libavcodec/g723_1.c - manifest_repos/ffmpeg - Git at Google

 /*
  * G.723.1 compatible decoder
  * Copyright (c) 2006 Benjamin Larsson
  * Copyright (c) 2010 Mohamed Naufal Basheer
  *
  * 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 <stdint.h>

 #include "libavutil/common.h"

 #include "acelp_vectors.h"
 #include "avcodec.h"
 #include "celp_math.h"
 #include "g723_1.h"

 int ff_g723_1_scale_vector(int16_t *dst, const int16_t *vector, int length)
 {
     int bits, max = 0;
     int i;

     for (i = 0; i < length; i++)
         max |= FFABS(vector[i]);

     bits= 14 - av_log2_16bit(max);
     bits= FFMAX(bits, 0);

     for (i = 0; i < length; i++)
         dst[i] = (vector[i] * (1 << bits)) >> 3;

     return bits - 3;
 }

 int ff_g723_1_normalize_bits(int num, int width)
 {
     return width - av_log2(num) - 1;
 }

 int ff_g723_1_dot_product(const int16_t *a, const int16_t *b, int length)
 {
     int sum = ff_dot_product(a, b, length);
     return av_sat_add32(sum, sum);
 }

 void ff_g723_1_get_residual(int16_t *residual, int16_t *prev_excitation,
                             int lag)
 {
     int offset = PITCH_MAX - PITCH_ORDER / 2 - lag;
     int i;

     residual[0] = prev_excitation[offset];
     residual[1] = prev_excitation[offset + 1];

     offset += 2;
     for (i = 2; i < SUBFRAME_LEN + PITCH_ORDER - 1; i++)
         residual[i] = prev_excitation[offset + (i - 2) % lag];
 }

 void ff_g723_1_gen_dirac_train(int16_t *buf, int pitch_lag)
 {
     int16_t vector[SUBFRAME_LEN];
     int i, j;

     memcpy(vector, buf, SUBFRAME_LEN * sizeof(*vector));
     for (i = pitch_lag; i < SUBFRAME_LEN; i += pitch_lag) {
         for (j = 0; j < SUBFRAME_LEN - i; j++)
             buf[i + j] += vector[j];
     }
 }

 void ff_g723_1_gen_acb_excitation(int16_t *vector, int16_t *prev_excitation,
                                   int pitch_lag, G723_1_Subframe *subfrm,
                                   enum Rate cur_rate)
 {
     int16_t residual[SUBFRAME_LEN + PITCH_ORDER - 1];
     const int16_t *cb_ptr;
     int lag = pitch_lag + subfrm->ad_cb_lag - 1;

     int i;
     int sum;

     ff_g723_1_get_residual(residual, prev_excitation, lag);

     /* Select quantization table */
     if (cur_rate == RATE_6300 && pitch_lag < SUBFRAME_LEN - 2) {
         cb_ptr = adaptive_cb_gain85;
     } else
         cb_ptr = adaptive_cb_gain170;

     /* Calculate adaptive vector */
     cb_ptr += subfrm->ad_cb_gain * 20;
     for (i = 0; i < SUBFRAME_LEN; i++) {
         sum = ff_dot_product(residual + i, cb_ptr, PITCH_ORDER);
         vector[i] = av_sat_dadd32(1 << 15, av_sat_add32(sum, sum)) >> 16;
     }
 }

 /**
  * Convert LSP frequencies to LPC coefficients.
  *
  * @param lpc buffer for LPC coefficients
  */
 static void lsp2lpc(int16_t *lpc)
 {
     int f1[LPC_ORDER / 2 + 1];
     int f2[LPC_ORDER / 2 + 1];
     int i, j;

