[deb_ffmpeg.git] / ffmpeg / libavcodec / acelp_pitch_delay.c

/*
 * gain code, gain pitch and pitch delay decoding
 *
 * 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
 */

#include "libavutil/common.h"
#include "libavutil/float_dsp.h"
#include "libavutil/libm.h"
#include "libavutil/mathematics.h"
#include "avcodec.h"
#include "acelp_pitch_delay.h"
#include "celp_math.h"
#include "audiodsp.h"

int ff_acelp_decode_8bit_to_1st_delay3(int ac_index)
{
    ac_index += 58;
    if(ac_index > 254)
        ac_index = 3 * ac_index - 510;
    return ac_index;
}

int ff_acelp_decode_4bit_to_2nd_delay3(
        int ac_index,
        int pitch_delay_min)
{
    if(ac_index < 4)
        return 3 * (ac_index + pitch_delay_min);
    else if(ac_index < 12)
        return 3 * pitch_delay_min + ac_index + 6;
    else
        return 3 * (ac_index + pitch_delay_min) - 18;
}

int ff_acelp_decode_5_6_bit_to_2nd_delay3(
        int ac_index,
        int pitch_delay_min)
{
        return 3 * pitch_delay_min + ac_index - 2;
}

int ff_acelp_decode_9bit_to_1st_delay6(int ac_index)
{
    if(ac_index < 463)
        return ac_index + 105;
    else
        return 6 * (ac_index - 368);
}
int ff_acelp_decode_6bit_to_2nd_delay6(
        int ac_index,
        int pitch_delay_min)
{
    return 6 * pitch_delay_min + ac_index - 3;
}

void ff_acelp_update_past_gain(
    int16_t* quant_energy,
    int gain_corr_factor,
    int log2_ma_pred_order,
    int erasure)
{
    int i;
    int avg_gain=quant_energy[(1 << log2_ma_pred_order) - 1]; // (5.10)

    for(i=(1 << log2_ma_pred_order) - 1; i>0; i--)
    {
        avg_gain       += quant_energy[i-1];
        quant_energy[i] = quant_energy[i-1];
    }

    if(erasure)
        quant_energy[0] = FFMAX(avg_gain >> log2_ma_pred_order, -10240) - 4096; // -10 and -4 in (5.10)
    else
        quant_energy[0] = (6165 * ((ff_log2_q15(gain_corr_factor) >> 2) - (13 << 13))) >> 13;
}

int16_t ff_acelp_decode_gain_code(
    AudioDSPContext *adsp,
    int gain_corr_factor,
    const int16_t* fc_v,
    int mr_energy,
    const int16_t* quant_energy,
    const int16_t* ma_prediction_coeff,
    int subframe_size,
    int ma_pred_order)
{
    int i;

    mr_energy <<= 10;

    for(i=0; i<ma_pred_order; i++)
        mr_energy += quant_energy[i] * ma_prediction_coeff[i];

#ifdef G729_BITEXACT
    mr_energy += (((-6165LL * ff_log2(dsp->scalarproduct_int16(fc_v, fc_v, subframe_size, 0))) >> 3) & ~0x3ff);

    mr_energy = (5439 * (mr_energy >> 15)) >> 8;           // (0.15) = (0.15) * (7.23)

    return bidir_sal(
               ((ff_exp2(mr_energy & 0x7fff) + 16) >> 5) * (gain_corr_factor >> 1),
               (mr_energy >> 15) - 25
           );
#else
    mr_energy = gain_corr_factor * exp(M_LN10 / (20 << 23) * mr_energy) /
                sqrt(adsp->scalarproduct_int16(fc_v, fc_v, subframe_size));
    return mr_energy >> 12;
#endif
}

float ff_amr_set_fixed_gain(float fixed_gain_factor, float fixed_mean_energy,
                            float *prediction_error, float energy_mean,
                            const float *pred_table)
{
    // Equations 66-69:
    // ^g_c = ^gamma_gc * 100.05 (predicted dB + mean dB - dB of fixed vector)
    // Note 10^(0.05 * -10log(average x2)) = 1/sqrt((average x2)).
    float val = fixed_gain_factor *
        exp2f(M_LOG2_10 * 0.05 *
              (avpriv_scalarproduct_float_c(pred_table, prediction_error, 4) +
               energy_mean)) /
        sqrtf(fixed_mean_energy);

