3 * Copyright (c) 2007 Reynaldo H. Verdejo Pinochet
5 * This file is part of FFmpeg.
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.
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.
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
23 * @file libavcodec/qcelpdec.c
25 * @author Reynaldo H. Verdejo Pinochet
26 * @remark FFmpeg merging spearheaded by Kenan Gillet
27 * @remark Development mentored by Benjamin Larson
34 #include "bitstream.h"
36 #include "qcelpdata.h"
38 #include "celp_math.h"
39 #include "celp_filters.h"
40 #include "acelp_vectors.h"
47 I_F_Q
= -1, /*!< insufficient frame quality */
58 qcelp_packet_rate bitrate
;
59 QCELPFrame frame
; /*!< unpacked data frame */
61 uint8_t erasure_count
;
62 uint8_t octave_count
; /*!< count the consecutive RATE_OCTAVE frames */
64 float predictor_lspf
[10];/*!< LSP predictor for RATE_OCTAVE and I_F_Q */
65 float pitch_synthesis_filter_mem
[303];
66 float pitch_pre_filter_mem
[303];
67 float rnd_fir_filter_mem
[180];
68 float formant_mem
[170];
69 float last_codebook_gain
;
75 uint8_t warned_buf_mismatch_bitrate
;
79 * Reconstructs LPC coefficients from the line spectral pair frequencies.
81 * TIA/EIA/IS-733 2.4.3.3.5
83 void ff_celp_lspf2lpc(const double *lspf
, float *lpc
);
86 * Initialize the speech codec according to the specification.
88 * TIA/EIA/IS-733 2.4.9
90 static av_cold
int qcelp_decode_init(AVCodecContext
*avctx
)
92 QCELPContext
*q
= avctx
->priv_data
;
95 avctx
->sample_fmt
= SAMPLE_FMT_FLT
;
98 q
->prev_lspf
[i
] = (i
+1)/11.;
104 * Decodes the 10 quantized LSP frequencies from the LSPV/LSP
105 * transmission codes of any bitrate and checks for badly received packets.
107 * @param q the context
108 * @param lspf line spectral pair frequencies
110 * @return 0 on success, -1 if the packet is badly received
112 * TIA/EIA/IS-733 2.4.3.2.6.2-2, 2.4.8.7.3
114 static int decode_lspf(QCELPContext
*q
, float *lspf
)
117 float tmp_lspf
, smooth
, erasure_coeff
;
118 const float *predictors
;
120 if(q
->bitrate
== RATE_OCTAVE
|| q
->bitrate
== I_F_Q
)
122 predictors
= (q
->prev_bitrate
!= RATE_OCTAVE
&&
123 q
->prev_bitrate
!= I_F_Q
?
124 q
->prev_lspf
: q
->predictor_lspf
);
126 if(q
->bitrate
== RATE_OCTAVE
)
132 q
->predictor_lspf
[i
] =
133 lspf
[i
] = (q
->frame
.lspv
[i
] ? QCELP_LSP_SPREAD_FACTOR
134 : -QCELP_LSP_SPREAD_FACTOR
)
135 + predictors
[i
] * QCELP_LSP_OCTAVE_PREDICTOR
136 + (i
+ 1) * ((1 - QCELP_LSP_OCTAVE_PREDICTOR
)/11);
138 smooth
= (q
->octave_count
< 10 ? .875 : 0.1);
141 erasure_coeff
= QCELP_LSP_OCTAVE_PREDICTOR
;
143 assert(q
->bitrate
== I_F_Q
);
145 if(q
->erasure_count
> 1)
146 erasure_coeff
*= (q
->erasure_count
< 4 ? 0.9 : 0.7);
150 q
->predictor_lspf
[i
] =
151 lspf
[i
] = (i
+ 1) * ( 1 - erasure_coeff
)/11
152 + erasure_coeff
* predictors
[i
];
157 // Check the stability of the LSP frequencies.
158 lspf
[0] = FFMAX(lspf
[0], QCELP_LSP_SPREAD_FACTOR
);
160 lspf
[i
] = FFMAX(lspf
[i
], (lspf
[i
-1] + QCELP_LSP_SPREAD_FACTOR
));
162 lspf
[9] = FFMIN(lspf
[9], (1.0 - QCELP_LSP_SPREAD_FACTOR
));
164 lspf
[i
-1] = FFMIN(lspf
[i
-1], (lspf
[i
] - QCELP_LSP_SPREAD_FACTOR
));
166 // Low-pass filter the LSP frequencies.
