1/*
2 * Windows Media Audio Voice decoder.
3 * Copyright (c) 2009 Ronald S. Bultje
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 * @brief Windows Media Audio Voice compatible decoder
25 * @author Ronald S. Bultje <rsbultje@gmail.com>
26 */
27
28#include <math.h>
29#include "avcodec.h"
30#include "get_bits.h"
31#include "put_bits.h"
32#include "wmavoice_data.h"
33#include "celp_math.h"
34#include "celp_filters.h"
35#include "acelp_vectors.h"
36#include "acelp_filters.h"
37#include "lsp.h"
38#include "libavutil/lzo.h"
39#include "avfft.h"
40#include "fft.h"
41
42#define MAX_BLOCKS           8   ///< maximum number of blocks per frame
43#define MAX_LSPS             16  ///< maximum filter order
44#define MAX_LSPS_ALIGN16     16  ///< same as #MAX_LSPS; needs to be multiple
45                                 ///< of 16 for ASM input buffer alignment
46#define MAX_FRAMES           3   ///< maximum number of frames per superframe
47#define MAX_FRAMESIZE        160 ///< maximum number of samples per frame
48#define MAX_SIGNAL_HISTORY   416 ///< maximum excitation signal history
49#define MAX_SFRAMESIZE       (MAX_FRAMESIZE * MAX_FRAMES)
50                                 ///< maximum number of samples per superframe
51#define SFRAME_CACHE_MAXSIZE 256 ///< maximum cache size for frame data that
52                                 ///< was split over two packets
53#define VLC_NBITS            6   ///< number of bits to read per VLC iteration
54
55/**
56 * Frame type VLC coding.
57 */
58static VLC frame_type_vlc;
59
60/**
61 * Adaptive codebook types.
62 */
63enum {
64    ACB_TYPE_NONE       = 0, ///< no adaptive codebook (only hardcoded fixed)
65    ACB_TYPE_ASYMMETRIC = 1, ///< adaptive codebook with per-frame pitch, which
66                             ///< we interpolate to get a per-sample pitch.
67                             ///< Signal is generated using an asymmetric sinc
68                             ///< window function
69                             ///< @note see #wmavoice_ipol1_coeffs
70    ACB_TYPE_HAMMING    = 2  ///< Per-block pitch with signal generation using
71                             ///< a Hamming sinc window function
72                             ///< @note see #wmavoice_ipol2_coeffs
73};
74
75/**
76 * Fixed codebook types.
77 */
78enum {
79    FCB_TYPE_SILENCE    = 0, ///< comfort noise during silence
80                             ///< generated from a hardcoded (fixed) codebook
81                             ///< with per-frame (low) gain values
82    FCB_TYPE_HARDCODED  = 1, ///< hardcoded (fixed) codebook with per-block
83                             ///< gain values
84    FCB_TYPE_AW_PULSES  = 2, ///< Pitch-adaptive window (AW) pulse signals,
85                             ///< used in particular for low-bitrate streams
86    FCB_TYPE_EXC_PULSES = 3, ///< Innovation (fixed) codebook pulse sets in
87                             ///< combinations of either single pulses or
88                             ///< pulse pairs
89};
90
91/**
92 * Description of frame types.
93 */
94static const struct frame_type_desc {
95    uint8_t n_blocks;     ///< amount of blocks per frame (each block
96                          ///< (contains 160/#n_blocks samples)
97    uint8_t log_n_blocks; ///< log2(#n_blocks)
98    uint8_t acb_type;     ///< Adaptive codebook type (ACB_TYPE_*)
99    uint8_t fcb_type;     ///< Fixed codebook type (FCB_TYPE_*)
100    uint8_t dbl_pulses;   ///< how many pulse vectors have pulse pairs
101                          ///< (rather than just one single pulse)
102                          ///< only if #fcb_type == #FCB_TYPE_EXC_PULSES
103    uint16_t frame_size;  ///< the amount of bits that make up the block
104                          ///< data (per frame)
105} frame_descs[17] = {
106    { 1, 0, ACB_TYPE_NONE,       FCB_TYPE_SILENCE,    0,   0 },
107    { 2, 1, ACB_TYPE_NONE,       FCB_TYPE_HARDCODED,  0,  28 },
108    { 2, 1, ACB_TYPE_ASYMMETRIC, FCB_TYPE_AW_PULSES,  0,  46 },
109    { 2, 1, ACB_TYPE_ASYMMETRIC, FCB_TYPE_EXC_PULSES, 2,  80 },
110    { 2, 1, ACB_TYPE_ASYMMETRIC, FCB_TYPE_EXC_PULSES, 5, 104 },
111    { 4, 2, ACB_TYPE_ASYMMETRIC, FCB_TYPE_EXC_PULSES, 0, 108 },
112    { 4, 2, ACB_TYPE_ASYMMETRIC, FCB_TYPE_EXC_PULSES, 2, 132 },
113    { 4, 2, ACB_TYPE_ASYMMETRIC, FCB_TYPE_EXC_PULSES, 5, 168 },
114    { 2, 1, ACB_TYPE_HAMMING,    FCB_TYPE_EXC_PULSES, 0,  64 },
115    { 2, 1, ACB_TYPE_HAMMING,    FCB_TYPE_EXC_PULSES, 2,  80 },
116    { 2, 1, ACB_TYPE_HAMMING,    FCB_TYPE_EXC_PULSES, 5, 104 },
117    { 4, 2, ACB_TYPE_HAMMING,    FCB_TYPE_EXC_PULSES, 0, 108 },
118    { 4, 2, ACB_TYPE_HAMMING,    FCB_TYPE_EXC_PULSES, 2, 132 },
119    { 4, 2, ACB_TYPE_HAMMING,    FCB_TYPE_EXC_PULSES, 5, 168 },
120    { 8, 3, ACB_TYPE_HAMMING,    FCB_TYPE_EXC_PULSES, 0, 176 },
121    { 8, 3, ACB_TYPE_HAMMING,    FCB_TYPE_EXC_PULSES, 2, 208 },
122    { 8, 3, ACB_TYPE_HAMMING,    FCB_TYPE_EXC_PULSES, 5, 256 }
123};
124
125/**
126 * WMA Voice decoding context.
127 */
128typedef struct {
129    /**
130     * @defgroup struct_global Global values
131     * Global values, specified in the stream header / extradata or used
132     * all over.
133     * @{
134     */
135    GetBitContext gb;             ///< packet bitreader. During decoder init,
136                                  ///< it contains the extradata from the
137                                  ///< demuxer. During decoding, it contains
138                                  ///< packet data.
139    int8_t vbm_tree[25];          ///< converts VLC codes to frame type
140
141    int spillover_bitsize;        ///< number of bits used to specify
142                                  ///< #spillover_nbits in the packet header
143                                  ///< = ceil(log2(ctx->block_align << 3))
144    int history_nsamples;         ///< number of samples in history for signal
145                                  ///< prediction (through ACB)
146
147    /* postfilter specific values */
148    int do_apf;                   ///< whether to apply the averaged
149                                  ///< projection filter (APF)
150    int denoise_strength;         ///< strength of denoising in Wiener filter
151                                  ///< [0-11]
152    int denoise_tilt_corr;        ///< Whether to apply tilt correction to the
153                                  ///< Wiener filter coefficients (postfilter)
154    int dc_level;                 ///< Predicted amount of DC noise, based
155                                  ///< on which a DC removal filter is used
156
157    int lsps;                     ///< number of LSPs per frame [10 or 16]
158    int lsp_q_mode;               ///< defines quantizer defaults [0, 1]
159    int lsp_def_mode;             ///< defines different sets of LSP defaults
160                                  ///< [0, 1]
161    int frame_lsp_bitsize;        ///< size (in bits) of LSPs, when encoded
162                                  ///< per-frame (independent coding)
163    int sframe_lsp_bitsize;       ///< size (in bits) of LSPs, when encoded
164                                  ///< per superframe (residual coding)
165
166    int min_pitch_val;            ///< base value for pitch parsing code
167    int max_pitch_val;            ///< max value + 1 for pitch parsing
168    int pitch_nbits;              ///< number of bits used to specify the
169                                  ///< pitch value in the frame header
170    int block_pitch_nbits;        ///< number of bits used to specify the
171                                  ///< first block's pitch value
172    int block_pitch_range;        ///< range of the block pitch
173    int block_delta_pitch_nbits;  ///< number of bits used to specify the
174                                  ///< delta pitch between this and the last
175                                  ///< block's pitch value, used in all but
176                                  ///< first block
177    int block_delta_pitch_hrange; ///< 1/2 range of the delta (full range is
178                                  ///< from -this to +this-1)
179    uint16_t block_conv_table[4]; ///< boundaries for block pitch unit/scale
180                                  ///< conversion
181
182    /**
183     * @}
184     * @defgroup struct_packet Packet values
185     * Packet values, specified in the packet header or related to a packet.
186     * A packet is considered to be a single unit of data provided to this
187     * decoder by the demuxer.
188     * @{
189     */
190    int spillover_nbits;          ///< number of bits of the previous packet's
191                                  ///< last superframe preceeding this
192                                  ///< packet's first full superframe (useful
193                                  ///< for re-synchronization also)
194    int has_residual_lsps;        ///< if set, superframes contain one set of
195                                  ///< LSPs that cover all frames, encoded as
196                                  ///< independent and residual LSPs; if not
197                                  ///< set, each frame contains its own, fully
198                                  ///< independent, LSPs
199    int skip_bits_next;           ///< number of bits to skip at the next call
200                                  ///< to #wmavoice_decode_packet() (since
201                                  ///< they're part of the previous superframe)
202
203    uint8_t sframe_cache[SFRAME_CACHE_MAXSIZE + FF_INPUT_BUFFER_PADDING_SIZE];
204                                  ///< cache for superframe data split over
205                                  ///< multiple packets
206    int sframe_cache_size;        ///< set to >0 if we have data from an
207                                  ///< (incomplete) superframe from a previous
208                                  ///< packet that spilled over in the current
209                                  ///< packet; specifies the amount of bits in
210                                  ///< #sframe_cache
211    PutBitContext pb;             ///< bitstream writer for #sframe_cache
212
213    /**
214     * @}
215     * @defgroup struct_frame Frame and superframe values
216     * Superframe and frame data - these can change from frame to frame,
217     * although some of them do in that case serve as a cache / history for
218     * the next frame or superframe.
219     * @{
220     */
221    double prev_lsps[MAX_LSPS];   ///< LSPs of the last frame of the previous
222                                  ///< superframe
223    int last_pitch_val;           ///< pitch value of the previous frame
224    int last_acb_type;            ///< frame type [0-2] of the previous frame
225    int pitch_diff_sh16;          ///< ((cur_pitch_val - #last_pitch_val)
226                                  ///< << 16) / #MAX_FRAMESIZE
227    float silence_gain;           ///< set for use in blocks if #ACB_TYPE_NONE
228
229    int aw_idx_is_ext;            ///< whether the AW index was encoded in
230                                  ///< 8 bits (instead of 6)
231    int aw_pulse_range;           ///< the range over which #aw_pulse_set1()
232                                  ///< can apply the pulse, relative to the
233                                  ///< value in aw_first_pulse_off. The exact
234                                  ///< position of the first AW-pulse is within
235                                  ///< [pulse_off, pulse_off + this], and
236                                  ///< depends on bitstream values; [16 or 24]
237    int aw_n_pulses[2];           ///< number of AW-pulses in each block; note
238                                  ///< that this number can be negative (in
239                                  ///< which case it basically means "zero")
240    int aw_first_pulse_off[2];    ///< index of first sample to which to
241                                  ///< apply AW-pulses, or -0xff if unset
242    int aw_next_pulse_off_cache;  ///< the position (relative to start of the
243                                  ///< second block) at which pulses should
244                                  ///< start to be positioned, serves as a
245                                  ///< cache for pitch-adaptive window pulses
246                                  ///< between blocks
247
248    int frame_cntr;               ///< current frame index [0 - 0xFFFE]; is
249                                  ///< only used for comfort noise in #pRNG()
250    float gain_pred_err[6];       ///< cache for gain prediction
251    float excitation_history[MAX_SIGNAL_HISTORY];
252                                  ///< cache of the signal of previous
253                                  ///< superframes, used as a history for
254                                  ///< signal generation
255    float synth_history[MAX_LSPS]; ///< see #excitation_history
256    /**
257     * @}
258     * @defgroup post_filter Postfilter values
259     * Varibales used for postfilter implementation, mostly history for
260     * smoothing and so on, and context variables for FFT/iFFT.
