/*
 * SpanDSP - a series of DSP components for telephony
 *
 * g722.h - The ITU G.722 codec.
 *
 * Written by Steve Underwood <steveu@coppice.org>
 *
 * Copyright (C) 2005 Steve Underwood
 *
 *  Despite my general liking of the GPL, I place my own contributions
 *  to this code in the public domain for the benefit of all mankind -
 *  even the slimy ones who might try to proprietize my work and use it
 *  to my detriment.
 *
 * Based on a single channel G.722 codec which is:
 *
 *****    Copyright (c) CMU    1993      *****
 * Computer Science, Speech Group
 * Chengxiang Lu and Alex Hauptmann
 *
 * $Id: g722.h,v 1.10 2006/06/16 12:45:53 steveu Exp $
 *
 * Modifications for WebRtc, 2011/04/28, by tlegrand:
 * -Changed to use WebRtc types
 * -Added new defines for minimum and maximum values of short int
 */

/*! \file */

#if !defined(_G722_ENC_DEC_H_)
#define _G722_ENC_DEC_H_

#include <stdint.h>

/*! \page g722_page G.722 encoding and decoding
\section g722_page_sec_1 What does it do?
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.

\section g722_page_sec_2 How does it work?
???.
*/

#define WEBRTC_INT16_MAX 32767
#define WEBRTC_INT16_MIN -32768

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

typedef struct {
  /*! 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;
} G722EncoderState;

typedef struct {
  /*! 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 decode to 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;
} G722DecoderState;

#ifdef __cplusplus
extern "C" {
#endif

G722EncoderState* WebRtc_g722_encode_init(G722EncoderState* s,
                                          int rate,
                                          int options);
int WebRtc_g722_encode_release(G722EncoderState* s);
size_t WebRtc_g722_encode(G722EncoderState* s,
                          uint8_t g722_data[],
                          const int16_t amp[],
                          size_t len);

G722DecoderState* WebRtc_g722_decode_init(G722DecoderState* s,
                                          int rate,
                                          int options);
int WebRtc_g722_decode_release(G722DecoderState* s);
size_t WebRtc_g722_decode(G722DecoderState* s,
                          int16_t amp[],
                          const uint8_t g722_data[],
                          size_t len);

#ifdef __cplusplus
}
#endif

#endif