167 ff_weighted_vector_sumf(lspf
, lspf
, q
->prev_lspf
, smooth
, 1.0-smooth
, 10);
175 lspf
[2*i
+0] = tmp_lspf
+= qcelp_lspvq
[i
][q
->frame
.lspv
[i
]][0] * 0.0001;
176 lspf
[2*i
+1] = tmp_lspf
+= qcelp_lspvq
[i
][q
->frame
.lspv
[i
]][1] * 0.0001;
179 // Check for badly received packets.
180 if(q
->bitrate
== RATE_QUARTER
)
182 if(lspf
[9] <= .70 || lspf
[9] >= .97)
185 if(fabs(lspf
[i
] - lspf
[i
-2]) < .08)
189 if(lspf
[9] <= .66 || lspf
[9] >= .985)
192 if (fabs(lspf
[i
] - lspf
[i
-4]) < .0931)
200 * Converts codebook transmission codes to GAIN and INDEX.
202 * @param q the context
203 * @param gain array holding the decoded gain
205 * TIA/EIA/IS-733 2.4.6.2
207 static void decode_gain_and_index(QCELPContext
*q
,
209 int i
, subframes_count
, g1
[16];
212 if(q
->bitrate
>= RATE_QUARTER
)
216 case RATE_FULL
: subframes_count
= 16; break;
217 case RATE_HALF
: subframes_count
= 4; break;
218 default: subframes_count
= 5;
220 for(i
=0; i
<subframes_count
; i
++)
222 g1
[i
] = 4 * q
->frame
.cbgain
[i
];
223 if(q
->bitrate
== RATE_FULL
&& !((i
+1) & 3))
225 g1
[i
] += av_clip((g1
[i
-1] + g1
[i
-2] + g1
[i
-3]) / 3 - 6, 0, 32);
228 gain
[i
] = qcelp_g12ga
[g1
[i
]];
230 if(q
->frame
.cbsign
[i
])
233 q
->frame
.cindex
[i
] = (q
->frame
.cindex
[i
]-89) & 127;
237 q
->prev_g1
[0] = g1
[i
-2];
238 q
->prev_g1
[1] = g1
[i
-1];
239 q
->last_codebook_gain
= qcelp_g12ga
[g1
[i
-1]];
241 if(q
->bitrate
== RATE_QUARTER
)
243 // Provide smoothing of the unvoiced excitation energy.
245 gain
[6] = 0.4*gain
[3] + 0.6*gain
[4];
247 gain
[4] = 0.8*gain
[2] + 0.2*gain
[3];
248 gain
[3] = 0.2*gain
[1] + 0.8*gain
[2];
250 gain
[1] = 0.6*gain
[0] + 0.4*gain
[1];
254 if(q
->bitrate
== RATE_OCTAVE
)
256 g1
[0] = 2 * q
->frame
.cbgain
[0]
257 + av_clip((q
->prev_g1
[0] + q
->prev_g1
[1]) / 2 - 5, 0, 54);
261 assert(q
->bitrate
== I_F_Q
);
263 g1
[0] = q
->prev_g1
[1];
264 switch(q
->erasure_count
)
267 case 2 : g1
[0] -= 1; break;
268 case 3 : g1
[0] -= 2; break;
275 // This interpolation is done to produce smoother background noise.
276 slope
= 0.5*(qcelp_g12ga
[g1
[0]] - q
->last_codebook_gain
) / subframes_count
;
277 for(i
=1; i
<=subframes_count
; i
++)
278 gain
[i
-1] = q
->last_codebook_gain
+ slope
* i
;
280 q
->last_codebook_gain
= gain
[i
-2];
281 q
->prev_g1
[0] = q
->prev_g1
[1];
282 q
->prev_g1
[1] = g1
[0];
287 * If the received packet is Rate 1/4 a further sanity check is made of the
290 * @param cbgain the unpacked cbgain array
291 * @return -1 if the sanity check fails, 0 otherwise
293 * TIA/EIA/IS-733 2.4.8.7.3
295 static int codebook_sanity_check_for_rate_quarter(const uint8_t *cbgain
)
297 int i
, diff
, prev_diff
=0;
301 diff
= cbgain
[i
] - cbgain
[i
-1];
304 else if(FFABS(diff
- prev_diff
) > 12)
312 * Computes the scaled codebook vector Cdn From INDEX and GAIN
315 * The specification lacks some information here.
