xref: /third_party/ffmpeg/libavcodec/speexdec.c (revision cabdff1a)
1/*
2 * Copyright 2002-2008  Xiph.org Foundation
3 * Copyright 2002-2008  Jean-Marc Valin
4 * Copyright 2005-2007  Analog Devices Inc.
5 * Copyright 2005-2008  Commonwealth Scientific and Industrial Research Organisation (CSIRO)
6 * Copyright 1993, 2002, 2006 David Rowe
7 * Copyright 2003       EpicGames
8 * Copyright 1992-1994  Jutta Degener, Carsten Bormann
9
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13
14 * - Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16
17 * - Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20
21 * - Neither the name of the Xiph.org Foundation nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
29 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
30 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
32 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
33 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
34 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
35 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * This file is part of FFmpeg.
38 *
39 * FFmpeg is free software; you can redistribute it and/or
40 * modify it under the terms of the GNU Lesser General Public
41 * License as published by the Free Software Foundation; either
42 * version 2.1 of the License, or (at your option) any later version.
43 *
44 * FFmpeg is distributed in the hope that it will be useful,
45 * but WITHOUT ANY WARRANTY; without even the implied warranty of
46 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
47 * Lesser General Public License for more details.
48 *
49 * You should have received a copy of the GNU Lesser General Public
50 * License along with FFmpeg; if not, write to the Free Software
51 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
52 */
53
54#include "libavutil/avassert.h"
55#include "libavutil/float_dsp.h"
56#include "avcodec.h"
57#include "bytestream.h"
58#include "codec_internal.h"
59#include "get_bits.h"
60#include "internal.h"
61#include "speexdata.h"
62
63#define SPEEX_NB_MODES 3
64#define SPEEX_INBAND_STEREO 9
65
66#define QMF_ORDER 64
67#define NB_ORDER 10
68#define NB_FRAME_SIZE 160
69#define NB_SUBMODES 9
70#define NB_SUBMODE_BITS 4
71#define SB_SUBMODE_BITS 3
72
73#define NB_SUBFRAME_SIZE 40
74#define NB_NB_SUBFRAMES 4
75#define NB_PITCH_START 17
76#define NB_PITCH_END 144
77
78#define NB_DEC_BUFFER (NB_FRAME_SIZE + 2 * NB_PITCH_END + NB_SUBFRAME_SIZE + 12)
79
80#define SPEEX_MEMSET(dst, c, n) (memset((dst), (c), (n) * sizeof(*(dst))))
81#define SPEEX_COPY(dst, src, n) (memcpy((dst), (src), (n) * sizeof(*(dst))))
82
83#define LSP_LINEAR(i) (.25f * (i) + .25f)
84#define LSP_LINEAR_HIGH(i) (.3125f * (i) + .75f)
85#define LSP_DIV_256(x) (0.00390625f * (x))
86#define LSP_DIV_512(x) (0.001953125f * (x))
87#define LSP_DIV_1024(x) (0.0009765625f * (x))
88
89typedef struct LtpParams {
90    const int8_t *gain_cdbk;
91    int gain_bits;
92    int pitch_bits;
93} LtpParam;
94
95static const LtpParam ltp_params_vlbr = { gain_cdbk_lbr, 5, 0 };
96static const LtpParam ltp_params_lbr  = { gain_cdbk_lbr, 5, 7 };
97static const LtpParam ltp_params_med  = { gain_cdbk_lbr, 5, 7 };
98static const LtpParam ltp_params_nb   = { gain_cdbk_nb,  7, 7 };
99
100typedef struct SplitCodebookParams {
101    int subvect_size;
102    int nb_subvect;
103    const signed char *shape_cb;
104    int shape_bits;
105    int have_sign;
106} SplitCodebookParams;
107
108static const SplitCodebookParams split_cb_nb_ulbr = { 20, 2, exc_20_32_table, 5, 0 };
109static const SplitCodebookParams split_cb_nb_vlbr = { 10, 4, exc_10_16_table, 4, 0 };
110static const SplitCodebookParams split_cb_nb_lbr  = { 10, 4, exc_10_32_table, 5, 0 };
111static const SplitCodebookParams split_cb_nb_med  = {  8, 5, exc_8_128_table, 7, 0 };
112static const SplitCodebookParams split_cb_nb      = {  5, 8, exc_5_64_table,  6, 0 };
113static const SplitCodebookParams split_cb_sb      = {  5, 8, exc_5_256_table, 8, 0 };
114static const SplitCodebookParams split_cb_high    = {  8, 5, hexc_table,      7, 1 };
115static const SplitCodebookParams split_cb_high_lbr= { 10, 4, hexc_10_32_table,5, 0 };
116
117/** Quantizes LSPs */
118typedef void (*lsp_quant_func)(float *, float *, int, GetBitContext *);
119
120/** Decodes quantized LSPs */
121typedef void (*lsp_unquant_func)(float *, int, GetBitContext *);
122
123/** Long-term predictor quantization */
124typedef int (*ltp_quant_func)(float *, float *, float *,
125    float *, float *, float *,
126    const void *, int, int, float, int, int,
127    GetBitContext *, char *, float *,
128    float *, int, int, int, float *);
129
130/** Long-term un-quantize */
131typedef void (*ltp_unquant_func)(float *, float *, int, int,
132    float, const void *, int, int *,
133    float *, GetBitContext *, int, int,
134    float, int);
135
136/** Innovation quantization function */
137typedef void (*innovation_quant_func)(float *, float *,
138    float *, float *, const void *,
139    int, int, float *, float *,
140    GetBitContext *, char *, int, int);
141
142/** Innovation unquantization function */
143typedef void (*innovation_unquant_func)(float *, const void *, int,
144    GetBitContext *, uint32_t *);
145
146typedef struct SpeexSubmode {
147    int lbr_pitch; /**< Set to -1 for "normal" modes, otherwise encode pitch using
148                  a global pitch and allowing a +- lbr_pitch variation (for
149                  low not-rates)*/
150    int forced_pitch_gain; /**< Use the same (forced) pitch gain for all
151                            sub-frames */
152    int have_subframe_gain; /**< Number of bits to use as sub-frame innovation
153                           gain */
154    int double_codebook; /**< Apply innovation quantization twice for higher
155                              quality (and higher bit-rate)*/
156    lsp_unquant_func lsp_unquant; /**< LSP unquantization function */
157
158    ltp_unquant_func ltp_unquant; /**< Long-term predictor (pitch) un-quantizer */
159    const void *LtpParam; /**< Pitch parameters (options) */
160
161    innovation_unquant_func innovation_unquant; /**< Innovation un-quantization */
162    const void *innovation_params; /**< Innovation quantization parameters*/
163
164    float comb_gain; /**< Gain of enhancer comb filter */
165} SpeexSubmode;
166
167typedef struct SpeexMode {
168    int modeID;                 /**< ID of the mode */
169    int (*decode)(AVCodecContext *avctx, void *dec, GetBitContext *gb, float *out);
170    int frame_size;             /**< Size of frames used for decoding */
171    int subframe_size;          /**< Size of sub-frames used for decoding */
172    int lpc_size;               /**< Order of LPC filter */
173    float folding_gain;         /**< Folding gain */
174    const SpeexSubmode *submodes[NB_SUBMODES]; /**< Sub-mode data for the mode */
175    int default_submode;        /**< Default sub-mode to use when decoding */
176} SpeexMode;
177
178typedef struct DecoderState {
179    const SpeexMode *mode;
180    int modeID;             /**< ID of the decoder mode */
181    int first;              /**< Is first frame  */
182    int full_frame_size;    /**< Length of full-band frames */
183    int is_wideband;        /**< If wideband is present */
