blob: f1ba5911b330b1a951c9585f74029c9861e6451e
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 "internal.h" |
26 | #include "put_bits.h" |
27 | |
28 | /** |
29 | * @file |
30 | * SEGA CRI adx codecs. |
31 | * |
32 | * Reference documents: |
33 | * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html |
34 | * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/ |
35 | */ |
36 | |
37 | static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav, |
38 | ADXChannelState *prev, int channels) |
39 | { |
40 | PutBitContext pb; |
41 | int scale; |
42 | int i, j; |
43 | int s0, s1, s2, d; |
44 | int max = 0; |
45 | int min = 0; |
46 | |
47 | s1 = prev->s1; |
48 | s2 = prev->s2; |
49 | for (i = 0, j = 0; j < 32; i += channels, j++) { |
50 | s0 = wav[i]; |
51 | d = ((s0 << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS; |
52 | if (max < d) |
53 | max = d; |
54 | if (min > d) |
55 | min = d; |
56 | s2 = s1; |
57 | s1 = s0; |
58 | } |
59 | |
60 | if (max == 0 && min == 0) { |
61 | prev->s1 = s1; |
62 | prev->s2 = s2; |
63 | memset(adx, 0, BLOCK_SIZE); |
64 | return; |
65 | } |
66 | |
67 | if (max / 7 > -min / 8) |
68 | scale = max / 7; |
69 | else |
70 | scale = -min / 8; |
71 | |
72 | if (scale == 0) |
73 | scale = 1; |
74 | |
75 | AV_WB16(adx, scale); |
76 | |
77 | init_put_bits(&pb, adx + 2, 16); |
78 | |
79 | s1 = prev->s1; |
80 | s2 = prev->s2; |
81 | for (i = 0, j = 0; j < 32; i += channels, j++) { |
82 | d = ((wav[i] << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS; |
83 | |
84 | d = av_clip_intp2(ROUNDED_DIV(d, scale), 3); |
85 | |
86 | put_sbits(&pb, 4, d); |
87 | |
88 | s0 = ((d << COEFF_BITS) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS; |
89 | s2 = s1; |
90 | s1 = s0; |
91 | } |
92 | prev->s1 = s1; |
93 | prev->s2 = s2; |
94 | |
95 | flush_put_bits(&pb); |
96 | } |
97 | |
98 | #define HEADER_SIZE 36 |
99 | |
100 | static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize) |
101 | { |
102 | ADXContext *c = avctx->priv_data; |
103 | |
104 | bytestream_put_be16(&buf, 0x8000); /* header signature */ |
105 | bytestream_put_be16(&buf, HEADER_SIZE - 4); /* copyright offset */ |
106 | bytestream_put_byte(&buf, 3); /* encoding */ |
107 | bytestream_put_byte(&buf, BLOCK_SIZE); /* block size */ |
108 | bytestream_put_byte(&buf, 4); /* sample size */ |
109 | bytestream_put_byte(&buf, avctx->channels); /* channels */ |
110 | bytestream_put_be32(&buf, avctx->sample_rate); /* sample rate */ |
111 | bytestream_put_be32(&buf, 0); /* total sample count */ |
112 | bytestream_put_be16(&buf, c->cutoff); /* cutoff frequency */ |
113 | bytestream_put_byte(&buf, 3); /* version */ |
114 | bytestream_put_byte(&buf, 0); /* flags */ |
115 | bytestream_put_be32(&buf, 0); /* unknown */ |
116 | bytestream_put_be32(&buf, 0); /* loop enabled */ |
117 | bytestream_put_be16(&buf, 0); /* padding */ |
118 | bytestream_put_buffer(&buf, "(c)CRI", 6); /* copyright signature */ |
119 | |
120 | return HEADER_SIZE; |
121 | } |
122 | |
123 | static av_cold int adx_encode_init(AVCodecContext *avctx) |
124 | { |
125 | ADXContext *c = avctx->priv_data; |
126 | |
127 | if (avctx->channels > 2) { |
128 | av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n"); |
129 | return AVERROR(EINVAL); |
130 | } |
131 | avctx->frame_size = BLOCK_SAMPLES; |
132 | |
133 | /* the cutoff can be adjusted, but this seems to work pretty well */ |
134 | c->cutoff = 500; |
135 | ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff); |
136 | |
137 | return 0; |
138 | } |
139 | |
140 | static int adx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, |
141 | const AVFrame *frame, int *got_packet_ptr) |
142 | { |
143 | ADXContext *c = avctx->priv_data; |
144 | const int16_t *samples = (const int16_t *)frame->data[0]; |
145 | uint8_t *dst; |
146 | int ch, out_size, ret; |
147 | |
148 | out_size = BLOCK_SIZE * avctx->channels + !c->header_parsed * HEADER_SIZE; |
149 | if ((ret = ff_alloc_packet2(avctx, avpkt, out_size, 0)) < 0) |
150 | return ret; |
151 | dst = avpkt->data; |
152 | |
153 | if (!c->header_parsed) { |
154 | int hdrsize; |
155 | if ((hdrsize = adx_encode_header(avctx, dst, avpkt->size)) < 0) { |
156 | av_log(avctx, AV_LOG_ERROR, "output buffer is too small\n"); |
157 | return AVERROR(EINVAL); |
158 | } |
159 | dst += hdrsize; |
160 | c->header_parsed = 1; |
161 | } |
162 | |
163 | for (ch = 0; ch < avctx->channels; ch++) { |
164 | adx_encode(c, dst, samples + ch, &c->prev[ch], avctx->channels); |
165 | dst += BLOCK_SIZE; |
166 | } |
167 | |
168 | *got_packet_ptr = 1; |
169 | return 0; |
170 | } |
171 | |
172 | AVCodec ff_adpcm_adx_encoder = { |
173 | .name = "adpcm_adx", |
174 | .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"), |
175 | .type = AVMEDIA_TYPE_AUDIO, |
176 | .id = AV_CODEC_ID_ADPCM_ADX, |
177 | .priv_data_size = sizeof(ADXContext), |
178 | .init = adx_encode_init, |
179 | .encode2 = adx_encode_frame, |
180 | .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, |
181 | AV_SAMPLE_FMT_NONE }, |
182 | }; |
183 |