     /* Calculate negative cosine */
     for (j = 0; j < LPC_ORDER; j++) {
         int index     = (lpc[j] >> 7) & 0x1FF;
         int offset    = lpc[j] & 0x7f;
         int temp1     = cos_tab[index] * (1 << 16);
         int temp2     = (cos_tab[index + 1] - cos_tab[index]) *
                           (((offset << 8) + 0x80) << 1);

         lpc[j] = -(av_sat_dadd32(1 << 15, temp1 + temp2) >> 16);
     }

     /*
      * Compute sum and difference polynomial coefficients
      * (bitexact alternative to lsp2poly() in lsp.c)
      */
     /* Initialize with values in Q28 */
     f1[0] = 1 << 28;
     f1[1] = (lpc[0] + lpc[2]) * (1 << 14);
     f1[2] = lpc[0] * lpc[2] + (2 << 28);

     f2[0] = 1 << 28;
     f2[1] = (lpc[1] + lpc[3]) * (1 << 14);
     f2[2] = lpc[1] * lpc[3] + (2 << 28);

     /*
      * Calculate and scale the coefficients by 1/2 in
      * each iteration for a final scaling factor of Q25
      */
     for (i = 2; i < LPC_ORDER / 2; i++) {
         f1[i + 1] = av_clipl_int32(f1[i - 1] + (int64_t)MULL2(f1[i], lpc[2 * i]));
         f2[i + 1] = av_clipl_int32(f2[i - 1] + (int64_t)MULL2(f2[i], lpc[2 * i + 1]));

         for (j = i; j >= 2; j--) {
             f1[j] = MULL2(f1[j - 1], lpc[2 * i]) +
                     (f1[j] >> 1) + (f1[j - 2] >> 1);
             f2[j] = MULL2(f2[j - 1], lpc[2 * i + 1]) +
                     (f2[j] >> 1) + (f2[j - 2] >> 1);
         }

         f1[0] >>= 1;
         f2[0] >>= 1;
         f1[1] = ((lpc[2 * i]     * 65536 >> i) + f1[1]) >> 1;
         f2[1] = ((lpc[2 * i + 1] * 65536 >> i) + f2[1]) >> 1;
     }

     /* Convert polynomial coefficients to LPC coefficients */
     for (i = 0; i < LPC_ORDER / 2; i++) {
         int64_t ff1 = f1[i + 1] + f1[i];
         int64_t ff2 = f2[i + 1] - f2[i];

         lpc[i] = av_clipl_int32(((ff1 + ff2) * 8) + (1 << 15)) >> 16;
         lpc[LPC_ORDER - i - 1] = av_clipl_int32(((ff1 - ff2) * 8) +
                                                 (1 << 15)) >> 16;
     }
 }

 void ff_g723_1_lsp_interpolate(int16_t *lpc, int16_t *cur_lsp,
                                int16_t *prev_lsp)
 {
     int i;
     int16_t *lpc_ptr = lpc;

     /* cur_lsp * 0.25 + prev_lsp * 0.75 */
     ff_acelp_weighted_vector_sum(lpc, cur_lsp, prev_lsp,
                                  4096, 12288, 1 << 13, 14, LPC_ORDER);
     ff_acelp_weighted_vector_sum(lpc + LPC_ORDER, cur_lsp, prev_lsp,
                                  8192, 8192, 1 << 13, 14, LPC_ORDER);
     ff_acelp_weighted_vector_sum(lpc + 2 * LPC_ORDER, cur_lsp, prev_lsp,
                                  12288, 4096, 1 << 13, 14, LPC_ORDER);
     memcpy(lpc + 3 * LPC_ORDER, cur_lsp, LPC_ORDER * sizeof(*lpc));

     for (i = 0; i < SUBFRAMES; i++) {
         lsp2lpc(lpc_ptr);
         lpc_ptr += LPC_ORDER;
     }
 }

 void ff_g723_1_inverse_quant(int16_t *cur_lsp, int16_t *prev_lsp,
                              uint8_t *lsp_index, int bad_frame)
 {
     int min_dist, pred;
     int i, j, temp, stable;

     /* Check for frame erasure */
     if (!bad_frame) {
         min_dist     = 0x100;
         pred         = 12288;
     } else {
         min_dist     = 0x200;
         pred         = 23552;
         lsp_index[0] = lsp_index[1] = lsp_index[2] = 0;
     }