184    int count_lost;         /**< Was the last frame lost? */
185    int frame_size;         /**< Length of high-band frames */
186    int subframe_size;      /**< Length of high-band sub-frames */
187    int nb_subframes;       /**< Number of high-band sub-frames */
188    int lpc_size;           /**< Order of high-band LPC analysis */
189    float last_ol_gain;     /**< Open-loop gain for previous frame */
190    float *innov_save;      /**< If non-NULL, innovation is copied here */
191
192    /* This is used in packet loss concealment */
193    int last_pitch;         /**< Pitch of last correctly decoded frame */
194    float last_pitch_gain;  /**< Pitch gain of last correctly decoded frame */
195    uint32_t seed;          /**< Seed used for random number generation */
196
197    int encode_submode;
198    const SpeexSubmode *const *submodes; /**< Sub-mode data */
199    int submodeID;          /**< Activated sub-mode */
200    int lpc_enh_enabled;    /**< 1 when LPC enhancer is on, 0 otherwise */
201
202    /* Vocoder data */
203    float voc_m1;
204    float voc_m2;
205    float voc_mean;
206    int voc_offset;
207
208    int dtx_enabled;
209    int highpass_enabled;   /**< Is the input filter enabled */
210
211    float *exc;             /**< Start of excitation frame */
212    float mem_hp[2];        /**< High-pass filter memory */
213    float exc_buf[NB_DEC_BUFFER]; /**< Excitation buffer */
214    float old_qlsp[NB_ORDER]; /**< Quantized LSPs for previous frame */
215    float interp_qlpc[NB_ORDER]; /**< Interpolated quantized LPCs */
216    float mem_sp[NB_ORDER]; /**< Filter memory for synthesis signal */
217    float g0_mem[QMF_ORDER];
218    float g1_mem[QMF_ORDER];
219    float pi_gain[NB_NB_SUBFRAMES]; /**< Gain of LPC filter at theta=pi (fe/2) */
220    float exc_rms[NB_NB_SUBFRAMES]; /**< RMS of excitation per subframe */
221} DecoderState;
222
223/* Default handler for user callbacks: skip it */
224static int speex_default_user_handler(GetBitContext *gb, void *state, void *data)
225{
226    const int req_size = get_bits(gb, 4);
227    skip_bits_long(gb, 5 + 8 * req_size);
228    return 0;
229}
230
231typedef struct StereoState {
232    float balance; /**< Left/right balance info */
233    float e_ratio; /**< Ratio of energies: E(left+right)/[E(left)+E(right)]  */
234    float smooth_left; /**< Smoothed left channel gain */
235    float smooth_right; /**< Smoothed right channel gain */
236} StereoState;
237
238typedef struct SpeexContext {
239    AVClass *class;
240    GetBitContext gb;
241
242    int32_t version_id; /**< Version for Speex (for checking compatibility) */
243    int32_t rate; /**< Sampling rate used */
244    int32_t mode; /**< Mode used (0 for narrowband, 1 for wideband) */
245    int32_t bitstream_version; /**< Version ID of the bit-stream */
246    int32_t nb_channels; /**< Number of channels decoded */
247    int32_t bitrate; /**< Bit-rate used */
248    int32_t frame_size; /**< Size of frames */
249    int32_t vbr; /**< 1 for a VBR decoding, 0 otherwise */
250    int32_t frames_per_packet; /**< Number of frames stored per Ogg packet */
251    int32_t extra_headers; /**< Number of additional headers after the comments */
252
253    int pkt_size;
254
255    StereoState stereo;
256    DecoderState st[SPEEX_NB_MODES];
257
258    AVFloatDSPContext *fdsp;
259} SpeexContext;
260
261static void lsp_unquant_lbr(float *lsp, int order, GetBitContext *gb)
262{
263    int id;
264
265    for (int i = 0; i < order; i++)
266        lsp[i] = LSP_LINEAR(i);
267
268    id = get_bits(gb, 6);
269    for (int i = 0; i < 10; i++)
270        lsp[i] += LSP_DIV_256(cdbk_nb[id * 10 + i]);
271
272    id = get_bits(gb, 6);
273    for (int i = 0; i < 5; i++)
274        lsp[i] += LSP_DIV_512(cdbk_nb_low1[id * 5 + i]);
275
276    id = get_bits(gb, 6);
277    for (int i = 0; i < 5; i++)
278        lsp[i + 5] += LSP_DIV_512(cdbk_nb_high1[id * 5 + i]);
279}
280
281static void forced_pitch_unquant(float *exc, float *exc_out, int start, int end,
282                                 float pitch_coef, const void *par, int nsf,
283                                 int *pitch_val, float *gain_val, GetBitContext *gb, int count_lost,
284                                 int subframe_offset, float last_pitch_gain, int cdbk_offset)
285{
286    av_assert0(!isnan(pitch_coef));
287    pitch_coef = fminf(pitch_coef, .99f);
288    for (int i = 0; i < nsf; i++) {
289        exc_out[i] = exc[i - start] * pitch_coef;
290        exc[i] = exc_out[i];
291    }
292    pitch_val[0] = start;
293    gain_val[0] = gain_val[2] = 0.f;
294    gain_val[1] = pitch_coef;
295}
296
297static inline float speex_rand(float std, uint32_t *seed)
298{
299    const uint32_t jflone = 0x3f800000;
300    const uint32_t jflmsk = 0x007fffff;
301    float fran;
302    uint32_t ran;
303    seed[0] = 1664525 * seed[0] + 1013904223;
304    ran = jflone | (jflmsk & seed[0]);
305    fran = av_int2float(ran);
306    fran -= 1.5f;
307    fran *= std;
308    return fran;
309}
310
311static void noise_codebook_unquant(float *exc, const void *par, int nsf,
312                                   GetBitContext *gb, uint32_t *seed)
313{
314    for (int i = 0; i < nsf; i++)
315        exc[i] = speex_rand(1.f, seed);
316}
317
318static void split_cb_shape_sign_unquant(float *exc, const void *par, int nsf,
319                                        GetBitContext *gb, uint32_t *seed)
320{
321    int subvect_size, nb_subvect, have_sign, shape_bits;
322    const SplitCodebookParams *params;
323    const signed char *shape_cb;
324    int signs[10], ind[10];
325
326    params = par;
327    subvect_size = params->subvect_size;
328    nb_subvect = params->nb_subvect;
329
330    shape_cb = params->shape_cb;
331    have_sign = params->have_sign;
332    shape_bits = params->shape_bits;
333
334    /* Decode codewords and gains */
335    for (int i = 0; i < nb_subvect; i++) {
336        signs[i] = have_sign ? get_bits1(gb) : 0;
337        ind[i] = get_bitsz(gb, shape_bits);
338    }
339    /* Compute decoded excitation */
340    for (int i = 0; i < nb_subvect; i++) {
341        const float s = signs[i] ? -1.f : 1.f;
342
343        for (int j = 0; j < subvect_size; j++)
344            exc[subvect_size * i + j] += s * 0.03125f * shape_cb[ind[i] * subvect_size + j];
345    }
346}
347
348#define SUBMODE(x) st->submodes[st->submodeID]->x
349
350#define gain_3tap_to_1tap(g) (FFABS(g[1]) + (g[0] > 0.f ? g[0] : -.5f * g[0]) + (g[2] > 0.f ? g[2] : -.5f * g[2]))
351
352static void
353pitch_unquant_3tap(float *exc, float *exc_out, int start, int end, float pitch_coef,
354                   const void *par, int nsf, int *pitch_val, float *gain_val, GetBitContext *gb,
355                   int count_lost, int subframe_offset, float last_pitch_gain, int cdbk_offset)
356{
357    int pitch, gain_index, gain_cdbk_size;
358    const int8_t *gain_cdbk;
359    const LtpParam *params;
360    float gain[3];
361
362    params = (const LtpParam *)par;
363    gain_cdbk_size = 1 << params->gain_bits;
364    gain_cdbk = params->gain_cdbk + 4 * gain_cdbk_size * cdbk_offset;
365
366    pitch = get_bitsz(gb, params->pitch_bits);
367    pitch += start;
368    gain_index = get_bitsz(gb, params->gain_bits);
