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 "libavutil/intreadwrite.h"
23 #include "avcodec.h"
24 #include "adx.h"
25 #include "get_bits.h"
26 #include "internal.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
adx_decode_init(AVCodecContext * avctx)37 static av_cold int adx_decode_init(AVCodecContext *avctx)
38 {
39 ADXContext *c = avctx->priv_data;
40 int ret, header_size;
41
42 if (avctx->extradata_size >= 24) {
43 if ((ret = ff_adx_decode_header(avctx, avctx->extradata,
44 avctx->extradata_size, &header_size,
45 c->coeff)) < 0) {
46 av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
47 return AVERROR_INVALIDDATA;
48 }
49 c->channels = avctx->channels;
50 c->header_parsed = 1;
51 }
52
53 avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
54
55 return 0;
56 }
57
58 /**
59 * Decode 32 samples from 18 bytes.
60 *
61 * A 16-bit scalar value is applied to 32 residuals, which then have a
62 * 2nd-order LPC filter applied to it to form the output signal for a single
63 * channel.
64 */
adx_decode(ADXContext * c,int16_t * out,int offset,const uint8_t * in,int ch)65 static int adx_decode(ADXContext *c, int16_t *out, int offset,
66 const uint8_t *in, int ch)
67 {
68 ADXChannelState *prev = &c->prev[ch];
69 GetBitContext gb;
70 int scale = AV_RB16(in);
71 int i;
72 int s0, s1, s2, d;
73
74 /* check if this is an EOF packet */
75 if (scale & 0x8000)
76 return -1;
77
78 init_get_bits(&gb, in + 2, (BLOCK_SIZE - 2) * 8);
79 out += offset;
80 s1 = prev->s1;
81 s2 = prev->s2;
82 for (i = 0; i < BLOCK_SAMPLES; i++) {
83 d = get_sbits(&gb, 4);
84 s0 = d * scale + ((c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS);
85 s2 = s1;
86 s1 = av_clip_int16(s0);
87 *out++ = s1;
88 }
89 prev->s1 = s1;
90 prev->s2 = s2;
91
92 return 0;
93 }
94
adx_decode_frame(AVCodecContext * avctx,void * data,int * got_frame_ptr,AVPacket * avpkt)95 static int adx_decode_frame(AVCodecContext *avctx, void *data,
96 int *got_frame_ptr, AVPacket *avpkt)
97 {
98 AVFrame *frame = data;
99 int buf_size = avpkt->size;
100 ADXContext *c = avctx->priv_data;
101 int16_t **samples;
102 int samples_offset;
103 const uint8_t *buf = avpkt->data;
104 const uint8_t *buf_end = buf + avpkt->size;
105 int num_blocks, ch, ret;
106 buffer_size_t new_extradata_size;
107 uint8_t *new_extradata;
108
109 new_extradata = av_packet_get_side_data(avpkt, AV_PKT_DATA_NEW_EXTRADATA,
110 &new_extradata_size);
111 if (new_extradata && new_extradata_size > 0) {
112 int header_size;
113 if ((ret = ff_adx_decode_header(avctx, new_extradata,
114 new_extradata_size, &header_size,
115 c->coeff)) < 0) {
116 av_log(avctx, AV_LOG_ERROR, "error parsing new ADX extradata\n");
117 return AVERROR_INVALIDDATA;
118 }
119
120 c->eof = 0;
121 }
122
123 if (c->eof) {
124 *got_frame_ptr = 0;
125 return buf_size;
126 }
127
128 if (!c->header_parsed && buf_size >= 2 && AV_RB16(buf) == 0x8000) {
129 int header_size;
130 if ((ret = ff_adx_decode_header(avctx, buf, buf_size, &header_size,
131 c->coeff)) < 0) {
132 av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
133 return AVERROR_INVALIDDATA;
134 }
135 c->channels = avctx->channels;
136 c->header_parsed = 1;
137 if (buf_size < header_size)
138 return AVERROR_INVALIDDATA;
139 buf += header_size;
140 buf_size -= header_size;
141 }
142 if (!c->header_parsed)
143 return AVERROR_INVALIDDATA;
144
145 /* calculate number of blocks in the packet */
146 num_blocks = buf_size / (BLOCK_SIZE * c->channels);
147
148 /* if the packet is not an even multiple of BLOCK_SIZE, check for an EOF
149 packet */
150 if (!num_blocks || buf_size % (BLOCK_SIZE * avctx->channels)) {
151 if (buf_size >= 4 && (AV_RB16(buf) & 0x8000)) {
152 c->eof = 1;
153 *got_frame_ptr = 0;
154 return avpkt->size;
155 }
156 return AVERROR_INVALIDDATA;
157 }
158
159 /* get output buffer */
160 frame->nb_samples = num_blocks * BLOCK_SAMPLES;
161 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
162 return ret;
163 samples = (int16_t **)frame->extended_data;
164 samples_offset = 0;
165
166 while (num_blocks--) {
167 for (ch = 0; ch < c->channels; ch++) {
168 if (buf_end - buf < BLOCK_SIZE || adx_decode(c, samples[ch], samples_offset, buf, ch)) {
169 c->eof = 1;
170 buf = avpkt->data + avpkt->size;
171 break;
172 }
173 buf_size -= BLOCK_SIZE;
174 buf += BLOCK_SIZE;
175 }
176 if (!c->eof)
177 samples_offset += BLOCK_SAMPLES;
178 }
179
180 frame->nb_samples = samples_offset;
181 *got_frame_ptr = 1;
182
183 return buf - avpkt->data;
184 }
185
adx_decode_flush(AVCodecContext * avctx)186 static void adx_decode_flush(AVCodecContext *avctx)
187 {
188 ADXContext *c = avctx->priv_data;
189 memset(c->prev, 0, sizeof(c->prev));
190 c->eof = 0;
191 }
192
193 AVCodec ff_adpcm_adx_decoder = {
194 .name = "adpcm_adx",
195 .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
196 .type = AVMEDIA_TYPE_AUDIO,
197 .id = AV_CODEC_ID_ADPCM_ADX,
198 .priv_data_size = sizeof(ADXContext),
199 .init = adx_decode_init,
200 .decode = adx_decode_frame,
201 .flush = adx_decode_flush,
202 .capabilities = AV_CODEC_CAP_CHANNEL_CONF |
203 AV_CODEC_CAP_DR1,
204 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
205 AV_SAMPLE_FMT_NONE },
206 };
207