Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / opus.h
1 /*
2 * Opus decoder/demuxer common functions
3 * Copyright (c) 2012 Andrew D'Addesio
4 * Copyright (c) 2013-2014 Mozilla Corporation
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #ifndef AVCODEC_OPUS_H
24 #define AVCODEC_OPUS_H
25
26 #include <stdint.h>
27
28 #include "libavutil/audio_fifo.h"
29 #include "libavutil/float_dsp.h"
30 #include "libavutil/frame.h"
31
32 #include "libswresample/swresample.h"
33
34 #include "avcodec.h"
35 #include "get_bits.h"
36
37 #define MAX_FRAME_SIZE 1275
38 #define MAX_FRAMES 48
39 #define MAX_PACKET_DUR 5760
40
41 #define CELT_SHORT_BLOCKSIZE 120
42 #define CELT_OVERLAP CELT_SHORT_BLOCKSIZE
43 #define CELT_MAX_LOG_BLOCKS 3
44 #define CELT_MAX_FRAME_SIZE (CELT_SHORT_BLOCKSIZE * (1 << CELT_MAX_LOG_BLOCKS))
45 #define CELT_MAX_BANDS 21
46 #define CELT_VECTORS 11
47 #define CELT_ALLOC_STEPS 6
48 #define CELT_FINE_OFFSET 21
49 #define CELT_MAX_FINE_BITS 8
50 #define CELT_NORM_SCALE 16384
51 #define CELT_QTHETA_OFFSET 4
52 #define CELT_QTHETA_OFFSET_TWOPHASE 16
53 #define CELT_DEEMPH_COEFF 0.85000610f
54 #define CELT_POSTFILTER_MINPERIOD 15
55 #define CELT_ENERGY_SILENCE (-28.0f)
56
57 #define SILK_HISTORY 322
58 #define SILK_MAX_LPC 16
59
60 #define ROUND_MULL(a,b,s) (((MUL64(a, b) >> ((s) - 1)) + 1) >> 1)
61 #define ROUND_MUL16(a,b) ((MUL16(a, b) + 16384) >> 15)
62 #define opus_ilog(i) (av_log2(i) + !!(i))
63
64 #define OPUS_TS_HEADER 0x7FE0 // 0x3ff (11 bits)
65 #define OPUS_TS_MASK 0xFFE0 // top 11 bits
66
67 static const uint8_t opus_default_extradata[30] = {
68 'O', 'p', 'u', 's', 'H', 'e', 'a', 'd',
69 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
70 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
71 };
72
73 enum OpusMode {
74 OPUS_MODE_SILK,
75 OPUS_MODE_HYBRID,
76 OPUS_MODE_CELT
77 };
78
79 enum OpusBandwidth {
80 OPUS_BANDWIDTH_NARROWBAND,
81 OPUS_BANDWIDTH_MEDIUMBAND,
82 OPUS_BANDWIDTH_WIDEBAND,
83 OPUS_BANDWIDTH_SUPERWIDEBAND,
84 OPUS_BANDWIDTH_FULLBAND
85 };
86
87 typedef struct RawBitsContext {
88 const uint8_t *position;
89 unsigned int bytes;
90 unsigned int cachelen;
91 unsigned int cacheval;
92 } RawBitsContext;
93
94 typedef struct OpusRangeCoder {
95 GetBitContext gb;
96 RawBitsContext rb;
97 unsigned int range;
98 unsigned int value;
99 unsigned int total_read_bits;
100 } OpusRangeCoder;
101
102 typedef struct SilkContext SilkContext;
103
104 typedef struct CeltContext CeltContext;
105
106 typedef struct OpusPacket {
107 int packet_size; /**< packet size */
108 int data_size; /**< size of the useful data -- packet size - padding */
109 int code; /**< packet code: specifies the frame layout */
110 int stereo; /**< whether this packet is mono or stereo */
111 int vbr; /**< vbr flag */
112 int config; /**< configuration: tells the audio mode,
113 ** bandwidth, and frame duration */
114 int frame_count; /**< frame count */
115 int frame_offset[MAX_FRAMES]; /**< frame offsets */
116 int frame_size[MAX_FRAMES]; /**< frame sizes */
117 int frame_duration; /**< frame duration, in samples @ 48kHz */
118 enum OpusMode mode; /**< mode */
119 enum OpusBandwidth bandwidth; /**< bandwidth */
120 } OpusPacket;
121
122 typedef struct OpusStreamContext {
123 AVCodecContext *avctx;
124 int output_channels;
125
126 OpusRangeCoder rc;
127 OpusRangeCoder redundancy_rc;
128 SilkContext *silk;
129 CeltContext *celt;
130 AVFloatDSPContext *fdsp;
131
132 float silk_buf[2][960];
133 float *silk_output[2];
134 DECLARE_ALIGNED(32, float, celt_buf)[2][960];
135 float *celt_output[2];
136
137 float redundancy_buf[2][960];
138 float *redundancy_output[2];
139
140 /* data buffers for the final output data */
141 float *out[2];
142 int out_size;
143
144 float *out_dummy;
145 int out_dummy_allocated_size;
146
147 SwrContext *swr;