317 * TIA/EIA/IS-733 has an omission on the codebook index determination
318 * formula for RATE_FULL and RATE_HALF frames at section 2.4.8.1.1. It says
319 * you have to subtract the decoded index parameter from the given scaled
320 * codebook vector index 'n' to get the desired circular codebook index, but
321 * it does not mention that you have to clamp 'n' to [0-9] in order to get
322 * RI-compliant results.
324 * The reason for this mistake seems to be the fact they forgot to mention you
325 * have to do these calculations per codebook subframe and adjust given
326 * equation values accordingly.
328 * @param q the context
329 * @param gain array holding the 4 pitch subframe gain values
330 * @param cdn_vector array for the generated scaled codebook vector
332 static void compute_svector(QCELPContext
*q
, const float *gain
,
336 uint16_t cbseed
, cindex
;
337 float *rnd
, tmp_gain
, fir_filter_value
;
344 tmp_gain
= gain
[i
] * QCELP_RATE_FULL_CODEBOOK_RATIO
;
345 cindex
= -q
->frame
.cindex
[i
];
347 *cdn_vector
++ = tmp_gain
* qcelp_rate_full_codebook
[cindex
++ & 127];
353 tmp_gain
= gain
[i
] * QCELP_RATE_HALF_CODEBOOK_RATIO
;
354 cindex
= -q
->frame
.cindex
[i
];
355 for (j
= 0; j
< 40; j
++)
356 *cdn_vector
++ = tmp_gain
* qcelp_rate_half_codebook
[cindex
++ & 127];
360 cbseed
= (0x0003 & q
->frame
.lspv
[4])<<14 |
361 (0x003F & q
->frame
.lspv
[3])<< 8 |
362 (0x0060 & q
->frame
.lspv
[2])<< 1 |
363 (0x0007 & q
->frame
.lspv
[1])<< 3 |
364 (0x0038 & q
->frame
.lspv
[0])>> 3 ;
365 rnd
= q
->rnd_fir_filter_mem
+ 20;
368 tmp_gain
= gain
[i
] * (QCELP_SQRT1887
/ 32768.0);
371 cbseed
= 521 * cbseed
+ 259;
372 *rnd
= (int16_t)cbseed
;
375 fir_filter_value
= 0.0;
377 fir_filter_value
+= qcelp_rnd_fir_coefs
[j
]
378 * (rnd
[-j
] + rnd
[-20+j
]);
380 fir_filter_value
+= qcelp_rnd_fir_coefs
[10] * rnd
[-10];
381 *cdn_vector
++ = tmp_gain
* fir_filter_value
;
385 memcpy(q
->rnd_fir_filter_mem
, q
->rnd_fir_filter_mem
+ 160, 20 * sizeof(float));
388 cbseed
= q
->first16bits
;
391 tmp_gain
= gain
[i
] * (QCELP_SQRT1887
/ 32768.0);
394 cbseed
= 521 * cbseed
+ 259;
395 *cdn_vector
++ = tmp_gain
* (int16_t)cbseed
;
400 cbseed
= -44; // random codebook index
403 tmp_gain
= gain
[i
] * QCELP_RATE_FULL_CODEBOOK_RATIO
;
405 *cdn_vector
++ = tmp_gain
* qcelp_rate_full_codebook
[cbseed
++ & 127];
409 memset(cdn_vector
, 0, 160 * sizeof(float));
415 * Apply generic gain control.
417 * @param v_out output vector
418 * @param v_in gain-controlled vector
419 * @param v_ref vector to control gain of
421 * FIXME: If v_ref is a zero vector, it energy is zero
422 * and the behavior of the gain control is
423 * undefined in the specs.
425 * TIA/EIA/IS-733 2.4.8.3-2/3/4/5, 2.4.8.6
427 static void apply_gain_ctrl(float *v_out
, const float *v_ref
,
433 for(i
=0, j
=0; i
<4; i
++)
435 scalefactor
= ff_dot_productf(v_in
+ j
, v_in
+ j
, 40);
437 scalefactor
= sqrt(ff_dot_productf(v_ref
+ j
, v_ref
+ j
, 40)
440 ff_log_missing_feature(NULL
, "Zero energy for gain control", 1);
441 for(len
=j
+40; j
<len
; j
++)
442 v_out
[j
] = scalefactor
* v_in
[j
];
447 * Apply filter in pitch-subframe steps.
