libavcodec/g722.h

   1 /*
   2  * Copyright (c) CMU 1993 Computer Science, Speech Group
   3  *                        Chengxiang Lu and Alex Hauptmann
   4  * Copyright (c) 2005 Steve Underwood <steveu at coppice.org>
   5  * Copyright (c) 2009 Kenan Gillet
   6  * Copyright (c) 2010 Martin Storsjo
   7  *
   8  * This file is part of Libav.
   9  *
  10  * Libav is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * Libav is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with Libav; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 #ifndef AVCODEC_G722_H
  26 #define AVCODEC_G722_H
  27
  28 #include <stdint.h>
  29 #include "avcodec.h"
  30
  31 #define PREV_SAMPLES_BUF_SIZE 1024
  32
  33 typedef struct G722Context {
  34     const AVClass *class;
  35     int     bits_per_codeword;
  36     int16_t prev_samples[PREV_SAMPLES_BUF_SIZE]; ///< memory of past decoded samples
  37     int     prev_samples_pos;        ///< the number of values in prev_samples
  38
  39     /**
  40      * The band[0] and band[1] correspond respectively to the lower band and higher band.
  41      */
  42     struct G722Band {
  43         int16_t s_predictor;         ///< predictor output value
  44         int32_t s_zero;              ///< previous output signal from zero predictor
  45         int8_t  part_reconst_mem[2]; ///< signs of previous partially reconstructed signals
  46         int16_t prev_qtzd_reconst;   ///< previous quantized reconstructed signal (internal value, using low_inv_quant4)
  47         int16_t pole_mem[2];         ///< second-order pole section coefficient buffer
  48         int32_t diff_mem[6];         ///< quantizer difference signal memory
  49         int16_t zero_mem[6];         ///< Seventh-order zero section coefficient buffer
  50         int16_t log_factor;          ///< delayed 2-logarithmic quantizer factor
  51         int16_t scale_factor;        ///< delayed quantizer scale factor
  52     } band[2];
  53
  54     struct TrellisNode {
  55         struct G722Band state;
  56         uint32_t ssd;
  57         int path;
  58     } *node_buf[2], **nodep_buf[2];
  59
  60     struct TrellisPath {
  61         int value;
  62         int prev;
  63     } *paths[2];
  64 } G722Context;
  65
  66 extern const int16_t ff_g722_high_inv_quant[4];
  67 extern const int16_t ff_g722_low_inv_quant4[16];
  68 extern const int16_t ff_g722_low_inv_quant6[64];
  69
  70 void ff_g722_update_low_predictor(struct G722Band *band, const int ilow);
  71
  72 void ff_g722_update_high_predictor(struct G722Band *band, const int dhigh,
  73                                    const int ihigh);
  74
  75 void ff_g722_apply_qmf(const int16_t *prev_samples, int *xout1, int *xout2);
  76
  77 #endif /* AVCODEC_G722_H */