1 /*
2 * Copyright (C) 2008 Jaikrishnan Menon
3 * Copyright (C) 2011 Stefano Sabatini
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 /**
23 * @file
24 * 8svx audio decoder
25 * @author Jaikrishnan Menon
26 *
27 * supports: fibonacci delta encoding
28 * : exponential encoding
29 *
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
35 *
36 * Samples can be found here:
37 * http://aminet.net/mods/smpl/
38 */
39
40 #include "config_components.h"
41
42 #include "libavutil/avassert.h"
43 #include "avcodec.h"
44 #include "codec_internal.h"
45 #include "internal.h"
46 #include "libavutil/common.h"
47
48 /** decoder context */
49 typedef struct EightSvxContext {
50 uint8_t fib_acc[2];
51 const int8_t *table;
52
53 /* buffer used to store the whole first packet.
54 data is only sent as one large packet */
55 uint8_t *data[2];
56 int data_size;
57 int data_idx;
58 } EightSvxContext;
59
60 static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8, 13, 21 };
61 static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0, 1, 2, 4, 8, 16, 32, 64 };
62
63 #define MAX_FRAME_SIZE 2048
64
65 /**
66 * Delta decode the compressed values in src, and put the resulting
67 * decoded samples in dst.
68 *
69 * @param[in,out] state starting value. it is saved for use in the next call.
70 * @param table delta sequence table
71 */
delta_decode(uint8_t *dst, const uint8_t *src, int src_size, uint8_t *state, const int8_t *table)72 static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
73 uint8_t *state, const int8_t *table)
74 {
75 uint8_t val = *state;
76
77 while (src_size--) {
78 uint8_t d = *src++;
79 val = av_clip_uint8(val + table[d & 0xF]);
80 *dst++ = val;
81 val = av_clip_uint8(val + table[d >> 4]);
82 *dst++ = val;
83 }
84
85 *state = val;
86 }
87
88 /** decode a frame */
eightsvx_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)89 static int eightsvx_decode_frame(AVCodecContext *avctx, AVFrame *frame,
90 int *got_frame_ptr, AVPacket *avpkt)
91 {
92 EightSvxContext *esc = avctx->priv_data;
93 int channels = avctx->ch_layout.nb_channels;
94 int buf_size;
95 int ch, ret;
96 int hdr_size = 2;
97
98 /* decode and interleave the first packet */
99 if (!esc->data[0] && avpkt) {
100 int chan_size = avpkt->size / channels - hdr_size;
101
102 if (avpkt->size % channels) {
103 av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n");
104 }
105 if (avpkt->size < (hdr_size + 1) * channels) {
106 av_log(avctx, AV_LOG_ERROR, "packet size is too small\n");
107 return AVERROR_INVALIDDATA;
108 }
109
110 esc->fib_acc[0] = avpkt->data[1] + 128;
111 if (channels == 2)
112 esc->fib_acc[1] = avpkt->data[2+chan_size+1] + 128;
113
114 esc->data_idx = 0;
115 esc->data_size = chan_size;
116 if (!(esc->data[0] = av_malloc(chan_size)))
117 return AVERROR(ENOMEM);
118 if (channels == 2) {
119 if (!(esc->data[1] = av_malloc(chan_size))) {
120 av_freep(&esc->data[0]);
121 return AVERROR(ENOMEM);
122 }
123 }
124 memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size);
125 if (channels == 2)
126 memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size);
127 }
128 if (!esc->data[0]) {
129 av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n");
130 return AVERROR_INVALIDDATA;
131 }
132
133 /* decode next piece of data from the buffer */
134 buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx);
135 if (buf_size <= 0) {
136 *got_frame_ptr = 0;
137 return avpkt->size;
138 }
139
140 /* get output buffer */
141 frame->nb_samples = buf_size * 2;
142 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
143 return ret;
144
145 for (ch = 0; ch < channels; ch++) {
146 delta_decode(frame->data[ch], &esc->data[ch][esc->data_idx],
147 buf_size, &esc->fib_acc[ch], esc->table);
148 }
149
150 esc->data_idx += buf_size;
151
152 *got_frame_ptr = 1;
153
154 return ((avctx->frame_number == 0) * hdr_size + buf_size) * channels;
155 }
156
eightsvx_decode_init(AVCodecContext *avctx)157 static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
158 {
159 EightSvxContext *esc = avctx->priv_data;
160
161 if (avctx->ch_layout.nb_channels < 1 || avctx->ch_layout.nb_channels > 2) {
162 av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n");
163 return AVERROR_INVALIDDATA;
164 }
165
166 switch (avctx->codec->id) {
167 case AV_CODEC_ID_8SVX_FIB: esc->table = fibonacci; break;
168 case AV_CODEC_ID_8SVX_EXP: esc->table = exponential; break;
169 default:
170 av_assert1(0);
171 }
172 avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
173
174 return 0;
175 }
176
eightsvx_decode_close(AVCodecContext *avctx)177 static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
178 {
179 EightSvxContext *esc = avctx->priv_data;
180
181 av_freep(&esc->data[0]);
182 av_freep(&esc->data[1]);
183 esc->data_size = 0;
184 esc->data_idx = 0;
185
186 return 0;
187 }
188
189 #if CONFIG_EIGHTSVX_FIB_DECODER
190 const FFCodec ff_eightsvx_fib_decoder = {
191 .p.name = "8svx_fib",
192 .p.long_name = NULL_IF_CONFIG_SMALL("8SVX fibonacci"),
193 .p.type = AVMEDIA_TYPE_AUDIO,
194 .p.id = AV_CODEC_ID_8SVX_FIB,
195 .priv_data_size = sizeof (EightSvxContext),
196 .init = eightsvx_decode_init,
197 FF_CODEC_DECODE_CB(eightsvx_decode_frame),
198 .close = eightsvx_decode_close,
199 .p.capabilities = AV_CODEC_CAP_DR1,
200 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
201 AV_SAMPLE_FMT_NONE },
202 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
203 };
204 #endif
205 #if CONFIG_EIGHTSVX_EXP_DECODER
206 const FFCodec ff_eightsvx_exp_decoder = {
207 .p.name = "8svx_exp",
208 .p.long_name = NULL_IF_CONFIG_SMALL("8SVX exponential"),
209 .p.type = AVMEDIA_TYPE_AUDIO,
210 .p.id = AV_CODEC_ID_8SVX_EXP,
211 .priv_data_size = sizeof (EightSvxContext),
212 .init = eightsvx_decode_init,
213 FF_CODEC_DECODE_CB(eightsvx_decode_frame),
214 .close = eightsvx_decode_close,
215 .p.capabilities = AV_CODEC_CAP_DR1,
216 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
217 AV_SAMPLE_FMT_NONE },
218 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
219 };
220 #endif
221