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FFmpeg
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#include <inttypes.h>#include <limits.h>#include "avcodec.h"#include "g729.h"#include "acelp_pitch_delay.h"#include "g729postfilter.h"#include "celp_math.h"#include "acelp_filters.h"#include "acelp_vectors.h"#include "celp_filters.h"#include "mathops.h"
Go to the source code of this file.
Macros | |
| #define | FRAC_BITS 15 |
Functions | |
| static void | residual_filter (int16_t *out, const int16_t *filter_coeffs, const int16_t *in, int subframe_size) |
| Residual signal calculation (4.2.1 if G.729) More... | |
| static int16_t | long_term_filter (DSPContext *dsp, int pitch_delay_int, const int16_t *residual, int16_t *residual_filt, int subframe_size) |
| long-term postfilter (4.2.1) More... | |
| static int16_t | get_tilt_comp (DSPContext *dsp, int16_t *lp_gn, const int16_t *lp_gd, int16_t *speech, int subframe_size) |
| Calculate reflection coefficient for tilt compensation filter (4.2.3). More... | |
| static int16_t | apply_tilt_comp (int16_t *out, int16_t *res_pst, int refl_coeff, int subframe_size, int16_t ht_prev_data) |
| Apply tilt compensation filter (4.2.3). More... | |
| void | ff_g729_postfilter (DSPContext *dsp, int16_t *ht_prev_data, int *voicing, const int16_t *lp_filter_coeffs, int pitch_delay_int, int16_t *residual, int16_t *res_filter_data, int16_t *pos_filter_data, int16_t *speech, int subframe_size) |
| Signal postfiltering (4.2) More... | |
| int16_t | ff_g729_adaptive_gain_control (int gain_before, int gain_after, int16_t *speech, int subframe_size, int16_t gain_prev) |
| Adaptive gain control (4.2.4) More... | |
Variables | |
| static const int16_t | ff_g729_interp_filt_short [(ANALYZED_FRAC_DELAYS+1)*SHORT_INT_FILT_LEN] |
| short interpolation filter (of length 33, according to spec) for computing signal with non-integer delay More... | |
| static const int16_t | ff_g729_interp_filt_long [(ANALYZED_FRAC_DELAYS+1)*LONG_INT_FILT_LEN] |
| long interpolation filter (of length 129, according to spec) for computing signal with non-integer delay More... | |
| static const int16_t | formant_pp_factor_num_pow [10] |
| formant_pp_factor_num_pow[i] = FORMANT_PP_FACTOR_NUM^(i+1) More... | |
| static const int16_t | formant_pp_factor_den_pow [10] |
| formant_pp_factor_den_pow[i] = FORMANT_PP_FACTOR_DEN^(i+1) More... | |
Macro Definition Documentation
| #define FRAC_BITS 15 |
Definition at line 33 of file g729postfilter.c.
Referenced by compute_stereo(), decode_frame(), decode_init_static(), encode_frame(), ff_mpa_synth_init(), ff_snow_inner_add_yblock(), get_block_rd(), get_dc(), imdct36(), long_term_filter(), and predict_slice_buffered().
Function Documentation
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Apply tilt compensation filter (4.2.3).
- Parameters
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res_pst [in/out] residual signal (partially filtered) k1 (3.12) reflection coefficient subframe_size size of subframe ht_prev_data previous data for 4.2.3, equation 86
- Returns
- new value for ht_prev_data
Definition at line 476 of file g729postfilter.c.
Referenced by ff_g729_postfilter().
| int16_t ff_g729_adaptive_gain_control | ( | int | gain_before, |
| int | gain_after, | ||
| int16_t * | speech, | ||
| int | subframe_size, | ||
| int16_t | gain_prev | ||
| ) |
Adaptive gain control (4.2.4)
- Parameters
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gain_before gain of speech before applying postfilters gain_after gain of speech after applying postfilters speech [in/out] signal buffer subframe_size length of subframe gain_prev (3.12) previous value of gain coefficient
- Returns
- (3.12) last value of gain coefficient
Definition at line 574 of file g729postfilter.c.
