interpretor/libsndfile-1.0.25/src/G72x/g72x.h

   1 /*
   2 ** Copyright (C) 1999-2011 Erik de Castro Lopo <erikd@mega-nerd.com>
   3 **
   4 ** This program is free software; you can redistribute it and/or modify
   5 ** it under the terms of the GNU Lesser General Public License as published by
   6 ** the Free Software Foundation; either version 2.1 of the License, or
   7 ** (at your option) any later version.
   8 **
   9 ** This program is distributed in the hope that it will be useful,
  10 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 ** GNU Lesser General Public License for more details.
  13 **
  14 ** You should have received a copy of the GNU Lesser General Public License
  15 ** along with this program; if not, write to the Free Software
  16 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17 */
  18
  19 /*
  20 ** This file is not the same as the original file from Sun Microsystems. Nearly
  21 ** all the original definitions and function prototypes that were in the file
  22 ** of this name have been moved to g72x_priv.h.
  23 */
  24
  25 #ifndef G72X_HEADER_FILE
  26 #define G72X_HEADER_FILE
  27
  28 /*
  29 ** Number of samples per block to process.
  30 ** Must be a common multiple of possible bits per sample : 2, 3, 4, 5 and 8.
  31 */
  32 #define G72x_BLOCK_SIZE         (3 * 5 * 8)
  33
  34 /*
  35 **      Identifiers for the differing kinds of G72x ADPCM codecs.
  36 **      The identifiers also define the number of encoded bits per sample.
  37 */
  38
  39 enum
  40 {       G723_16_BITS_PER_SAMPLE = 2,
  41         G723_24_BITS_PER_SAMPLE = 3,
  42         G723_40_BITS_PER_SAMPLE = 5,
  43
  44         G721_32_BITS_PER_SAMPLE = 4,
  45         G721_40_BITS_PER_SAMPLE = 5,
  46
  47         G723_16_SAMPLES_PER_BLOCK = G72x_BLOCK_SIZE,
  48         G723_24_SAMPLES_PER_BLOCK = G723_24_BITS_PER_SAMPLE * (G72x_BLOCK_SIZE / G723_24_BITS_PER_SAMPLE),
  49         G723_40_SAMPLES_PER_BLOCK = G723_40_BITS_PER_SAMPLE * (G72x_BLOCK_SIZE / G723_40_BITS_PER_SAMPLE),
  50
  51         G721_32_SAMPLES_PER_BLOCK = G72x_BLOCK_SIZE,
  52         G721_40_SAMPLES_PER_BLOCK = G721_40_BITS_PER_SAMPLE * (G72x_BLOCK_SIZE / G721_40_BITS_PER_SAMPLE),
  53
  54         G723_16_BYTES_PER_BLOCK = (G723_16_BITS_PER_SAMPLE * G72x_BLOCK_SIZE) / 8,
  55         G723_24_BYTES_PER_BLOCK = (G723_24_BITS_PER_SAMPLE * G72x_BLOCK_SIZE) / 8,
  56         G723_40_BYTES_PER_BLOCK = (G723_40_BITS_PER_SAMPLE * G72x_BLOCK_SIZE) / 8,
  57
  58         G721_32_BYTES_PER_BLOCK = (G721_32_BITS_PER_SAMPLE * G72x_BLOCK_SIZE) / 8,
  59         G721_40_BYTES_PER_BLOCK = (G721_40_BITS_PER_SAMPLE * G72x_BLOCK_SIZE) / 8
  60 } ;
  61
  62 /* Forward declaration of of g72x_state. */
  63
  64 struct g72x_state ;
  65
  66 /* External function definitions. */
  67
  68 struct g72x_state * g72x_reader_init (int codec, int *blocksize, int *samplesperblock) ;
  69 struct g72x_state * g72x_writer_init (int codec, int *blocksize, int *samplesperblock) ;
  70 /*
  71 **      Initialize the ADPCM state table for the given codec.
  72 **      Return 0 on success, 1 on fail.
  73 */
  74
  75 int g72x_decode_block (struct g72x_state *pstate, const unsigned char *block, short *samples) ;
  76 /*
  77 **      The caller fills data->block with data->bytes bytes before calling the
  78 **      function. The value data->bytes must be an integer multiple of
  79 **      data->blocksize and be <= data->max_bytes.
  80 **      When it returns, the caller can read out data->samples samples.
  81 */
  82
  83 int g72x_encode_block (struct g72x_state *pstate, short *samples, unsigned char *block) ;
  84 /*
  85 **      The caller fills state->samples some integer multiple data->samples_per_block
  86 **      (up to G72x_BLOCK_SIZE) samples before calling the function.
  87 **      When it returns, the caller can read out bytes encoded bytes.
  88 */
  89
  90 #endif /* !G72X_HEADER_FILE */
  91