    // update quantified prediction error energy history
    memmove(&prediction_error[0], &prediction_error[1],
            3 * sizeof(prediction_error[0]));
    prediction_error[3] = 20.0 * log10f(fixed_gain_factor);

    return val;
}

void ff_decode_pitch_lag(int *lag_int, int *lag_frac, int pitch_index,
                         const int prev_lag_int, const int subframe,
                         int third_as_first, int resolution)
{
    /* Note n * 10923 >> 15 is floor(x/3) for 0 <= n <= 32767 */
    if (subframe == 0 || (subframe == 2 && third_as_first)) {

        if (pitch_index < 197)
            pitch_index += 59;
        else
            pitch_index = 3 * pitch_index - 335;

    } else {
        if (resolution == 4) {
            int search_range_min = av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
                                           PITCH_DELAY_MAX - 9);

            // decoding with 4-bit resolution
            if (pitch_index < 4) {
                // integer only precision for [search_range_min, search_range_min+3]
                pitch_index = 3 * (pitch_index + search_range_min) + 1;
            } else if (pitch_index < 12) {
                // 1/3 fractional precision for [search_range_min+3 1/3, search_range_min+5 2/3]
                pitch_index += 3 * search_range_min + 7;
            } else {
                // integer only precision for [search_range_min+6, search_range_min+9]
                pitch_index = 3 * (pitch_index + search_range_min - 6) + 1;
            }
        } else {
            // decoding with 5 or 6 bit resolution, 1/3 fractional precision
            pitch_index--;

