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
24 #include "libavutil/channel_layout.h"
25 #include "libavutil/common.h"
26 #include "libavutil/intreadwrite.h"
32 * Westwood SNDx codecs
34 * Reference documents about VQA format and its audio codecs
36 * http://www.multimedia.cx
39 static const int8_t ws_adpcm_4bit
[] = {
40 -9, -8, -6, -5, -4, -3, -2, -1,
41 0, 1, 2, 3, 4, 5, 6, 8
44 static av_cold
int ws_snd_decode_init(AVCodecContext
*avctx
)
47 avctx
->channel_layout
= AV_CH_LAYOUT_MONO
;
48 avctx
->sample_fmt
= AV_SAMPLE_FMT_U8
;
53 static int ws_snd_decode_frame(AVCodecContext
*avctx
, void *data
,
54 int *got_frame_ptr
, AVPacket
*avpkt
)
56 AVFrame
*frame
= data
;
57 const uint8_t *buf
= avpkt
->data
;
58 int buf_size
= avpkt
->size
;
60 int in_size
, out_size
, ret
;
69 av_log(avctx
, AV_LOG_ERROR
, "packet is too small\n");
70 return AVERROR(EINVAL
);
73 out_size
= AV_RL16(&buf
[0]);
74 in_size
= AV_RL16(&buf
[2]);
77 if (in_size
> buf_size
) {
78 av_log(avctx
, AV_LOG_ERROR
, "Frame data is larger than input buffer\n");
79 return AVERROR_INVALIDDATA
;
82 /* get output buffer */
83 frame
->nb_samples
= out_size
;
84 if ((ret
= ff_get_buffer(avctx
, frame
, 0)) < 0)
86 samples
= frame
->data
[0];
87 samples_end
= samples
+ out_size
;
89 if (in_size
== out_size
) {
90 memcpy(samples
, buf
, out_size
);
95 while (samples
< samples_end
&& buf
- avpkt
->data
< buf_size
) {
102 /* make sure we don't write past the output buffer */
104 case 0: smp
= 4 * (count
+ 1); break;
105 case 1: smp
= 2 * (count
+ 1); break;
106 case 2: smp
= (count
& 0x20) ? 1 : count
+ 1; break;
107 default: smp
= count
+ 1; break;
109 if (samples_end
- samples
< smp
)
112 /* make sure we don't read past the input buffer */
113 size
= ((code
== 2 && (count
& 0x20)) || code
== 3) ? 0 : count
+ 1;
114 if ((buf
- avpkt
->data
) + size
> buf_size
)
118 case 0: /* ADPCM 2-bit */
119 for (count
++; count
> 0; count
--) {
121 sample
+= ( code
& 0x3) - 2;
122 sample
= av_clip_uint8(sample
);
124 sample
+= ((code
>> 2) & 0x3) - 2;
125 sample
= av_clip_uint8(sample
);
127 sample
+= ((code
>> 4) & 0x3) - 2;
128 sample
= av_clip_uint8(sample
);
130 sample
+= (code
>> 6) - 2;
131 sample
= av_clip_uint8(sample
);
135 case 1: /* ADPCM 4-bit */
136 for (count
++; count
> 0; count
--) {
138 sample
+= ws_adpcm_4bit
[code
& 0xF];
139 sample
= av_clip_uint8(sample
);
141 sample
+= ws_adpcm_4bit
[code
>> 4];
142 sample
= av_clip_uint8(sample
);
146 case 2: /* no compression */
147 if (count
& 0x20) { /* big delta */
152 sample
= av_clip_uint8(sample
);
155 memcpy(samples
, buf
, smp
);
162 memset(samples
, sample
, smp
);
167 frame
->nb_samples
= samples
- frame
->data
[0];
173 AVCodec ff_ws_snd1_decoder
= {
175 .long_name
= NULL_IF_CONFIG_SMALL("Westwood Audio (SND1)"),
176 .type
= AVMEDIA_TYPE_AUDIO
,
177 .id
= AV_CODEC_ID_WESTWOOD_SND1
,
178 .init
= ws_snd_decode_init
,
179 .decode
= ws_snd_decode_frame
,
180 .capabilities
= CODEC_CAP_DR1
,