148 AVAudioFifo *celt_delay;
149 int silk_samplerate;
150 /* number of samples we still want to get from the resampler */
151 int delayed_samples;
152
153 OpusPacket packet;
154
155 int redundancy_idx;
156 } OpusStreamContext;
157
158 // a mapping between an opus stream and an output channel
159 typedef struct ChannelMap {
160 int stream_idx;
161 int channel_idx;
162
163 // when a single decoded channel is mapped to multiple output channels, we
164 // write to the first output directly and copy from it to the others
165 // this field is set to 1 for those copied output channels
166 int copy;
167 // this is the index of the output channel to copy from
168 int copy_idx;
169
170 // this channel is silent
171 int silence;
172 } ChannelMap;
173
174 typedef struct OpusContext {
175 OpusStreamContext *streams;
176 int nb_streams;
177 int nb_stereo_streams;
178
179 AVFloatDSPContext *fdsp;
180 int16_t gain_i;
181 float gain;
182
183 ChannelMap *channel_maps;
184 } OpusContext;
185
186 static av_always_inline void opus_rc_normalize(OpusRangeCoder *rc)
187 {
188 while (rc->range <= 1<<23) {
189 rc->value = ((rc->value << 8) | (get_bits(&rc->gb, 8) ^ 0xFF)) & ((1u << 31) - 1);
190 rc->range <<= 8;
191 rc->total_read_bits += 8;
192 }
193 }
194
195 static av_always_inline void opus_rc_update(OpusRangeCoder *rc, unsigned int scale,
196 unsigned int low, unsigned int high,
197 unsigned int total)
198 {
199 rc->value -= scale * (total - high);
200 rc->range = low ? scale * (high - low)
201 : rc->range - scale * (total - high);
202 opus_rc_normalize(rc);
203 }
204
205 static av_always_inline unsigned int opus_rc_getsymbol(OpusRangeCoder *rc, const uint16_t *cdf)
206 {
207 unsigned int k, scale, total, symbol, low, high;
208
209 total = *cdf++;
210
211 scale = rc->range / total;
212 symbol = rc->value / scale + 1;
213 symbol = total - FFMIN(symbol, total);
214
215 for (k = 0; cdf[k] <= symbol; k++);
216 high = cdf[k];
217 low = k ? cdf[k-1] : 0;
218
219 opus_rc_update(rc, scale, low, high, total);
220
221 return k;
222 }
223
224 static av_always_inline unsigned int opus_rc_p2model(OpusRangeCoder *rc, unsigned int bits)
225 {
226 unsigned int k, scale;
227 scale = rc->range >> bits; // in this case, scale = symbol
228
229 if (rc->value >= scale) {
230 rc->value -= scale;
231 rc->range -= scale;
232 k = 0;
233 } else {
234 rc->range = scale;
235 k = 1;
236 }
237 opus_rc_normalize(rc);
238 return k;
239 }
240
241 /**
242 * CELT: estimate bits of entropy that have thus far been consumed for the
243 * current CELT frame, to integer and fractional (1/8th bit) precision
244 */
245 static av_always_inline unsigned int opus_rc_tell(const OpusRangeCoder *rc)
246 {
247 return rc->total_read_bits - av_log2(rc->range) - 1;
248 }
249
250 static av_always_inline unsigned int opus_rc_tell_frac(const OpusRangeCoder *rc)
251 {
252 unsigned int i, total_bits, rcbuffer, range;
253
254 total_bits = rc->total_read_bits << 3;
255 rcbuffer = av_log2(rc->range) + 1;
256 range = rc->range >> (rcbuffer-16);
257
258 for (i = 0; i < 3; i++) {
259 int bit;
260 range = range * range >> 15;
261 bit = range >> 16;
262 rcbuffer = rcbuffer << 1 | bit;
263 range >>= bit;
264 }
265
266 return total_bits - rcbuffer;
267 }
268
269 /**
270 * CELT: read 1-25 raw bits at the end of the frame, backwards byte-wise
271 */
272 static av_always_inline unsigned int opus_getrawbits(OpusRangeCoder *rc, unsigned int count)
273 {
274 unsigned int value = 0;
275
276 while (rc->rb.bytes && rc->rb.cachelen < count) {
277 rc->rb.cacheval |= *--rc->rb.position << rc->rb.cachelen;
278 rc->rb.cachelen += 8;
279 rc->rb.bytes--;
280 }
281
282 value = rc->rb.cacheval & ((1<<count)-1);
283 rc->rb.cacheval >>= count;
284 rc->rb.cachelen -= count;
285 rc->total_read_bits += count;
286
287 return value;
288 }
289
290 /**