449 * @param memory buffer for the previous state of the filter
450 * - must be able to contain 303 elements
451 * - the 143 first elements are from the previous state
452 * - the next 160 are for output
453 * @param v_in input filter vector
454 * @param gain per-subframe gain array, each element is between 0.0 and 2.0
455 * @param lag per-subframe lag array, each element is
456 * - between 16 and 143 if its corresponding pfrac is 0,
457 * - between 16 and 139 otherwise
458 * @param pfrac per-subframe boolean array, 1 if the lag is fractional, 0
461 * @return filter output vector
463 static const float *do_pitchfilter(float memory
[303], const float v_in
[160],
464 const float gain
[4], const uint8_t *lag
,
465 const uint8_t pfrac
[4])
468 float *v_lag
, *v_out
;
471 v_out
= memory
+ 143; // Output vector starts at memory[143].
477 v_lag
= memory
+ 143 + 40 * i
- lag
[i
];
478 for(v_len
=v_in
+40; v_in
<v_len
; v_in
++)
480 if(pfrac
[i
]) // If it is a fractional lag...
482 for(j
=0, *v_out
=0.; j
<4; j
++)
483 *v_out
+= qcelp_hammsinc_table
[j
] * (v_lag
[j
-4] + v_lag
[3-j
]);
487 *v_out
= *v_in
+ gain
[i
] * *v_out
;
494 memcpy(v_out
, v_in
, 40 * sizeof(float));
500 memmove(memory
, memory
+ 160, 143 * sizeof(float));
505 * Apply pitch synthesis filter and pitch prefilter to the scaled codebook vector.
506 * TIA/EIA/IS-733 2.4.5.2, 2.4.8.7.2
508 * @param q the context
509 * @param cdn_vector the scaled codebook vector
511 static void apply_pitch_filters(QCELPContext
*q
, float *cdn_vector
)
514 const float *v_synthesis_filtered
, *v_pre_filtered
;
516 if(q
->bitrate
>= RATE_HALF
||
517 q
->bitrate
== SILENCE
||
518 (q
->bitrate
== I_F_Q
&& (q
->prev_bitrate
>= RATE_HALF
)))
521 if(q
->bitrate
>= RATE_HALF
)
524 // Compute gain & lag for the whole frame.
527 q
->pitch_gain
[i
] = q
->frame
.plag
[i
] ? (q
->frame
.pgain
[i
] + 1) * 0.25 : 0.0;
529 q
->pitch_lag
[i
] = q
->frame
.plag
[i
] + 16;
533 float max_pitch_gain
;
535 if (q
->bitrate
== I_F_Q
)
537 if (q
->erasure_count
< 3)
538 max_pitch_gain
= 0.9 - 0.3 * (q
->erasure_count
- 1);
540 max_pitch_gain
= 0.0;
543 assert(q
->bitrate
== SILENCE
);
544 max_pitch_gain
= 1.0;
547 q
->pitch_gain
[i
] = FFMIN(q
->pitch_gain
[i
], max_pitch_gain
);
549 memset(q
->frame
.pfrac
, 0, sizeof(q
->frame
.pfrac
));
552 // pitch synthesis filter
553 v_synthesis_filtered
= do_pitchfilter(q
->pitch_synthesis_filter_mem
,
554 cdn_vector
, q
->pitch_gain
,
555 q
->pitch_lag
, q
->frame
.pfrac
);
557 // pitch prefilter update
559 q
->pitch_gain
[i
] = 0.5 * FFMIN(q
->pitch_gain
[i
], 1.0);
561 v_pre_filtered
= do_pitchfilter(q
->pitch_pre_filter_mem
,
562 v_synthesis_filtered
,
563 q
->pitch_gain
, q
->pitch_lag
,
566 apply_gain_ctrl(cdn_vector
, v_synthesis_filtered
, v_pre_filtered
);
569 memcpy(q
->pitch_synthesis_filter_mem
, cdn_vector
+ 17,
570 143 * sizeof(float));
571 memcpy(q
->pitch_pre_filter_mem
, cdn_vector
+ 17, 143 * sizeof(float));
572 memset(q
->pitch_gain
, 0, sizeof(q
->pitch_gain
));
573 memset(q
->pitch_lag
, 0, sizeof(q
->pitch_lag
));
578 * Reconstructs LPC coefficients from the line spectral pair frequencies
579 * and performs bandwidth expansion.