261     * @{
262     */
263    RDFTContext rdft, irdft;      ///< contexts for FFT-calculation in the
264                                  ///< postfilter (for denoise filter)
265    DCTContext dct, dst;          ///< contexts for phase shift (in Hilbert
266                                  ///< transform, part of postfilter)
267    float sin[511], cos[511];     ///< 8-bit cosine/sine windows over [-pi,pi]
268                                  ///< range
269    float postfilter_agc;         ///< gain control memory, used in
270                                  ///< #adaptive_gain_control()
271    float dcf_mem[2];             ///< DC filter history
272    float zero_exc_pf[MAX_SIGNAL_HISTORY + MAX_SFRAMESIZE];
273                                  ///< zero filter output (i.e. excitation)
274                                  ///< by postfilter
275    float denoise_filter_cache[MAX_FRAMESIZE];
276    int   denoise_filter_cache_size; ///< samples in #denoise_filter_cache
277    DECLARE_ALIGNED(16, float, tilted_lpcs_pf)[0x80];
278                                  ///< aligned buffer for LPC tilting
279    DECLARE_ALIGNED(16, float, denoise_coeffs_pf)[0x80];
280                                  ///< aligned buffer for denoise coefficients
281    DECLARE_ALIGNED(16, float, synth_filter_out_buf)[0x80 + MAX_LSPS_ALIGN16];
282                                  ///< aligned buffer for postfilter speech
283                                  ///< synthesis
284    /**
285     * @}
286     */
287} WMAVoiceContext;
288
289/**
290 * Sets up the variable bit mode (VBM) tree from container extradata.
291 * @param gb bit I/O context.
292 *           The bit context (s->gb) should be loaded with byte 23-46 of the
293 *           container extradata (i.e. the ones containing the VBM tree).
294 * @param vbm_tree pointer to array to which the decoded VBM tree will be
295 *                 written.
296 * @return 0 on success, <0 on error.
297 */
298static av_cold int decode_vbmtree(GetBitContext *gb, int8_t vbm_tree[25])
299{
300    static const uint8_t bits[] = {
301         2,  2,  2,  4,  4,  4,
302         6,  6,  6,  8,  8,  8,
303        10, 10, 10, 12, 12, 12,
304        14, 14, 14, 14
305    };
306    static const uint16_t codes[] = {
307          0x0000, 0x0001, 0x0002,        //              00/01/10
308          0x000c, 0x000d, 0x000e,        //           11+00/01/10
309          0x003c, 0x003d, 0x003e,        //         1111+00/01/10
310          0x00fc, 0x00fd, 0x00fe,        //       111111+00/01/10
311          0x03fc, 0x03fd, 0x03fe,        //     11111111+00/01/10
312          0x0ffc, 0x0ffd, 0x0ffe,        //   1111111111+00/01/10
313          0x3ffc, 0x3ffd, 0x3ffe, 0x3fff // 111111111111+xx
314    };
315    int cntr[8], n, res;
316
317    memset(vbm_tree, 0xff, sizeof(vbm_tree));
318    memset(cntr,     0,    sizeof(cntr));
319    for (n = 0; n < 17; n++) {
320        res = get_bits(gb, 3);
321        if (cntr[res] > 3) // should be >= 3 + (res == 7))
322            return -1;
323        vbm_tree[res * 3 + cntr[res]++] = n;
324    }
325    INIT_VLC_STATIC(&frame_type_vlc, VLC_NBITS, sizeof(bits),
326                    bits, 1, 1, codes, 2, 2, 132);
327    return 0;
328}
329
330/**
331 * Set up decoder with parameters from demuxer (extradata etc.).
332 */
333static av_cold int wmavoice_decode_init(AVCodecContext *ctx)
334{
335    int n, flags, pitch_range, lsp16_flag;
336    WMAVoiceContext *s = ctx->priv_data;
337
338    /**
339     * Extradata layout:
340     * - byte  0-18: WMAPro-in-WMAVoice extradata (see wmaprodec.c),
341     * - byte 19-22: flags field (annoyingly in LE; see below for known
342     *               values),
343     * - byte 23-46: variable bitmode tree (really just 17 * 3 bits,
344     *               rest is 0).
345     */
346    if (ctx->extradata_size != 46) {
347        av_log(ctx, AV_LOG_ERROR,
348               "Invalid extradata size %d (should be 46)\n",
349               ctx->extradata_size);
350        return -1;
351    }
352    flags                = AV_RL32(ctx->extradata + 18);
353    s->spillover_bitsize = 3 + av_ceil_log2(ctx->block_align);
354    s->do_apf            =    flags & 0x1;
355    if (s->do_apf) {
356        ff_rdft_init(&s->rdft,  7, DFT_R2C);
357        ff_rdft_init(&s->irdft, 7, IDFT_C2R);
358        ff_dct_init(&s->dct,  6, DCT_I);
359        ff_dct_init(&s->dst,  6, DST_I);
360
361        ff_sine_window_init(s->cos, 256);
362        memcpy(&s->sin[255], s->cos, 256 * sizeof(s->cos[0]));
363        for (n = 0; n < 255; n++) {
364            s->sin[n]       = -s->sin[510 - n];
365            s->cos[510 - n] =  s->cos[n];
366        }
367    }
368    s->denoise_strength  =   (flags >> 2) & 0xF;
369    if (s->denoise_strength >= 12) {
370        av_log(ctx, AV_LOG_ERROR,
371               "Invalid denoise filter strength %d (max=11)\n",
372               s->denoise_strength);
373        return -1;
374    }
375    s->denoise_tilt_corr = !!(flags & 0x40);
376    s->dc_level          =   (flags >> 7) & 0xF;
377    s->lsp_q_mode        = !!(flags & 0x2000);
378    s->lsp_def_mode      = !!(flags & 0x4000);
379    lsp16_flag           =    flags & 0x1000;
380    if (lsp16_flag) {
381        s->lsps               = 16;
382        s->frame_lsp_bitsize  = 34;
383        s->sframe_lsp_bitsize = 60;
384    } else {
385        s->lsps               = 10;
386        s->frame_lsp_bitsize  = 24;
387        s->sframe_lsp_bitsize = 48;
388    }
389    for (n = 0; n < s->lsps; n++)
390        s->prev_lsps[n] = M_PI * (n + 1.0) / (s->lsps + 1.0);
391
392    init_get_bits(&s->gb, ctx->extradata + 22, (ctx->extradata_size - 22) << 3);
393    if (decode_vbmtree(&s->gb, s->vbm_tree) < 0) {
394        av_log(ctx, AV_LOG_ERROR, "Invalid VBM tree; broken extradata?\n");
395        return -1;
396    }
397
398    s->min_pitch_val    = ((ctx->sample_rate << 8)      /  400 + 50) >> 8;
399    s->max_pitch_val    = ((ctx->sample_rate << 8) * 37 / 2000 + 50) >> 8;
400    pitch_range         = s->max_pitch_val - s->min_pitch_val;
401    s->pitch_nbits      = av_ceil_log2(pitch_range);
402    s->last_pitch_val   = 40;
403    s->last_acb_type    = ACB_TYPE_NONE;
404    s->history_nsamples = s->max_pitch_val + 8;
405
406    if (s->min_pitch_val < 1 || s->history_nsamples > MAX_SIGNAL_HISTORY) {
407        int min_sr = ((((1 << 8) - 50) * 400) + 0xFF) >> 8,
408            max_sr = ((((MAX_SIGNAL_HISTORY - 8) << 8) + 205) * 2000 / 37) >> 8;
409
410        av_log(ctx, AV_LOG_ERROR,
411               "Unsupported samplerate %d (min=%d, max=%d)\n",
412               ctx->sample_rate, min_sr, max_sr); // 322-22097 Hz
413
414        return -1;
415    }
416
417    s->block_conv_table[0]      = s->min_pitch_val;
418    s->block_conv_table[1]      = (pitch_range * 25) >> 6;
419    s->block_conv_table[2]      = (pitch_range * 44) >> 6;
420    s->block_conv_table[3]      = s->max_pitch_val - 1;
421    s->block_delta_pitch_hrange = (pitch_range >> 3) & ~0xF;
422    s->block_delta_pitch_nbits  = 1 + av_ceil_log2(s->block_delta_pitch_hrange);
423    s->block_pitch_range        = s->block_conv_table[2] +
424                                  s->block_conv_table[3] + 1 +
425                                  2 * (s->block_conv_table[1] - 2 * s->min_pitch_val);
426    s->block_pitch_nbits        = av_ceil_log2(s->block_pitch_range);
427
428    ctx->sample_fmt             = SAMPLE_FMT_FLT;
429
430    return 0;
431}
432
433/**
434 * @defgroup postfilter Postfilter functions
435 * Postfilter functions (gain control, wiener denoise filter, DC filter,
436 * kalman smoothening, plus surrounding code to wrap it)
437 * @{
438 */
439/**
440 * Adaptive gain control (as used in postfilter).
441 *
442 * Identical to #ff_adaptive_gain_control() in acelp_vectors.c, except
443 * that the energy here is calculated using sum(abs(...)), whereas the
444 * other codecs (e.g. AMR-NB, SIPRO) use sqrt(dotproduct(...)).
445 *
446 * @param out output buffer for filtered samples
447 * @param in input buffer containing the samples as they are after the
448 *           postfilter steps so far
449 * @param speech_synth input buffer containing speech synth before postfilter
450 * @param size input buffer size
451 * @param alpha exponential filter factor
452 * @param gain_mem pointer to filter memory (single float)
453 */
454static void adaptive_gain_control(float *out, const float *in,
455                                  const float *speech_synth,
456                                  int size, float alpha, float *gain_mem)
457{
458    int i;
459    float speech_energy = 0.0, postfilter_energy = 0.0, gain_scale_factor;
460    float mem = *gain_mem;
461
462    for (i = 0; i < size; i++) {
463        speech_energy     += fabsf(speech_synth[i]);
464        postfilter_energy += fabsf(in[i]);
465    }
466    gain_scale_factor = (1.0 - alpha) * speech_energy / postfilter_energy;
467
468    for (i = 0; i < size; i++) {
469        mem = alpha * mem + gain_scale_factor;
470        out[i] = in[i] * mem;
471    }
472
473    *gain_mem = mem;
474}
475
476/**
477 * Kalman smoothing function.
478 *
479 * This function looks back pitch +/- 3 samples back into history to find
480 * the best fitting curve (that one giving the optimal gain of the two
481 * signals, i.e. the highest dot product between the two), and then
482 * uses that signal history to smoothen the output of the speech synthesis
483 * filter.
484 *
485 * @param s WMA Voice decoding context
486 * @param pitch pitch of the speech signal
487 * @param in input speech signal
488 * @param out output pointer for smoothened signal
489 * @param size input/output buffer size
490 *
491 * @returns -1 if no smoothening took place, e.g. because no optimal
492 *          fit could be found, or 0 on success.