369    gain[0] = 0.015625f * gain_cdbk[gain_index * 4] + .5f;
370    gain[1] = 0.015625f * gain_cdbk[gain_index * 4 + 1] + .5f;
371    gain[2] = 0.015625f * gain_cdbk[gain_index * 4 + 2] + .5f;
372
373    if (count_lost && pitch > subframe_offset) {
374        float tmp = count_lost < 4 ? last_pitch_gain : 0.5f * last_pitch_gain;
375        float gain_sum;
376
377        tmp = fminf(tmp, .95f);
378        gain_sum = gain_3tap_to_1tap(gain);
379
380        if (gain_sum > tmp && gain_sum > 0.f) {
381            float fact = tmp / gain_sum;
382            for (int i = 0; i < 3; i++)
383                gain[i] *= fact;
384        }
385    }
386
387    pitch_val[0] = pitch;
388    gain_val[0] = gain[0];
389    gain_val[1] = gain[1];
390    gain_val[2] = gain[2];
391    SPEEX_MEMSET(exc_out, 0, nsf);
392
393    for (int i = 0; i < 3; i++) {
394        int tmp1, tmp3;
395        int pp = pitch + 1 - i;
396        tmp1 = nsf;
397        if (tmp1 > pp)
398            tmp1 = pp;
399        for (int j = 0; j < tmp1; j++)
400            exc_out[j] += gain[2 - i] * exc[j - pp];
401        tmp3 = nsf;
402        if (tmp3 > pp + pitch)
403            tmp3 = pp + pitch;
404        for (int j = tmp1; j < tmp3; j++)
405            exc_out[j] += gain[2 - i] * exc[j - pp - pitch];
406    }
407}
408
409static void lsp_unquant_nb(float *lsp, int order, GetBitContext *gb)
410{
411    int id;
412
413    for (int i = 0; i < order; i++)
414        lsp[i] = LSP_LINEAR(i);
415
416    id = get_bits(gb, 6);
417    for (int i = 0; i < 10; i++)
418        lsp[i] += LSP_DIV_256(cdbk_nb[id * 10 + i]);
419
420    id = get_bits(gb, 6);
421    for (int i = 0; i < 5; i++)
422        lsp[i] += LSP_DIV_512(cdbk_nb_low1[id * 5 + i]);
423
424    id = get_bits(gb, 6);
425    for (int i = 0; i < 5; i++)
426        lsp[i] += LSP_DIV_1024(cdbk_nb_low2[id * 5 + i]);
427
428    id = get_bits(gb, 6);
429    for (int i = 0; i < 5; i++)
430        lsp[i + 5] += LSP_DIV_512(cdbk_nb_high1[id * 5 + i]);
431
432    id = get_bits(gb, 6);
433    for (int i = 0; i < 5; i++)
434        lsp[i + 5] += LSP_DIV_1024(cdbk_nb_high2[id * 5 + i]);
435}
436
437static void lsp_unquant_high(float *lsp, int order, GetBitContext *gb)
438{
439    int id;
440
441    for (int i = 0; i < order; i++)
442        lsp[i] = LSP_LINEAR_HIGH(i);
443
444    id = get_bits(gb, 6);
445    for (int i = 0; i < order; i++)
446        lsp[i] += LSP_DIV_256(high_lsp_cdbk[id * order + i]);
447
448    id = get_bits(gb, 6);
449    for (int i = 0; i < order; i++)
450        lsp[i] += LSP_DIV_512(high_lsp_cdbk2[id * order + i]);
451}
452
453/* 2150 bps "vocoder-like" mode for comfort noise */
454static const SpeexSubmode nb_submode1 = {
455    0, 1, 0, 0, lsp_unquant_lbr, forced_pitch_unquant, NULL,
456    noise_codebook_unquant, NULL, -1.f
457};
458
459/* 5.95 kbps very low bit-rate mode */
460static const SpeexSubmode nb_submode2 = {
461    0, 0, 0, 0, lsp_unquant_lbr, pitch_unquant_3tap, &ltp_params_vlbr,
462    split_cb_shape_sign_unquant, &split_cb_nb_vlbr, .6f
463};
464
465/* 8 kbps low bit-rate mode */
466static const SpeexSubmode nb_submode3 = {
467    -1, 0, 1, 0, lsp_unquant_lbr, pitch_unquant_3tap, &ltp_params_lbr,
468    split_cb_shape_sign_unquant, &split_cb_nb_lbr, .55f
469};
470
471/* 11 kbps medium bit-rate mode */
472static const SpeexSubmode nb_submode4 = {
473    -1, 0, 1, 0, lsp_unquant_lbr, pitch_unquant_3tap, &ltp_params_med,
474    split_cb_shape_sign_unquant, &split_cb_nb_med, .45f
475};
476
477/* 15 kbps high bit-rate mode */
478static const SpeexSubmode nb_submode5 = {
479    -1, 0, 3, 0, lsp_unquant_nb, pitch_unquant_3tap, &ltp_params_nb,
480    split_cb_shape_sign_unquant, &split_cb_nb, .25f
481};
482
483/* 18.2 high bit-rate mode */
484static const SpeexSubmode nb_submode6 = {
485    -1, 0, 3, 0, lsp_unquant_nb, pitch_unquant_3tap, &ltp_params_nb,
486    split_cb_shape_sign_unquant, &split_cb_sb, .15f
487};
488
489/* 24.6 kbps high bit-rate mode */
490static const SpeexSubmode nb_submode7 = {
491    -1, 0, 3, 1, lsp_unquant_nb, pitch_unquant_3tap, &ltp_params_nb,
492    split_cb_shape_sign_unquant, &split_cb_nb, 0.05f
493};
494
495/* 3.95 kbps very low bit-rate mode */
496static const SpeexSubmode nb_submode8 = {
497    0, 1, 0, 0, lsp_unquant_lbr, forced_pitch_unquant, NULL,
498    split_cb_shape_sign_unquant, &split_cb_nb_ulbr, .5f
499};
500
501static const SpeexSubmode wb_submode1 = {
502    0, 0, 1, 0, lsp_unquant_high, NULL, NULL,
503    NULL, NULL, -1.f
504};
505
506static const SpeexSubmode wb_submode2 = {
507    0, 0, 1, 0, lsp_unquant_high, NULL, NULL,
508    split_cb_shape_sign_unquant, &split_cb_high_lbr, -1.f
509};
510
511static const SpeexSubmode wb_submode3 = {
512    0, 0, 1, 0, lsp_unquant_high, NULL, NULL,
513    split_cb_shape_sign_unquant, &split_cb_high, -1.f
514};
515
516static const SpeexSubmode wb_submode4 = {
517    0, 0, 1, 1, lsp_unquant_high, NULL, NULL,
518    split_cb_shape_sign_unquant, &split_cb_high, -1.f
519};
520
521static int nb_decode(AVCodecContext *, void *, GetBitContext *, float *);
522static int sb_decode(AVCodecContext *, void *, GetBitContext *, float *);
523
524static const SpeexMode speex_modes[SPEEX_NB_MODES] = {
525    {
526        .modeID = 0,
527        .decode = nb_decode,
528        .frame_size = NB_FRAME_SIZE,
529        .subframe_size = NB_SUBFRAME_SIZE,
530        .lpc_size = NB_ORDER,
531        .submodes = {
532            NULL, &nb_submode1, &nb_submode2, &nb_submode3, &nb_submode4,
533            &nb_submode5, &nb_submode6, &nb_submode7, &nb_submode8
534        },
535        .default_submode = 5,
536    },
537    {
538        .modeID = 1,
539        .decode = sb_decode,
540        .frame_size = NB_FRAME_SIZE,
541        .subframe_size = NB_SUBFRAME_SIZE,
542        .lpc_size = 8,
543        .folding_gain = 0.9f,
544        .submodes = {
545            NULL, &wb_submode1, &wb_submode2, &wb_submode3, &wb_submode4
546        },
547        .default_submode = 3,
548    },
549    {
550        .modeID = 2,
551        .decode = sb_decode,
552        .frame_size = 320,
553        .subframe_size = 80,
554        .lpc_size = 8,
555        .folding_gain = 0.7f,
556        .submodes = {
557            NULL, &wb_submode1
558        },
559        .default_submode = 1,
560    },
561};
562
563static float compute_rms(const float *x, int len)
564{
565    float sum = 0.f;
566
567    for (int i = 0; i < len; i++)
568        sum += x[i] * x[i];
569
570    av_assert0(len > 0);
571    return sqrtf(.1f + sum / len);
572}
573
574static void bw_lpc(float gamma, const float *lpc_in,
575                   float *lpc_out, int order)
576{
577    float tmp = gamma;
578
579    for (int i = 0; i < order; i++) {
580        lpc_out[i] = tmp * lpc_in[i];
581        tmp *= gamma;
582    }
583}
584
585static void iir_mem(const float *x, const float *den,
586    float *y, int N, int ord, float *mem)
587{
588    for (int i = 0; i < N; i++) {
589        float yi = x[i] + mem[0];
590        float nyi = -yi;
591        for (int j = 0; j < ord - 1; j++)
592            mem[j] = mem[j + 1] + den[j] * nyi;
593        mem[ord - 1] = den[ord - 1] * nyi;
594        y[i] = yi;
595    }
596}
597
598static void highpass(const float *x, float *y, int len, float *mem, int wide)
