blob: edc945c6973e4e1ef889bb3ec13c9d4d2a747435
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 = AV_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 = AV_CODEC_CAP_DR1, |
213 | .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P, |
214 | AV_SAMPLE_FMT_NONE }, |
215 | }; |
216 | #endif |
217 |