apps/codecs/libwavpack/float.c

   1 ////////////////////////////////////////////////////////////////////////////
   2 //                           **** WAVPACK ****                            //
   3 //                  Hybrid Lossless Wavefile Compressor                   //
   4 //              Copyright (c) 1998 - 2004 Conifer Software.               //
   5 //                          All Rights Reserved.                          //
   6 //      Distributed under the BSD Software License (see license.txt)      //
   7 ////////////////////////////////////////////////////////////////////////////
   8
   9 // float.c
  10
  11 #include "wavpack.h"
  12
  13 int read_float_info (WavpackStream *wps, WavpackMetadata *wpmd)
  14 {
  15     int bytecnt = wpmd->byte_length;
  16     char *byteptr = wpmd->data;
  17
  18     if (bytecnt != 4)
  19         return FALSE;
  20
  21     wps->float_flags = *byteptr++;
  22     wps->float_shift = *byteptr++;
  23     wps->float_max_exp = *byteptr++;
  24     wps->float_norm_exp = *byteptr;
  25     return TRUE;
  26 }
  27
  28 /* This function converts WavPack floating point data into standard Rockbox
  29  * 28-bit integers. It is assumed that clipping will be taken care of later.
  30  */
  31
  32 void float_values (WavpackStream *wps, int32_t *values, int32_t num_values)
  33 {
  34     int shift = wps->float_max_exp - wps->float_norm_exp + wps->float_shift + 5;
  35
  36     if (shift > 32)
  37         shift = 32;
  38     else if (shift < -32)
  39         shift = -32;
  40
  41     if (shift > 0)
  42         while (num_values--)
  43             *values++ <<= shift;
  44     else if (shift < 0)
  45         while (num_values--)
  46             *values++ >>= -shift;
  47 }