77052544f7ab70a1c0c5fc7b140cdc91cb950291
[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) max=d;
54 if (min>d) min=d;
55 s2 = s1;
56 s1 = s0;
57 }
58 prev->s1 = s1;
59 prev->s2 = s2;
60
61 if (max==0 && min==0) {
62 memset(adx,0,18);
63 return;
64 }
65
66 if (max/7>-min/8) scale = max/7;
67 else scale = -min/8;
68
69 if (scale==0) scale=1;
70
71 AV_WB16(adx, scale);
72
73 init_put_bits(&pb, adx + 2, 16);
74 for (i = 0; i < 32; i++)
75 put_sbits(&pb, 4, av_clip(data[i]/scale, -8, 7));
76 flush_put_bits(&pb);
77 }
78
79 static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize)
80 {
81 ADXContext *c = avctx->priv_data;
82
83 AV_WB32(buf+0x00,0x80000000|0x20);
84 AV_WB32(buf+0x04,0x03120400|avctx->channels);
85 AV_WB32(buf+0x08,avctx->sample_rate);
86 AV_WB32(buf+0x0c,0);
87 AV_WB16(buf + 0x10, c->cutoff);
88 AV_WB32(buf + 0x12, 0x03000000);
89 AV_WB32(buf + 0x16, 0x00000000);
90 AV_WB32(buf + 0x1a, 0x00000000);
91 memcpy (buf + 0x1e, "(c)CRI", 6);
92 return 0x20+4;
93 }
94
95 static av_cold int adx_encode_init(AVCodecContext *avctx)
96 {
97 ADXContext *c = avctx->priv_data;
98
99 if (avctx->channels > 2)
100 return -1;
101 avctx->frame_size = 32;
102
103 avctx->coded_frame= avcodec_alloc_frame();
104 avctx->coded_frame->key_frame= 1;
105
106 /* the cutoff can be adjusted, but this seems to work pretty well */
107 c->cutoff = 500;
108 ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff);
109
110 return 0;
111 }
112
113 static av_cold int adx_encode_close(AVCodecContext *avctx)
114 {
115 av_freep(&avctx->coded_frame);
116
117 return 0;
118 }
119
120 static int adx_encode_frame(AVCodecContext *avctx,
121 uint8_t *frame, int buf_size, void *data)
122 {
123 ADXContext *c = avctx->priv_data;
124 const int16_t *samples = data;
125 uint8_t *dst = frame;
126 int rest = avctx->frame_size;
127
128 if (!c->header_parsed) {
129 int hdrsize = adx_encode_header(avctx,dst,buf_size);
130 dst+=hdrsize;
131 c->header_parsed = 1;
132 }
133
134 if (avctx->channels==1) {
135 while(rest>=32) {
136 adx_encode(c, dst, samples, c->prev);
137 dst+=18;
138 samples+=32;
139 rest-=32;
140 }
141 } else {
142 while(rest>=32*2) {
143 int16_t tmpbuf[32*2];
144 int i;
145
146 for(i=0;i<32;i++) {
147 tmpbuf[i] = samples[i*2];
148 tmpbuf[i+32] = samples[i*2+1];
149 }
150
151 adx_encode(c, dst, tmpbuf, c->prev);
152 adx_encode(c, dst + 18, tmpbuf + 32, c->prev + 1);
153 dst+=18*2;
154 samples+=32*2;
155 rest-=32*2;
156 }
157 }
158 return dst-frame;
159 }
160
161 AVCodec ff_adpcm_adx_encoder = {
162 .name = "adpcm_adx",
163 .type = AVMEDIA_TYPE_AUDIO,
164 .id = CODEC_ID_ADPCM_ADX,
165 .priv_data_size = sizeof(ADXContext),
166 .init = adx_encode_init,
167 .encode = adx_encode_frame,
168 .close = adx_encode_close,
169 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
170 .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
171 };