Referenced by decode_frame().
| void ff_g729_postfilter | ( | DSPContext * | dsp, |
| int16_t * | ht_prev_data, | ||
| int * | voicing, | ||
| const int16_t * | lp_filter_coeffs, | ||
| int | pitch_delay_int, | ||
| int16_t * | residual, | ||
| int16_t * | res_filter_data, | ||
| int16_t * | pos_filter_data, | ||
| int16_t * | speech, | ||
| int | subframe_size | ||
| ) |
Signal postfiltering (4.2)
- Parameters
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dsp initialized DSP context ht_prev_data [in/out] (Q12) pointer to variable receiving tilt compensation filter data from previous subframe voicing [in/out] (Q0) pointer to variable receiving voicing decision lp_filter_coeffs (Q12) LP filter coefficients pitch_delay_int integer part of the pitch delay residual [in/out] (Q0) residual signal buffer (used in long-term postfilter) res_filter_data [in/out] (Q0) speech data of previous subframe pos_filter_data [in/out] (Q0) previous speech data for short-term postfilter speech [in/out] (Q0) signal buffer subframe_size size of subframe
Filtering has the following stages: Long-term postfilter (4.2.1) Short-term postfilter (4.2.2). Tilt-compensation (4.2.3)
Definition at line 514 of file g729postfilter.c.
Referenced by decode_frame().
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Calculate reflection coefficient for tilt compensation filter (4.2.3).
- Parameters
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dsp initialized DSP context lp_gn (3.12) coefficients of A(z/FORMANT_PP_FACTOR_NUM) filter lp_gd (3.12) coefficients of A(z/FORMANT_PP_FACTOR_DEN) filter speech speech to update subframe_size size of subframe
- Returns
- (3.12) reflection coefficient
- Remarks
- The routine also calculates the gain term for the short-term filter (gf) and multiplies the speech data by 1/gf.
- Note
- All members of lp_gn, except 10-19 must be equal to zero.
Definition at line 424 of file g729postfilter.c.
Referenced by ff_g729_postfilter().
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long-term postfilter (4.2.1)
- Parameters
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dsp initialized DSP context pitch_delay_int integer part of the pitch delay in the first subframe residual filtering input data residual_filt [out] speech signal with applied A(z/FORMANT_PP_FACTOR_NUM) filter subframe_size size of subframe
- Returns
- 0 if long-term prediction gain is less than 3dB, 1 - otherwise
Definition at line 110 of file g729postfilter.c.
Referenced by ff_g729_postfilter().
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Residual signal calculation (4.2.1 if G.729)
- Parameters
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out [out] output data filtered through A(z/FORMANT_PP_FACTOR_NUM) filter_coeffs (3.12) A(z/FORMANT_PP_FACTOR_NUM) filter coefficients in input speech data to process subframe_size size of one subframe
- Note
- in buffer must contain 10 items of previous speech data before top of the buffer
- Remarks
- It is safe to pass the same buffer for input and output.
Definition at line 86 of file g729postfilter.c.
Referenced by ff_g729_postfilter().
Variable Documentation
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long interpolation filter (of length 129, according to spec) for computing signal with non-integer delay
Definition at line 49 of file g729postfilter.c.
Referenced by long_term_filter().
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short interpolation filter (of length 33, according to spec) for computing signal with non-integer delay
Definition at line 40 of file g729postfilter.c.
Referenced by long_term_filter().
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formant_pp_factor_den_pow[i] = FORMANT_PP_FACTOR_DEN^(i+1)
Definition at line 71 of file g729postfilter.c.
Referenced by ff_g729_postfilter().
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formant_pp_factor_num_pow[i] = FORMANT_PP_FACTOR_NUM^(i+1)
Definition at line 63 of file g729postfilter.c.
Referenced by ff_g729_postfilter().
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