493 */
494static int kalman_smoothen(WMAVoiceContext *s, int pitch,
495                           const float *in, float *out, int size)
496{
497    int n;
498    float optimal_gain = 0, dot;
499    const float *ptr = &in[-FFMAX(s->min_pitch_val, pitch - 3)],
500                *end = &in[-FFMIN(s->max_pitch_val, pitch + 3)],
501                *best_hist_ptr;
502
503    /* find best fitting point in history */
504    do {
505        dot = ff_dot_productf(in, ptr, size);
506        if (dot > optimal_gain) {
507            optimal_gain  = dot;
508            best_hist_ptr = ptr;
509        }
510    } while (--ptr >= end);
511
512    if (optimal_gain <= 0)
513        return -1;
514    dot = ff_dot_productf(best_hist_ptr, best_hist_ptr, size);
515    if (dot <= 0) // would be 1.0
516        return -1;
517
518    if (optimal_gain <= dot) {
519        dot = dot / (dot + 0.6 * optimal_gain); // 0.625-1.000
520    } else
521        dot = 0.625;
522
523    /* actual smoothing */
524    for (n = 0; n < size; n++)
525        out[n] = best_hist_ptr[n] + dot * (in[n] - best_hist_ptr[n]);
526
527    return 0;
528}
529
530/**
531 * Get the tilt factor of a formant filter from its transfer function
532 * @see #tilt_factor() in amrnbdec.c, which does essentially the same,
533 *      but somehow (??) it does a speech synthesis filter in the
534 *      middle, which is missing here
535 *
536 * @param lpcs LPC coefficients
537 * @param n_lpcs Size of LPC buffer
538 * @returns the tilt factor
539 */
540static float tilt_factor(const float *lpcs, int n_lpcs)
541{
542    float rh0, rh1;
543
544    rh0 = 1.0     + ff_dot_productf(lpcs,  lpcs,    n_lpcs);
545    rh1 = lpcs[0] + ff_dot_productf(lpcs, &lpcs[1], n_lpcs - 1);
546
547    return rh1 / rh0;
548}
549
550/**
551 * Derive denoise filter coefficients (in real domain) from the LPCs.
552 */
553static void calc_input_response(WMAVoiceContext *s, float *lpcs,
554                                int fcb_type, float *coeffs, int remainder)
555{
556    float last_coeff, min = 15.0, max = -15.0;
557    float irange, angle_mul, gain_mul, range, sq;
558    int n, idx;
559
560    /* Create frequency power spectrum of speech input (i.e. RDFT of LPCs) */
561    ff_rdft_calc(&s->rdft, lpcs);
562#define log_range(var, assign) do { \
563        float tmp = log10f(assign);  var = tmp; \
564        max       = FFMAX(max, tmp); min = FFMIN(min, tmp); \
565    } while (0)
566    log_range(last_coeff,  lpcs[1]         * lpcs[1]);
567    for (n = 1; n < 64; n++)
568        log_range(lpcs[n], lpcs[n * 2]     * lpcs[n * 2] +
569                           lpcs[n * 2 + 1] * lpcs[n * 2 + 1]);
570    log_range(lpcs[0],     lpcs[0]         * lpcs[0]);
571#undef log_range
572    range    = max - min;
573    lpcs[64] = last_coeff;
574
575    /* Now, use this spectrum to pick out these frequencies with higher
576     * (relative) power/energy (which we then take to be "not noise"),
577     * and set up a table (still in lpc[]) of (relative) gains per frequency.
578     * These frequencies will be maintained, while others ("noise") will be
579     * decreased in the filter output. */
580    irange    = 64.0 / range; // so irange*(max-value) is in the range [0, 63]
581    gain_mul  = range * (fcb_type == FCB_TYPE_HARDCODED ? (5.0 / 13.0) :
582                                                          (5.0 / 14.7));
583    angle_mul = gain_mul * (8.0 * M_LN10 / M_PI);
584    for (n = 0; n <= 64; n++) {
585        float pow;
586
587        idx = FFMAX(0, lrint((max - lpcs[n]) * irange) - 1);
588        pow = wmavoice_denoise_power_table[s->denoise_strength][idx];
589        lpcs[n] = angle_mul * pow;
590
591        /* 70.57 =~ 1/log10(1.0331663) */
592        idx = (pow * gain_mul - 0.0295) * 70.570526123;
593        if (idx > 127) { // fallback if index falls outside table range
594            coeffs[n] = wmavoice_energy_table[127] *
595                        powf(1.0331663, idx - 127);
596        } else
597            coeffs[n] = wmavoice_energy_table[FFMAX(0, idx)];
598    }
599
600    /* calculate the Hilbert transform of the gains, which we do (since this
601     * is a sinus input) by doing a phase shift (in theory, H(sin())=cos()).
602     * Hilbert_Transform(RDFT(x)) = Laplace_Transform(x), which calculates the
603     * "moment" of the LPCs in this filter. */
604    ff_dct_calc(&s->dct, lpcs);
605    ff_dct_calc(&s->dst, lpcs);
606
607    /* Split out the coefficient indexes into phase/magnitude pairs */
608    idx = 255 + av_clip(lpcs[64],               -255, 255);
609    coeffs[0]  = coeffs[0]  * s->cos[idx];
610    idx = 255 + av_clip(lpcs[64] - 2 * lpcs[63], -255, 255);
611    last_coeff = coeffs[64] * s->cos[idx];
612    for (n = 63;; n--) {
613        idx = 255 + av_clip(-lpcs[64] - 2 * lpcs[n - 1], -255, 255);
614        coeffs[n * 2 + 1] = coeffs[n] * s->sin[idx];
615        coeffs[n * 2]     = coeffs[n] * s->cos[idx];
616
617        if (!--n) break;
618
619        idx = 255 + av_clip( lpcs[64] - 2 * lpcs[n - 1], -255, 255);
620        coeffs[n * 2 + 1] = coeffs[n] * s->sin[idx];
621        coeffs[n * 2]     = coeffs[n] * s->cos[idx];
622    }
623    coeffs[1] = last_coeff;
624
625    /* move into real domain */
626    ff_rdft_calc(&s->irdft, coeffs);
627
628    /* tilt correction and normalize scale */
629    memset(&coeffs[remainder], 0, sizeof(coeffs[0]) * (128 - remainder));
630    if (s->denoise_tilt_corr) {
631        float tilt_mem = 0;
632
633        coeffs[remainder - 1] = 0;
634        ff_tilt_compensation(&tilt_mem,
635                             -1.8 * tilt_factor(coeffs, remainder - 1),
636                             coeffs, remainder);
637    }
638    sq = (1.0 / 64.0) * sqrtf(1 / ff_dot_productf(coeffs, coeffs, remainder));
639    for (n = 0; n < remainder; n++)
640        coeffs[n] *= sq;
641}
642
643/**
644 * This function applies a Wiener filter on the (noisy) speech signal as
645 * a means to denoise it.
646 *
647 * - take RDFT of LPCs to get the power spectrum of the noise + speech;
648 * - using this power spectrum, calculate (for each frequency) the Wiener
649 *    filter gain, which depends on the frequency power and desired level
650 *    of noise subtraction (when set too high, this leads to artifacts)
651 *    We can do this symmetrically over the X-axis (so 0-4kHz is the inverse
652 *    of 4-8kHz);
653 * - by doing a phase shift, calculate the Hilbert transform of this array
654 *    of per-frequency filter-gains to get the filtering coefficients;
655 * - smoothen/normalize/de-tilt these filter coefficients as desired;
656 * - take RDFT of noisy sound, apply the coefficients and take its IRDFT
657 *    to get the denoised speech signal;
658 * - the leftover (i.e. output of the IRDFT on denoised speech data beyond
659 *    the frame boundary) are saved and applied to subsequent frames by an
660 *    overlap-add method (otherwise you get clicking-artifacts).
661 *
662 * @param s WMA Voice decoding context
663 * @param s fcb_type Frame (codebook) type
664 * @param synth_pf input: the noisy speech signal, output: denoised speech
665 *                 data; should be 16-byte aligned (for ASM purposes)
666 * @param size size of the speech data
667 * @param lpcs LPCs used to synthesize this frame's speech data
668 */
669static void wiener_denoise(WMAVoiceContext *s, int fcb_type,
670                           float *synth_pf, int size,
671                           const float *lpcs)
672{
673    int remainder, lim, n;
674
675    if (fcb_type != FCB_TYPE_SILENCE) {
676        float *tilted_lpcs = s->tilted_lpcs_pf,
677              *coeffs = s->denoise_coeffs_pf, tilt_mem = 0;
678
679        tilted_lpcs[0]           = 1.0;
680        memcpy(&tilted_lpcs[1], lpcs, sizeof(lpcs[0]) * s->lsps);
681        memset(&tilted_lpcs[s->lsps + 1], 0,
682               sizeof(tilted_lpcs[0]) * (128 - s->lsps - 1));
683        ff_tilt_compensation(&tilt_mem, 0.7 * tilt_factor(lpcs, s->lsps),
684                             tilted_lpcs, s->lsps + 2);
685
686        /* The IRDFT output (127 samples for 7-bit filter) beyond the frame
687         * size is applied to the next frame. All input beyond this is zero,
688         * and thus all output beyond this will go towards zero, hence we can
689         * limit to min(size-1, 127-size) as a performance consideration. */
690        remainder = FFMIN(127 - size, size - 1);
691        calc_input_response(s, tilted_lpcs, fcb_type, coeffs, remainder);
692
693        /* apply coefficients (in frequency spectrum domain), i.e. complex
694         * number multiplication */
695        memset(&synth_pf[size], 0, sizeof(synth_pf[0]) * (128 - size));
696        ff_rdft_calc(&s->rdft, synth_pf);
697        ff_rdft_calc(&s->rdft, coeffs);
698        synth_pf[0] *= coeffs[0];
699        synth_pf[1] *= coeffs[1];
700        for (n = 1; n < 64; n++) {
701            float v1 = synth_pf[n * 2], v2 = synth_pf[n * 2 + 1];
702            synth_pf[n * 2]     = v1 * coeffs[n * 2] - v2 * coeffs[n * 2 + 1];
703            synth_pf[n * 2 + 1] = v2 * coeffs[n * 2] + v1 * coeffs[n * 2 + 1];
704        }
705        ff_rdft_calc(&s->irdft, synth_pf);
706    }
707
708    /* merge filter output with the history of previous runs */
709    if (s->denoise_filter_cache_size) {
710        lim = FFMIN(s->denoise_filter_cache_size, size);
711        for (n = 0; n < lim; n++)
712            synth_pf[n] += s->denoise_filter_cache[n];
713        s->denoise_filter_cache_size -= lim;
714        memmove(s->denoise_filter_cache, &s->denoise_filter_cache[size],
715                sizeof(s->denoise_filter_cache[0]) * s->denoise_filter_cache_size);
716    }
717
718    /* move remainder of filter output into a cache for future runs */
719    if (fcb_type != FCB_TYPE_SILENCE) {
720        lim = FFMIN(remainder, s->denoise_filter_cache_size);
721        for (n = 0; n < lim; n++)
722            s->denoise_filter_cache[n] += synth_pf[size + n];
723        if (lim < remainder) {
724            memcpy(&s->denoise_filter_cache[lim], &synth_pf[size + lim],
725                   sizeof(s->denoise_filter_cache[0]) * (remainder - lim));
726            s->denoise_filter_cache_size = remainder;
727        }
728    }
729}
730
731/**
732 * Averaging projection filter, the postfilter used in WMAVoice.
