src/media/audio/codecs/g722.h

/*
 *  Copyright (C) 2004-2015 Savoir-Faire Linux Inc.
 *  Author:  Alexandre Savard <alexandre.savard@savoirfairelinux.com>
 *
 *  Mostly borrowed from asterisk's sources (Steve Underwood <steveu@coppice.org>)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.
 *
 *  Additional permission under GNU GPL version 3 section 7:
 *
 *  If you modify this program, or any covered work, by linking or
 *  combining it with the OpenSSL project's OpenSSL library (or a
 *  modified version of that library), containing parts covered by the
 *  terms of the OpenSSL or SSLeay licenses, Savoir-Faire Linux Inc.
 *  grants you additional permission to convey the resulting work.
 *  Corresponding Source for a non-source form of such a combination
 *  shall include the source code for the parts of OpenSSL used as well
 *  as that of the covered work.
 */

#ifndef G722_H_
#define G722_H_

/**

The G.722 module is a bit exact implementation of the ITU G.722 specification for all three
specified bit rates - 64000bps, 56000bps and 48000bps. It passes the ITU tests.

To allow fast and flexible interworking with narrow band telephony, the encoder and decoder
support an option for the linear audio to be an 8k samples/second stream. In this mode the
codec is considerably faster, and still fully compatible with wideband terminals using G.722.

*/

#include <stdint.h>

enum {
    G722_SAMPLE_RATE_8000 = 0x0001,
    G722_PACKED = 0x0002
};

#ifndef INT16_MAX
#define INT16_MAX 32767
#endif
#ifndef INT16_MIN
#define INT16_MIN (-32768)
#endif

struct g722_state_t {
    /*! TRUE if the operating in the special ITU test mode, with the band split filters
             disabled. */
    int itu_test_mode;
    /*! TRUE if the G.722 data is packed */
    int packed;
    /*! TRUE if encode from 8k samples/second */
    int eight_k;
    /*! 6 for 48000kbps, 7 for 56000kbps, or 8 for 64000kbps. */
    int bits_per_sample;

    /*! Signal history for the QMF */
    int x[24];

    struct {
        int s;
        int sp;
        int sz;
        int r[3];
        int a[3];
        int ap[3];
        int p[3];
        int d[7];
        int b[7];
        int bp[7];
        int sg[7];
        int nb;
        int det;
    } band[2];

    unsigned int in_buffer;
    int in_bits;
    unsigned int out_buffer;
    int out_bits;
};

#endif  // G722_H_