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  • /*
     * adaptive and fixed codebook vector operations for ACELP-based codecs
     *
     * Copyright (c) 2008 Vladimir Voroshilov
     *
     * This file is part of FFmpeg.
     *
     * FFmpeg is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     *
     * FFmpeg is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     *
     * You should have received a copy of the GNU Lesser General Public
     * License along with FFmpeg; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     */
    
    
    #ifndef AVCODEC_ACELP_VECTORS_H
    #define AVCODEC_ACELP_VECTORS_H
    
    /** Sparse representation for the algebraic codebook (fixed) vector */
    typedef struct {
        int      n;
        int      x[10];
        float    y[10];
        int      pitch_lag;
        float    pitch_fac;
    } AMRFixed;
    
    
     * Track|Pulse|        Positions
     * -------------------------------------------------------------------------
     *  1   | 0   | 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75
     * -------------------------------------------------------------------------
     *  2   | 1   | 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76
     * -------------------------------------------------------------------------
     *  3   | 2   | 2, 7, 12, 17, 22, 27, 32, 37, 42, 47, 52, 57, 62, 67, 72, 77
     * -------------------------------------------------------------------------
     *
     * Table contains only first the pulse indexes.
     *
     * Used in G.729 @8k, G.729 @4.4k, AMR @7.95k, AMR @7.40k
     */
    extern const uint8_t ff_fc_4pulses_8bits_tracks_13[16];
    
    
     * Track|Pulse|        Positions
     * -------------------------------------------------------------------------
     *  4   | 3   | 3, 8, 13, 18, 23, 28, 33, 38, 43, 48, 53, 58, 63, 68, 73, 78
     *      |     | 4, 9, 14, 19, 24, 29, 34, 39, 44, 49, 54, 59, 64, 69, 74, 79
     * -------------------------------------------------------------------------
     *
    
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     * @remark Track in the table should be read top-to-bottom, left-to-right.
    
     *
     * Used in G.729 @8k, G.729 @4.4k, AMR @7.95k, AMR @7.40k
     */
    extern const uint8_t ff_fc_4pulses_8bits_track_4[32];
    
    
     * Track|Pulse|        Positions
     * -----------------------------------------
     *  1   | 0   | 1, 6, 11, 16, 21, 26, 31, 36
     *      |     | 3, 8, 13, 18, 23, 28, 33, 38
     * -----------------------------------------
     *
    
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     * @remark Track in the table should be read top-to-bottom, left-to-right.
    
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     * @note (EE) Reference G.729D code also uses gray decoding for each
    
     *            pulse index before looking up the value in the table.
     *
    
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     * Used in G.729 @6.4k (with gray coding), AMR @5.9k (without gray coding)
    
     */
    extern const uint8_t ff_fc_2pulses_9bits_track1[16];
    extern const uint8_t ff_fc_2pulses_9bits_track1_gray[16];
    
    
     * Track|Pulse|        Positions
     * -----------------------------------------
     *  2   | 1   | 0, 7, 14, 20, 27, 34,  1, 21
     *      |     | 2, 9, 15, 22, 29, 35,  6, 26
     *      |     | 4,10, 17, 24, 30, 37, 11, 31
     *      |     | 5,12, 19, 25, 32, 39, 16, 36
     * -----------------------------------------
     *
    
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     * @remark Track in the table should be read top-to-bottom, left-to-right.
    
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     * @note (EE.1) This table (from the reference code) does not comply with
    
     *              the specification.
     *              The specification contains the following table:
     *
     * Track|Pulse|        Positions
     * -----------------------------------------
     *  2   | 1   | 0, 5, 10, 15, 20, 25, 30, 35
     *      |     | 1, 6, 11, 16, 21, 26, 31, 36
     *      |     | 2, 7, 12, 17, 22, 27, 32, 37
     *      |     | 4, 9, 14, 19, 24, 29, 34, 39
     *
     * -----------------------------------------
     *
    
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     * @note (EE.2) Reference G.729D code also uses gray decoding for each
    
     *              pulse index before looking up the value in the table.
     *
     * Used in G.729 @6.4k (with gray coding)
     */
    extern const uint8_t ff_fc_2pulses_9bits_track2_gray[32];
    
    
    /**
     * b60 hamming windowed sinc function coefficients
     */
    extern const float ff_b60_sinc[61];
    
    /**
     * Table of pow(0.7,n)
     */
    extern const float ff_pow_0_7[10];
    
    /**
     * Table of pow(0.75,n)
     */
    extern const float ff_pow_0_75[10];
    
    /**
     * Table of pow(0.55,n)
     */
    extern const float ff_pow_0_55[10];
    