599{
600    static const float Pcoef[2][3] = {{ 1.00000f, -1.92683f, 0.93071f }, { 1.00000f, -1.97226f, 0.97332f } };
601    static const float Zcoef[2][3] = {{ 0.96446f, -1.92879f, 0.96446f }, { 0.98645f, -1.97277f, 0.98645f } };
602    const float *den, *num;
603
604    den = Pcoef[wide];
605    num = Zcoef[wide];
606    for (int i = 0; i < len; i++) {
607        float yi = num[0] * x[i] + mem[0];
608        mem[0] = mem[1] + num[1] * x[i] + -den[1] * yi;
609        mem[1] = num[2] * x[i] + -den[2] * yi;
610        y[i] = yi;
611    }
612}
613
614#define median3(a, b, c)                                     \
615    ((a) < (b) ? ((b) < (c) ? (b) : ((a) < (c) ? (c) : (a))) \
616               : ((c) < (b) ? (b) : ((c) < (a) ? (c) : (a))))
617
618static int speex_std_stereo(GetBitContext *gb, void *state, void *data)
619{
620    StereoState *stereo = data;
621    float sign = get_bits1(gb) ? -1.f : 1.f;
622
623    stereo->balance = exp(sign * .25f * get_bits(gb, 5));
624    stereo->e_ratio = e_ratio_quant[get_bits(gb, 2)];
625
626    return 0;
627}
628
629static int speex_inband_handler(GetBitContext *gb, void *state, StereoState *stereo)
630{
631    int id = get_bits(gb, 4);
632
633    if (id == SPEEX_INBAND_STEREO) {
634        return speex_std_stereo(gb, state, stereo);
635    } else {
636        int adv;
637
638        if (id < 2)
639            adv = 1;
640        else if (id < 8)
641            adv = 4;
642        else if (id < 10)
643            adv = 8;
644        else if (id < 12)
645            adv = 16;
646        else if (id < 14)
647            adv = 32;
648        else
649            adv = 64;
650        skip_bits_long(gb, adv);
651    }
652    return 0;
653}
654
655static void sanitize_values(float *vec, float min_val, float max_val, int len)
656{
657    for (int i = 0; i < len; i++) {
658        if (!isnormal(vec[i]) || fabsf(vec[i]) < 1e-8f)
659            vec[i] = 0.f;
660        else
661            vec[i] = av_clipf(vec[i], min_val, max_val);
662    }
663}
664
665static void signal_mul(const float *x, float *y, float scale, int len)
666{
667    for (int i = 0; i < len; i++)
668        y[i] = scale * x[i];
669}
670
671static float inner_prod(const float *x, const float *y, int len)
672{
673    float sum = 0.f;
674
675    for (int i = 0; i < len; i += 8) {
676        float part = 0.f;
677        part += x[i + 0] * y[i + 0];
678        part += x[i + 1] * y[i + 1];
679        part += x[i + 2] * y[i + 2];
680        part += x[i + 3] * y[i + 3];
681        part += x[i + 4] * y[i + 4];
682        part += x[i + 5] * y[i + 5];
683        part += x[i + 6] * y[i + 6];
684        part += x[i + 7] * y[i + 7];
685        sum += part;
686    }
687
688    return sum;
689}
690
691static int interp_pitch(const float *exc, float *interp, int pitch, int len)
692{
693    float corr[4][7], maxcorr;
694    int maxi, maxj;
695
696    for (int i = 0; i < 7; i++)
697        corr[0][i] = inner_prod(exc, exc - pitch - 3 + i, len);
698    for (int i = 0; i < 3; i++) {
699        for (int j = 0; j < 7; j++) {
700            int i1, i2;
701            float tmp = 0.f;
702
703            i1 = 3 - j;
704            if (i1 < 0)
705                i1 = 0;
706            i2 = 10 - j;
707            if (i2 > 7)
708                i2 = 7;
709            for (int k = i1; k < i2; k++)
710                tmp += shift_filt[i][k] * corr[0][j + k - 3];
711            corr[i + 1][j] = tmp;
712        }
713    }
714    maxi = maxj = 0;
715    maxcorr = corr[0][0];
716    for (int i = 0; i < 4; i++) {
717        for (int j = 0; j < 7; j++) {
718            if (corr[i][j] > maxcorr) {
719                maxcorr = corr[i][j];
720                maxi = i;
721                maxj = j;
722            }
723        }
724    }
725    for (int i = 0; i < len; i++) {
726        float tmp = 0.f;
727        if (maxi > 0.f) {
728            for (int k = 0; k < 7; k++)
729                tmp += exc[i - (pitch - maxj + 3) + k - 3] * shift_filt[maxi - 1][k];
730        } else {
731            tmp = exc[i - (pitch - maxj + 3)];
732        }
733        interp[i] = tmp;
734    }
735    return pitch - maxj + 3;
736}
737
738static void multicomb(const float *exc, float *new_exc, float *ak, int p, int nsf,
739                      int pitch, int max_pitch, float comb_gain)
740{
741    float old_ener, new_ener;
742    float iexc0_mag, iexc1_mag, exc_mag;
743    float iexc[4 * NB_SUBFRAME_SIZE];
744    float corr0, corr1, gain0, gain1;
745    float pgain1, pgain2;
746    float c1, c2, g1, g2;
747    float ngain, gg1, gg2;
748    int corr_pitch = pitch;
749
750    interp_pitch(exc, iexc, corr_pitch, 80);
751    if (corr_pitch > max_pitch)
752        interp_pitch(exc, iexc + nsf, 2 * corr_pitch, 80);
753    else
754        interp_pitch(exc, iexc + nsf, -corr_pitch, 80);
755
756    iexc0_mag = sqrtf(1000.f + inner_prod(iexc, iexc, nsf));
757    iexc1_mag = sqrtf(1000.f + inner_prod(iexc + nsf, iexc + nsf, nsf));
758    exc_mag = sqrtf(1.f + inner_prod(exc, exc, nsf));
759    corr0 = inner_prod(iexc, exc, nsf);
760    corr1 = inner_prod(iexc + nsf, exc, nsf);
761    if (corr0 > iexc0_mag * exc_mag)
762        pgain1 = 1.f;
763    else
764        pgain1 = (corr0 / exc_mag) / iexc0_mag;
765    if (corr1 > iexc1_mag * exc_mag)
766        pgain2 = 1.f;
767    else
768        pgain2 = (corr1 / exc_mag) / iexc1_mag;
769    gg1 = exc_mag / iexc0_mag;
770    gg2 = exc_mag / iexc1_mag;
771    if (comb_gain > 0.f) {
772        c1 = .4f * comb_gain + .07f;
773        c2 = .5f + 1.72f * (c1 - .07f);
774    } else {
775        c1 = c2 = 0.f;
776    }
777    g1 = 1.f - c2 * pgain1 * pgain1;
778    g2 = 1.f - c2 * pgain2 * pgain2;
779    g1 = fmaxf(g1, c1);
780    g2 = fmaxf(g2, c1);
781    g1 = c1 / g1;
782    g2 = c1 / g2;
783
784    if (corr_pitch > max_pitch) {
785        gain0 = .7f * g1 * gg1;
786        gain1 = .3f * g2 * gg2;
787    } else {
788        gain0 = .6f * g1 * gg1;
789        gain1 = .6f * g2 * gg2;
790    }
791    for (int i = 0; i < nsf; i++)
792        new_exc[i] = exc[i] + (gain0 * iexc[i]) + (gain1 * iexc[i + nsf]);
793    new_ener = compute_rms(new_exc, nsf);
794    old_ener = compute_rms(exc, nsf);
795
796    old_ener = fmaxf(old_ener, 1.f);
797    new_ener = fmaxf(new_ener, 1.f);
798    old_ener = fminf(old_ener, new_ener);
799    ngain = old_ener / new_ener;
800
801    for (int i = 0; i < nsf; i++)
802        new_exc[i] *= ngain;
803}
804
805static void lsp_interpolate(const float *old_lsp, const float *new_lsp,
806                            float *lsp, int len, int subframe,
807                            int nb_subframes, float margin)
808{
809    const float tmp = (1.f + subframe) / nb_subframes;
810
811    for (int i = 0; i < len; i++) {
812        lsp[i] = (1.f - tmp) * old_lsp[i] + tmp * new_lsp[i];
813        lsp[i] = av_clipf(lsp[i], margin, M_PI - margin);
814    }
815    for (int i = 1; i < len - 1; i++) {
816        lsp[i] = fmaxf(lsp[i], lsp[i - 1] + margin);
817        if (lsp[i] > lsp[i + 1] - margin)
818            lsp[i] = .5f * (lsp[i] + lsp[i + 1] - margin);
819    }
820}
821
822static void lsp_to_lpc(const float *freq, float *ak, int lpcrdr)
823{
824    float xout1, xout2, xin1, xin2;
825    float *pw, *n0;
826    float Wp[4 * NB_ORDER + 2] = { 0 };
