2 * Copyright (C) 2008 Jaikrishnan Menon
3 * Copyright (C) 2011 Stefano Sabatini
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 * @author Jaikrishnan Menon
27 * supports: fibonacci delta encoding
28 * : exponential encoding
30 * For more information about the 8SVX format:
31 * http://netghost.narod.ru/gff/vendspec/iff/iff.txt
32 * http://sox.sourceforge.net/AudioFormats-11.html
33 * http://aminet.net/package/mus/misc/wavepak
34 * http://amigan.1emu.net/reg/8SVX.txt
36 * Samples can be found here:
37 * http://aminet.net/mods/smpl/
40 #include "libavutil/avassert.h"
43 #include "libavutil/common.h"
45 /** decoder context */
46 typedef struct EightSvxContext
{
50 /* buffer used to store the whole first packet.
51 data is only sent as one large packet */
57 static const int8_t fibonacci
[16] = { -34, -21, -13, -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8, 13, 21 };
58 static const int8_t exponential
[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0, 1, 2, 4, 8, 16, 32, 64 };
60 #define MAX_FRAME_SIZE 2048
63 * Delta decode the compressed values in src, and put the resulting
64 * decoded samples in dst.
66 * @param[in,out] state starting value. it is saved for use in the next call.
67 * @param table delta sequence table
69 static void delta_decode(uint8_t *dst
, const uint8_t *src
, int src_size
,
70 uint8_t *state
, const int8_t *table
)
76 val
= av_clip_uint8(val
+ table
[d
& 0xF]);
78 val
= av_clip_uint8(val
+ table
[d
>> 4]);
86 static int eightsvx_decode_frame(AVCodecContext
*avctx
, void *data
,
87 int *got_frame_ptr
, AVPacket
*avpkt
)
89 EightSvxContext
*esc
= avctx
->priv_data
;
90 AVFrame
*frame
= data
;
95 /* decode and interleave the first packet */
96 if (!esc
->data
[0] && avpkt
) {
97 int chan_size
= avpkt
->size
/ avctx
->channels
- hdr_size
;
99 if (avpkt
->size
% avctx
->channels
) {
100 av_log(avctx
, AV_LOG_WARNING
, "Packet with odd size, ignoring last byte\n");
102 if (avpkt
->size
< (hdr_size
+ 1) * avctx
->channels
) {
103 av_log(avctx
, AV_LOG_ERROR
, "packet size is too small\n");
104 return AVERROR_INVALIDDATA
;
107 esc
->fib_acc
[0] = avpkt
->data
[1] + 128;
108 if (avctx
->channels
== 2)
109 esc
->fib_acc
[1] = avpkt
->data
[2+chan_size
+1] + 128;
112 esc
->data_size
= chan_size
;
113 if (!(esc
->data
[0] = av_malloc(chan_size
)))
114 return AVERROR(ENOMEM
);
115 if (avctx
->channels
== 2) {
116 if (!(esc
->data
[1] = av_malloc(chan_size
))) {
117 av_freep(&esc
->data
[0]);
118 return AVERROR(ENOMEM
);
121 memcpy(esc
->data
[0], &avpkt
->data
[hdr_size
], chan_size
);
122 if (avctx
->channels
== 2)
123 memcpy(esc
->data
[1], &avpkt
->data
[2*hdr_size
+chan_size
], chan_size
);
126 av_log(avctx
, AV_LOG_ERROR
, "unexpected empty packet\n");
127 return AVERROR_INVALIDDATA
;
130 /* decode next piece of data from the buffer */
131 buf_size
= FFMIN(MAX_FRAME_SIZE
, esc
->data_size
- esc
->data_idx
);
137 /* get output buffer */
138 frame
->nb_samples
= buf_size
* 2;
139 if ((ret
= ff_get_buffer(avctx
, frame
, 0)) < 0)
142 for (ch
= 0; ch
< avctx
->channels
; ch
++) {
143 delta_decode(frame
->data
[ch
], &esc
->data
[ch
][esc
->data_idx
],
144 buf_size
, &esc
->fib_acc
[ch
], esc
->table
);
147 esc
->data_idx
+= buf_size
;
151 return ((avctx
->frame_number
== 0)*hdr_size
+ buf_size
)*avctx
->channels
;
154 static av_cold
int eightsvx_decode_init(AVCodecContext
*avctx
)
156 EightSvxContext
*esc
= avctx
->priv_data
;
158 if (avctx
->channels
< 1 || avctx
->channels
> 2) {
159 av_log(avctx
, AV_LOG_ERROR
, "8SVX does not support more than 2 channels\n");
160 return AVERROR_INVALIDDATA
;
163 switch (avctx
->codec
->id
) {
164 case AV_CODEC_ID_8SVX_FIB
: esc
->table
= fibonacci
; break;
165 case AV_CODEC_ID_8SVX_EXP
: esc
->table
= exponential
; break;
167 av_log(avctx
, AV_LOG_ERROR
, "Invalid codec id %d.\n", avctx
->codec
->id
);
168 return AVERROR_INVALIDDATA
;
170 avctx
->sample_fmt
= AV_SAMPLE_FMT_U8P
;
175 static av_cold
int eightsvx_decode_close(AVCodecContext
*avctx
)
177 EightSvxContext
*esc
= avctx
->priv_data
;
179 av_freep(&esc
->data
[0]);
180 av_freep(&esc
->data
[1]);
187 #if CONFIG_EIGHTSVX_FIB_DECODER
188 AVCodec ff_eightsvx_fib_decoder
= {
190 .long_name
= NULL_IF_CONFIG_SMALL("8SVX fibonacci"),
191 .type
= AVMEDIA_TYPE_AUDIO
,
192 .id
= AV_CODEC_ID_8SVX_FIB
,
193 .priv_data_size
= sizeof (EightSvxContext
),
194 .init
= eightsvx_decode_init
,
195 .decode
= eightsvx_decode_frame
,
196 .close
= eightsvx_decode_close
,
197 .capabilities
= CODEC_CAP_DR1
,
198 .sample_fmts
= (const enum AVSampleFormat
[]) { AV_SAMPLE_FMT_U8P
,
199 AV_SAMPLE_FMT_NONE
},
202 #if CONFIG_EIGHTSVX_EXP_DECODER
203 AVCodec ff_eightsvx_exp_decoder
= {
205 .long_name
= NULL_IF_CONFIG_SMALL("8SVX exponential"),
206 .type
= AVMEDIA_TYPE_AUDIO
,
207 .id
= AV_CODEC_ID_8SVX_EXP
,
208 .priv_data_size
= sizeof (EightSvxContext
),
209 .init
= eightsvx_decode_init
,
210 .decode
= eightsvx_decode_frame
,
211 .close
= eightsvx_decode_close
,
212 .capabilities
= CODEC_CAP_DR1
,
213 .sample_fmts
= (const enum AVSampleFormat
[]) { AV_SAMPLE_FMT_U8P
,
214 AV_SAMPLE_FMT_NONE
},