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annotate spandsp-0.0.6pre17/src/spandsp/ima_adpcm.h @ 5:f762bf195c4b

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import spandsp-0.0.3
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Fri, 25 Jun 2010 16:00:21 +0200
parents 26cd8f1ef0b1
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
1 /*
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
2 * SpanDSP - a series of DSP components for telephony
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
3 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
4 * ima_adpcm.c - Conversion routines between linear 16 bit PCM data and
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
5 * IMA/DVI/Intel ADPCM format.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
6 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
7 * Written by Steve Underwood <steveu@coppice.org>
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
8 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
9 * Copyright (C) 2004 Steve Underwood
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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10 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
11 * All rights reserved.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
12 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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13 * This program is free software; you can redistribute it and/or modify
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
14 * it under the terms of the GNU Lesser General Public License version 2.1,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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15 * as published by the Free Software Foundation.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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16 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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17 * This program is distributed in the hope that it will be useful,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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20 * GNU Lesser General Public License for more details.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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21 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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22 * You should have received a copy of the GNU Lesser General Public
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
23 * License along with this program; if not, write to the Free Software
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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25 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
26 * Based on a bit from here, a bit from there, eye of toad,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
27 * ear of bat, etc - plus, of course, my own 2 cents.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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28 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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29 * $Id: ima_adpcm.h,v 1.25 2009/04/11 18:11:19 steveu Exp $
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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30 */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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31
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
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32 /*! \file */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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33
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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34 #if !defined(_SPANDSP_IMA_ADPCM_H_)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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35 #define _SPANDSP_IMA_ADPCM_H_
26cd8f1ef0b1 import spandsp-0.0.6pre17
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parents:
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36
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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37 /*! \page ima_adpcm_page IMA/DVI/Intel ADPCM encoding and decoding
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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38 \section ima_adpcm_page_sec_1 What does it do?
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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39 IMA ADPCM offers a good balance of simplicity and quality at a rate of
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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40 32kbps.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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41
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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42 \section ima_adpcm_page_sec_2 How does it work?
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
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43
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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44 \section ima_adpcm_page_sec_3 How do I use it?
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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45 */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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46
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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47 enum
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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48 {
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
49 /*! IMA4 is the original IMA ADPCM variant */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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50 IMA_ADPCM_IMA4 = 0,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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51 /*! DVI4 is the IMA ADPCM variant defined in RFC3551 */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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52 IMA_ADPCM_DVI4 = 1,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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53 /*! VDVI is the variable bit rate IMA ADPCM variant defined in RFC3551 */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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54 IMA_ADPCM_VDVI = 2
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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55 };
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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56
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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57 /*!
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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58 IMA (DVI/Intel) ADPCM conversion state descriptor. This defines the state of
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
59 a single working instance of the IMA ADPCM converter. This is used for
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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60 either linear to ADPCM or ADPCM to linear conversion.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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61 */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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62 typedef struct ima_adpcm_state_s ima_adpcm_state_t;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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63
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
64 #if defined(__cplusplus)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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65 extern "C"
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
66 {
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
67 #endif
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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68
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
69 /*! Initialise an IMA ADPCM encode or decode context.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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70 \param s The IMA ADPCM context.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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71 \param variant IMA_ADPCM_IMA4, IMA_ADPCM_DVI4, or IMA_ADPCM_VDVI.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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72 \param chunk_size The size of a chunk, in samples. A chunk size of
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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73 zero sample samples means treat each encode or decode operation
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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74 as a chunk.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
75 \return A pointer to the IMA ADPCM context, or NULL for error. */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
76 SPAN_DECLARE(ima_adpcm_state_t *) ima_adpcm_init(ima_adpcm_state_t *s,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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77 int variant,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
78 int chunk_size);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
79
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
80 /*! Release an IMA ADPCM encode or decode context.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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81 \param s The IMA ADPCM context.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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82 \return 0 for OK. */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
83 SPAN_DECLARE(int) ima_adpcm_release(ima_adpcm_state_t *s);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
84
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
85 /*! Free an IMA ADPCM encode or decode context.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
86 \param s The IMA ADPCM context.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
87 \return 0 for OK. */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
88 SPAN_DECLARE(int) ima_adpcm_free(ima_adpcm_state_t *s);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
89
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
90 /*! Encode a buffer of linear PCM data to IMA ADPCM.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
91 \param s The IMA ADPCM context.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
92 \param ima_data The IMA ADPCM data produced.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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93 \param amp The audio sample buffer.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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94 \param len The number of samples in the buffer.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
95 \return The number of bytes of IMA ADPCM data produced. */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
96 SPAN_DECLARE(int) ima_adpcm_encode(ima_adpcm_state_t *s,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
97 uint8_t ima_data[],
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
98 const int16_t amp[],
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
99 int len);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
100
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
101 /*! Decode a buffer of IMA ADPCM data to linear PCM.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
102 \param s The IMA ADPCM context.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
103 \param amp The audio sample buffer.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
104 \param ima_data The IMA ADPCM data
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
105 \param ima_bytes The number of bytes of IMA ADPCM data
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
106 \return The number of samples returned. */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
107 SPAN_DECLARE(int) ima_adpcm_decode(ima_adpcm_state_t *s,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
108 int16_t amp[],
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
109 const uint8_t ima_data[],
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
110 int ima_bytes);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
111
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
112 #if defined(__cplusplus)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
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113 }
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
114 #endif
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
115
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
116 #endif
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
117 /*- End of file ------------------------------------------------------------*/

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