827    float x_freq[NB_ORDER];
828    const int m = lpcrdr >> 1;
829
830    pw = Wp;
831
832    xin1 = xin2 = 1.f;
833
834    for (int i = 0; i < lpcrdr; i++)
835        x_freq[i] = -cosf(freq[i]);
836
837    /* reconstruct P(z) and Q(z) by  cascading second order
838     * polynomials in form 1 - 2xz(-1) +z(-2), where x is the
839     * LSP coefficient
840     */
841    for (int j = 0; j <= lpcrdr; j++) {
842        int i2 = 0;
843        for (int i = 0; i < m; i++, i2 += 2) {
844            n0 = pw + (i * 4);
845            xout1 = xin1 + 2.f * x_freq[i2    ] * n0[0] + n0[1];
846            xout2 = xin2 + 2.f * x_freq[i2 + 1] * n0[2] + n0[3];
847            n0[1] = n0[0];
848            n0[3] = n0[2];
849            n0[0] = xin1;
850            n0[2] = xin2;
851            xin1 = xout1;
852            xin2 = xout2;
853        }
854        xout1 = xin1 + n0[4];
855        xout2 = xin2 - n0[5];
856        if (j > 0)
857            ak[j - 1] = (xout1 + xout2) * 0.5f;
858        n0[4] = xin1;
859        n0[5] = xin2;
860
861        xin1 = 0.f;
862        xin2 = 0.f;
863    }
864}
865
866static int nb_decode(AVCodecContext *avctx, void *ptr_st,
867                     GetBitContext *gb, float *out)
868{
869    DecoderState *st = ptr_st;
870    float ol_gain = 0, ol_pitch_coef = 0, best_pitch_gain = 0, pitch_average = 0;
871    int m, pitch, wideband, ol_pitch = 0, best_pitch = 40;
872    SpeexContext *s = avctx->priv_data;
873    float innov[NB_SUBFRAME_SIZE];
874    float exc32[NB_SUBFRAME_SIZE];
875    float interp_qlsp[NB_ORDER];
876    float qlsp[NB_ORDER];
877    float ak[NB_ORDER];
878    float pitch_gain[3] = { 0 };
879
880    st->exc = st->exc_buf + 2 * NB_PITCH_END + NB_SUBFRAME_SIZE + 6;
881
882    if (st->encode_submode) {
883        do { /* Search for next narrowband block (handle requests, skip wideband blocks) */
884            if (get_bits_left(gb) < 5)
885                return AVERROR_INVALIDDATA;
886            wideband = get_bits1(gb);
887            if (wideband) /* Skip wideband block (for compatibility) */ {
888                int submode, advance;
889
890                submode = get_bits(gb, SB_SUBMODE_BITS);
891                advance = wb_skip_table[submode];
892                advance -= SB_SUBMODE_BITS + 1;
893                if (advance < 0)
894                    return AVERROR_INVALIDDATA;
895                skip_bits_long(gb, advance);
896
897                if (get_bits_left(gb) < 5)
898                    return AVERROR_INVALIDDATA;
899                wideband = get_bits1(gb);
900                if (wideband) {
901                    submode = get_bits(gb, SB_SUBMODE_BITS);
902                    advance = wb_skip_table[submode];
903                    advance -= SB_SUBMODE_BITS + 1;
904                    if (advance < 0)
905                        return AVERROR_INVALIDDATA;
906                    skip_bits_long(gb, advance);
907                    wideband = get_bits1(gb);
908                    if (wideband) {
909                        av_log(avctx, AV_LOG_ERROR, "more than two wideband layers found\n");
910                        return AVERROR_INVALIDDATA;
911                    }
912                }
913            }
914            if (get_bits_left(gb) < 4)
915                return AVERROR_INVALIDDATA;
916            m = get_bits(gb, 4);
917            if (m == 15) /* We found a terminator */ {
918                return AVERROR_INVALIDDATA;
919            } else if (m == 14) /* Speex in-band request */ {
920                int ret = speex_inband_handler(gb, st, &s->stereo);
921                if (ret)
922                    return ret;
923            } else if (m == 13) /* User in-band request */ {
924                int ret = speex_default_user_handler(gb, st, NULL);
925                if (ret)
926                    return ret;
927            } else if (m > 8) /* Invalid mode */ {
928                return AVERROR_INVALIDDATA;
929            }
930        } while (m > 8);
931
932        st->submodeID = m; /* Get the sub-mode that was used */
933    }
934
935    /* Shift all buffers by one frame */
936    memmove(st->exc_buf, st->exc_buf + NB_FRAME_SIZE, (2 * NB_PITCH_END + NB_SUBFRAME_SIZE + 12) * sizeof(float));
937
938    /* If null mode (no transmission), just set a couple things to zero */
939    if (st->submodes[st->submodeID] == NULL) {
940        float lpc[NB_ORDER];
941        float innov_gain = 0.f;
942
943        bw_lpc(0.93f, st->interp_qlpc, lpc, NB_ORDER);
944        innov_gain = compute_rms(st->exc, NB_FRAME_SIZE);
945        for (int i = 0; i < NB_FRAME_SIZE; i++)
946            st->exc[i] = speex_rand(innov_gain, &st->seed);
947
948        /* Final signal synthesis from excitation */
949        iir_mem(st->exc, lpc, out, NB_FRAME_SIZE, NB_ORDER, st->mem_sp);
950        st->count_lost = 0;
951
952        return 0;
953    }
954
955    /* Unquantize LSPs */
956    SUBMODE(lsp_unquant)(qlsp, NB_ORDER, gb);
957
958    /* Damp memory if a frame was lost and the LSP changed too much */
959    if (st->count_lost) {
960        float fact, lsp_dist = 0;
961
962        for (int i = 0; i < NB_ORDER; i++)
963            lsp_dist = lsp_dist + FFABS(st->old_qlsp[i] - qlsp[i]);
964        fact = .6f * exp(-.2f * lsp_dist);
965        for (int i = 0; i < NB_ORDER; i++)
966            st->mem_sp[i] = fact * st->mem_sp[i];
967    }
968
969    /* Handle first frame and lost-packet case */
970    if (st->first || st->count_lost)
971        memcpy(st->old_qlsp, qlsp, sizeof(st->old_qlsp));
972
973    /* Get open-loop pitch estimation for low bit-rate pitch coding */
974    if (SUBMODE(lbr_pitch) != -1)
975        ol_pitch = NB_PITCH_START + get_bits(gb, 7);
976
977    if (SUBMODE(forced_pitch_gain))
978        ol_pitch_coef = 0.066667f * get_bits(gb, 4);
979
980    /* Get global excitation gain */
981    ol_gain = expf(get_bits(gb, 5) / 3.5f);
982
983    if (st->submodeID == 1)
984        st->dtx_enabled = get_bits(gb, 4) == 15;
985
986    if (st->submodeID > 1)
987        st->dtx_enabled = 0;
988
989    for (int sub = 0; sub < NB_NB_SUBFRAMES; sub++) { /* Loop on subframes */
990        float *exc, *innov_save = NULL, tmp, ener;
991        int pit_min, pit_max, offset, q_energy;
992
993        offset = NB_SUBFRAME_SIZE * sub; /* Offset relative to start of frame */
994        exc = st->exc + offset; /* Excitation */
995        if (st->innov_save) /* Original signal */
996            innov_save = st->innov_save + offset;
997
998        SPEEX_MEMSET(exc, 0, NB_SUBFRAME_SIZE); /* Reset excitation */
999
1000        /* Adaptive codebook contribution */
1001        av_assert0(SUBMODE(ltp_unquant));
1002        /* Handle pitch constraints if any */
1003        if (SUBMODE(lbr_pitch) != -1) {
1004            int margin = SUBMODE(lbr_pitch);
1005
1006            if (margin) {
1007                pit_min = ol_pitch - margin + 1;
1008                pit_min = FFMAX(pit_min, NB_PITCH_START);
1009                pit_max = ol_pitch + margin;
1010                pit_max = FFMIN(pit_max, NB_PITCH_START);
1011            } else {
1012                pit_min = pit_max = ol_pitch;
1013            }
1014        } else {
1015            pit_min = NB_PITCH_START;