291 * CELT: read a uniform distribution
292 */
293 static av_always_inline unsigned int opus_rc_unimodel(OpusRangeCoder *rc, unsigned int size)
294 {
295 unsigned int bits, k, scale, total;
296
297 bits = opus_ilog(size - 1);
298 total = (bits > 8) ? ((size - 1) >> (bits - 8)) + 1 : size;
299
300 scale = rc->range / total;
301 k = rc->value / scale + 1;
302 k = total - FFMIN(k, total);
303 opus_rc_update(rc, scale, k, k + 1, total);
304
305 if (bits > 8) {
306 k = k << (bits - 8) | opus_getrawbits(rc, bits - 8);
307 return FFMIN(k, size - 1);
308 } else
309 return k;
310 }
311
312 static av_always_inline int opus_rc_laplace(OpusRangeCoder *rc, unsigned int symbol, int decay)
313 {
314 /* extends the range coder to model a Laplace distribution */
315 int value = 0;
316 unsigned int scale, low = 0, center;
317
318 scale = rc->range >> 15;
319 center = rc->value / scale + 1;
320 center = (1 << 15) - FFMIN(center, 1 << 15);
321
322 if (center >= symbol) {
323 value++;
324 low = symbol;
325 symbol = 1 + ((32768 - 32 - symbol) * (16384-decay) >> 15);
326
327 while (symbol > 1 && center >= low + 2 * symbol) {
328 value++;
329 symbol *= 2;
330 low += symbol;
331 symbol = (((symbol - 2) * decay) >> 15) + 1;
332 }
333
334 if (symbol <= 1) {
335 int distance = (center - low) >> 1;
336 value += distance;
337 low += 2 * distance;
338 }
339
340 if (center < low + symbol)
341 value *= -1;
342 else
343 low += symbol;
344 }
345
346 opus_rc_update(rc, scale, low, FFMIN(low + symbol, 32768), 32768);
347
348 return value;
349 }
350
351 static av_always_inline unsigned int opus_rc_stepmodel(OpusRangeCoder *rc, int k0)
352 {
353 /* Use a probability of 3 up to itheta=8192 and then use 1 after */
354 unsigned int k, scale, symbol, total = (k0+1)*3 + k0;
355 scale = rc->range / total;
356 symbol = rc->value / scale + 1;
357 symbol = total - FFMIN(symbol, total);
358
359 k = (symbol < (k0+1)*3) ? symbol/3 : symbol - (k0+1)*2;
360
361 opus_rc_update(rc, scale, (k <= k0) ? 3*(k+0) : (k-1-k0) + 3*(k0+1),
362 (k <= k0) ? 3*(k+1) : (k-0-k0) + 3*(k0+1), total);
363 return k;
364 }
365
366 static av_always_inline unsigned int opus_rc_trimodel(OpusRangeCoder *rc, int qn)
367 {
368 unsigned int k, scale, symbol, total, low, center;
369
370 total = ((qn>>1) + 1) * ((qn>>1) + 1);
371 scale = rc->range / total;
372 center = rc->value / scale + 1;
373 center = total - FFMIN(center, total);
374
375 if (center < total >> 1) {
376 k = (ff_sqrt(8 * center + 1) - 1) >> 1;
377 low = k * (k + 1) >> 1;
378 symbol = k + 1;
379 } else {
380 k = (2*(qn + 1) - ff_sqrt(8*(total - center - 1) + 1)) >> 1;
381 low = total - ((qn + 1 - k) * (qn + 2 - k) >> 1);
382 symbol = qn + 1 - k;
383 }
384
385 opus_rc_update(rc, scale, low, low + symbol, total);
386
387 return k;
388 }
389
390 int ff_opus_parse_packet(OpusPacket *pkt, const uint8_t *buf, int buf_size,
391 int self_delimited);
392
393 int ff_opus_parse_extradata(AVCodecContext *avctx, OpusContext *s);
394
395 int ff_silk_init(AVCodecContext *avctx, SilkContext **ps, int output_channels);
396 void ff_silk_free(SilkContext **ps);
397 void ff_silk_flush(SilkContext *s);
398
399 /**
400 * Decode the LP layer of one Opus frame (which may correspond to several SILK
401 * frames).
402 */
403 int ff_silk_decode_superframe(SilkContext *s, OpusRangeCoder *rc,
404 float *output[2],
405 enum OpusBandwidth bandwidth, int coded_channels,
406 int duration_ms);
407
408 int ff_celt_init(AVCodecContext *avctx, CeltContext **s, int output_channels);
409
410 void ff_celt_free(CeltContext **s);
411
412 void ff_celt_flush(CeltContext *s);
413
414 int ff_celt_decode_frame(CeltContext *s, OpusRangeCoder *rc,
415 float **output, int coded_channels, int frame_size,
416 int startband, int endband);
417
418 extern const float ff_celt_window2[120];
419
420 #endif /* AVCODEC_OPUS_H */