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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 "libavutil/avassert.h" | |
41 | #include "avcodec.h" | |
42 | #include "internal.h" | |
43 | #include "libavutil/common.h" | |
44 | ||
45 | /** decoder context */ | |
46 | typedef struct EightSvxContext { | |
47 | uint8_t fib_acc[2]; | |
48 | const int8_t *table; | |
49 | ||
50 | /* buffer used to store the whole first packet. | |
51 | data is only sent as one large packet */ | |
52 | uint8_t *data[2]; | |
53 | int data_size; | |
54 | int data_idx; | |
55 | } EightSvxContext; | |
56 | ||
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 }; | |
59 | ||
60 | #define MAX_FRAME_SIZE 2048 | |
61 | ||
62 | /** | |
63 | * Delta decode the compressed values in src, and put the resulting | |
64 | * decoded samples in dst. | |
65 | * | |
66 | * @param[in,out] state starting value. it is saved for use in the next call. | |
67 | * @param table delta sequence table | |
68 | */ | |
69 | static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size, | |
70 | uint8_t *state, const int8_t *table) | |
71 | { | |
72 | uint8_t val = *state; | |
73 | ||
74 | while (src_size--) { | |
75 | uint8_t d = *src++; | |
76 | val = av_clip_uint8(val + table[d & 0xF]); | |
77 | *dst++ = val; | |
78 | val = av_clip_uint8(val + table[d >> 4]); | |
79 | *dst++ = val; | |
80 | } | |
81 | ||
82 | *state = val; | |
83 | } | |
84 | ||
85 | /** decode a frame */ | |
86 | static int eightsvx_decode_frame(AVCodecContext *avctx, void *data, | |
87 | int *got_frame_ptr, AVPacket *avpkt) | |
88 | { | |
89 | EightSvxContext *esc = avctx->priv_data; | |
90 | AVFrame *frame = data; | |
91 | int buf_size; | |
92 | int ch, ret; | |
93 | int hdr_size = 2; | |
94 | ||
95 | /* decode and interleave the first packet */ | |
96 | if (!esc->data[0] && avpkt) { | |
97 | int chan_size = avpkt->size / avctx->channels - hdr_size; | |
98 | ||
99 | if (avpkt->size % avctx->channels) { | |
100 | av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n"); | |
101 | } | |
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; | |
105 | } | |
106 | ||
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; | |
110 | ||
111 | esc->data_idx = 0; | |
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); | |
119 | } | |
120 | } | |
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); | |
124 | } | |
125 | if (!esc->data[0]) { | |
126 | av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n"); | |
127 | return AVERROR_INVALIDDATA; | |
128 | } | |
129 | ||
130 | /* decode next piece of data from the buffer */ | |
131 | buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx); | |
132 | if (buf_size <= 0) { | |
133 | *got_frame_ptr = 0; | |
134 | return avpkt->size; | |
135 | } | |
136 | ||
137 | /* get output buffer */ | |
138 | frame->nb_samples = buf_size * 2; | |
139 | if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) | |
140 | return ret; | |
141 | ||
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); | |
145 | } | |
146 | ||
147 | esc->data_idx += buf_size; | |
148 | ||
149 | *got_frame_ptr = 1; | |
150 | ||
151 | return ((avctx->frame_number == 0)*hdr_size + buf_size)*avctx->channels; | |
152 | } | |
153 | ||
154 | static av_cold int eightsvx_decode_init(AVCodecContext *avctx) | |
155 | { | |
156 | EightSvxContext *esc = avctx->priv_data; | |
157 | ||
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; | |
161 | } | |
162 | ||
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; | |
166 | default: | |
167 | av_log(avctx, AV_LOG_ERROR, "Invalid codec id %d.\n", avctx->codec->id); | |
168 | return AVERROR_INVALIDDATA; | |
169 | } | |
170 | avctx->sample_fmt = AV_SAMPLE_FMT_U8P; | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | static av_cold int eightsvx_decode_close(AVCodecContext *avctx) | |
176 | { | |
177 | EightSvxContext *esc = avctx->priv_data; | |
178 | ||
179 | av_freep(&esc->data[0]); | |
180 | av_freep(&esc->data[1]); | |
181 | esc->data_size = 0; | |
182 | esc->data_idx = 0; | |
183 | ||
184 | return 0; | |
185 | } | |
186 | ||
187 | #if CONFIG_EIGHTSVX_FIB_DECODER | |
188 | AVCodec ff_eightsvx_fib_decoder = { | |
189 | .name = "8svx_fib", | |
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 }, | |
200 | }; | |
201 | #endif | |
202 | #if CONFIG_EIGHTSVX_EXP_DECODER | |
203 | AVCodec ff_eightsvx_exp_decoder = { | |
204 | .name = "8svx_exp", | |
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 }, | |
215 | }; | |
216 | #endif |