adx: calculate correct LPC coeffs
[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
26 /**
27 * @file
28 * SEGA CRI adx codecs.
29 *
30 * Reference documents:
31 * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
32 * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
33 */
34
35 /* 18 bytes <-> 32 samples */
36
37 static void adx_encode(ADXContext *c, unsigned char *adx, const short *wav,
38 ADXChannelState *prev)
39 {
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 /* -8..+7 */
62
63 if (max==0 && min==0) {
64 memset(adx,0,18);
65 return;
66 }
67
68 if (max/7>-min/8) scale = max/7;
69 else scale = -min/8;
70
71 if (scale==0) scale=1;
72
73 AV_WB16(adx, scale);
74
75 for(i=0;i<16;i++) {
76 adx[i+2] = ((data[i*2]/scale)<<4) | ((data[i*2+1]/scale)&0xf);
77 }
78 }
79
80 static int adx_encode_header(AVCodecContext *avctx,unsigned char *buf,size_t bufsize)
81 {
82 #if 0
83 struct {
84 uint32_t offset; /* 0x80000000 + sample start - 4 */
85 unsigned char unknown1[3]; /* 03 12 04 */
86 unsigned char channel; /* 1 or 2 */
87 uint32_t freq;
88 uint32_t size;
89 uint32_t unknown2; /* 01 f4 03 00 */
90 uint32_t unknown3; /* 00 00 00 00 */
91 uint32_t unknown4; /* 00 00 00 00 */
92
93 /* if loop
94 unknown3 00 15 00 01
95 unknown4 00 00 00 01
96 long loop_start_sample;
97 long loop_start_byte;
98 long loop_end_sample;
99 long loop_end_byte;
100 long
101 */
102 } adxhdr; /* big endian */
103 /* offset-6 "(c)CRI" */
104 #endif
105 ADXContext *c = avctx->priv_data;
106
107 AV_WB32(buf+0x00,0x80000000|0x20);
108 AV_WB32(buf+0x04,0x03120400|avctx->channels);
109 AV_WB32(buf+0x08,avctx->sample_rate);
110 AV_WB32(buf+0x0c,0); /* FIXME: set after */
111 AV_WB16(buf + 0x10, c->cutoff);
112 AV_WB32(buf + 0x12, 0x03000000);
113 AV_WB32(buf + 0x16, 0x00000000);
114 AV_WB32(buf + 0x1a, 0x00000000);
115 memcpy (buf + 0x1e, "(c)CRI", 6);
116 return 0x20+4;
117 }
118
119 static av_cold int adx_encode_init(AVCodecContext *avctx)
120 {
121 ADXContext *c = avctx->priv_data;
122
123 if (avctx->channels > 2)
124 return -1; /* only stereo or mono =) */
125 avctx->frame_size = 32;
126
127 avctx->coded_frame= avcodec_alloc_frame();
128 avctx->coded_frame->key_frame= 1;
129
130 // avctx->bit_rate = avctx->sample_rate*avctx->channels*18*8/32;
131
132 /* the cutoff can be adjusted, but this seems to work pretty well */
133 c->cutoff = 500;
134 ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff);
135
136 av_log(avctx, AV_LOG_DEBUG, "adx encode init\n");
137
138 return 0;
139 }
140
141 static av_cold int adx_encode_close(AVCodecContext *avctx)
142 {
143 av_freep(&avctx->coded_frame);
144
145 return 0;
146 }
147
148 static int adx_encode_frame(AVCodecContext *avctx,
149 uint8_t *frame, int buf_size, void *data)
150 {
151 ADXContext *c = avctx->priv_data;
152 const short *samples = data;
153 unsigned char *dst = frame;
154 int rest = avctx->frame_size;
155
156 /*
157 input data size =
158 avconv.c:do_audio_out()
159 frame_bytes = enc->frame_size * 2 * enc->channels;
160 */
161
162 // printf("sz=%d ",buf_size); fflush(stdout);
163 if (!c->header_parsed) {
164 int hdrsize = adx_encode_header(avctx,dst,buf_size);
165 dst+=hdrsize;
166 c->header_parsed = 1;
167 }
168
169 if (avctx->channels==1) {
170 while(rest>=32) {
171 adx_encode(c, dst, samples, c->prev);
172 dst+=18;
173 samples+=32;
174 rest-=32;
175 }
176 } else {
177 while(rest>=32*2) {
178 short tmpbuf[32*2];
179 int i;
180
181 for(i=0;i<32;i++) {
182 tmpbuf[i] = samples[i*2];
183 tmpbuf[i+32] = samples[i*2+1];
184 }
185
186 adx_encode(c, dst, tmpbuf, c->prev);
187 adx_encode(c, dst + 18, tmpbuf + 32, c->prev + 1);
188 dst+=18*2;
189 samples+=32*2;
190 rest-=32*2;
191 }
192 }
193 return dst-frame;
194 }
195
196 AVCodec ff_adpcm_adx_encoder = {
197 .name = "adpcm_adx",
198 .type = AVMEDIA_TYPE_AUDIO,
199 .id = CODEC_ID_ADPCM_ADX,
200 .priv_data_size = sizeof(ADXContext),
201 .init = adx_encode_init,
202 .encode = adx_encode_frame,
203 .close = adx_encode_close,
204 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
205 .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
206 };