733 *
734 * This uses the following steps:
735 * - A zero-synthesis filter (generate excitation from synth signal)
736 * - Kalman smoothing on excitation, based on pitch
737 * - Re-synthesized smoothened output
738 * - Iterative Wiener denoise filter
739 * - Adaptive gain filter
740 * - DC filter
741 *
742 * @param s WMAVoice decoding context
743 * @param synth Speech synthesis output (before postfilter)
744 * @param samples Output buffer for filtered samples
745 * @param size Buffer size of synth & samples
746 * @param lpcs Generated LPCs used for speech synthesis
747 * @param fcb_type Frame type (silence, hardcoded, AW-pulses or FCB-pulses)
748 * @param pitch Pitch of the input signal
749 */
750static void postfilter(WMAVoiceContext *s, const float *synth,
751                       float *samples,    int size,
752                       const float *lpcs, float *zero_exc_pf,
753                       int fcb_type,      int pitch)
754{
755    float synth_filter_in_buf[MAX_FRAMESIZE / 2],
756          *synth_pf = &s->synth_filter_out_buf[MAX_LSPS_ALIGN16],
757          *synth_filter_in = zero_exc_pf;
758
759    assert(size <= MAX_FRAMESIZE / 2);
760
761    /* generate excitation from input signal */
762    ff_celp_lp_zero_synthesis_filterf(zero_exc_pf, lpcs, synth, size, s->lsps);
763
764    if (fcb_type >= FCB_TYPE_AW_PULSES &&
765        !kalman_smoothen(s, pitch, zero_exc_pf, synth_filter_in_buf, size))
766        synth_filter_in = synth_filter_in_buf;
767
768    /* re-synthesize speech after smoothening, and keep history */
769    ff_celp_lp_synthesis_filterf(synth_pf, lpcs,
770                                 synth_filter_in, size, s->lsps);
771    memcpy(&synth_pf[-s->lsps], &synth_pf[size - s->lsps],
772           sizeof(synth_pf[0]) * s->lsps);
773
774    wiener_denoise(s, fcb_type, synth_pf, size, lpcs);
775
776    adaptive_gain_control(samples, synth_pf, synth, size, 0.99,
777                          &s->postfilter_agc);
778
779    if (s->dc_level > 8) {
780        /* remove ultra-low frequency DC noise / highpass filter;
781         * coefficients are identical to those used in SIPR decoding,
782         * and very closely resemble those used in AMR-NB decoding. */
783        ff_acelp_apply_order_2_transfer_function(samples, samples,
784            (const float[2]) { -1.99997,      1.0 },
785            (const float[2]) { -1.9330735188, 0.93589198496 },
786            0.93980580475, s->dcf_mem, size);
787    }
788}
789/**
790 * @}
791 */
792
793/**
794 * Dequantize LSPs
795 * @param lsps output pointer to the array that will hold the LSPs
796 * @param num number of LSPs to be dequantized
797 * @param values quantized values, contains n_stages values
798 * @param sizes range (i.e. max value) of each quantized value
799 * @param n_stages number of dequantization runs
800 * @param table dequantization table to be used
801 * @param mul_q LSF multiplier
802 * @param base_q base (lowest) LSF values
803 */
804static void dequant_lsps(double *lsps, int num,
805                         const uint16_t *values,
806                         const uint16_t *sizes,
807                         int n_stages, const uint8_t *table,
808                         const double *mul_q,
809                         const double *base_q)
810{
811    int n, m;
812
813    memset(lsps, 0, num * sizeof(*lsps));
814    for (n = 0; n < n_stages; n++) {
815        const uint8_t *t_off = &table[values[n] * num];
816        double base = base_q[n], mul = mul_q[n];
817
818        for (m = 0; m < num; m++)
819            lsps[m] += base + mul * t_off[m];
820
821        table += sizes[n] * num;
822    }
823}
824
825/**
826 * @defgroup lsp_dequant LSP dequantization routines
827 * LSP dequantization routines, for 10/16LSPs and independent/residual coding.
828 * @note we assume enough bits are available, caller should check.
829 * lsp10i() consumes 24 bits; lsp10r() consumes an additional 24 bits;
830 * lsp16i() consumes 34 bits; lsp16r() consumes an additional 26 bits.
831 * @{
832 */
833/**
834 * Parse 10 independently-coded LSPs.
835 */
836static void dequant_lsp10i(GetBitContext *gb, double *lsps)
837{
838    static const uint16_t vec_sizes[4] = { 256, 64, 32, 32 };
839    static const double mul_lsf[4] = {
840        5.2187144800e-3,    1.4626986422e-3,
841        9.6179549166e-4,    1.1325736225e-3
842    };
843    static const double base_lsf[4] = {
844        M_PI * -2.15522e-1, M_PI * -6.1646e-2,
845        M_PI * -3.3486e-2,  M_PI * -5.7408e-2
846    };
847    uint16_t v[4];
848
849    v[0] = get_bits(gb, 8);
850    v[1] = get_bits(gb, 6);
851    v[2] = get_bits(gb, 5);
852    v[3] = get_bits(gb, 5);
853
854    dequant_lsps(lsps, 10, v, vec_sizes, 4, wmavoice_dq_lsp10i,
855                 mul_lsf, base_lsf);
856}
857
858/**
859 * Parse 10 independently-coded LSPs, and then derive the tables to
860 * generate LSPs for the other frames from them (residual coding).
861 */
862static void dequant_lsp10r(GetBitContext *gb,
863                           double *i_lsps, const double *old,
864                           double *a1, double *a2, int q_mode)
865{
866    static const uint16_t vec_sizes[3] = { 128, 64, 64 };
867    static const double mul_lsf[3] = {
868        2.5807601174e-3,    1.2354460219e-3,   1.1763821673e-3
869    };
870    static const double base_lsf[3] = {
871        M_PI * -1.07448e-1, M_PI * -5.2706e-2, M_PI * -5.1634e-2
872    };
873    const float (*ipol_tab)[2][10] = q_mode ?
874        wmavoice_lsp10_intercoeff_b : wmavoice_lsp10_intercoeff_a;
875    uint16_t interpol, v[3];
876    int n;
877
878    dequant_lsp10i(gb, i_lsps);
879
880    interpol = get_bits(gb, 5);
881    v[0]     = get_bits(gb, 7);
882    v[1]     = get_bits(gb, 6);
883    v[2]     = get_bits(gb, 6);
884
885    for (n = 0; n < 10; n++) {
886        double delta = old[n] - i_lsps[n];
887        a1[n]        = ipol_tab[interpol][0][n] * delta + i_lsps[n];
888        a1[10 + n]   = ipol_tab[interpol][1][n] * delta + i_lsps[n];
889    }
890
891    dequant_lsps(a2, 20, v, vec_sizes, 3, wmavoice_dq_lsp10r,
892                 mul_lsf, base_lsf);
893}
894
895/**
896 * Parse 16 independently-coded LSPs.
897 */
898static void dequant_lsp16i(GetBitContext *gb, double *lsps)
899{
900    static const uint16_t vec_sizes[5] = { 256, 64, 128, 64, 128 };
901    static const double mul_lsf[5] = {
902        3.3439586280e-3,    6.9908173703e-4,
903        3.3216608306e-3,    1.0334960326e-3,
904        3.1899104283e-3
905    };
906    static const double base_lsf[5] = {
907        M_PI * -1.27576e-1, M_PI * -2.4292e-2,
908        M_PI * -1.28094e-1, M_PI * -3.2128e-2,
909        M_PI * -1.29816e-1
910    };
911    uint16_t v[5];
912
913    v[0] = get_bits(gb, 8);
914    v[1] = get_bits(gb, 6);
915    v[2] = get_bits(gb, 7);
916    v[3] = get_bits(gb, 6);
917    v[4] = get_bits(gb, 7);
918
919    dequant_lsps( lsps,     5,  v,     vec_sizes,    2,
920                 wmavoice_dq_lsp16i1,  mul_lsf,     base_lsf);
921    dequant_lsps(&lsps[5],  5, &v[2], &vec_sizes[2], 2,
922                 wmavoice_dq_lsp16i2, &mul_lsf[2], &base_lsf[2]);
923    dequant_lsps(&lsps[10], 6, &v[4], &vec_sizes[4], 1,
924                 wmavoice_dq_lsp16i3, &mul_lsf[4], &base_lsf[4]);
925}
926
927/**
928 * Parse 16 independently-coded LSPs, and then derive the tables to
929 * generate LSPs for the other frames from them (residual coding).
930 */
931static void dequant_lsp16r(GetBitContext *gb,
932                           double *i_lsps, const double *old,
933                           double *a1, double *a2, int q_mode)
934{
935    static const uint16_t vec_sizes[3] = { 128, 128, 128 };
936    static const double mul_lsf[3] = {
937        1.2232979501e-3,   1.4062241527e-3,   1.6114744851e-3
938    };
939    static const double base_lsf[3] = {
940        M_PI * -5.5830e-2, M_PI * -5.2908e-2, M_PI * -5.4776e-2
941    };
942    const float (*ipol_tab)[2][16] = q_mode ?
943        wmavoice_lsp16_intercoeff_b : wmavoice_lsp16_intercoeff_a;
944    uint16_t interpol, v[3];
945    int n;
946
947    dequant_lsp16i(gb, i_lsps);
948
949    interpol = get_bits(gb, 5);
950    v[0]     = get_bits(gb, 7);
951    v[1]     = get_bits(gb, 7);
952    v[2]     = get_bits(gb, 7);
953
954    for (n = 0; n < 16; n++) {
955        double delta = old[n] - i_lsps[n];
956        a1[n]        = ipol_tab[interpol][0][n] * delta + i_lsps[n];
957        a1[16 + n]   = ipol_tab[interpol][1][n] * delta + i_lsps[n];
958    }
959
960    dequant_lsps( a2,     10,  v,     vec_sizes,    1,
961                 wmavoice_dq_lsp16r1,  mul_lsf,     base_lsf);
962    dequant_lsps(&a2[10], 10, &v[1], &vec_sizes[1], 1,
963                 wmavoice_dq_lsp16r2, &mul_lsf[1], &base_lsf[1]);
964    dequant_lsps(&a2[20], 12, &v[2], &vec_sizes[2], 1,
965                 wmavoice_dq_lsp16r3, &mul_lsf[2], &base_lsf[2]);
966}
967
968/**
969 * @}
970 * @defgroup aw Pitch-adaptive window coding functions
971 * The next few functions are for pitch-adaptive window coding.
972 * @{
973 */
974/**
975 * Parse the offset of the first pitch-adaptive window pulses, and
976 * the distribution of pulses between the two blocks in this frame.
977 * @param s WMA Voice decoding context private data
978 * @param gb bit I/O context
979 * @param pitch pitch for each block in this frame
980 */
981static void aw_parse_coords(WMAVoiceContext *s, GetBitContext *gb,
982                            const int *pitch)
983{
984    static const int16_t start_offset[94] = {
985        -11,  -9,  -7,  -5,  -3,  -1,   1,   3,   5,   7,   9,  11,
986         13,  15,  18,  17,  19,  20,  21,  22,  23,  24,  25,  26,
987         27,  28,  29,  30,  31,  32,  33,  35,  37,  39,  41,  43,
988         45,  47,  49,  51,  53,  55,  57,  59,  61,  63,  65,  67,
989         69,  71,  73,  75,  77,  79,  81,  83,  85,  87,  89,  91,
990         93,  95,  97,  99, 101, 103, 105, 107, 109, 111, 113, 115,
991        117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139,
992        141, 143, 145, 147, 149, 151, 153, 155, 157, 159
993    };
994    int bits, offset;
995
996    /* position of pulse */
997    s->aw_idx_is_ext = 0;
998    if ((bits = get_bits(gb, 6)) >= 54) {
999        s->aw_idx_is_ext = 1;
1000        bits += (bits - 54) * 3 + get_bits(gb, 2);
1001    }
1002
1003    /* for a repeated pulse at pulse_off with a pitch_lag of pitch[], count
1004     * the distribution of the pulses in each block contained in this frame. */
1005    s->aw_pulse_range        = FFMIN(pitch[0], pitch[1]) > 32 ? 24 : 16;
1006    for (offset = start_offset[bits]; offset < 0; offset += pitch[0]) ;
1007    s->aw_n_pulses[0]        = (pitch[0] - 1 + MAX_FRAMESIZE / 2 - offset) / pitch[0];
1008    s->aw_first_pulse_off[0] = offset - s->aw_pulse_range / 2;
1009    offset                  += s->aw_n_pulses[0] * pitch[0];
1010    s->aw_n_pulses[1]        = (pitch[1] - 1 + MAX_FRAMESIZE - offset) / pitch[1];
1011    s->aw_first_pulse_off[1] = offset - (MAX_FRAMESIZE + s->aw_pulse_range) / 2;
1012
1013    /* if continuing from a position before the block, reset position to
1014     * start of block (when corrected for the range over which it can be
1015     * spread in aw_pulse_set1()). */
1016    if (start_offset[bits] < MAX_FRAMESIZE / 2) {
1017        while (s->aw_first_pulse_off[1] - pitch[1] + s->aw_pulse_range > 0)
1018            s->aw_first_pulse_off[1] -= pitch[1];
1019        if (start_offset[bits] < 0)
1020            while (s->aw_first_pulse_off[0] - pitch[0] + s->aw_pulse_range > 0)
1021                s->aw_first_pulse_off[0] -= pitch[0];
1022    }
1023}
1024
1025/**
1026 * Apply second set of pitch-adaptive window pulses.
