ch[ch].gr[gr].mixed_block_flag);
                     for (i=0; i<2; i++)
                     { 
                         printf("side_info->ch[%d].gr[%d].table_select[%d] = %d\n",ch,gr,i,si->ch[ch].gr[gr].table_select[i]); 
                     }

                     for (i=0; i<3; i++)
                     {
                         printf("side_info->ch[%d].gr[%d].subblock_gain[%d] = %d\n",ch,gr,i,si->ch[ch].gr[gr].subblock_gain[i]);
                     }
                     printf("side_info->ch[%d].gr[%d].region0_count = %d\n",ch,gr,si->ch[ch].gr[gr].region0_count);
                     printf("side_info->ch[%d].gr[%d].region1_count = %d\n",ch,gr,si->ch[ch].gr[gr].region1_count);
#endif                      
             }
            else {
               for (i=0; i<3; i++)
                   si->ch[ch].gr[gr].table_select[i] = getbits(bs, 5);
               si->ch[ch].gr[gr].region0_count = getbits(bs, 4);
               si->ch[ch].gr[gr].region1_count = getbits(bs, 3);
               si->ch[ch].gr[gr].block_type = 0;
#ifdef DEBUG_SIDE_INFO
                     for (i=0; i<3; i++)   
                     {
                          printf("side_info->ch[%d].gr[%d].table_select[%d] = %d\n",ch,gr,i,si->ch[ch].gr[gr].table_select[i]);
                     }
                     printf("side_info->ch[%d].gr[%d].region0_count = %d\n",ch,gr,si->ch[ch].gr[gr].region0_count);
                     printf("side_info->ch[%d].gr[%d].region1_count = %d\n",ch,gr,si->ch[ch].gr[gr].region1_count);
                     printf("side_info->ch[%d].gr[%d].block_type    = %d\n",ch,gr,si->ch[ch].gr[gr].block_type   );

#endif                  
            }
         si->ch[ch].gr[gr].preflag = get1bit(bs);
         si->ch[ch].gr[gr].scalefac_scale = get1bit(bs);
         si->ch[ch].gr[gr].count1table_select = get1bit(bs);
#ifdef DEBUG_SIDE_INFO 
                 printf("side_info->ch[%d].gr[%d].preflag            =%d\n",ch,gr,si->ch[ch].gr[gr].preflag           );
                 printf("side_info->ch[%d].gr[%d].scalefac_scale     =%d\n",ch,gr,si->ch[ch].gr[gr].scalefac_scale    );
                 printf("side_info->ch[%d].gr[%d].count1table_select =%d\n",ch,gr,si->ch[ch].gr[gr].count1table_select);
#endif 
         }
      }
    }
    else /* Layer 3 LSF */
    {
        si->main_data_begin = getbits(bs, 8);
        if (stereo == 1)
                 si->private_bits = getbits(bs,1);
         else si->private_bits = getbits(bs,2);

        for (gr=0; gr< 1 ; gr++) {
           for (ch=0; ch<stereo; ch++) {
              si->ch[ch].gr[gr].part2_3_length = getbits(bs, 12);
              si->ch[ch].gr[gr].big_values = getbits(bs, 9);
              si->ch[ch].gr[gr].global_gain = getbits(bs, 8);
              si->ch[ch].gr[gr].scalefac_compress = getbits(bs, 9);
              si->ch[ch].gr[gr].window_switching_flag = get1bit(bs);
              if (si->ch[ch].gr[gr].window_switching_flag) {
                 si->ch[ch].gr[gr].block_type = getbits(bs, 2);
                 si->ch[ch].gr[gr].mixed_block_flag = get1bit(bs);
                 for (i=0; i<2; i++)
                    si->ch[ch].gr[gr].table_select[i] = getbits(bs, 5);
                 for (i=0; i<3; i++)
                    si->ch[ch].gr[gr].subblock_gain[i] = getbits(bs, 3);

