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
22 #include "libavutil/intreadwrite.h"
26 * @file libavcodec/ws-snd1.c
27 * Westwood SNDx codecs.
29 * Reference documents about VQA format and its audio codecs
31 * http://www.multimedia.cx
34 static const char ws_adpcm_2bit
[] = { -2, -1, 0, 1};
35 static const char ws_adpcm_4bit
[] = {
36 -9, -8, -6, -5, -4, -3, -2, -1,
37 0, 1, 2, 3, 4, 5, 6, 8 };
39 #define CLIP8(a) if(a>127)a=127;if(a<-128)a=-128;
41 static av_cold
int ws_snd_decode_init(AVCodecContext
* avctx
)
43 // WSSNDContext *c = avctx->priv_data;
45 avctx
->sample_fmt
= SAMPLE_FMT_S16
;
49 static int ws_snd_decode_frame(AVCodecContext
*avctx
,
50 void *data
, int *data_size
,
51 const uint8_t *buf
, int buf_size
)
53 // WSSNDContext *c = avctx->priv_data;
55 int in_size
, out_size
;
58 short *samples
= data
;
63 out_size
= AV_RL16(&buf
[0]);
64 *data_size
= out_size
* 2;
65 in_size
= AV_RL16(&buf
[2]);
68 if (out_size
> *data_size
) {
69 av_log(avctx
, AV_LOG_ERROR
, "Frame is too large to fit in buffer\n");
72 if (in_size
> buf_size
) {
73 av_log(avctx
, AV_LOG_ERROR
, "Frame data is larger than input buffer\n");
76 if (in_size
== out_size
) {
77 for (i
= 0; i
< out_size
; i
++)
78 *samples
++ = (*buf
++ - 0x80) << 8;
82 while (out_size
> 0) {
86 count
= (*buf
) & 0x3F;
89 case 0: /* ADPCM 2-bit */
90 for (count
++; count
> 0; count
--) {
92 sample
+= ws_adpcm_2bit
[code
& 0x3];
94 *samples
++ = sample
<< 8;
95 sample
+= ws_adpcm_2bit
[(code
>> 2) & 0x3];
97 *samples
++ = sample
<< 8;
98 sample
+= ws_adpcm_2bit
[(code
>> 4) & 0x3];
100 *samples
++ = sample
<< 8;
101 sample
+= ws_adpcm_2bit
[(code
>> 6) & 0x3];
103 *samples
++ = sample
<< 8;
107 case 1: /* ADPCM 4-bit */
108 for (count
++; count
> 0; count
--) {
110 sample
+= ws_adpcm_4bit
[code
& 0xF];
112 *samples
++ = sample
<< 8;
113 sample
+= ws_adpcm_4bit
[code
>> 4];
115 *samples
++ = sample
<< 8;
119 case 2: /* no compression */
120 if (count
& 0x20) { /* big delta */
125 *samples
++ = sample
<< 8;
128 for (count
++; count
> 0; count
--) {
129 *samples
++ = (*buf
++ - 0x80) << 8;
132 sample
= buf
[-1] - 0x80;
136 for(count
++; count
> 0; count
--) {
137 *samples
++ = sample
<< 8;
146 AVCodec ws_snd1_decoder
= {
149 CODEC_ID_WESTWOOD_SND1
,
155 .long_name
= NULL_IF_CONFIG_SMALL("Westwood Audio (SND1)"),