1027 * @param s WMA Voice decoding context private data
1028 * @param gb bit I/O context
1029 * @param block_idx block index in frame [0, 1]
1030 * @param fcb structure containing fixed codebook vector info
1031 */
1032static void aw_pulse_set2(WMAVoiceContext *s, GetBitContext *gb,
1033                          int block_idx, AMRFixed *fcb)
1034{
1035    uint16_t use_mask[7]; // only 5 are used, rest is padding
1036    /* in this function, idx is the index in the 80-bit (+ padding) use_mask
1037     * bit-array. Since use_mask consists of 16-bit values, the lower 4 bits
1038     * of idx are the position of the bit within a particular item in the
1039     * array (0 being the most significant bit, and 15 being the least
1040     * significant bit), and the remainder (>> 4) is the index in the
1041     * use_mask[]-array. This is faster and uses less memory than using a
1042     * 80-byte/80-int array. */
1043    int pulse_off = s->aw_first_pulse_off[block_idx],
1044        pulse_start, n, idx, range, aidx, start_off = 0;
1045
1046    /* set offset of first pulse to within this block */
1047    if (s->aw_n_pulses[block_idx] > 0)
1048        while (pulse_off + s->aw_pulse_range < 1)
1049            pulse_off += fcb->pitch_lag;
1050
1051    /* find range per pulse */
1052    if (s->aw_n_pulses[0] > 0) {
1053        if (block_idx == 0) {
1054            range = 32;
1055        } else /* block_idx = 1 */ {
1056            range = 8;
1057            if (s->aw_n_pulses[block_idx] > 0)
1058                pulse_off = s->aw_next_pulse_off_cache;
1059        }
1060    } else
1061        range = 16;
1062    pulse_start = s->aw_n_pulses[block_idx] > 0 ? pulse_off - range / 2 : 0;
1063
1064    /* aw_pulse_set1() already applies pulses around pulse_off (to be exactly,
1065     * in the range of [pulse_off, pulse_off + s->aw_pulse_range], and thus
1066     * we exclude that range from being pulsed again in this function. */
1067    memset( use_mask,   -1, 5 * sizeof(use_mask[0]));
1068    memset(&use_mask[5], 0, 2 * sizeof(use_mask[0]));
1069    if (s->aw_n_pulses[block_idx] > 0)
1070        for (idx = pulse_off; idx < MAX_FRAMESIZE / 2; idx += fcb->pitch_lag) {
1071            int excl_range         = s->aw_pulse_range; // always 16 or 24
1072            uint16_t *use_mask_ptr = &use_mask[idx >> 4];
1073            int first_sh           = 16 - (idx & 15);
1074            *use_mask_ptr++       &= 0xFFFF << first_sh;
1075            excl_range            -= first_sh;
1076            if (excl_range >= 16) {
1077                *use_mask_ptr++    = 0;
1078                *use_mask_ptr     &= 0xFFFF >> (excl_range - 16);
1079            } else
1080                *use_mask_ptr     &= 0xFFFF >> excl_range;
1081        }
1082
1083    /* find the 'aidx'th offset that is not excluded */
1084    aidx = get_bits(gb, s->aw_n_pulses[0] > 0 ? 5 - 2 * block_idx : 4);
1085    for (n = 0; n <= aidx; pulse_start++) {
1086        for (idx = pulse_start; idx < 0; idx += fcb->pitch_lag) ;
1087        if (idx >= MAX_FRAMESIZE / 2) { // find from zero
1088            if (use_mask[0])      idx = 0x0F;
1089            else if (use_mask[1]) idx = 0x1F;
1090            else if (use_mask[2]) idx = 0x2F;
1091            else if (use_mask[3]) idx = 0x3F;
1092            else if (use_mask[4]) idx = 0x4F;
1093            else                  return;
1094            idx -= av_log2_16bit(use_mask[idx >> 4]);
1095        }
1096        if (use_mask[idx >> 4] & (0x8000 >> (idx & 15))) {
1097            use_mask[idx >> 4] &= ~(0x8000 >> (idx & 15));
1098            n++;
1099            start_off = idx;
1100        }
1101    }
1102
1103    fcb->x[fcb->n] = start_off;
1104    fcb->y[fcb->n] = get_bits1(gb) ? -1.0 : 1.0;
1105    fcb->n++;
1106
1107    /* set offset for next block, relative to start of that block */
1108    n = (MAX_FRAMESIZE / 2 - start_off) % fcb->pitch_lag;
1109    s->aw_next_pulse_off_cache = n ? fcb->pitch_lag - n : 0;
1110}
1111
1112/**
1113 * Apply first set of pitch-adaptive window pulses.
1114 * @param s WMA Voice decoding context private data
1115 * @param gb bit I/O context
1116 * @param block_idx block index in frame [0, 1]
1117 * @param fcb storage location for fixed codebook pulse info
1118 */
1119static void aw_pulse_set1(WMAVoiceContext *s, GetBitContext *gb,
1120                          int block_idx, AMRFixed *fcb)
1121{
1122    int val = get_bits(gb, 12 - 2 * (s->aw_idx_is_ext && !block_idx));
1123    float v;
1124
1125    if (s->aw_n_pulses[block_idx] > 0) {
1126        int n, v_mask, i_mask, sh, n_pulses;
1127
1128        if (s->aw_pulse_range == 24) { // 3 pulses, 1:sign + 3:index each
1129            n_pulses = 3;
1130            v_mask   = 8;
1131            i_mask   = 7;
1132            sh       = 4;
1133        } else { // 4 pulses, 1:sign + 2:index each
1134            n_pulses = 4;
1135            v_mask   = 4;
1136            i_mask   = 3;
1137            sh       = 3;
1138        }
1139
1140        for (n = n_pulses - 1; n >= 0; n--, val >>= sh) {
1141            fcb->y[fcb->n] = (val & v_mask) ? -1.0 : 1.0;
1142            fcb->x[fcb->n] = (val & i_mask) * n_pulses + n +
1143                                 s->aw_first_pulse_off[block_idx];
1144            while (fcb->x[fcb->n] < 0)
1145                fcb->x[fcb->n] += fcb->pitch_lag;
1146            if (fcb->x[fcb->n] < MAX_FRAMESIZE / 2)
1147                fcb->n++;
1148        }
1149    } else {
1150        int num2 = (val & 0x1FF) >> 1, delta, idx;
1151
1152        if (num2 < 1 * 79)      { delta = 1; idx = num2 + 1; }
1153        else if (num2 < 2 * 78) { delta = 3; idx = num2 + 1 - 1 * 77; }
1154        else if (num2 < 3 * 77) { delta = 5; idx = num2 + 1 - 2 * 76; }
1155        else                    { delta = 7; idx = num2 + 1 - 3 * 75; }
1156        v = (val & 0x200) ? -1.0 : 1.0;
1157
1158        fcb->no_repeat_mask |= 3 << fcb->n;
1159        fcb->x[fcb->n]       = idx - delta;
1160        fcb->y[fcb->n]       = v;
1161        fcb->x[fcb->n + 1]   = idx;
1162        fcb->y[fcb->n + 1]   = (val & 1) ? -v : v;
1163        fcb->n              += 2;
1164    }
1165}
1166
1167/**
1168 * @}
1169 *
1170 * Generate a random number from frame_cntr and block_idx, which will lief
1171 * in the range [0, 1000 - block_size] (so it can be used as an index in a
1172 * table of size 1000 of which you want to read block_size entries).
1173 *
1174 * @param frame_cntr current frame number
1175 * @param block_num current block index
1176 * @param block_size amount of entries we want to read from a table
1177 *                   that has 1000 entries
1178 * @return a (non-)random number in the [0, 1000 - block_size] range.
1179 */
1180static int pRNG(int frame_cntr, int block_num, int block_size)
1181{
1182    /* array to simplify the calculation of z:
1183     * y = (x % 9) * 5 + 6;
1184     * z = (49995 * x) / y;
1185     * Since y only has 9 values, we can remove the division by using a
1186     * LUT and using FASTDIV-style divisions. For each of the 9 values
1187     * of y, we can rewrite z as:
1188     * z = x * (49995 / y) + x * ((49995 % y) / y)
1189     * In this table, each col represents one possible value of y, the
1190     * first number is 49995 / y, and the second is the FASTDIV variant
1191     * of 49995 % y / y. */
1192    static const unsigned int div_tbl[9][2] = {
1193        { 8332,  3 * 715827883U }, // y =  6
1194        { 4545,  0 * 390451573U }, // y = 11
1195        { 3124, 11 * 268435456U }, // y = 16
1196        { 2380, 15 * 204522253U }, // y = 21
1197        { 1922, 23 * 165191050U }, // y = 26
1198        { 1612, 23 * 138547333U }, // y = 31
1199        { 1388, 27 * 119304648U }, // y = 36
1200        { 1219, 16 * 104755300U }, // y = 41
1201        { 1086, 39 *  93368855U }  // y = 46
1202    };
1203    unsigned int z, y, x = MUL16(block_num, 1877) + frame_cntr;
1204    if (x >= 0xFFFF) x -= 0xFFFF;   // max value of x is 8*1877+0xFFFE=0x13AA6,
1205                                    // so this is effectively a modulo (%)
1206    y = x - 9 * MULH(477218589, x); // x % 9
1207    z = (uint16_t) (x * div_tbl[y][0] + UMULH(x, div_tbl[y][1]));
1208                                    // z = x * 49995 / (y * 5 + 6)
1209    return z % (1000 - block_size);
1210}
1211
1212/**
1213 * Parse hardcoded signal for a single block.
1214 * @note see #synth_block().
1215 */
1216static void synth_block_hardcoded(WMAVoiceContext *s, GetBitContext *gb,
1217                                 int block_idx, int size,
1218                                 const struct frame_type_desc *frame_desc,
1219                                 float *excitation)
1220{
1221    float gain;
1222    int n, r_idx;
1223
1224    assert(size <= MAX_FRAMESIZE);
1225
1226    /* Set the offset from which we start reading wmavoice_std_codebook */
1227    if (frame_desc->fcb_type == FCB_TYPE_SILENCE) {
1228        r_idx = pRNG(s->frame_cntr, block_idx, size);
1229        gain  = s->silence_gain;
1230    } else /* FCB_TYPE_HARDCODED */ {
1231        r_idx = get_bits(gb, 8);
1232        gain  = wmavoice_gain_universal[get_bits(gb, 6)];
1233    }
1234
1235    /* Clear gain prediction parameters */
1236    memset(s->gain_pred_err, 0, sizeof(s->gain_pred_err));
1237
1238    /* Apply gain to hardcoded codebook and use that as excitation signal */
1239    for (n = 0; n < size; n++)
1240        excitation[n] = wmavoice_std_codebook[r_idx + n] * gain;
1241}
1242
1243/**
1244 * Parse FCB/ACB signal for a single block.
1245 * @note see #synth_block().