1016            pit_max = NB_PITCH_END;
1017        }
1018
1019        SUBMODE(ltp_unquant)(exc, exc32, pit_min, pit_max, ol_pitch_coef, SUBMODE(LtpParam),
1020                             NB_SUBFRAME_SIZE, &pitch, pitch_gain, gb, st->count_lost, offset,
1021                             st->last_pitch_gain, 0);
1022
1023        sanitize_values(exc32, -32000, 32000, NB_SUBFRAME_SIZE);
1024
1025        tmp = gain_3tap_to_1tap(pitch_gain);
1026
1027        pitch_average += tmp;
1028        if ((tmp > best_pitch_gain &&
1029             FFABS(2 * best_pitch - pitch) >= 3 &&
1030             FFABS(3 * best_pitch - pitch) >= 4 &&
1031             FFABS(4 * best_pitch - pitch) >= 5) ||
1032            (tmp > .6f * best_pitch_gain &&
1033             (FFABS(best_pitch - 2 * pitch) < 3 ||
1034              FFABS(best_pitch - 3 * pitch) < 4 ||
1035              FFABS(best_pitch - 4 * pitch) < 5)) ||
1036            ((.67f * tmp) > best_pitch_gain &&
1037             (FFABS(2 * best_pitch - pitch) < 3 ||
1038              FFABS(3 * best_pitch - pitch) < 4 ||
1039              FFABS(4 * best_pitch - pitch) < 5))) {
1040            best_pitch = pitch;
1041            if (tmp > best_pitch_gain)
1042                best_pitch_gain = tmp;
1043        }
1044
1045        memset(innov, 0, sizeof(innov));
1046
1047        /* Decode sub-frame gain correction */
1048        if (SUBMODE(have_subframe_gain) == 3) {
1049            q_energy = get_bits(gb, 3);
1050            ener = exc_gain_quant_scal3[q_energy] * ol_gain;
1051        } else if (SUBMODE(have_subframe_gain) == 1) {
1052            q_energy = get_bits1(gb);
1053            ener = exc_gain_quant_scal1[q_energy] * ol_gain;
1054        } else {
1055            ener = ol_gain;
1056        }
1057
1058        av_assert0(SUBMODE(innovation_unquant));
1059        /* Fixed codebook contribution */
1060        SUBMODE(innovation_unquant)(innov, SUBMODE(innovation_params), NB_SUBFRAME_SIZE, gb, &st->seed);
1061        /* De-normalize innovation and update excitation */
1062
1063        signal_mul(innov, innov, ener, NB_SUBFRAME_SIZE);
1064
1065        /* Decode second codebook (only for some modes) */
1066        if (SUBMODE(double_codebook)) {
1067            float innov2[NB_SUBFRAME_SIZE] = { 0 };
1068
1069            SUBMODE(innovation_unquant)(innov2, SUBMODE(innovation_params), NB_SUBFRAME_SIZE, gb, &st->seed);
1070            signal_mul(innov2, innov2, 0.454545f * ener, NB_SUBFRAME_SIZE);
1071            for (int i = 0; i < NB_SUBFRAME_SIZE; i++)
1072                innov[i] += innov2[i];
1073        }
1074        for (int i = 0; i < NB_SUBFRAME_SIZE; i++)
1075            exc[i] = exc32[i] + innov[i];
1076        if (innov_save)
1077            memcpy(innov_save, innov, sizeof(innov));
1078
1079        /* Vocoder mode */
1080        if (st->submodeID == 1) {
1081            float g = ol_pitch_coef;
1082
1083            g = av_clipf(1.5f * (g - .2f), 0.f, 1.f);
1084
1085            SPEEX_MEMSET(exc, 0, NB_SUBFRAME_SIZE);
1086            while (st->voc_offset < NB_SUBFRAME_SIZE) {
1087                if (st->voc_offset >= 0)
1088                    exc[st->voc_offset] = sqrtf(2.f * ol_pitch) * (g * ol_gain);
1089                st->voc_offset += ol_pitch;
1090            }
1091            st->voc_offset -= NB_SUBFRAME_SIZE;
1092
1093            for (int i = 0; i < NB_SUBFRAME_SIZE; i++) {
1094                float exci = exc[i];
1095                exc[i] = (.7f * exc[i] + .3f * st->voc_m1) + ((1.f - .85f * g) * innov[i]) - .15f * g * st->voc_m2;
1096                st->voc_m1 = exci;
1097                st->voc_m2 = innov[i];
1098                st->voc_mean = .8f * st->voc_mean + .2f * exc[i];
1099                exc[i] -= st->voc_mean;
1100            }
1101        }
1102    }
1103
1104    if (st->lpc_enh_enabled && SUBMODE(comb_gain) > 0 && !st->count_lost) {
1105        multicomb(st->exc - NB_SUBFRAME_SIZE, out, st->interp_qlpc, NB_ORDER,
1106            2 * NB_SUBFRAME_SIZE, best_pitch, 40, SUBMODE(comb_gain));
1107        multicomb(st->exc + NB_SUBFRAME_SIZE, out + 2 * NB_SUBFRAME_SIZE,
1108            st->interp_qlpc, NB_ORDER, 2 * NB_SUBFRAME_SIZE, best_pitch, 40,
1109            SUBMODE(comb_gain));
1110    } else {
1111        SPEEX_COPY(out, &st->exc[-NB_SUBFRAME_SIZE], NB_FRAME_SIZE);
1112    }
1113
1114    /* If the last packet was lost, re-scale the excitation to obtain the same
1115     * energy as encoded in ol_gain */
1116    if (st->count_lost) {
1117        float exc_ener, gain;
1118
1119        exc_ener = compute_rms(st->exc, NB_FRAME_SIZE);
1120        av_assert0(exc_ener + 1.f > 0.f);
1121        gain = fminf(ol_gain / (exc_ener + 1.f), 2.f);
1122        for (int i = 0; i < NB_FRAME_SIZE; i++) {
1123            st->exc[i] *= gain;
1124            out[i] = st->exc[i - NB_SUBFRAME_SIZE];
1125        }
1126    }
1127
1128    for (int sub = 0; sub < NB_NB_SUBFRAMES; sub++) { /* Loop on subframes */
1129        const int offset = NB_SUBFRAME_SIZE * sub; /* Offset relative to start of frame */
1130        float pi_g = 1.f, *sp = out + offset; /* Original signal */
1131
1132        lsp_interpolate(st->old_qlsp, qlsp, interp_qlsp, NB_ORDER, sub, NB_NB_SUBFRAMES, 0.002f);
1133        lsp_to_lpc(interp_qlsp, ak, NB_ORDER); /* Compute interpolated LPCs (unquantized) */
1134
1135        for (int i = 0; i < NB_ORDER; i += 2) /* Compute analysis filter at w=pi */
1136            pi_g += ak[i + 1] - ak[i];
1137        st->pi_gain[sub] = pi_g;
1138        st->exc_rms[sub] = compute_rms(st->exc + offset, NB_SUBFRAME_SIZE);
1139
1140        iir_mem(sp, st->interp_qlpc, sp, NB_SUBFRAME_SIZE, NB_ORDER, st->mem_sp);
1141
1142        memcpy(st->interp_qlpc, ak, sizeof(st->interp_qlpc));
1143    }
1144
1145    if (st->highpass_enabled)
1146        highpass(out, out, NB_FRAME_SIZE, st->mem_hp, st->is_wideband);
1147
1148    /* Store the LSPs for interpolation in the next frame */
1149    memcpy(st->old_qlsp, qlsp, sizeof(st->old_qlsp));
1150
1151    st->count_lost = 0;
1152    st->last_pitch = best_pitch;
1153    st->last_pitch_gain = .25f * pitch_average;
1154    st->last_ol_gain = ol_gain;
1155    st->first = 0;
1156
1157    return 0;
1158}
1159
1160static void qmf_synth(const float *x1, const float *x2, const float *a, float *y, int N, int M, float *mem1, float *mem2)
1161{
1162    const int M2 = M >> 1, N2 = N >> 1;
1163    float xx1[352], xx2[352];
1164
1165    for (int i = 0; i < N2; i++)
1166        xx1[i] = x1[N2-1-i];
1167    for (int i = 0; i < M2; i++)
1168        xx1[N2+i] = mem1[2*i+1];
1169    for (int i = 0; i < N2; i++)
1170        xx2[i] = x2[N2-1-i];
1171    for (int i = 0; i < M2; i++)
1172        xx2[N2+i] = mem2[2*i+1];
1173
1174    for (int i = 0; i < N2; i += 2) {
1175        float y0, y1, y2, y3;
1176        float x10, x20;
1177
1178        y0 = y1 = y2 = y3 = 0.f;
1179        x10 = xx1[N2-2-i];
1180        x20 = xx2[N2-2-i];
1181
1182        for (int j = 0; j < M2; j += 2) {
1183            float x11, x21;
1184            float a0, a1;
1185
1186            a0 = a[2*j];
1187            a1 = a[2*j+1];
1188            x11 = xx1[N2-1+j-i];
1189            x21 = xx2[N2-1+j-i];
1190
1191            y0 += a0 * (x11-x21);
1192            y1 += a1 * (x11+x21);
1193            y2 += a0 * (x10-x20);
