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authorYoshihisa Uchida <uchida@rockbox.org>2010-02-20 02:04:56 +0000
committerYoshihisa Uchida <uchida@rockbox.org>2010-02-20 02:04:56 +0000
commit3716abba9274f544dd31cdf4e6c83a845bf2a801 (patch)
tree07bca7cdd3e40bb176e938fcb5ea8eb2f7c3e9cb /apps/codecs/libpcm/ms_adpcm.c
parent93caf52db5e0afe826278c148936bdfa563724f1 (diff)
downloadrockbox-3716abba9274f544dd31cdf4e6c83a845bf2a801.tar.gz
rockbox-3716abba9274f544dd31cdf4e6c83a845bf2a801.zip
commit FS#10424 and FS#10425
- wav(RIFF) supports Microsoft ADPCM, Dialogic OKI ADPCM, YAMAHA ADPCM, Adobe SWF ADPCM. - AIFF supports QuickTime IMA ADPCM. - DVI ADPCM(IMA ADPCM) reworks. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24782 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/codecs/libpcm/ms_adpcm.c')
-rw-r--r--apps/codecs/libpcm/ms_adpcm.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/apps/codecs/libpcm/ms_adpcm.c b/apps/codecs/libpcm/ms_adpcm.c
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1/***************************************************************************
2 * __________ __ ___.
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
7 * \/ \/ \/ \/ \/
8 * $Id$
9 *
10 * Copyright (C) 2010 Yoshihisa Uchida
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version 2
15 * of the License, or (at your option) any later version.
16 *
17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
18 * KIND, either express or implied.
19 *
20 ****************************************************************************/
21#include "codeclib.h"
22#include "pcm_common.h"
23
24/*
25 * Microsoft ADPCM
26 *
27 * References
28 * [1] Microsoft, New Multimedia Data Types and Data Techniques Revision 3.0, 1994
29 * [2] MulitimediaWiki, Microsoft ADPCM, 2006
30 * (http://wiki.multimedia.cx/index.php?title=Microsoft_ADPCM)
31 * [3] ffmpeg source code, libavcodec/adpcm.c
32 */
33
34#define ADPCM_NUM_COEFF 7
35
36static int16_t dec_coeff[2][2];
37static uint16_t delta[2];
38static int16_t sample[2][2];
39
40static struct pcm_format *fmt;
41
42static const int16_t adaptation_table[] ICONST_ATTR = {
43 230, 230, 230, 230, 307, 409, 512, 614,
44 768, 614, 512, 409, 307, 230, 230, 230
45};
46
47static bool set_format(struct pcm_format *format)
48{
49 fmt = format;
50
51 if (fmt->bitspersample != 4)
52 {
53 DEBUGF("CODEC_ERROR: microsoft adpcm must be 4 bitspersample: %d\n",
54 fmt->bitspersample);
55 return false;
56 }
57
58 fmt->chunksize = fmt->blockalign;
59
60 return true;
61}
62
63static struct pcm_pos *get_seek_pos(long seek_time,
64 uint8_t *(*read_buffer)(size_t *realsize))
65{
66 static struct pcm_pos newpos;
67 uint32_t newblock = ((uint64_t)seek_time * ci->id3->frequency)
68 / (1000LL * fmt->samplesperblock);
69
70 (void)read_buffer;
71 newpos.pos = newblock * fmt->blockalign;
72 newpos.samples = newblock * fmt->samplesperblock;
73 return &newpos;
74}
75
76static int16_t create_pcmdata(int ch, uint8_t nibble)
77{
78 int32_t pcmdata;
79
80 pcmdata = (sample[ch][0] * dec_coeff[ch][0] +
81 sample[ch][1] * dec_coeff[ch][1]) / 256;
82 pcmdata += (delta[ch] * (nibble - ((nibble & 0x8) << 1)));
83
84 CLIP(pcmdata, -32768, 32767);
85
86 sample[ch][1] = sample[ch][0];
87 sample[ch][0] = pcmdata;
88
89 delta[ch] = (adaptation_table[nibble] * delta[ch]) >> 8;
90 if (delta[ch] < 16)
91 delta[ch] = 16;
92
93 return (int16_t)pcmdata;
94}
95
96static int decode(const uint8_t *inbuf, size_t inbufsize,
97 int32_t *outbuf, int *outbufcount)
98{
99 int ch;
100 size_t nsamples = 0;
101 int size = fmt->samplesperblock;
102
103 /* read block header */
104 for (ch = 0; ch < fmt->channels; ch++)
105 {
106 if (*inbuf >= ADPCM_NUM_COEFF)
107 {
108 DEBUGF("CODEC_ERROR: microsoft adpcm illegal initial coeff=%d > 7\n",
109 *inbuf);
110 return CODEC_ERROR;
111 }
112 dec_coeff[ch][0] = fmt->coeffs[*inbuf][0];
113 dec_coeff[ch][1] = fmt->coeffs[*inbuf][1];
114 inbuf++;
115 }
116
117 for (ch = 0; ch < fmt->channels; ch++)
118 {
119 delta[ch] = inbuf[0] | (SE(inbuf[1]) << 8);
120 inbuf += 2;
121 }
122
123 for (ch = 0; ch < fmt->channels; ch++)
124 {
125 sample[ch][0] = inbuf[0] | (SE(inbuf[1]) << 8);
126 inbuf += 2;
127 }
128
129 for (ch = 0; ch < fmt->channels; ch++)
130 {
131 sample[ch][1] = inbuf[0] | (SE(inbuf[1]) << 8);
132 inbuf += 2;
133 }
134
135 inbufsize -= 7 * fmt->channels;
136 ch = fmt->channels - 1;
137
138 while (size-- > 0)
139 {
140 *outbuf++ = create_pcmdata(0, *inbuf >> 4 ) << 13;
141 *outbuf++ = create_pcmdata(ch, *inbuf & 0xf) << 13;
142 nsamples += 2;
143
144 inbuf++;
145 inbufsize--;
146 if (inbufsize <= 0)
147 break;
148 }
149
150 if (fmt->channels == 2)
151 nsamples >>= 1;
152 *outbufcount = nsamples;
153
154 return CODEC_OK;
155}
156
157static const struct pcm_codec codec = {
158 set_format,
159 get_seek_pos,
160 decode,
161 };
162
163const struct pcm_codec *get_ms_adpcm_codec(void)
164{
165 return &codec;
166}