1246 */
1247static void synth_block_fcb_acb(WMAVoiceContext *s, GetBitContext *gb,
1248                                int block_idx, int size,
1249                                int block_pitch_sh2,
1250                                const struct frame_type_desc *frame_desc,
1251                                float *excitation)
1252{
1253    static const float gain_coeff[6] = {
1254        0.8169, -0.06545, 0.1726, 0.0185, -0.0359, 0.0458
1255    };
1256    float pulses[MAX_FRAMESIZE / 2], pred_err, acb_gain, fcb_gain;
1257    int n, idx, gain_weight;
1258    AMRFixed fcb;
1259
1260    assert(size <= MAX_FRAMESIZE / 2);
1261    memset(pulses, 0, sizeof(*pulses) * size);
1262
1263    fcb.pitch_lag      = block_pitch_sh2 >> 2;
1264    fcb.pitch_fac      = 1.0;
1265    fcb.no_repeat_mask = 0;
1266    fcb.n              = 0;
1267
1268    /* For the other frame types, this is where we apply the innovation
1269     * (fixed) codebook pulses of the speech signal. */
1270    if (frame_desc->fcb_type == FCB_TYPE_AW_PULSES) {
1271        aw_pulse_set1(s, gb, block_idx, &fcb);
1272        aw_pulse_set2(s, gb, block_idx, &fcb);
1273    } else /* FCB_TYPE_EXC_PULSES */ {
1274        int offset_nbits = 5 - frame_desc->log_n_blocks;
1275
1276        fcb.no_repeat_mask = -1;
1277        /* similar to ff_decode_10_pulses_35bits(), but with single pulses
1278         * (instead of double) for a subset of pulses */
1279        for (n = 0; n < 5; n++) {
1280            float sign;
1281            int pos1, pos2;
1282
1283            sign           = get_bits1(gb) ? 1.0 : -1.0;
1284            pos1           = get_bits(gb, offset_nbits);
1285            fcb.x[fcb.n]   = n + 5 * pos1;
1286            fcb.y[fcb.n++] = sign;
1287            if (n < frame_desc->dbl_pulses) {
1288                pos2           = get_bits(gb, offset_nbits);
1289                fcb.x[fcb.n]   = n + 5 * pos2;
1290                fcb.y[fcb.n++] = (pos1 < pos2) ? -sign : sign;
1291            }
1292        }
1293    }
1294    ff_set_fixed_vector(pulses, &fcb, 1.0, size);
1295
1296    /* Calculate gain for adaptive & fixed codebook signal.
1297     * see ff_amr_set_fixed_gain(). */
1298    idx = get_bits(gb, 7);
1299    fcb_gain = expf(ff_dot_productf(s->gain_pred_err, gain_coeff, 6) -
1300                    5.2409161640 + wmavoice_gain_codebook_fcb[idx]);
1301    acb_gain = wmavoice_gain_codebook_acb[idx];
1302    pred_err = av_clipf(wmavoice_gain_codebook_fcb[idx],
1303                        -2.9957322736 /* log(0.05) */,
1304                         1.6094379124 /* log(5.0)  */);
1305
1306    gain_weight = 8 >> frame_desc->log_n_blocks;
1307    memmove(&s->gain_pred_err[gain_weight], s->gain_pred_err,
1308            sizeof(*s->gain_pred_err) * (6 - gain_weight));
1309    for (n = 0; n < gain_weight; n++)
1310        s->gain_pred_err[n] = pred_err;
1311
1312    /* Calculation of adaptive codebook */
1313    if (frame_desc->acb_type == ACB_TYPE_ASYMMETRIC) {
1314        int len;
1315        for (n = 0; n < size; n += len) {
1316            int next_idx_sh16;
1317            int abs_idx    = block_idx * size + n;
1318            int pitch_sh16 = (s->last_pitch_val << 16) +
1319                             s->pitch_diff_sh16 * abs_idx;
1320            int pitch      = (pitch_sh16 + 0x6FFF) >> 16;
1321            int idx_sh16   = ((pitch << 16) - pitch_sh16) * 8 + 0x58000;
1322            idx            = idx_sh16 >> 16;
1323            if (s->pitch_diff_sh16) {
1324                if (s->pitch_diff_sh16 > 0) {
1325                    next_idx_sh16 = (idx_sh16) &~ 0xFFFF;
1326                } else
1327                    next_idx_sh16 = (idx_sh16 + 0x10000) &~ 0xFFFF;
1328                len = av_clip((idx_sh16 - next_idx_sh16) / s->pitch_diff_sh16 / 8,
1329                              1, size - n);
1330            } else
1331                len = size;
1332
1333            ff_acelp_interpolatef(&excitation[n], &excitation[n - pitch],
1334                                  wmavoice_ipol1_coeffs, 17,
1335                                  idx, 9, len);
1336        }
1337    } else /* ACB_TYPE_HAMMING */ {
1338        int block_pitch = block_pitch_sh2 >> 2;
1339        idx             = block_pitch_sh2 & 3;
1340        if (idx) {
1341            ff_acelp_interpolatef(excitation, &excitation[-block_pitch],
1342                                  wmavoice_ipol2_coeffs, 4,
1343                                  idx, 8, size);
1344        } else
1345            av_memcpy_backptr(excitation, sizeof(float) * block_pitch,
1346                              sizeof(float) * size);
1347    }
1348
1349    /* Interpolate ACB/FCB and use as excitation signal */
1350    ff_weighted_vector_sumf(excitation, excitation, pulses,
1351                            acb_gain, fcb_gain, size);
1352}
1353
1354/**
1355 * Parse data in a single block.
1356 * @note we assume enough bits are available, caller should check.
1357 *
1358 * @param s WMA Voice decoding context private data
1359 * @param gb bit I/O context
1360 * @param block_idx index of the to-be-read block
1361 * @param size amount of samples to be read in this block
1362 * @param block_pitch_sh2 pitch for this block << 2
1363 * @param lsps LSPs for (the end of) this frame
1364 * @param prev_lsps LSPs for the last frame
1365 * @param frame_desc frame type descriptor
1366 * @param excitation target memory for the ACB+FCB interpolated signal
1367 * @param synth target memory for the speech synthesis filter output
1368 * @return 0 on success, <0 on error.
1369 */
1370static void synth_block(WMAVoiceContext *s, GetBitContext *gb,
1371                        int block_idx, int size,
1372                        int block_pitch_sh2,
1373                        const double *lsps, const double *prev_lsps,
1374                        const struct frame_type_desc *frame_desc,
1375                        float *excitation, float *synth)
1376{
1377    double i_lsps[MAX_LSPS];
1378    float lpcs[MAX_LSPS];
1379    float fac;
1380    int n;
1381
1382    if (frame_desc->acb_type == ACB_TYPE_NONE)
1383        synth_block_hardcoded(s, gb, block_idx, size, frame_desc, excitation);
1384    else
1385        synth_block_fcb_acb(s, gb, block_idx, size, block_pitch_sh2,
1386                            frame_desc, excitation);
1387
1388    /* convert interpolated LSPs to LPCs */
1389    fac = (block_idx + 0.5) / frame_desc->n_blocks;
1390    for (n = 0; n < s->lsps; n++) // LSF -> LSP
1391        i_lsps[n] = cos(prev_lsps[n] + fac * (lsps[n] - prev_lsps[n]));
1392    ff_acelp_lspd2lpc(i_lsps, lpcs, s->lsps >> 1);
1393
1394    /* Speech synthesis */
1395    ff_celp_lp_synthesis_filterf(synth, lpcs, excitation, size, s->lsps);
1396}
1397
1398/**
1399 * Synthesize output samples for a single frame.
1400 * @note we assume enough bits are available, caller should check.
1401 *
1402 * @param ctx WMA Voice decoder context
1403 * @param gb bit I/O context (s->gb or one for cross-packet superframes)
1404 * @param frame_idx Frame number within superframe [0-2]
1405 * @param samples pointer to output sample buffer, has space for at least 160
1406 *                samples
1407 * @param lsps LSP array
1408 * @param prev_lsps array of previous frame's LSPs
1409 * @param excitation target buffer for excitation signal
1410 * @param synth target buffer for synthesized speech data
1411 * @return 0 on success, <0 on error.
1412 */
1413static int synth_frame(AVCodecContext *ctx, GetBitContext *gb, int frame_idx,
1414                       float *samples,
1415                       const double *lsps, const double *prev_lsps,
1416                       float *excitation, float *synth)
1417{
1418    WMAVoiceContext *s = ctx->priv_data;
1419    int n, n_blocks_x2, log_n_blocks_x2, cur_pitch_val;
1420    int pitch[MAX_BLOCKS], last_block_pitch;
1421
1422    /* Parse frame type ("frame header"), see frame_descs */
1423    int bd_idx = s->vbm_tree[get_vlc2(gb, frame_type_vlc.table, 6, 3)],
1424        block_nsamples = MAX_FRAMESIZE / frame_descs[bd_idx].n_blocks;
1425
1426    if (bd_idx < 0) {
1427        av_log(ctx, AV_LOG_ERROR,
1428               "Invalid frame type VLC code, skipping\n");
1429        return -1;
1430    }
1431
1432    /* Pitch calculation for ACB_TYPE_ASYMMETRIC ("pitch-per-frame") */
1433    if (frame_descs[bd_idx].acb_type == ACB_TYPE_ASYMMETRIC) {
1434        /* Pitch is provided per frame, which is interpreted as the pitch of
1435         * the last sample of the last block of this frame. We can interpolate
1436         * the pitch of other blocks (and even pitch-per-sample) by gradually
1437         * incrementing/decrementing prev_frame_pitch to cur_pitch_val. */
1438        n_blocks_x2      = frame_descs[bd_idx].n_blocks << 1;
1439        log_n_blocks_x2  = frame_descs[bd_idx].log_n_blocks + 1;
1440        cur_pitch_val    = s->min_pitch_val + get_bits(gb, s->pitch_nbits);
1441        cur_pitch_val    = FFMIN(cur_pitch_val, s->max_pitch_val - 1);
1442        if (s->last_acb_type == ACB_TYPE_NONE ||
1443            20 * abs(cur_pitch_val - s->last_pitch_val) >
1444                (cur_pitch_val + s->last_pitch_val))
1445            s->last_pitch_val = cur_pitch_val;
1446
1447        /* pitch per block */
1448        for (n = 0; n < frame_descs[bd_idx].n_blocks; n++) {
1449            int fac = n * 2 + 1;
1450
1451            pitch[n] = (MUL16(fac,                 cur_pitch_val) +
1452                        MUL16((n_blocks_x2 - fac), s->last_pitch_val) +
1453                        frame_descs[bd_idx].n_blocks) >> log_n_blocks_x2;
1454        }
1455
1456        /* "pitch-diff-per-sample" for calculation of pitch per sample */
1457        s->pitch_diff_sh16 =
1458            ((cur_pitch_val - s->last_pitch_val) << 16) / MAX_FRAMESIZE;
1459    }
1460
1461    /* Global gain (if silence) and pitch-adaptive window coordinates */
1462    switch (frame_descs[bd_idx].fcb_type) {
1463    case FCB_TYPE_SILENCE:
1464        s->silence_gain = wmavoice_gain_silence[get_bits(gb, 8)];
1465        break;
1466    case FCB_TYPE_AW_PULSES:
1467        aw_parse_coords(s, gb, pitch);
1468        break;
1469    }
1470
1471    for (n = 0; n < frame_descs[bd_idx].n_blocks; n++) {
1472        int bl_pitch_sh2;
1473
1474        /* Pitch calculation for ACB_TYPE_HAMMING ("pitch-per-block") */
1475        switch (frame_descs[bd_idx].acb_type) {
1476        case ACB_TYPE_HAMMING: {
1477            /* Pitch is given per block. Per-block pitches are encoded as an
1478             * absolute value for the first block, and then delta values
1479             * relative to this value) for all subsequent blocks. The scale of
1480             * this pitch value is semi-logaritmic compared to its use in the
1481             * decoder, so we convert it to normal scale also. */
1482            int block_pitch,
1483                t1 = (s->block_conv_table[1] - s->block_conv_table[0]) << 2,
1484                t2 = (s->block_conv_table[2] - s->block_conv_table[1]) << 1,
1485                t3 =  s->block_conv_table[3] - s->block_conv_table[2] + 1;
1486
1487            if (n == 0) {
1488                block_pitch = get_bits(gb, s->block_pitch_nbits);
1489            } else
1490                block_pitch = last_block_pitch - s->block_delta_pitch_hrange +
1491                                 get_bits(gb, s->block_delta_pitch_nbits);
1492            /* Convert last_ so that any next delta is within _range */
1493            last_block_pitch = av_clip(block_pitch,
1494                                       s->block_delta_pitch_hrange,
1495                                       s->block_pitch_range -
1496                                           s->block_delta_pitch_hrange);
1497
1498            /* Convert semi-log-style scale back to normal scale */
1499            if (block_pitch < t1) {
1500                bl_pitch_sh2 = (s->block_conv_table[0] << 2) + block_pitch;
1501            } else {
1502                block_pitch -= t1;
1503                if (block_pitch < t2) {
1504                    bl_pitch_sh2 =
1505                        (s->block_conv_table[1] << 2) + (block_pitch << 1);
1506                } else {
1507                    block_pitch -= t2;
1508                    if (block_pitch < t3) {
1509                        bl_pitch_sh2 =
1510                            (s->block_conv_table[2] + block_pitch) << 2;
1511                    } else
1512                        bl_pitch_sh2 = s->block_conv_table[3] << 2;
1513                }
1514            }
1515            pitch[n] = bl_pitch_sh2 >> 2;
1516            break;
1517        }
1518
1519        case ACB_TYPE_ASYMMETRIC: {
1520            bl_pitch_sh2 = pitch[n] << 2;
1521            break;
1522        }
1523
1524        default: // ACB_TYPE_NONE has no pitch
1525            bl_pitch_sh2 = 0;
1526            break;
1527        }
1528
1529        synth_block(s, gb, n, block_nsamples, bl_pitch_sh2,
1530                    lsps, prev_lsps, &frame_descs[bd_idx],
1531                    &excitation[n * block_nsamples],
1532                    &synth[n * block_nsamples]);
1533    }
1534
1535    /* Averaging projection filter, if applicable. Else, just copy samples
1536     * from synthesis buffer */
1537    if (s->do_apf) {
1538        double i_lsps[MAX_LSPS];
1539        float lpcs[MAX_LSPS];
1540
1541        for (n = 0; n < s->lsps; n++) // LSF -> LSP
1542            i_lsps[n] = cos(0.5 * (prev_lsps[n] + lsps[n]));
1543        ff_acelp_lspd2lpc(i_lsps, lpcs, s->lsps >> 1);
1544        postfilter(s, synth, samples, 80, lpcs,
1545                   &s->zero_exc_pf[s->history_nsamples + MAX_FRAMESIZE * frame_idx],
1546                   frame_descs[bd_idx].fcb_type, pitch[0]);
1547
1548        for (n = 0; n < s->lsps; n++) // LSF -> LSP
1549            i_lsps[n] = cos(lsps[n]);
1550        ff_acelp_lspd2lpc(i_lsps, lpcs, s->lsps >> 1);
1551        postfilter(s, &synth[80], &samples[80], 80, lpcs,
1552                   &s->zero_exc_pf[s->history_nsamples + MAX_FRAMESIZE * frame_idx + 80],
1553                   frame_descs[bd_idx].fcb_type, pitch[0]);
1554    } else
1555        memcpy(samples, synth, 160 * sizeof(synth[0]));
1556
1557    /* Cache values for next frame */
1558    s->frame_cntr++;
1559    if (s->frame_cntr >= 0xFFFF) s->frame_cntr -= 0xFFFF; // i.e. modulo (%)
1560    s->last_acb_type = frame_descs[bd_idx].acb_type;
1561    switch (frame_descs[bd_idx].acb_type) {
1562    case ACB_TYPE_NONE:
1563        s->last_pitch_val = 0;
1564        break;
1565    case ACB_TYPE_ASYMMETRIC:
1566        s->last_pitch_val = cur_pitch_val;
1567        break;
1568    case ACB_TYPE_HAMMING:
1569        s->last_pitch_val = pitch[frame_descs[bd_idx].n_blocks - 1];
1570        break;
1571    }
1572
1573    return 0;
1574}
1575
1576/**
1577 * Ensure minimum value for first item, maximum value for last value,
1578 * proper spacing between each value and proper ordering.