            if (resolution == 5) {
                pitch_index += 3 * av_clip(prev_lag_int - 10, PITCH_DELAY_MIN,
                                           PITCH_DELAY_MAX - 19);
            } else
                pitch_index += 3 * av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
                                           PITCH_DELAY_MAX - 9);
        }
    }
    *lag_int  = pitch_index * 10923 >> 15;
    *lag_frac = pitch_index - 3 * *lag_int - 1;
}
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* gain code, gain pitch and pitch delay decoding
	3	*
	4	* Copyright (c) 2008 Vladimir Voroshilov
	5	*
	6	* This file is part of FFmpeg.
	7	*
	8	* FFmpeg is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; either
	11	* version 2.1 of the License, or (at your option) any later version.
	12	*
	13	* FFmpeg is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with FFmpeg; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	21	*/
	22
	23	#include "libavutil/common.h"
	24	#include "libavutil/float_dsp.h"
	25	#include "libavutil/libm.h"
	26	#include "libavutil/mathematics.h"
	27	#include "avcodec.h"
	28	#include "acelp_pitch_delay.h"
	29	#include "celp_math.h"
	30	#include "audiodsp.h"
	31
	32	int ff_acelp_decode_8bit_to_1st_delay3(int ac_index)
	33	{
	34	ac_index += 58;
	35	if(ac_index > 254)
	36	ac_index = 3 * ac_index - 510;
	37	return ac_index;
	38	}
	39
	40	int ff_acelp_decode_4bit_to_2nd_delay3(
	41	int ac_index,
	42	int pitch_delay_min)
	43	{
	44	if(ac_index < 4)
	45	return 3 * (ac_index + pitch_delay_min);
	46	else if(ac_index < 12)
	47	return 3 * pitch_delay_min + ac_index + 6;
	48	else
	49	return 3 * (ac_index + pitch_delay_min) - 18;
	50	}
	51
	52	int ff_acelp_decode_5_6_bit_to_2nd_delay3(
	53	int ac_index,
	54	int pitch_delay_min)
	55	{
	56	return 3 * pitch_delay_min + ac_index - 2;
	57	}
	58
	59	int ff_acelp_decode_9bit_to_1st_delay6(int ac_index)
	60	{
	61	if(ac_index < 463)
	62	return ac_index + 105;
	63	else
	64	return 6 * (ac_index - 368);
65	}
66	int ff_acelp_decode_6bit_to_2nd_delay6(
67	int ac_index,
68	int pitch_delay_min)
69	{
70	return 6 * pitch_delay_min + ac_index - 3;
71	}
72
73	void ff_acelp_update_past_gain(
74	int16_t* quant_energy,
75	int gain_corr_factor,
76	int log2_ma_pred_order,
77	int erasure)
78	{
79	int i;
80	int avg_gain=quant_energy[(1 << log2_ma_pred_order) - 1]; // (5.10)
81
82	for(i=(1 << log2_ma_pred_order) - 1; i>0; i--)
83	{
84	avg_gain += quant_energy[i-1];
85	quant_energy[i] = quant_energy[i-1];
86	}
87
88	if(erasure)
89	quant_energy[0] = FFMAX(avg_gain >> log2_ma_pred_order, -10240) - 4096; // -10 and -4 in (5.10)
90	else
91	quant_energy[0] = (6165 * ((ff_log2_q15(gain_corr_factor) >> 2) - (13 << 13))) >> 13;
92	}
93
94	int16_t ff_acelp_decode_gain_code(
95	AudioDSPContext *adsp,
96	int gain_corr_factor,
97	const int16_t* fc_v,
98	int mr_energy,
99	const int16_t* quant_energy,
100	const int16_t* ma_prediction_coeff,
101	int subframe_size,
102	int ma_pred_order)
103	{
104	int i;
105
106	mr_energy <<= 10;
107
108	for(i=0; i<ma_pred_order; i++)
109	mr_energy += quant_energy[i] * ma_prediction_coeff[i];
110
111	#ifdef G729_BITEXACT
112	mr_energy += (((-6165LL * ff_log2(dsp->scalarproduct_int16(fc_v, fc_v, subframe_size, 0))) >> 3) & ~0x3ff);
113
114	mr_energy = (5439 * (mr_energy >> 15)) >> 8; // (0.15) = (0.15) * (7.23)
115
116	return bidir_sal(
117	((ff_exp2(mr_energy & 0x7fff) + 16) >> 5) * (gain_corr_factor >> 1),
118	(mr_energy >> 15) - 25
119	);
120	#else
121	mr_energy = gain_corr_factor * exp(M_LN10 / (20 << 23) * mr_energy) /
122	sqrt(adsp->scalarproduct_int16(fc_v, fc_v, subframe_size));
123	return mr_energy >> 12;
124	#endif
125	}
126
127	float ff_amr_set_fixed_gain(float fixed_gain_factor, float fixed_mean_energy,
128	float *prediction_error, float energy_mean,
129	const float *pred_table)
130	{
131	// Equations 66-69:
132	// ^g_c = ^gamma_gc * 100.05 (predicted dB + mean dB - dB of fixed vector)
133	// Note 10^(0.05 * -10log(average x2)) = 1/sqrt((average x2)).
134	float val = fixed_gain_factor *
135	exp2f(M_LOG2_10 * 0.05 *
136	(avpriv_scalarproduct_float_c(pred_table, prediction_error, 4) +
137	energy_mean)) /
138	sqrtf(fixed_mean_energy);
139
140	// update quantified prediction error energy history
141	memmove(&prediction_error[0], &prediction_error[1],
142	3 * sizeof(prediction_error[0]));
143	prediction_error[3] = 20.0 * log10f(fixed_gain_factor);
144
145	return val;
146	}
147
148	void ff_decode_pitch_lag(int lag_int, int lag_frac, int pitch_index,
149	const int prev_lag_int, const int subframe,
150	int third_as_first, int resolution)
151	{
152	/* Note n * 10923 >> 15 is floor(x/3) for 0 <= n <= 32767 */
153	if (subframe == 0 \|\| (subframe == 2 && third_as_first)) {
154
155	if (pitch_index < 197)
156	pitch_index += 59;
157	else
158	pitch_index = 3 * pitch_index - 335;
159
160	} else {
161	if (resolution == 4) {
162	int search_range_min = av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
163	PITCH_DELAY_MAX - 9);
164
165	// decoding with 4-bit resolution
166	if (pitch_index < 4) {
167	// integer only precision for [search_range_min, search_range_min+3]
168	pitch_index = 3 * (pitch_index + search_range_min) + 1;
169	} else if (pitch_index < 12) {
170	// 1/3 fractional precision for [search_range_min+3 1/3, search_range_min+5 2/3]
171	pitch_index += 3 * search_range_min + 7;
172	} else {
173	// integer only precision for [search_range_min+6, search_range_min+9]
174	pitch_index = 3 * (pitch_index + search_range_min - 6) + 1;
175	}
176	} else {
177	// decoding with 5 or 6 bit resolution, 1/3 fractional precision
178	pitch_index--;
179
180	if (resolution == 5) {
181	pitch_index += 3 * av_clip(prev_lag_int - 10, PITCH_DELAY_MIN,
182	PITCH_DELAY_MAX - 19);
183	} else
184	pitch_index += 3 * av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
185	PITCH_DELAY_MAX - 9);
186	}
187	}
188	lag_int = pitch_index 10923 >> 15;
189	lag_frac = pitch_index - 3 *lag_int - 1;
190	}