     /* Get the VQ table entry corresponding to the transmitted index */
     cur_lsp[0] = lsp_band0[lsp_index[0]][0];
     cur_lsp[1] = lsp_band0[lsp_index[0]][1];
     cur_lsp[2] = lsp_band0[lsp_index[0]][2];
     cur_lsp[3] = lsp_band1[lsp_index[1]][0];
     cur_lsp[4] = lsp_band1[lsp_index[1]][1];
     cur_lsp[5] = lsp_band1[lsp_index[1]][2];
     cur_lsp[6] = lsp_band2[lsp_index[2]][0];
     cur_lsp[7] = lsp_band2[lsp_index[2]][1];
     cur_lsp[8] = lsp_band2[lsp_index[2]][2];
     cur_lsp[9] = lsp_band2[lsp_index[2]][3];

     /* Add predicted vector & DC component to the previously quantized vector */
     for (i = 0; i < LPC_ORDER; i++) {
         temp        = ((prev_lsp[i] - dc_lsp[i]) * pred + (1 << 14)) >> 15;
         cur_lsp[i] += dc_lsp[i] + temp;
     }

     for (i = 0; i < LPC_ORDER; i++) {
         cur_lsp[0]             = FFMAX(cur_lsp[0],  0x180);
         cur_lsp[LPC_ORDER - 1] = FFMIN(cur_lsp[LPC_ORDER - 1], 0x7e00);

         /* Stability check */
         for (j = 1; j < LPC_ORDER; j++) {
             temp = min_dist + cur_lsp[j - 1] - cur_lsp[j];
             if (temp > 0) {
                 temp >>= 1;
                 cur_lsp[j - 1] -= temp;
                 cur_lsp[j]     += temp;
             }
         }
         stable = 1;
         for (j = 1; j < LPC_ORDER; j++) {
             temp = cur_lsp[j - 1] + min_dist - cur_lsp[j] - 4;
             if (temp > 0) {
                 stable = 0;
                 break;
             }
         }
         if (stable)
             break;
     }
     if (!stable)
         memcpy(cur_lsp, prev_lsp, LPC_ORDER * sizeof(*cur_lsp));
 }
	/*
	* G.723.1 compatible decoder
	* Copyright (c) 2006 Benjamin Larsson
	* Copyright (c) 2010 Mohamed Naufal Basheer
	*
	* 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 <stdint.h>

	#include "libavutil/common.h"

	#include "acelp_vectors.h"
	#include "avcodec.h"
	#include "celp_math.h"
	#include "g723_1.h"

	int ff_g723_1_scale_vector(int16_t dst, const int16_t vector, int length)
	{
	int bits, max = 0;
	int i;

	for (i = 0; i < length; i++)
	max \|= FFABS(vector[i]);

	bits= 14 - av_log2_16bit(max);
	bits= FFMAX(bits, 0);

	for (i = 0; i < length; i++)
	dst[i] = (vector[i] * (1 << bits)) >> 3;

	return bits - 3;
	}

	int ff_g723_1_normalize_bits(int num, int width)
	{
	return width - av_log2(num) - 1;
	}

	int ff_g723_1_dot_product(const int16_t a, const int16_t b, int length)
	{
	int sum = ff_dot_product(a, b, length);
	return av_sat_add32(sum, sum);
	}

	void ff_g723_1_get_residual(int16_t residual, int16_t prev_excitation,
	int lag)
	{
	int offset = PITCH_MAX - PITCH_ORDER / 2 - lag;
	int i;

	residual[0] = prev_excitation[offset];
	residual[1] = prev_excitation[offset + 1];

	offset += 2;
	for (i = 2; i < SUBFRAME_LEN + PITCH_ORDER - 1; i++)
	residual[i] = prev_excitation[offset + (i - 2) % lag];
	}

	void ff_g723_1_gen_dirac_train(int16_t *buf, int pitch_lag)
	{
	int16_t vector[SUBFRAME_LEN];
	int i, j;