1194            y3 += a1 * (x10+x20);
1195            a0 = a[2*j+2];
1196            a1 = a[2*j+3];
1197            x10 = xx1[N2+j-i];
1198            x20 = xx2[N2+j-i];
1199
1200            y0 += a0 * (x10-x20);
1201            y1 += a1 * (x10+x20);
1202            y2 += a0 * (x11-x21);
1203            y3 += a1 * (x11+x21);
1204        }
1205        y[2 * i  ] = 2.f * y0;
1206        y[2 * i+1] = 2.f * y1;
1207        y[2 * i+2] = 2.f * y2;
1208        y[2 * i+3] = 2.f * y3;
1209    }
1210
1211    for (int i = 0; i < M2; i++)
1212        mem1[2*i+1] = xx1[i];
1213    for (int i = 0; i < M2; i++)
1214        mem2[2*i+1] = xx2[i];
1215}
1216
1217static int sb_decode(AVCodecContext *avctx, void *ptr_st,
1218                     GetBitContext *gb, float *out)
1219{
1220    SpeexContext *s = avctx->priv_data;
1221    DecoderState *st = ptr_st;
1222    float low_pi_gain[NB_NB_SUBFRAMES];
1223    float low_exc_rms[NB_NB_SUBFRAMES];
1224    float interp_qlsp[NB_ORDER];
1225    int ret, wideband;
1226    float *low_innov_alias;
1227    float qlsp[NB_ORDER];
1228    float ak[NB_ORDER];
1229    const SpeexMode *mode;
1230
1231    mode = st->mode;
1232
1233    if (st->modeID > 0) {
1234        low_innov_alias = out + st->frame_size;
1235        s->st[st->modeID - 1].innov_save = low_innov_alias;
1236        ret = speex_modes[st->modeID - 1].decode(avctx, &s->st[st->modeID - 1], gb, out);
1237        if (ret < 0)
1238            return ret;
1239    }
1240
1241    if (st->encode_submode) { /* Check "wideband bit" */
1242        if (get_bits_left(gb) > 0)
1243            wideband = show_bits1(gb);
1244        else
1245            wideband = 0;
1246        if (wideband) { /* Regular wideband frame, read the submode */
1247            wideband = get_bits1(gb);
1248            st->submodeID = get_bits(gb, SB_SUBMODE_BITS);
1249        } else { /* Was a narrowband frame, set "null submode" */
1250            st->submodeID = 0;
1251        }
1252        if (st->submodeID != 0 && st->submodes[st->submodeID] == NULL)
1253            return AVERROR_INVALIDDATA;
1254    }
1255
1256    /* If null mode (no transmission), just set a couple things to zero */
1257    if (st->submodes[st->submodeID] == NULL) {
1258        for (int i = 0; i < st->frame_size; i++)
1259            out[st->frame_size + i] = 1e-15f;
1260
1261        st->first = 1;
1262
1263        /* Final signal synthesis from excitation */
1264        iir_mem(out + st->frame_size, st->interp_qlpc, out + st->frame_size, st->frame_size, st->lpc_size, st->mem_sp);
1265
1266        qmf_synth(out, out + st->frame_size, h0, out, st->full_frame_size, QMF_ORDER, st->g0_mem, st->g1_mem);
1267
1268        return 0;
1269    }
1270
1271    memcpy(low_pi_gain, s->st[st->modeID - 1].pi_gain, sizeof(low_pi_gain));
1272    memcpy(low_exc_rms, s->st[st->modeID - 1].exc_rms, sizeof(low_exc_rms));
1273
1274    SUBMODE(lsp_unquant)(qlsp, st->lpc_size, gb);
1275
1276    if (st->first)
1277        memcpy(st->old_qlsp, qlsp, sizeof(st->old_qlsp));
1278
1279    for (int sub = 0; sub < st->nb_subframes; sub++) {
1280        float filter_ratio, el, rl, rh;
1281        float *innov_save = NULL, *sp;
1282        float exc[80];
1283        int offset;
1284
1285        offset = st->subframe_size * sub;
1286        sp = out + st->frame_size + offset;
1287        /* Pointer for saving innovation */
1288        if (st->innov_save) {
1289            innov_save = st->innov_save + 2 * offset;
1290            SPEEX_MEMSET(innov_save, 0, 2 * st->subframe_size);
1291        }
1292
1293        av_assert0(st->nb_subframes > 0);
1294        lsp_interpolate(st->old_qlsp, qlsp, interp_qlsp, st->lpc_size, sub, st->nb_subframes, 0.05f);
1295        lsp_to_lpc(interp_qlsp, ak, st->lpc_size);
1296
1297        /* Calculate reponse ratio between the low and high filter in the middle
1298           of the band (4000 Hz) */
1299        st->pi_gain[sub] = 1.f;
1300        rh = 1.f;
1301        for (int i = 0; i < st->lpc_size; i += 2) {
1302            rh += ak[i + 1] - ak[i];
1303            st->pi_gain[sub] += ak[i] + ak[i + 1];
1304        }
1305
1306        rl = low_pi_gain[sub];
1307        filter_ratio = (rl + .01f) / (rh + .01f);
1308
1309        SPEEX_MEMSET(exc, 0, st->subframe_size);
1310        if (!SUBMODE(innovation_unquant)) {
1311            const int x = get_bits(gb, 5);
1312            const float g = expf(.125f * (x - 10)) / filter_ratio;
1313
1314            for (int i = 0; i < st->subframe_size; i += 2) {
1315                exc[i    ] =  mode->folding_gain * low_innov_alias[offset + i    ] * g;
1316                exc[i + 1] = -mode->folding_gain * low_innov_alias[offset + i + 1] * g;
1317            }
1318        } else {
1319            float gc, scale;
1320
1321            el = low_exc_rms[sub];
1322            gc = 0.87360f * gc_quant_bound[get_bits(gb, 4)];
1323
1324            if (st->subframe_size == 80)
1325                gc *= M_SQRT2;
1326
1327            scale = (gc * el) / filter_ratio;
1328            SUBMODE(innovation_unquant)
1329                (exc, SUBMODE(innovation_params), st->subframe_size,
1330                 gb, &st->seed);
1331
1332            signal_mul(exc, exc, scale, st->subframe_size);
1333            if (SUBMODE(double_codebook)) {
1334                float innov2[80];
1335
1336                SPEEX_MEMSET(innov2, 0, st->subframe_size);
1337                SUBMODE(innovation_unquant)(innov2, SUBMODE(innovation_params), st->subframe_size, gb, &st->seed);
1338                signal_mul(innov2, innov2, 0.4f * scale, st->subframe_size);
1339                for (int i = 0; i < st->subframe_size; i++)
1340                    exc[i] += innov2[i];
1341            }
1342        }
1343
1344        if (st->innov_save) {
1345            for (int i = 0; i < st->subframe_size; i++)
1346                innov_save[2 * i] = exc[i];
1347        }
1348
1349        iir_mem(st->exc_buf, st->interp_qlpc, sp, st->subframe_size, st->lpc_size, st->mem_sp);
1350        memcpy(st->exc_buf, exc, sizeof(exc));
1351        memcpy(st->interp_qlpc, ak, sizeof(st->interp_qlpc));
1352        st->exc_rms[sub] = compute_rms(st->exc_buf, st->subframe_size);
1353    }
1354
1355    qmf_synth(out, out + st->frame_size, h0, out, st->full_frame_size, QMF_ORDER, st->g0_mem, st->g1_mem);
1356    memcpy(st->old_qlsp, qlsp, sizeof(st->old_qlsp));
1357
1358    st->first = 0;
1359
1360    return 0;
1361}
1362
1363static int decoder_init(SpeexContext *s, DecoderState *st, const SpeexMode *mode)
1364{
1365    st->mode = mode;
1366    st->modeID = mode->modeID;
1367
1368    st->first = 1;
1369    st->encode_submode = 1;
1370    st->is_wideband = st->modeID > 0;
1371    st->innov_save = NULL;
1372
1373    st->submodes = mode->submodes;
1374    st->submodeID = mode->default_submode;
1375    st->subframe_size = mode->subframe_size;
1376    st->lpc_size = mode->lpc_size;
1377    st->full_frame_size = (1 + (st->modeID > 0)) * mode->frame_size;
1378    st->nb_subframes = mode->frame_size / mode->subframe_size;
1379    st->frame_size = mode->frame_size;
1380
1381    st->lpc_enh_enabled = 1;
1382
1383    st->last_pitch = 40;
1384    st->count_lost = 0;
1385    st->seed = 1000;
1386    st->last_ol_gain = 0;
1387