            /* Set region_count parameters since they are implicit in this case. */

                 if (si->ch[ch].gr[gr].block_type == 0) {
                   printf("Side info bad: block_type == 0 in split block.\n");
                   exit(0);
                 }
                 else if (si->ch[ch].gr[gr].block_type == 2
                      && si->ch[ch].gr[gr].mixed_block_flag == 0)
                             si->ch[ch].gr[gr].region0_count = 8; /* MI 9; */
                 else si->ch[ch].gr[gr].region0_count = 7; /* MI 8; */
                      si->ch[ch].gr[gr].region1_count = 20 - si->ch[ch].gr[gr].region0_count;

              }
              else {
                for (i=0; i<3; i++)
                   si->ch[ch].gr[gr].table_select[i] = getbits(bs, 5);
               si->ch[ch].gr[gr].region0_count = getbits(bs, 4);
               si->ch[ch].gr[gr].region1_count = getbits(bs, 3);
               si->ch[ch].gr[gr].block_type = 0;
              }

         si->ch[ch].gr[gr].scalefac_scale = get1bit(bs);
         si->ch[ch].gr[gr].count1table_select = get1bit(bs);
         }
     }
  }
}

void III_put_side_info(bs, si, fr_ps)
frame_params *fr_ps;
Bit_stream_struc *bs;
III_side_info_t *si;
{
   int ch, gr, i;
   int stereo = fr_ps->stereo;

 if(fr_ps->header->version != MPEG_PHASE2_LSF)
 {
   putbits(bs, si->main_data_begin,9);
   if (stereo == 1)
      putbits(bs, si->private_bits, 5);
      else putbits(bs, si->private_bits, 3);

   for (ch=0; ch<stereo; ch++)
      for (i=0; i<4; i++)
         put1bit(bs, si->ch[ch].scfsi[i]);

   for (gr=0; gr<2; gr++) {
      for (ch=0; ch<stereo; ch++) {
         putbits(bs, si->ch[ch].gr[gr].part2_3_length, 12);
         putbits(bs, si->ch[ch].gr[gr].big_values, 9);
         putbits(bs, si->ch[ch].gr[gr].global_gain, 8);
         putbits(bs, si->ch[ch].gr[gr].scalefac_compress, 4);
         put1bit(bs, si->ch[ch].gr[gr].window_switching_flag);
         if (si->ch[ch].gr[gr].window_switching_flag) {
            putbits(bs, si->ch[ch].gr[gr].block_type, 2);
            put1bit(bs, si->ch[ch].gr[gr].mixed_block_flag);
            for (i=0; i<2; i++)
               putbits(bs, si->ch[ch].gr[gr].table_select[i], 5);
            for (i=0; i<3; i++)
               putbits(bs, si->ch[ch].gr[gr].subblock_gain[i], 3);
            }
         else {
            for (i=0; i<3; i++)
            putbits(bs, si->ch[ch].gr[gr].table_select[i], 5);
            putbits(bs, si->ch[ch].gr[gr].region0_count, 4);
            putbits(bs, si->ch[ch].gr[gr].region1_count, 3);
            }

         put1bit(bs, si->ch[ch].gr[gr].preflag);
         put1bit(bs, si->ch[ch].gr[gr].scalefac_scale);
         put1bit(bs, si->ch[ch].gr[gr].count1table_select);
         }
      }
 }
 else /* Layer 3 LSF */
 {
    putbits(bs, si->main_data_begin,8);
    if (stereo == 1)
      putbits(bs, si->private_bits, 1);
      else putbits(bs, si->private_bits, 2);


     for (gr=0; gr<1; gr++) {
       for (ch=0; ch<stereo; ch++) {
         putbits(bs, si->ch[ch].gr[gr].part2_3_length, 12);
         putbits(bs, si->ch[ch].gr[gr].big_values, 9);
         putbits(bs, si->ch[ch].gr[gr].global_gain, 8);
         putbits(bs, si->ch[ch].gr[gr].scalefac_compress, 9);