581 * @param lspf line spectral pair frequencies
582 * @param lpc linear predictive coding coefficients
584 * @note: bandwith_expansion_coeff could be precalculated into a table
585 * but it seems to be slower on x86
587 * TIA/EIA/IS-733 2.4.3.3.5
589 void lspf2lpc(const float *lspf
, float *lpc
)
592 double bandwith_expansion_coeff
= QCELP_BANDWITH_EXPANSION_COEFF
;
596 lsf
[i
] = cos(M_PI
* lspf
[i
]);
598 ff_celp_lspf2lpc(lsf
, lpc
);
602 lpc
[i
] *= bandwith_expansion_coeff
;
603 bandwith_expansion_coeff
*= QCELP_BANDWITH_EXPANSION_COEFF
;
608 * Interpolates LSP frequencies and computes LPC coefficients
609 * for a given bitrate & pitch subframe.
611 * TIA/EIA/IS-733 2.4.3.3.4, 2.4.8.7.2
613 * @param q the context
614 * @param curr_lspf LSP frequencies vector of the current frame
615 * @param lpc float vector for the resulting LPC
616 * @param subframe_num frame number in decoded stream
618 void interpolate_lpc(QCELPContext
*q
, const float *curr_lspf
, float *lpc
,
619 const int subframe_num
)
621 float interpolated_lspf
[10];
624 if(q
->bitrate
>= RATE_QUARTER
)
625 weight
= 0.25 * (subframe_num
+ 1);
626 else if(q
->bitrate
== RATE_OCTAVE
&& !subframe_num
)
633 ff_weighted_vector_sumf(interpolated_lspf
, curr_lspf
, q
->prev_lspf
,
634 weight
, 1.0 - weight
, 10);
635 lspf2lpc(interpolated_lspf
, lpc
);
636 }else if(q
->bitrate
>= RATE_QUARTER
||
637 (q
->bitrate
== I_F_Q
&& !subframe_num
))
638 lspf2lpc(curr_lspf
, lpc
);
639 else if(q
->bitrate
== SILENCE
&& !subframe_num
)
640 lspf2lpc(q
->prev_lspf
, lpc
);
643 static qcelp_packet_rate
buf_size2bitrate(const int buf_size
)
647 case 35: return RATE_FULL
;
648 case 17: return RATE_HALF
;
649 case 8: return RATE_QUARTER
;
650 case 4: return RATE_OCTAVE
;
651 case 1: return SILENCE
;
658 * Determine the bitrate from the frame size and/or the first byte of the frame.
660 * @param avctx the AV codec context
661 * @param buf_size length of the buffer
662 * @param buf the bufffer
664 * @return the bitrate on success,
665 * I_F_Q if the bitrate cannot be satisfactorily determined
667 * TIA/EIA/IS-733 2.4.8.7.1
669 static qcelp_packet_rate
determine_bitrate(AVCodecContext
*avctx
, const int buf_size
,
672 qcelp_packet_rate bitrate
;
674 if((bitrate
= buf_size2bitrate(buf_size
)) >= 0)
678 QCELPContext
*q
= avctx
->priv_data
;
679 if (!q
->warned_buf_mismatch_bitrate
)
681 av_log(avctx
, AV_LOG_WARNING
,
682 "Claimed bitrate and buffer size mismatch.\n");
683 q
->warned_buf_mismatch_bitrate
= 1;
686 }else if(bitrate
< **buf
)
688 av_log(avctx
, AV_LOG_ERROR
,
689 "Buffer is too small for the claimed bitrate.\n");
693 }else if((bitrate
= buf_size2bitrate(buf_size
+ 1)) >= 0)
695 av_log(avctx
, AV_LOG_WARNING
,
696 "Bitrate byte is missing, guessing the bitrate from packet size.\n");
700 if(bitrate
== SILENCE
)
702 //FIXME: Remove experimental warning when tested with samples.