1388    st->voc_m1 = st->voc_m2 = st->voc_mean = 0;
1389    st->voc_offset = 0;
1390    st->dtx_enabled = 0;
1391    st->highpass_enabled = mode->modeID == 0;
1392
1393    return 0;
1394}
1395
1396static int parse_speex_extradata(AVCodecContext *avctx,
1397    const uint8_t *extradata, int extradata_size)
1398{
1399    SpeexContext *s = avctx->priv_data;
1400    const uint8_t *buf = extradata;
1401
1402    if (memcmp(buf, "Speex   ", 8))
1403        return AVERROR_INVALIDDATA;
1404
1405    buf += 28;
1406
1407    s->version_id = bytestream_get_le32(&buf);
1408    buf += 4;
1409    s->rate = bytestream_get_le32(&buf);
1410    if (s->rate <= 0)
1411        return AVERROR_INVALIDDATA;
1412    s->mode = bytestream_get_le32(&buf);
1413    if (s->mode < 0 || s->mode >= SPEEX_NB_MODES)
1414        return AVERROR_INVALIDDATA;
1415    s->bitstream_version = bytestream_get_le32(&buf);
1416    if (s->bitstream_version != 4)
1417        return AVERROR_INVALIDDATA;
1418    s->nb_channels = bytestream_get_le32(&buf);
1419    if (s->nb_channels <= 0 || s->nb_channels > 2)
1420        return AVERROR_INVALIDDATA;
1421    s->bitrate = bytestream_get_le32(&buf);
1422    s->frame_size = bytestream_get_le32(&buf);
1423    if (s->frame_size < NB_FRAME_SIZE << s->mode)
1424        return AVERROR_INVALIDDATA;
1425    s->vbr = bytestream_get_le32(&buf);
1426    s->frames_per_packet = bytestream_get_le32(&buf);
1427    if (s->frames_per_packet <= 0 ||
1428        s->frames_per_packet > 64 ||
1429        s->frames_per_packet >= INT32_MAX / s->nb_channels / s->frame_size)
1430        return AVERROR_INVALIDDATA;
1431    s->extra_headers = bytestream_get_le32(&buf);
1432
1433    return 0;
1434}
1435
1436static av_cold int speex_decode_init(AVCodecContext *avctx)
1437{
1438    SpeexContext *s = avctx->priv_data;
1439    int ret;
1440
1441    s->fdsp = avpriv_float_dsp_alloc(0);
1442    if (!s->fdsp)
1443        return AVERROR(ENOMEM);
1444
1445    if (avctx->extradata && avctx->extradata_size >= 80) {
1446        ret = parse_speex_extradata(avctx, avctx->extradata, avctx->extradata_size);
1447        if (ret < 0)
1448            return ret;
1449    } else {
1450        s->rate = avctx->sample_rate;
1451        if (s->rate <= 0)
1452            return AVERROR_INVALIDDATA;
1453
1454        s->nb_channels = avctx->ch_layout.nb_channels;
1455        if (s->nb_channels <= 0 || s->nb_channels > 2)
1456            return AVERROR_INVALIDDATA;
1457
1458        switch (s->rate) {
1459        case 8000:  s->mode = 0; break;
1460        case 16000: s->mode = 1; break;
1461        case 32000: s->mode = 2; break;
1462        default: s->mode = 2;
1463        }
1464
1465        s->frames_per_packet = 1;
1466        s->frame_size = NB_FRAME_SIZE << s->mode;
1467    }
1468
1469    if (avctx->codec_tag == MKTAG('S', 'P', 'X', 'N')) {
1470        int quality;
1471
1472        if (!avctx->extradata || avctx->extradata && avctx->extradata_size < 47) {
1473            av_log(avctx, AV_LOG_ERROR, "Missing or invalid extradata.\n");
1474            return AVERROR_INVALIDDATA;
1475        }
1476
1477        quality = avctx->extradata[37];
1478        if (quality > 10) {
1479            av_log(avctx, AV_LOG_ERROR, "Unsupported quality mode %d.\n", quality);
1480            return AVERROR_PATCHWELCOME;
1481        }
1482
1483        s->pkt_size = ((const uint8_t[]){ 5, 10, 15, 20, 20, 28, 28, 38, 38, 46, 62 })[quality];
1484
1485        s->mode = 0;
1486        s->nb_channels = 1;
1487        s->rate = avctx->sample_rate;
1488        if (s->rate <= 0)
1489            return AVERROR_INVALIDDATA;
1490        s->frames_per_packet = 1;
1491        s->frame_size = NB_FRAME_SIZE;
1492    }
1493
1494    if (s->bitrate > 0)
1495        avctx->bit_rate = s->bitrate;
1496    av_channel_layout_uninit(&avctx->ch_layout);
1497    avctx->ch_layout.order       = AV_CHANNEL_ORDER_UNSPEC;
1498    avctx->ch_layout.nb_channels = s->nb_channels;
1499    avctx->sample_rate = s->rate;
1500    avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
1501
1502    for (int m = 0; m <= s->mode; m++) {
1503        ret = decoder_init(s, &s->st[m], &speex_modes[m]);
1504        if (ret < 0)
1505            return ret;
1506    }
1507
1508    s->stereo.balance = 1.f;
1509    s->stereo.e_ratio = .5f;
1510    s->stereo.smooth_left = 1.f;
1511    s->stereo.smooth_right = 1.f;
1512
1513    return 0;
1514}
1515
1516static void speex_decode_stereo(float *data, int frame_size, StereoState *stereo)
1517{
1518    float balance, e_left, e_right, e_ratio;
1519
1520    balance = stereo->balance;
1521    e_ratio = stereo->e_ratio;
1522
1523    /* These two are Q14, with max value just below 2. */
1524    e_right = 1.f / sqrtf(e_ratio * (1.f + balance));
1525    e_left = sqrtf(balance) * e_right;
1526
1527    for (int i = frame_size - 1; i >= 0; i--) {
1528        float tmp = data[i];
1529        stereo->smooth_left  = stereo->smooth_left  * 0.98f + e_left  * 0.02f;
1530        stereo->smooth_right = stereo->smooth_right * 0.98f + e_right * 0.02f;
1531        data[2 * i    ] = stereo->smooth_left  * tmp;
1532        data[2 * i + 1] = stereo->smooth_right * tmp;
1533    }
1534}
1535
1536static int speex_decode_frame(AVCodecContext *avctx, AVFrame *frame,
1537                              int *got_frame_ptr, AVPacket *avpkt)
1538{
1539    SpeexContext *s = avctx->priv_data;
1540    const float scale = 1.f / 32768.f;
1541    int buf_size = avpkt->size;
1542    float *dst;
1543    int ret;
1544
1545    if (s->pkt_size && avpkt->size == 62)
1546        buf_size = s->pkt_size;
1547    if ((ret = init_get_bits8(&s->gb, avpkt->data, buf_size)) < 0)
1548        return ret;
1549
1550    frame->nb_samples = FFALIGN(s->frame_size * s->frames_per_packet, 4);
1551    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1552        return ret;
1553
1554    dst = (float *)frame->extended_data[0];
1555    for (int i = 0; i < s->frames_per_packet; i++) {
1556        ret = speex_modes[s->mode].decode(avctx, &s->st[s->mode], &s->gb, dst + i * s->frame_size);
1557        if (ret < 0)
1558            return ret;
1559        if (avctx->ch_layout.nb_channels == 2)
1560            speex_decode_stereo(dst + i * s->frame_size, s->frame_size, &s->stereo);
1561    }
1562
1563    dst = (float *)frame->extended_data[0];
1564    s->fdsp->vector_fmul_scalar(dst, dst, scale, frame->nb_samples * frame->ch_layout.nb_channels);
1565    frame->nb_samples = s->frame_size * s->frames_per_packet;
1566
1567    *got_frame_ptr = 1;
1568
1569    return buf_size;
1570}
1571
1572static av_cold int speex_decode_close(AVCodecContext *avctx)
1573{
1574    SpeexContext *s = avctx->priv_data;
1575    av_freep(&s->fdsp);
1576    return 0;
1577}
1578
1579const FFCodec ff_speex_decoder = {
1580    .p.name         = "speex",
1581    .p.long_name    = NULL_IF_CONFIG_SMALL("Speex"),
1582    .p.type         = AVMEDIA_TYPE_AUDIO,
1583    .p.id           = AV_CODEC_ID_SPEEX,
1584    .init           = speex_decode_init,
1585    FF_CODEC_DECODE_CB(speex_decode_frame),
1586    .close          = speex_decode_close,
1587    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
1588    .priv_data_size = sizeof(SpeexContext),
1589    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
1590};
1591