1579 *
1580 * @param lsps array of LSPs
1581 * @param num size of LSP array
1582 *
1583 * @note basically a double version of #ff_acelp_reorder_lsf(), might be
1584 *       useful to put in a generic location later on. Parts are also
1585 *       present in #ff_set_min_dist_lsf() + #ff_sort_nearly_sorted_floats(),
1586 *       which is in float.
1587 */
1588static void stabilize_lsps(double *lsps, int num)
1589{
1590    int n, m, l;
1591
1592    /* set minimum value for first, maximum value for last and minimum
1593     * spacing between LSF values.
1594     * Very similar to ff_set_min_dist_lsf(), but in double. */
1595    lsps[0]       = FFMAX(lsps[0],       0.0015 * M_PI);
1596    for (n = 1; n < num; n++)
1597        lsps[n]   = FFMAX(lsps[n],       lsps[n - 1] + 0.0125 * M_PI);
1598    lsps[num - 1] = FFMIN(lsps[num - 1], 0.9985 * M_PI);
1599
1600    /* reorder (looks like one-time / non-recursed bubblesort).
1601     * Very similar to ff_sort_nearly_sorted_floats(), but in double. */
1602    for (n = 1; n < num; n++) {
1603        if (lsps[n] < lsps[n - 1]) {
1604            for (m = 1; m < num; m++) {
1605                double tmp = lsps[m];
1606                for (l = m - 1; l >= 0; l--) {
1607                    if (lsps[l] <= tmp) break;
1608                    lsps[l + 1] = lsps[l];
1609                }
1610                lsps[l + 1] = tmp;
1611            }
1612            break;
1613        }
1614    }
1615}
1616
1617/**
1618 * Test if there's enough bits to read 1 superframe.
1619 *
1620 * @param orig_gb bit I/O context used for reading. This function
1621 *                does not modify the state of the bitreader; it
1622 *                only uses it to copy the current stream position
1623 * @param s WMA Voice decoding context private data
1624 * @return -1 if unsupported, 1 on not enough bits or 0 if OK.
1625 */
1626static int check_bits_for_superframe(GetBitContext *orig_gb,
1627                                     WMAVoiceContext *s)
1628{
1629    GetBitContext s_gb, *gb = &s_gb;
1630    int n, need_bits, bd_idx;
1631    const struct frame_type_desc *frame_desc;
1632
1633    /* initialize a copy */
1634    init_get_bits(gb, orig_gb->buffer, orig_gb->size_in_bits);
1635    skip_bits_long(gb, get_bits_count(orig_gb));
1636    assert(get_bits_left(gb) == get_bits_left(orig_gb));
1637
1638    /* superframe header */
1639    if (get_bits_left(gb) < 14)
1640        return 1;
1641    if (!get_bits1(gb))
1642        return -1;                        // WMAPro-in-WMAVoice superframe
1643    if (get_bits1(gb)) skip_bits(gb, 12); // number of  samples in superframe
1644    if (s->has_residual_lsps) {           // residual LSPs (for all frames)
1645        if (get_bits_left(gb) < s->sframe_lsp_bitsize)
1646            return 1;
1647        skip_bits_long(gb, s->sframe_lsp_bitsize);
1648    }
1649
1650    /* frames */
1651    for (n = 0; n < MAX_FRAMES; n++) {
1652        int aw_idx_is_ext = 0;
1653
1654        if (!s->has_residual_lsps) {     // independent LSPs (per-frame)
1655           if (get_bits_left(gb) < s->frame_lsp_bitsize) return 1;
1656           skip_bits_long(gb, s->frame_lsp_bitsize);
1657        }
1658        bd_idx = s->vbm_tree[get_vlc2(gb, frame_type_vlc.table, 6, 3)];
1659        if (bd_idx < 0)
1660            return -1;                   // invalid frame type VLC code
1661        frame_desc = &frame_descs[bd_idx];
1662        if (frame_desc->acb_type == ACB_TYPE_ASYMMETRIC) {
1663            if (get_bits_left(gb) < s->pitch_nbits)
1664                return 1;
1665            skip_bits_long(gb, s->pitch_nbits);
1666        }
1667        if (frame_desc->fcb_type == FCB_TYPE_SILENCE) {
1668            skip_bits(gb, 8);
1669        } else if (frame_desc->fcb_type == FCB_TYPE_AW_PULSES) {
1670            int tmp = get_bits(gb, 6);
1671            if (tmp >= 0x36) {
1672                skip_bits(gb, 2);
1673                aw_idx_is_ext = 1;
1674            }
1675        }
1676
1677        /* blocks */
1678        if (frame_desc->acb_type == ACB_TYPE_HAMMING) {
1679            need_bits = s->block_pitch_nbits +
1680                (frame_desc->n_blocks - 1) * s->block_delta_pitch_nbits;
1681        } else if (frame_desc->fcb_type == FCB_TYPE_AW_PULSES) {
1682            need_bits = 2 * !aw_idx_is_ext;
1683        } else
1684            need_bits = 0;
1685        need_bits += frame_desc->frame_size;
1686        if (get_bits_left(gb) < need_bits)
1687            return 1;
1688        skip_bits_long(gb, need_bits);
1689    }
1690
1691    return 0;
1692}
1693
1694/**
1695 * Synthesize output samples for a single superframe. If we have any data
1696 * cached in s->sframe_cache, that will be used instead of whatever is loaded
1697 * in s->gb.
1698 *
1699 * WMA Voice superframes contain 3 frames, each containing 160 audio samples,
1700 * to give a total of 480 samples per frame. See #synth_frame() for frame
1701 * parsing. In addition to 3 frames, superframes can also contain the LSPs
1702 * (if these are globally specified for all frames (residually); they can
1703 * also be specified individually per-frame. See the s->has_residual_lsps
1704 * option), and can specify the number of samples encoded in this superframe
1705 * (if less than 480), usually used to prevent blanks at track boundaries.
1706 *
1707 * @param ctx WMA Voice decoder context
1708 * @param samples pointer to output buffer for voice samples
1709 * @param data_size pointer containing the size of #samples on input, and the
1710 *                  amount of #samples filled on output
1711 * @return 0 on success, <0 on error or 1 if there was not enough data to
1712 *         fully parse the superframe
1713 */
1714static int synth_superframe(AVCodecContext *ctx,
1715                            float *samples, int *data_size)
1716{
1717    WMAVoiceContext *s = ctx->priv_data;
1718    GetBitContext *gb = &s->gb, s_gb;
1719    int n, res, n_samples = 480;
1720    double lsps[MAX_FRAMES][MAX_LSPS];
1721    const double *mean_lsf = s->lsps == 16 ?