703 ff_log_ask_for_sample(avctx
, "'Blank frame handling is experimental.");
708 static void warn_insufficient_frame_quality(AVCodecContext
*avctx
,
711 av_log(avctx
, AV_LOG_WARNING
, "Frame #%d, IFQ: %s\n", avctx
->frame_number
,
715 static int qcelp_decode_frame(AVCodecContext
*avctx
, void *data
, int *data_size
,
716 const uint8_t *buf
, int buf_size
)
718 QCELPContext
*q
= avctx
->priv_data
;
719 float *outbuffer
= data
;
721 float quantized_lspf
[10], lpc
[10];
725 if((q
->bitrate
= determine_bitrate(avctx
, buf_size
, &buf
)) == I_F_Q
)
727 warn_insufficient_frame_quality(avctx
, "bitrate cannot be determined.");
731 if(q
->bitrate
== RATE_OCTAVE
&&
732 (q
->first16bits
= AV_RB16(buf
)) == 0xFFFF)
734 warn_insufficient_frame_quality(avctx
, "Bitrate is 1/8 and first 16 bits are on.");
738 if(q
->bitrate
> SILENCE
)
740 const QCELPBitmap
*bitmaps
= qcelp_unpacking_bitmaps_per_rate
[q
->bitrate
];
741 const QCELPBitmap
*bitmaps_end
= qcelp_unpacking_bitmaps_per_rate
[q
->bitrate
]
742 + qcelp_unpacking_bitmaps_lengths
[q
->bitrate
];
743 uint8_t *unpacked_data
= (uint8_t *)&q
->frame
;
745 init_get_bits(&q
->gb
, buf
, 8*buf_size
);
747 memset(&q
->frame
, 0, sizeof(QCELPFrame
));
749 for(; bitmaps
< bitmaps_end
; bitmaps
++)
750 unpacked_data
[bitmaps
->index
] |= get_bits(&q
->gb
, bitmaps
->bitlen
) << bitmaps
->bitpos
;
752 // Check for erasures/blanks on rates 1, 1/4 and 1/8.
753 if(q
->frame
.reserved
)
755 warn_insufficient_frame_quality(avctx
, "Wrong data in reserved frame area.");
758 if(q
->bitrate
== RATE_QUARTER
&&
759 codebook_sanity_check_for_rate_quarter(q
->frame
.cbgain
))
761 warn_insufficient_frame_quality(avctx
, "Codebook gain sanity check failed.");
765 if(q
->bitrate
>= RATE_HALF
)
769 if(q
->frame
.pfrac
[i
] && q
->frame
.plag
[i
] >= 124)
771 warn_insufficient_frame_quality(avctx
, "Cannot initialize pitch filter.");
778 decode_gain_and_index(q
, gain
);
779 compute_svector(q
, gain
, outbuffer
);
781 if(decode_lspf(q
, quantized_lspf
) < 0)
783 warn_insufficient_frame_quality(avctx
, "Badly received packets in frame.");
788 apply_pitch_filters(q
, outbuffer
);
790 if(q
->bitrate
== I_F_Q
)
795 decode_gain_and_index(q
, gain
);
796 compute_svector(q
, gain
, outbuffer
);
797 decode_lspf(q
, quantized_lspf
);
798 apply_pitch_filters(q
, outbuffer
);
800 q
->erasure_count
= 0;
802 formant_mem
= q
->formant_mem
+ 10;
805 interpolate_lpc(q
, quantized_lspf
, lpc
, i
);
806 ff_celp_lp_synthesis_filterf(formant_mem
, lpc
, outbuffer
+ i
* 40, 40,
810 memcpy(q
->formant_mem
, q
->formant_mem
+ 160, 10 * sizeof(float));
812 // FIXME: postfilter and final gain control should be here.
813 // TIA/EIA/IS-733 2.4.8.6
815 formant_mem
= q
->formant_mem
+ 10;
817 *outbuffer
++ = av_clipf(*formant_mem
++, QCELP_CLIP_LOWER_BOUND
,
818 QCELP_CLIP_UPPER_BOUND
);
820 memcpy(q
->prev_lspf
, quantized_lspf
, sizeof(q
->prev_lspf
));
821 q
->prev_bitrate
= q
->bitrate
;
823 *data_size
= 160 * sizeof(*outbuffer
);
828 AVCodec qcelp_decoder
=
831 .type
= CODEC_TYPE_AUDIO
,
832 .id
= CODEC_ID_QCELP
,
833 .init
= qcelp_decode_init
,
834 .decode
= qcelp_decode_frame
,
835 .priv_data_size
= sizeof(QCELPContext
),
836 .long_name
= NULL_IF_CONFIG_SMALL("QCELP / PureVoice"),