4f2a8971e79bfa3978ab0fa327a412cf8bfc312d
[libav.git] / libavcodec / 8svx.c
1 /*
2 * 8SVX audio decoder
3 * Copyright (C) 2008 Jaikrishnan Menon
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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
31 #include "avcodec.h"
32 #include "internal.h"
33 #include "libavutil/common.h"
34
35 /** decoder context */
36 typedef struct EightSvxContext {
37 uint8_t fib_acc[2];
38 const int8_t *table;
39
40 /* buffer used to store the whole first packet.
41 data is only sent as one large packet */
42 uint8_t *data[2];
43 int data_size;
44 int data_idx;
45 } EightSvxContext;
46
47 static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1,
48 0, 1, 2, 3, 5, 8, 13, 21 };
49 static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1,
50 0, 1, 2, 4, 8, 16, 32, 64 };
51
52 #define MAX_FRAME_SIZE 32768
53
54 /**
55 * Delta decode the compressed values in src, and put the resulting
56 * decoded samples in dst.
57 *
58 * @param[in,out] state starting value. it is saved for use in the next call.
59 */
60 static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
61 uint8_t *state, const int8_t *table)
62 {
63 uint8_t val = *state;
64
65 while (src_size--) {
66 uint8_t d = *src++;
67 val = av_clip_uint8(val + table[d & 0xF]);
68 *dst++ = val;
69 val = av_clip_uint8(val + table[d >> 4]);
70 *dst++ = val;
71 }
72
73 *state = val;
74 }
75
76 static void raw_decode(uint8_t *dst, const int8_t *src, int src_size)
77 {
78 while (src_size--)
79 *dst++ = *src++ + 128;
80 }
81
82 /** decode a frame */
83 static int eightsvx_decode_frame(AVCodecContext *avctx, void *data,
84 int *got_frame_ptr, AVPacket *avpkt)
85 {
86 EightSvxContext *esc = avctx->priv_data;
87 AVFrame *frame = data;
88 int buf_size;
89 int ch, ret;
90 int is_compr = (avctx->codec_id != AV_CODEC_ID_PCM_S8_PLANAR);
91
92 /* for the first packet, copy data to buffer */
93 if (avpkt->data) {
94 int hdr_size = is_compr ? 2 : 0;
95 int chan_size = (avpkt->size - hdr_size * avctx->channels) / avctx->channels;
96
97 if (avpkt->size < hdr_size * avctx->channels) {
98 av_log(avctx, AV_LOG_ERROR, "packet size is too small\n");
99 return AVERROR(EINVAL);
100 }
101 if (esc->data[0]) {
102 av_log(avctx, AV_LOG_ERROR, "unexpected data after first packet\n");
103 return AVERROR(EINVAL);
104 }
105
106 if (is_compr) {
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
112 esc->data_idx = 0;
113 esc->data_size = chan_size;
114 if (!(esc->data[0] = av_malloc(chan_size)))
115 return AVERROR(ENOMEM);
116 if (avctx->channels == 2) {
117 if (!(esc->data[1] = av_malloc(chan_size))) {
118 av_freep(&esc->data[0]);
119 return AVERROR(ENOMEM);
120 }
121 }
122 memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size);
123 if (avctx->channels == 2)
124 memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size);
125 }
126 if (!esc->data[0]) {
127 av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n");
128 return AVERROR(EINVAL);
129 }
130
131 /* decode next piece of data from the buffer */
132 buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx);
133 if (buf_size <= 0) {
134 *got_frame_ptr = 0;
135 return avpkt->size;
136 }
137
138 /* get output buffer */
139 frame->nb_samples = buf_size * (is_compr + 1);
140 if ((ret = ff_get_buffer(avctx, frame)) < 0) {
141 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
142 return ret;
143 }
144
145 for (ch = 0; ch < avctx->channels; ch++) {
146 if (is_compr) {
147 delta_decode(frame->data[ch], &esc->data[ch][esc->data_idx],
148 buf_size, &esc->fib_acc[ch], esc->table);
149 } else {
150 raw_decode(frame->data[ch], &esc->data[ch][esc->data_idx],
151 buf_size);
152 }
153 }
154
155 esc->data_idx += buf_size;
156
157 *got_frame_ptr = 1;
158
159 return avpkt->size;
160 }
161
162 /** initialize 8svx decoder */
163 static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
164 {
165 EightSvxContext *esc = avctx->priv_data;
166
167 if (avctx->channels < 1 || avctx->channels > 2) {
168 av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n");
169 return AVERROR(EINVAL);
170 }
171
172 switch(avctx->codec->id) {
173 case AV_CODEC_ID_8SVX_FIB:
174 esc->table = fibonacci;
175 break;
176 case AV_CODEC_ID_8SVX_EXP:
177 esc->table = exponential;
178 break;
179 case AV_CODEC_ID_PCM_S8_PLANAR:
180 break;
181 default:
182 return -1;
183 }
184 avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
185
186 return 0;
187 }
188
189 static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
190 {
191 EightSvxContext *esc = avctx->priv_data;
192
193 av_freep(&esc->data[0]);
194 av_freep(&esc->data[1]);
195
196 return 0;
197 }
198
199 AVCodec ff_eightsvx_fib_decoder = {
200 .name = "8svx_fib",
201 .type = AVMEDIA_TYPE_AUDIO,
202 .id = AV_CODEC_ID_8SVX_FIB,
203 .priv_data_size = sizeof (EightSvxContext),
204 .init = eightsvx_decode_init,
205 .close = eightsvx_decode_close,
206 .decode = eightsvx_decode_frame,
207 .capabilities = CODEC_CAP_DELAY | CODEC_CAP_DR1,
208 .long_name = NULL_IF_CONFIG_SMALL("8SVX fibonacci"),
209 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
210 AV_SAMPLE_FMT_NONE },
211 };
212
213 AVCodec ff_eightsvx_exp_decoder = {
214 .name = "8svx_exp",
215 .type = AVMEDIA_TYPE_AUDIO,
216 .id = AV_CODEC_ID_8SVX_EXP,
217 .priv_data_size = sizeof (EightSvxContext),
218 .init = eightsvx_decode_init,
219 .close = eightsvx_decode_close,
220 .decode = eightsvx_decode_frame,
221 .capabilities = CODEC_CAP_DELAY | CODEC_CAP_DR1,
222 .long_name = NULL_IF_CONFIG_SMALL("8SVX exponential"),
223 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
224 AV_SAMPLE_FMT_NONE },
225 };
226
227 AVCodec ff_pcm_s8_planar_decoder = {
228 .name = "pcm_s8_planar",
229 .type = AVMEDIA_TYPE_AUDIO,
230 .id = AV_CODEC_ID_PCM_S8_PLANAR,
231 .priv_data_size = sizeof(EightSvxContext),
232 .init = eightsvx_decode_init,
233 .close = eightsvx_decode_close,
234 .decode = eightsvx_decode_frame,
235 .capabilities = CODEC_CAP_DELAY | CODEC_CAP_DR1,
236 .long_name = NULL_IF_CONFIG_SMALL("PCM signed 8-bit planar"),
237 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
238 AV_SAMPLE_FMT_NONE },
239 };