1722        wmavoice_mean_lsf16[s->lsp_def_mode] : wmavoice_mean_lsf10[s->lsp_def_mode];
1723    float excitation[MAX_SIGNAL_HISTORY + MAX_SFRAMESIZE + 12];
1724    float synth[MAX_LSPS + MAX_SFRAMESIZE];
1725
1726    memcpy(synth,      s->synth_history,
1727           s->lsps             * sizeof(*synth));
1728    memcpy(excitation, s->excitation_history,
1729           s->history_nsamples * sizeof(*excitation));
1730
1731    if (s->sframe_cache_size > 0) {
1732        gb = &s_gb;
1733        init_get_bits(gb, s->sframe_cache, s->sframe_cache_size);
1734        s->sframe_cache_size = 0;
1735    }
1736
1737    if ((res = check_bits_for_superframe(gb, s)) == 1) return 1;
1738
1739    /* First bit is speech/music bit, it differentiates between WMAVoice
1740     * speech samples (the actual codec) and WMAVoice music samples, which
1741     * are really WMAPro-in-WMAVoice-superframes. I've never seen those in
1742     * the wild yet. */
1743    if (!get_bits1(gb)) {
1744        av_log_missing_feature(ctx, "WMAPro-in-WMAVoice support", 1);
1745        return -1;
1746    }
1747
1748    /* (optional) nr. of samples in superframe; always <= 480 and >= 0 */
1749    if (get_bits1(gb)) {
1750        if ((n_samples = get_bits(gb, 12)) > 480) {
1751            av_log(ctx, AV_LOG_ERROR,
1752                   "Superframe encodes >480 samples (%d), not allowed\n",
1753                   n_samples);
1754            return -1;
1755        }
1756    }
1757    /* Parse LSPs, if global for the superframe (can also be per-frame). */
1758    if (s->has_residual_lsps) {
1759        double prev_lsps[MAX_LSPS], a1[MAX_LSPS * 2], a2[MAX_LSPS * 2];
1760
1761        for (n = 0; n < s->lsps; n++)
1762            prev_lsps[n] = s->prev_lsps[n] - mean_lsf[n];
1763
1764        if (s->lsps == 10) {
1765            dequant_lsp10r(gb, lsps[2], prev_lsps, a1, a2, s->lsp_q_mode);
1766        } else /* s->lsps == 16 */
1767            dequant_lsp16r(gb, lsps[2], prev_lsps, a1, a2, s->lsp_q_mode);
1768
1769        for (n = 0; n < s->lsps; n++) {
1770            lsps[0][n]  = mean_lsf[n] + (a1[n]           - a2[n * 2]);
1771            lsps[1][n]  = mean_lsf[n] + (a1[s->lsps + n] - a2[n * 2 + 1]);
1772            lsps[2][n] += mean_lsf[n];
1773        }
1774        for (n = 0; n < 3; n++)
1775            stabilize_lsps(lsps[n], s->lsps);
1776    }
1777
1778    /* Parse frames, optionally preceeded by per-frame (independent) LSPs. */
1779    for (n = 0; n < 3; n++) {
1780        if (!s->has_residual_lsps) {
1781            int m;
1782
1783            if (s->lsps == 10) {
1784                dequant_lsp10i(gb, lsps[n]);
1785            } else /* s->lsps == 16 */
1786                dequant_lsp16i(gb, lsps[n]);
1787
1788            for (m = 0; m < s->lsps; m++)
1789                lsps[n][m] += mean_lsf[m];
1790            stabilize_lsps(lsps[n], s->lsps);
1791        }
1792
1793        if ((res = synth_frame(ctx, gb, n,
1794                               &samples[n * MAX_FRAMESIZE],
1795                               lsps[n], n == 0 ? s->prev_lsps : lsps[n - 1],
1796                               &excitation[s->history_nsamples + n * MAX_FRAMESIZE],
1797                               &synth[s->lsps + n * MAX_FRAMESIZE])))
1798            return res;
1799    }
1800
1801    /* Statistics? FIXME - we don't check for length, a slight overrun
1802     * will be caught by internal buffer padding, and anything else
1803     * will be skipped, not read. */
1804    if (get_bits1(gb)) {
1805        res = get_bits(gb, 4);
1806        skip_bits(gb, 10 * (res + 1));
1807    }
1808
1809    /* Specify nr. of output samples */
1810    *data_size = n_samples * sizeof(float);
1811
1812    /* Update history */
1813    memcpy(s->prev_lsps,           lsps[2],
1814           s->lsps             * sizeof(*s->prev_lsps));
1815    memcpy(s->synth_history,      &synth[MAX_SFRAMESIZE],
1816           s->lsps             * sizeof(*synth));
1817    memcpy(s->excitation_history, &excitation[MAX_SFRAMESIZE],
1818           s->history_nsamples * sizeof(*excitation));
1819    if (s->do_apf)
1820        memmove(s->zero_exc_pf,       &s->zero_exc_pf[MAX_SFRAMESIZE],
1821                s->history_nsamples * sizeof(*s->zero_exc_pf));
1822
1823    return 0;
1824}
1825
1826/**
1827 * Parse the packet header at the start of each packet (input data to this
1828 * decoder).
1829 *
1830 * @param s WMA Voice decoding context private data
1831 * @return 1 if not enough bits were available, or 0 on success.
1832 */
1833static int parse_packet_header(WMAVoiceContext *s)
1834{
1835    GetBitContext *gb = &s->gb;
1836    unsigned int res;
1837
1838    if (get_bits_left(gb) < 11)
1839        return 1;
1840    skip_bits(gb, 4);          // packet sequence number
1841    s->has_residual_lsps = get_bits1(gb);
1842    do {
1843        res = get_bits(gb, 6); // number of superframes per packet
1844                               // (minus first one if there is spillover)
1845        if (get_bits_left(gb) < 6 * (res == 0x3F) + s->spillover_bitsize)
1846            return 1;
1847    } while (res == 0x3F);
1848    s->spillover_nbits   = get_bits(gb, s->spillover_bitsize);
1849
1850    return 0;
1851}
1852
1853/**
1854 * Copy (unaligned) bits from gb/data/size to pb.
1855 *
1856 * @param pb target buffer to copy bits into
1857 * @param data source buffer to copy bits from
1858 * @param size size of the source data, in bytes
1859 * @param gb bit I/O context specifying the current position in the source.
1860 *           data. This function might use this to align the bit position to
1861 *           a whole-byte boundary before calling #ff_copy_bits() on aligned
1862 *           source data
1863 * @param nbits the amount of bits to copy from source to target
1864 *
1865 * @note after calling this function, the current position in the input bit
1866 *       I/O context is undefined.
1867 */
1868static void copy_bits(PutBitContext *pb,
1869                      const uint8_t *data, int size,
1870                      GetBitContext *gb, int nbits)
1871{
1872    int rmn_bytes, rmn_bits;
1873
1874    rmn_bits = rmn_bytes = get_bits_left(gb);
1875    if (rmn_bits < nbits)
1876        return;
1877    rmn_bits &= 7; rmn_bytes >>= 3;
1878    if ((rmn_bits = FFMIN(rmn_bits, nbits)) > 0)
1879        put_bits(pb, rmn_bits, get_bits(gb, rmn_bits));
1880    ff_copy_bits(pb, data + size - rmn_bytes,
1881                 FFMIN(nbits - rmn_bits, rmn_bytes << 3));
1882}
1883
1884/**
1885 * Packet decoding: a packet is anything that the (ASF) demuxer contains,
1886 * and we expect that the demuxer / application provides it to us as such
1887 * (else you'll probably get garbage as output). Every packet has a size of
1888 * ctx->block_align bytes, starts with a packet header (see
1889 * #parse_packet_header()), and then a series of superframes. Superframe
1890 * boundaries may exceed packets, i.e. superframes can split data over
1891 * multiple (two) packets.
1892 *
1893 * For more information about frames, see #synth_superframe().
1894 */
1895static int wmavoice_decode_packet(AVCodecContext *ctx, void *data,
1896                                  int *data_size, AVPacket *avpkt)
1897{
1898    WMAVoiceContext *s = ctx->priv_data;
1899    GetBitContext *gb = &s->gb;
1900    int size, res, pos;
1901
1902    if (*data_size < 480 * sizeof(float)) {
1903        av_log(ctx, AV_LOG_ERROR,
1904               "Output buffer too small (%d given - %lu needed)\n",
1905               *data_size, 480 * sizeof(float));
1906        return -1;
1907    }
1908    *data_size = 0;
1909
1910    /* Packets are sometimes a multiple of ctx->block_align, with a packet
1911     * header at each ctx->block_align bytes. However, FFmpeg's ASF demuxer
1912     * feeds us ASF packets, which may concatenate multiple "codec" packets
1913     * in a single "muxer" packet, so we artificially emulate that by
1914     * capping the packet size at ctx->block_align. */
1915    for (size = avpkt->size; size > ctx->block_align; size -= ctx->block_align);
1916    if (!size)
1917        return 0;
1918    init_get_bits(&s->gb, avpkt->data, size << 3);
1919
1920    /* size == ctx->block_align is used to indicate whether we are dealing with
1921     * a new packet or a packet of which we already read the packet header
1922     * previously. */
1923    if (size == ctx->block_align) { // new packet header
1924        if ((res = parse_packet_header(s)) < 0)
1925            return res;
1926
1927        /* If the packet header specifies a s->spillover_nbits, then we want
1928         * to push out all data of the previous packet (+ spillover) before
1929         * continuing to parse new superframes in the current packet. */
1930        if (s->spillover_nbits > 0) {
1931            if (s->sframe_cache_size > 0) {
1932                int cnt = get_bits_count(gb);
1933                copy_bits(&s->pb, avpkt->data, size, gb, s->spillover_nbits);
1934                flush_put_bits(&s->pb);
1935                s->sframe_cache_size += s->spillover_nbits;
1936                if ((res = synth_superframe(ctx, data, data_size)) == 0 &&
1937                    *data_size > 0) {
1938                    cnt += s->spillover_nbits;
1939                    s->skip_bits_next = cnt & 7;
1940                    return cnt >> 3;
1941                } else
1942                    skip_bits_long (gb, s->spillover_nbits - cnt +
1943                                    get_bits_count(gb)); // resync
1944            } else
1945                skip_bits_long(gb, s->spillover_nbits);  // resync
1946        }
1947    } else if (s->skip_bits_next)
1948        skip_bits(gb, s->skip_bits_next);
1949
1950    /* Try parsing superframes in current packet */
1951    s->sframe_cache_size = 0;
1952    s->skip_bits_next = 0;
1953    pos = get_bits_left(gb);
1954    if ((res = synth_superframe(ctx, data, data_size)) < 0) {
1955        return res;
1956    } else if (*data_size > 0) {
1957        int cnt = get_bits_count(gb);
1958        s->skip_bits_next = cnt & 7;
1959        return cnt >> 3;
1960    } else if ((s->sframe_cache_size = pos) > 0) {
1961        /* rewind bit reader to start of last (incomplete) superframe... */
1962        init_get_bits(gb, avpkt->data, size << 3);
1963        skip_bits_long(gb, (size << 3) - pos);
1964        assert(get_bits_left(gb) == pos);
1965
1966        /* ...and cache it for spillover in next packet */
1967        init_put_bits(&s->pb, s->sframe_cache, SFRAME_CACHE_MAXSIZE);
1968        copy_bits(&s->pb, avpkt->data, size, gb, s->sframe_cache_size);
1969        // FIXME bad - just copy bytes as whole and add use the
1970        // skip_bits_next field
1971    }
1972
1973    return size;
1974}
1975
1976static av_cold int wmavoice_decode_end(AVCodecContext *ctx)
1977{
1978    WMAVoiceContext *s = ctx->priv_data;
1979
1980    if (s->do_apf) {
1981        ff_rdft_end(&s->rdft);
1982        ff_rdft_end(&s->irdft);
1983        ff_dct_end(&s->dct);
1984        ff_dct_end(&s->dst);
1985    }
1986
1987    return 0;
1988}
1989
1990static av_cold void wmavoice_flush(AVCodecContext *ctx)
1991{
1992    WMAVoiceContext *s = ctx->priv_data;
1993    int n;
1994
1995    s->postfilter_agc    = 0;
1996    s->sframe_cache_size = 0;
1997    s->skip_bits_next    = 0;
1998    for (n = 0; n < s->lsps; n++)
1999        s->prev_lsps[n] = M_PI * (n + 1.0) / (s->lsps + 1.0);
2000    memset(s->excitation_history, 0,
2001           sizeof(*s->excitation_history) * MAX_SIGNAL_HISTORY);
2002    memset(s->synth_history,      0,
2003           sizeof(*s->synth_history)      * MAX_LSPS);
2004    memset(s->gain_pred_err,      0,
2005           sizeof(s->gain_pred_err));
2006
2007    if (s->do_apf) {
2008        memset(&s->synth_filter_out_buf[MAX_LSPS_ALIGN16 - s->lsps], 0,
2009               sizeof(*s->synth_filter_out_buf) * s->lsps);
2010        memset(s->dcf_mem,              0,
2011               sizeof(*s->dcf_mem)              * 2);
2012        memset(s->zero_exc_pf,          0,
2013               sizeof(*s->zero_exc_pf)          * s->history_nsamples);
2014        memset(s->denoise_filter_cache, 0, sizeof(s->denoise_filter_cache));
2015    }
2016}
2017
2018AVCodec wmavoice_decoder = {
2019    "wmavoice",
2020    AVMEDIA_TYPE_AUDIO,
2021    CODEC_ID_WMAVOICE,
2022    sizeof(WMAVoiceContext),
2023    wmavoice_decode_init,
2024    NULL,
2025    wmavoice_decode_end,
2026    wmavoice_decode_packet,
2027    CODEC_CAP_SUBFRAMES,
2028    .flush     = wmavoice_flush,
2029    .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio Voice"),
2030};
2031