webrtc/webrtc/modules/audio_coding/codecs/g711/include/g711_interface.h

/*
 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef MODULES_AUDIO_CODING_CODECS_G711_MAIN_INTERFACE_G711_INTERFACE_H_
#define MODULES_AUDIO_CODING_CODECS_G711_MAIN_INTERFACE_G711_INTERFACE_H_

#include "webrtc/typedefs.h"

// Comfort noise constants
#define G711_WEBRTC_SPEECH 1
#define G711_WEBRTC_CNG 2

#ifdef __cplusplus
extern "C" {
#endif

/****************************************************************************
 * WebRtcG711_EncodeA(...)
 *
 * This function encodes a G711 A-law frame and inserts it into a packet.
 * Input speech length has be of any length.
 *
 * Input:
 *      - speechIn           : Input speech vector
 *      - len                : Samples in speechIn
 *
 * Output:
 *      - encoded            : The encoded data vector
 *
 * Return value              : Length (in bytes) of coded data.
 *                             Always equal to len input parameter.
 */

int16_t WebRtcG711_EncodeA(const int16_t* speechIn,
                           int16_t len,
                           uint8_t* encoded);

/****************************************************************************
 * WebRtcG711_EncodeU(...)
 *
 * This function encodes a G711 U-law frame and inserts it into a packet.
 * Input speech length has be of any length.
 *
 * Input:
 *      - speechIn           : Input speech vector
 *      - len                : Samples in speechIn
 *
 * Output:
 *      - encoded            : The encoded data vector
 *
 * Return value              : Length (in bytes) of coded data.
 *                             Always equal to len input parameter.
 */

int16_t WebRtcG711_EncodeU(const int16_t* speechIn,
                           int16_t len,
                           uint8_t* encoded);

/****************************************************************************
 * WebRtcG711_DecodeA(...)
 *
 * This function decodes a packet G711 A-law frame.
 *
 * Input:
 *      - encoded            : Encoded data
 *      - len                : Bytes in encoded vector
 *
 * Output:
 *      - decoded            : The decoded vector
 *      - speechType         : 1 normal, 2 CNG (for G711 it should
 *                             always return 1 since G711 does not have a
 *                             built-in DTX/CNG scheme)
 *
 * Return value              : >0 - Samples in decoded vector
 *                             -1 - Error
 */

int16_t WebRtcG711_DecodeA(const uint8_t* encoded,
                           int16_t len,
                           int16_t* decoded,
                           int16_t* speechType);

/****************************************************************************
 * WebRtcG711_DecodeU(...)
 *
 * This function decodes a packet G711 U-law frame.
 *
 * Input:
 *      - encoded            : Encoded data
 *      - len                : Bytes in encoded vector
 *
 * Output:
 *      - decoded            : The decoded vector
 *      - speechType         : 1 normal, 2 CNG (for G711 it should
 *                             always return 1 since G711 does not have a
 *                             built-in DTX/CNG scheme)
 *
 * Return value              : >0 - Samples in decoded vector
 *                             -1 - Error
 */

int16_t WebRtcG711_DecodeU(const uint8_t* encoded,
                           int16_t len,
                           int16_t* decoded,
                           int16_t* speechType);

/****************************************************************************
 * WebRtcG711_DurationEst(...)
 *
 * This function estimates the duration of a G711 packet in samples.
 *
 * Input:
 *      - payload            : Encoded data
 *      - payloadLengthBytes : Bytes in encoded vector
 *
 * Return value              : The duration of the packet in samples, which is
 *                             just payload_length_bytes, since G.711 uses one
 *                             byte per sample.
 */

int WebRtcG711_DurationEst(const uint8_t* payload,
                           int payload_length_bytes);

/**********************************************************************
* WebRtcG711_Version(...)
*
* This function gives the version string of the G.711 codec.
*
* Input:
*      - lenBytes:     the size of Allocated space (in Bytes) where
*                      the version number is written to (in string format).
*
* Output:
*      - version:      Pointer to a buffer where the version number is
*                      written to.
*
*/

int16_t WebRtcG711_Version(char* version, int16_t lenBytes);

#ifdef __cplusplus
}
#endif

#endif /* MODULES_AUDIO_CODING_CODECS_G711_MAIN_INTERFACE_G711_INTERFACE_H_ */