3 * Copyright (c) 2005 Konstantin Shishkov
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
25 * Westwood SNDx codecs.
27 * Reference documents about VQA format and its audio codecs
29 * http://www.multimedia.cx
32 static const char ws_adpcm_2bit[] = { -2, -1, 0, 1};
33 static const char ws_adpcm_4bit[] = {
34 -9, -8, -6, -5, -4, -3, -2, -1,
35 0, 1, 2, 3, 4, 5, 6, 8 };
37 #define CLIP8(a) if(a>127)a=127;if(a<-128)a=-128;
39 static int ws_snd_decode_init(AVCodecContext * avctx)
41 // WSSNDContext *c = avctx->priv_data;
46 static int ws_snd_decode_frame(AVCodecContext *avctx,
47 void *data, int *data_size,
48 uint8_t *buf, int buf_size)
50 // WSSNDContext *c = avctx->priv_data;
52 int in_size, out_size;
55 short *samples = data;
60 out_size = LE_16(&buf[0]);
61 *data_size = out_size * 2;
62 in_size = LE_16(&buf[2]);
65 if (in_size == out_size) {
66 for (i = 0; i < out_size; i++)
67 *samples++ = (*buf++ - 0x80) << 8;
71 while (out_size > 0) {
75 count = (*buf) & 0x3F;
78 case 0: /* ADPCM 2-bit */
79 for (count++; count > 0; count--) {
81 sample += ws_adpcm_2bit[code & 0x3];
83 *samples++ = sample << 8;
84 sample += ws_adpcm_2bit[(code >> 2) & 0x3];
86 *samples++ = sample << 8;
87 sample += ws_adpcm_2bit[(code >> 4) & 0x3];
89 *samples++ = sample << 8;
90 sample += ws_adpcm_2bit[(code >> 6) & 0x3];
92 *samples++ = sample << 8;
96 case 1: /* ADPCM 4-bit */
97 for (count++; count > 0; count--) {
99 sample += ws_adpcm_4bit[code & 0xF];
101 *samples++ = sample << 8;
102 sample += ws_adpcm_4bit[code >> 4];
104 *samples++ = sample << 8;
108 case 2: /* no compression */
109 if (count & 0x20) { /* big delta */
114 *samples++ = sample << 8;
117 for (count++; count > 0; count--) {
118 *samples++ = (*buf++ - 0x80) << 8;
121 sample = buf[-1] - 0x80;
125 for(count++; count > 0; count--) {
126 *samples++ = sample << 8;
135 AVCodec ws_snd1_decoder = {
138 CODEC_ID_WESTWOOD_SND1,