1 /*
2 * ADX ADPCM codecs
3 * Copyright (c) 2001,2003 BERO
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "avcodec.h"
23 #include "adx.h"
24 #include "bytestream.h"
25 #include "codec_internal.h"
26 #include "encode.h"
27 #include "put_bits.h"
28
29 /**
30 * @file
31 * SEGA CRI adx codecs.
32 *
33 * Reference documents:
34 * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
35 * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
36 */
37
adx_encode(ADXContext * c,uint8_t * adx,const int16_t * wav,ADXChannelState * prev,int channels)38 static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav,
39 ADXChannelState *prev, int channels)
40 {
41 PutBitContext pb;
42 int scale;
43 int i, j;
44 int s0, s1, s2, d;
45 int max = 0;
46 int min = 0;
47
48 s1 = prev->s1;
49 s2 = prev->s2;
50 for (i = 0, j = 0; j < 32; i += channels, j++) {
51 s0 = wav[i];
52 d = s0 + ((-c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS);
53 if (max < d)
54 max = d;
55 if (min > d)
56 min = d;
57 s2 = s1;
58 s1 = s0;
59 }
60
61 if (max == 0 && min == 0) {
62 prev->s1 = s1;
63 prev->s2 = s2;
64 memset(adx, 0, BLOCK_SIZE);
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
80 s1 = prev->s1;
81 s2 = prev->s2;
82 for (i = 0, j = 0; j < 32; i += channels, j++) {
83 d = wav[i] + ((-c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS);
84
85 d = av_clip_intp2(ROUNDED_DIV(d, scale), 3);
86
87 put_sbits(&pb, 4, d);
88
89 s0 = d * scale + ((c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS);
90 s2 = s1;
91 s1 = s0;
92 }
93 prev->s1 = s1;
94 prev->s2 = s2;
95
96 flush_put_bits(&pb);
97 }
98
99 #define HEADER_SIZE 36
100
adx_encode_header(AVCodecContext * avctx,uint8_t * buf,int bufsize)101 static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize)
102 {
103 ADXContext *c = avctx->priv_data;
104
105 bytestream_put_be16(&buf, 0x8000); /* header signature */
106 bytestream_put_be16(&buf, HEADER_SIZE - 4); /* copyright offset */
107 bytestream_put_byte(&buf, 3); /* encoding */
108 bytestream_put_byte(&buf, BLOCK_SIZE); /* block size */
109 bytestream_put_byte(&buf, 4); /* sample size */
110 bytestream_put_byte(&buf, avctx->ch_layout.nb_channels); /* channels */
111 bytestream_put_be32(&buf, avctx->sample_rate); /* sample rate */
112 bytestream_put_be32(&buf, 0); /* total sample count */
113 bytestream_put_be16(&buf, c->cutoff); /* cutoff frequency */
114 bytestream_put_byte(&buf, 3); /* version */
115 bytestream_put_byte(&buf, 0); /* flags */
116 bytestream_put_be32(&buf, 0); /* unknown */
117 bytestream_put_be32(&buf, 0); /* loop enabled */
118 bytestream_put_be16(&buf, 0); /* padding */
119 bytestream_put_buffer(&buf, "(c)CRI", 6); /* copyright signature */
120
121 return HEADER_SIZE;
122 }
123
adx_encode_init(AVCodecContext * avctx)124 static av_cold int adx_encode_init(AVCodecContext *avctx)
125 {
126 ADXContext *c = avctx->priv_data;
127
128 if (avctx->ch_layout.nb_channels > 2) {
129 av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
130 return AVERROR(EINVAL);
131 }
132 avctx->frame_size = BLOCK_SAMPLES;
133
134 /* the cutoff can be adjusted, but this seems to work pretty well */
135 c->cutoff = 500;
136 ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff);
137
138 return 0;
139 }
140
adx_encode_frame(AVCodecContext * avctx,AVPacket * avpkt,const AVFrame * frame,int * got_packet_ptr)141 static int adx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
142 const AVFrame *frame, int *got_packet_ptr)
143 {
144 ADXContext *c = avctx->priv_data;
145 const int16_t *samples = frame ? (const int16_t *)frame->data[0] : NULL;
146 uint8_t *dst;
147 int channels = avctx->ch_layout.nb_channels;
148 int ch, out_size, ret;
149
150 if (!samples) {
151 if (c->eof)
152 return 0;
153 if ((ret = ff_get_encode_buffer(avctx, avpkt, 18, 0)) < 0)
154 return ret;
155 c->eof = 1;
156 dst = avpkt->data;
157 bytestream_put_be16(&dst, 0x8001);
158 bytestream_put_be16(&dst, 0x000E);
159 bytestream_put_be64(&dst, 0x0);
160 bytestream_put_be32(&dst, 0x0);
161 bytestream_put_be16(&dst, 0x0);
162 *got_packet_ptr = 1;
163 return 0;
164 }
165
166 out_size = BLOCK_SIZE * channels + !c->header_parsed * HEADER_SIZE;
167 if ((ret = ff_get_encode_buffer(avctx, avpkt, out_size, 0)) < 0)
168 return ret;
169 dst = avpkt->data;
170
171 if (!c->header_parsed) {
172 int hdrsize;
173 if ((hdrsize = adx_encode_header(avctx, dst, avpkt->size)) < 0) {
174 av_log(avctx, AV_LOG_ERROR, "output buffer is too small\n");
175 return AVERROR(EINVAL);
176 }
177 dst += hdrsize;
178 c->header_parsed = 1;
179 }
180
181 for (ch = 0; ch < channels; ch++) {
182 adx_encode(c, dst, samples + ch, &c->prev[ch], channels);
183 dst += BLOCK_SIZE;
184 }
185
186 avpkt->pts = frame->pts;
187 avpkt->duration = frame->nb_samples;
188 *got_packet_ptr = 1;
189 return 0;
190 }
191
192 const FFCodec ff_adpcm_adx_encoder = {
193 .p.name = "adpcm_adx",
194 .p.long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
195 .p.type = AVMEDIA_TYPE_AUDIO,
196 .p.id = AV_CODEC_ID_ADPCM_ADX,
197 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
198 .priv_data_size = sizeof(ADXContext),
199 .init = adx_encode_init,
200 FF_CODEC_ENCODE_CB(adx_encode_frame),
201 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16,
202 AV_SAMPLE_FMT_NONE },
203 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
204 };
205