	memcpy(vector, buf, SUBFRAME_LEN * sizeof(*vector));
	for (i = pitch_lag; i < SUBFRAME_LEN; i += pitch_lag) {
	for (j = 0; j < SUBFRAME_LEN - i; j++)
	buf[i + j] += vector[j];
	}
	}

	void ff_g723_1_gen_acb_excitation(int16_t vector, int16_t prev_excitation,
	int pitch_lag, G723_1_Subframe *subfrm,
	enum Rate cur_rate)
	{
	int16_t residual[SUBFRAME_LEN + PITCH_ORDER - 1];
	const int16_t *cb_ptr;
	int lag = pitch_lag + subfrm->ad_cb_lag - 1;

	int i;
	int sum;

	ff_g723_1_get_residual(residual, prev_excitation, lag);

	/* Select quantization table */
	if (cur_rate == RATE_6300 && pitch_lag < SUBFRAME_LEN - 2) {
	cb_ptr = adaptive_cb_gain85;
	} else
	cb_ptr = adaptive_cb_gain170;

	/* Calculate adaptive vector */
	cb_ptr += subfrm->ad_cb_gain * 20;
	for (i = 0; i < SUBFRAME_LEN; i++) {
	sum = ff_dot_product(residual + i, cb_ptr, PITCH_ORDER);
	vector[i] = av_sat_dadd32(1 << 15, av_sat_add32(sum, sum)) >> 16;
	}
	}

	/**
	* Convert LSP frequencies to LPC coefficients.
	*
	* @param lpc buffer for LPC coefficients
	*/
	static void lsp2lpc(int16_t *lpc)
	{
	int f1[LPC_ORDER / 2 + 1];
	int f2[LPC_ORDER / 2 + 1];
	int i, j;

	/* Calculate negative cosine */
	for (j = 0; j < LPC_ORDER; j++) {
	int index = (lpc[j] >> 7) & 0x1FF;
	int offset = lpc[j] & 0x7f;
	int temp1 = cos_tab[index] * (1 << 16);
	int temp2 = (cos_tab[index + 1] - cos_tab[index]) *
	(((offset << 8) + 0x80) << 1);

	lpc[j] = -(av_sat_dadd32(1 << 15, temp1 + temp2) >> 16);
	}

	/*
	* Compute sum and difference polynomial coefficients
	* (bitexact alternative to lsp2poly() in lsp.c)
	*/
	/* Initialize with values in Q28 */
	f1[0] = 1 << 28;
	f1[1] = (lpc[0] + lpc[2]) * (1 << 14);
	f1[2] = lpc[0] * lpc[2] + (2 << 28);

	f2[0] = 1 << 28;
	f2[1] = (lpc[1] + lpc[3]) * (1 << 14);
	f2[2] = lpc[1] * lpc[3] + (2 << 28);

	/*
	* Calculate and scale the coefficients by 1/2 in
	* each iteration for a final scaling factor of Q25
	*/
	for (i = 2; i < LPC_ORDER / 2; i++) {
	f1[i + 1] = av_clipl_int32(f1[i - 1] + (int64_t)MULL2(f1[i], lpc[2 * i]));
	f2[i + 1] = av_clipl_int32(f2[i - 1] + (int64_t)MULL2(f2[i], lpc[2 * i + 1]));

	for (j = i; j >= 2; j--) {
	f1[j] = MULL2(f1[j - 1], lpc[2 * i]) +
	(f1[j] >> 1) + (f1[j - 2] >> 1);
	f2[j] = MULL2(f2[j - 1], lpc[2 * i + 1]) +
	(f2[j] >> 1) + (f2[j - 2] >> 1);
	}

	f1[0] >>= 1;
	f2[0] >>= 1;
	f1[1] = ((lpc[2 * i] * 65536 >> i) + f1[1]) >> 1;
	f2[1] = ((lpc[2 * i + 1] * 65536 >> i) + f2[1]) >> 1;
	}