    
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     * Decode fixed-codebook vector (3.8 and D.5.8 of G.729, 5.7.1 of AMR).
     * @param fc_v [out] decoded fixed codebook vector (2.13)
     * @param tab1 table used for first pulse_count pulses
     * @param tab2 table used for last pulse
     * @param pulse_indexes fixed codebook indexes
     * @param pulse_signs signs of the excitation pulses (0 bit value
    
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     * @param bits number of bits per one pulse index
     * @param pulse_count number of pulses decoded using first table
     * @param bits length of one pulse index in bits
    
     *
     * Used in G.729 @8k, G.729 @4.4k, G.729 @6.4k, AMR @7.95k, AMR @7.40k
     */
    
    void ff_acelp_fc_pulse_per_track(int16_t* fc_v,
                                     const uint8_t *tab1,
                                     const uint8_t *tab2,
                                     int pulse_indexes,
                                     int pulse_signs,
                                     int pulse_count,
                                     int bits);
    
    /**
     * Decode the algebraic codebook index to pulse positions and signs and
     * construct the algebraic codebook vector for MODE_12k2.
     *
     * @note: The positions and signs are explicitly coded in MODE_12k2.
     *
     * @param fixed_index          positions of the ten pulses
     * @param fixed_sparse         pointer to the algebraic codebook vector
     * @param gray_decode          gray decoding table
     * @param half_pulse_count     number of couples of pulses
     * @param bits                 length of one pulse index in bits
     */
    void ff_decode_10_pulses_35bits(const int16_t *fixed_index,
                                    AMRFixed *fixed_sparse,
                                    const uint8_t *gray_decode,
                                    int half_pulse_count, int bits);
    
    
    
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     * weighted sum of two vectors with rounding.
     * @param out [out] result of addition
     * @param in_a first vector
     * @param in_b second vector
     * @param weight_coeff_a first vector weight coefficient
     * @param weight_coeff_a second vector weight coefficient
     * @param rounder this value will be added to the sum of the two vectors
     * @param shift result will be shifted to right by this value
     * @param length vectors length
     *
     * @note It is safe to pass the same buffer for out and in_a or in_b.
    
     *  out[i] = (in_a[i]*weight_a + in_b[i]*weight_b + rounder) >> shift
    
    void ff_acelp_weighted_vector_sum(int16_t* out,
                                      const int16_t *in_a,
                                      const int16_t *in_b,
                                      int16_t weight_coeff_a,
                                      int16_t weight_coeff_b,
                                      int16_t rounder,
                                      int shift,
                                      int length);
    
    /**
     * float implementation of weighted sum of two vectors.
     * @param out [out] result of addition
     * @param in_a first vector
     * @param in_b second vector
     * @param weight_coeff_a first vector weight coefficient
     * @param weight_coeff_a second vector weight coefficient
     * @param length vectors length
     *
     * @note It is safe to pass the same buffer for out and in_a or in_b.
     */
    void ff_weighted_vector_sumf(float *out, const float *in_a, const float *in_b,
    
                                 float weight_coeff_a, float weight_coeff_b,
                                 int length);
    
    /**
     * Adaptative gain control (as used in AMR postfiltering)
     *
     * @param buf_out the input speech buffer
     * @param speech_energ input energy
     * @param size the input buffer size
     * @param alpha exponential filter factor
     * @param gain_mem a pointer to the filter memory (single float of size)
     */
    void ff_adaptative_gain_control(float *buf_out, float speech_energ,
                                    int size, float alpha, float *gain_mem);
    
    
    /**
     * Set the sum of squares of a signal by scaling
     *
     * @param out output samples
     * @param in input samples
     * @param sum_of_squares new sum of squares
     * @param n number of samples
     *
     * @note If the input is zero (or its energy underflows), the output is zero.
     *       This is the behavior of AGC in the AMR reference decoder. The QCELP
     *       reference decoder seems to have undefined behavior.
     *
     * TIA/EIA/IS-733 2.4.8.3-2/3/4/5, 2.4.8.6
     * 3GPP TS 26.090 6.1 (6)
     */
    void ff_scale_vector_to_given_sum_of_squares(float *out, const float *in,
                                                 float sum_of_squares, const int n);
    
    
    /**
     * Add fixed vector to an array from a sparse representation
     *
     * @param out fixed vector with pitch sharpening
     * @param in sparse fixed vector
     * @param scale number to multiply the fixed vector by
     * @param size the output vector size
     */
    void ff_set_fixed_vector(float *out, const AMRFixed *in, float scale, int size);
    
    /**
     * Clear array values set by set_fixed_vector
     *
     * @param out fixed vector to be cleared
     * @param in sparse fixed vector
     * @param size the output vector size
     */
    void ff_clear_fixed_vector(float *out, const AMRFixed *in, int size);
    
    
    #endif /* AVCODEC_ACELP_VECTORS_H */