xref: /third_party/libsnd/src/G72x/g72x.h (revision b815c7f3)
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
39enum
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
64struct g72x_state ;
65
66/* External function definitions. */
67
68struct g72x_state * g72x_reader_init (int codec, int *blocksize, int *samplesperblock) ;
69struct 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
75int 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
83int 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
92