	/* Convert polynomial coefficients to LPC coefficients */
	for (i = 0; i < LPC_ORDER / 2; i++) {
	int64_t ff1 = f1[i + 1] + f1[i];
	int64_t ff2 = f2[i + 1] - f2[i];

	lpc[i] = av_clipl_int32(((ff1 + ff2) * 8) + (1 << 15)) >> 16;
	lpc[LPC_ORDER - i - 1] = av_clipl_int32(((ff1 - ff2) * 8) +
	(1 << 15)) >> 16;
	}
	}

	void ff_g723_1_lsp_interpolate(int16_t lpc, int16_t cur_lsp,
	int16_t *prev_lsp)
	{
	int i;
	int16_t *lpc_ptr = lpc;

	/* cur_lsp * 0.25 + prev_lsp * 0.75 */
	ff_acelp_weighted_vector_sum(lpc, cur_lsp, prev_lsp,
	4096, 12288, 1 << 13, 14, LPC_ORDER);
	ff_acelp_weighted_vector_sum(lpc + LPC_ORDER, cur_lsp, prev_lsp,
	8192, 8192, 1 << 13, 14, LPC_ORDER);
	ff_acelp_weighted_vector_sum(lpc + 2 * LPC_ORDER, cur_lsp, prev_lsp,
	12288, 4096, 1 << 13, 14, LPC_ORDER);
	memcpy(lpc + 3 * LPC_ORDER, cur_lsp, LPC_ORDER * sizeof(*lpc));

	for (i = 0; i < SUBFRAMES; i++) {
	lsp2lpc(lpc_ptr);
	lpc_ptr += LPC_ORDER;
	}
	}

	void ff_g723_1_inverse_quant(int16_t cur_lsp, int16_t prev_lsp,
	uint8_t *lsp_index, int bad_frame)
	{
	int min_dist, pred;
	int i, j, temp, stable;

	/* Check for frame erasure */
	if (!bad_frame) {
	min_dist = 0x100;
	pred = 12288;
	} else {
	min_dist = 0x200;
	pred = 23552;
	lsp_index[0] = lsp_index[1] = lsp_index[2] = 0;
	}

	/* Get the VQ table entry corresponding to the transmitted index */
	cur_lsp[0] = lsp_band0[lsp_index[0]][0];
	cur_lsp[1] = lsp_band0[lsp_index[0]][1];
	cur_lsp[2] = lsp_band0[lsp_index[0]][2];
	cur_lsp[3] = lsp_band1[lsp_index[1]][0];
	cur_lsp[4] = lsp_band1[lsp_index[1]][1];
	cur_lsp[5] = lsp_band1[lsp_index[1]][2];
	cur_lsp[6] = lsp_band2[lsp_index[2]][0];
	cur_lsp[7] = lsp_band2[lsp_index[2]][1];
	cur_lsp[8] = lsp_band2[lsp_index[2]][2];
	cur_lsp[9] = lsp_band2[lsp_index[2]][3];

	/* Add predicted vector & DC component to the previously quantized vector */
	for (i = 0; i < LPC_ORDER; i++) {
	temp = ((prev_lsp[i] - dc_lsp[i]) * pred + (1 << 14)) >> 15;
	cur_lsp[i] += dc_lsp[i] + temp;
	}

	for (i = 0; i < LPC_ORDER; i++) {
	cur_lsp[0] = FFMAX(cur_lsp[0], 0x180);
	cur_lsp[LPC_ORDER - 1] = FFMIN(cur_lsp[LPC_ORDER - 1], 0x7e00);

	/* Stability check */
	for (j = 1; j < LPC_ORDER; j++) {
	temp = min_dist + cur_lsp[j - 1] - cur_lsp[j];
	if (temp > 0) {
	temp >>= 1;
	cur_lsp[j - 1] -= temp;
	cur_lsp[j] += temp;
	}
	}
	stable = 1;
	for (j = 1; j < LPC_ORDER; j++) {
	temp = cur_lsp[j - 1] + min_dist - cur_lsp[j] - 4;
	if (temp > 0) {
	stable = 0;
	break;
	}
	}
	if (stable)
	break;
	}
	if (!stable)
	memcpy(cur_lsp, prev_lsp, LPC_ORDER * sizeof(*cur_lsp));
	}