43f78018436f12ab00811211dba3fbaa23f13d06
[libav.git] / libavcodec / adxenc.c
1 /*
2 * ADX ADPCM codecs
3 * Copyright (c) 2001,2003 BERO
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "libavutil/intreadwrite.h"
23 #include "avcodec.h"
24 #include "adx.h"
25 #include "put_bits.h"
26
27 /**
28 * @file
29 * SEGA CRI adx codecs.
30 *
31 * Reference documents:
32 * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
33 * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
34 */
35
36 static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav,
37 ADXChannelState *prev)
38 {
39 PutBitContext pb;
40 int scale;
41 int i;
42 int s0, s1, s2, d;
43 int max = 0;
44 int min = 0;
45 int data[32];
46
47 s1 = prev->s1;
48 s2 = prev->s2;
49 for (i = 0; i < 32; i++) {
50 s0 = wav[i];
51 d = ((s0 << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS;
52 data[i] = d;
53 if (max < d)
54 max = d;
55 if (min > d)
56 min = d;
57 s2 = s1;
58 s1 = s0;
59 }
60 prev->s1 = s1;
61 prev->s2 = s2;
62
63 if (max == 0 && min == 0) {
64 memset(adx, 0, 18);
65 return;
66 }
67
68 if (max / 7 > -min / 8)
69 scale = max / 7;
70 else
71 scale = -min / 8;
72
73 if (scale == 0)
74 scale = 1;
75
76 AV_WB16(adx, scale);
77
78 init_put_bits(&pb, adx + 2, 16);
79 for (i = 0; i < 32; i++)
80 put_sbits(&pb, 4, av_clip(data[i] / scale, -8, 7));
81 flush_put_bits(&pb);
82 }
83
84 static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize)
85 {
86 ADXContext *c = avctx->priv_data;
87
88 AV_WB32(buf + 0x00, 0x80000000 | 0x20);
89 AV_WB32(buf + 0x04, 0x03120400 | avctx->channels);
90 AV_WB32(buf + 0x08, avctx->sample_rate);
91 AV_WB32(buf + 0x0c, 0);
92 AV_WB16(buf + 0x10, c->cutoff);
93 AV_WB32(buf + 0x12, 0x03000000);
94 AV_WB32(buf + 0x16, 0x00000000);
95 AV_WB32(buf + 0x1a, 0x00000000);
96 memcpy (buf + 0x1e, "(c)CRI", 6);
97 return 0x20 + 4;
98 }
99
100 static av_cold int adx_encode_init(AVCodecContext *avctx)
101 {
102 ADXContext *c = avctx->priv_data;
103
104 if (avctx->channels > 2) {
105 av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
106 return AVERROR(EINVAL);
107 }
108 avctx->frame_size = 32;
109
110 avctx->coded_frame = avcodec_alloc_frame();
111
112 /* the cutoff can be adjusted, but this seems to work pretty well */
113 c->cutoff = 500;
114 ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff);
115
116 return 0;
117 }
118
119 static av_cold int adx_encode_close(AVCodecContext *avctx)
120 {
121 av_freep(&avctx->coded_frame);
122 return 0;
123 }
124
125 static int adx_encode_frame(AVCodecContext *avctx, uint8_t *frame,
126 int buf_size, void *data)
127 {
128 ADXContext *c = avctx->priv_data;
129 const int16_t *samples = data;
130 uint8_t *dst = frame;
131 int rest = avctx->frame_size;
132
133 if (!c->header_parsed) {
134 int hdrsize = adx_encode_header(avctx, dst, buf_size);
135 dst += hdrsize;
136 c->header_parsed = 1;
137 }
138
139 if (avctx->channels == 1) {
140 while (rest >= 32) {
141 adx_encode(c, dst, samples, c->prev);
142 dst += 18;
143 samples += 32;
144 rest -= 32;
145 }
146 } else {
147 while (rest >= 32*2) {
148 int16_t tmpbuf[32*2];
149 int i;
150
151 for (i = 0; i < 32; i++) {
152 tmpbuf[i ] = samples[i*2 ];
153 tmpbuf[i+32] = samples[i*2+1];
154 }
155
156 adx_encode(c, dst, tmpbuf, c->prev );
157 adx_encode(c, dst + 18, tmpbuf + 32, c->prev + 1);
158 dst += 18*2;
159 samples += 32*2;
160 rest -= 32*2;
161 }
162 }
163 return dst - frame;
164 }
165
166 AVCodec ff_adpcm_adx_encoder = {
167 .name = "adpcm_adx",
168 .type = AVMEDIA_TYPE_AUDIO,
169 .id = CODEC_ID_ADPCM_ADX,
170 .priv_data_size = sizeof(ADXContext),
171 .init = adx_encode_init,
172 .encode = adx_encode_frame,
173 .close = adx_encode_close,
174 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16,
175 AV_SAMPLE_FMT_NONE },
176 .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
177 };