3 * Copyright (c) 2001,2003 BERO
5 * This file is part of FFmpeg.
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.
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.
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
26 * SEGA CRI adx codecs.
28 * Reference documents:
29 * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
30 * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
33 /* 18 bytes <-> 32 samples */
35 static void adx_decode(short *out,const unsigned char *in,PREV *prev)
37 int scale = AV_RB16(in);
41 // printf("%x ",scale);
48 // d>>=4; if (d&8) d-=16;
49 d = ((signed char)d >> 4);
50 s0 = (BASEVOL*d*scale + SCALE1*s1 - SCALE2*s2)>>14;
52 s1 = av_clip_int16(s0);
56 //d&=15; if (d&8) d-=16;
57 d = ((signed char)(d<<4) >> 4);
58 s0 = (BASEVOL*d*scale + SCALE1*s1 - SCALE2*s2)>>14;
60 s1 = av_clip_int16(s0);
68 static void adx_decode_stereo(short *out,const unsigned char *in,PREV *prev)
73 adx_decode(tmp ,in ,prev);
74 adx_decode(tmp+32,in+18,prev+1);
77 out[i*2+1] = tmp[i+32];
81 /* return data offset or 0 */
82 static int adx_decode_header(AVCodecContext *avctx,const unsigned char *buf,size_t bufsize)
86 if (buf[0]!=0x80) return 0;
87 offset = (AV_RB32(buf)^0x80000000)+4;
88 if (bufsize<offset || memcmp(buf+offset-6,"(c)CRI",6)) return 0;
90 avctx->channels = buf[7];
91 avctx->sample_rate = AV_RB32(buf+8);
92 avctx->bit_rate = avctx->sample_rate*avctx->channels*18*8/32;
97 static int adx_decode_frame(AVCodecContext *avctx,
98 void *data, int *data_size,
99 const uint8_t *buf0, int buf_size)
101 ADXContext *c = avctx->priv_data;
102 short *samples = data;
103 const uint8_t *buf = buf0;
106 if (!c->header_parsed) {
107 int hdrsize = adx_decode_header(avctx,buf,rest);
108 if (hdrsize==0) return -1;
109 c->header_parsed = 1;
114 /* 18 bytes of data are expanded into 32*2 bytes of audio,
115 so guard against buffer overflows */
116 if(rest/18 > *data_size/64)
117 rest = (*data_size/64) * 18;
120 int copysize = 18*avctx->channels - c->in_temp;
121 memcpy(c->dec_temp+c->in_temp,buf,copysize);
124 if (avctx->channels==1) {
125 adx_decode(samples,c->dec_temp,c->prev);
128 adx_decode_stereo(samples,c->dec_temp,c->prev);
133 if (avctx->channels==1) {
135 adx_decode(samples,buf,c->prev);
142 adx_decode_stereo(samples,buf,c->prev);
151 memcpy(c->dec_temp,buf,rest);
154 *data_size = (uint8_t*)samples - (uint8_t*)data;
155 // printf("%d:%d ",buf-buf0,*data_size); fflush(stdout);
159 AVCodec adpcm_adx_decoder = {
168 .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX"),