gsmamr_enc.h

实现3GPP的GSM中AMR语音的CODECS。

/* ------------------------------------------------------------------
 * Copyright (C) 2008 PacketVideo
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 * -------------------------------------------------------------------
 */
/****************************************************************************************
Portions of this file are derived from the following 3GPP standard:

    3GPP TS 26.073
    ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
    Available from http://www.3gpp.org

(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
Permission to distribute, modify and use this file under the standard license
terms listed above has been obtained from the copyright holder.
****************************************************************************************/
/*
------------------------------------------------------------------------------



 Filename: /audio/gsm-amr/c/include/gsmamr_enc.h

     Date: 09/26/2001

------------------------------------------------------------------------------
 REVISION HISTORY

 Description: Changing code as per review comments. These changes include
              removing unnecessary tables and changing function descriptions.
              The comments were changed to "slash-star" rather than double
              slash, and some wordings of comments were corrected.

 Description: Replaced GSMEncodeFrame function prototype with that of
              AMREncode. Updated copyright year.

 Description: Added #define for WMF and IF2, and updated function prototype
              of AMREncode.

 Description: Renamed WMF and IF2 to AMR_WMF and AMR_IF2, respectively. Added
              AMR_ETS, and changed output_type to output_format in the
              function prototype of AMREncode(). Removed function prototypes
              for frame_header_move() and reverse_bits() since they are not
              needed anymore.

 Description: Moved WMFBytesUsed and IF2BytesUsed tables to
              enc_output_format_tab.c.

 Description: Added function prototypes for init, reset, and exit functions
              in amrencode.c. Renamed output format #defines so that it it
              unique to the encoder.

 Description: Added comment to describe L_FRAME.

 Description: Added Frame_Type_3GPP type definition.

 Description: Moved _cplusplus #ifdef after Include section.

 Description:

------------------------------------------------------------------------------
 INCLUDE DESCRIPTION

 This header contains all the necessary information needed to use the
 GSM AMR encoder library.

------------------------------------------------------------------------------
*/
#ifndef _GSMAMR_ENC_H_
#define _GSMAMR_ENC_H_

/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/

#include "gsm_amr_typedefs.h"

/*--------------------------------------------------------------------------*/
#ifdef __cplusplus
extern "C"
{
#endif

    /*----------------------------------------------------------------------------
    ; MACROS
    ----------------------------------------------------------------------------*/


    /*----------------------------------------------------------------------------
    ; DEFINES
    ----------------------------------------------------------------------------*/
    /* Number of 13-bit linear PCM samples per 20 ms frame */
    /* L_FRAME = (8 kHz) * (20 msec) = 160 samples         */
#define L_FRAME     160

    /* Output format types */
#define AMR_TX_WMF  0
#define AMR_TX_IF2  1
#define AMR_TX_ETS  2

    /*----------------------------------------------------------------------------
    ; EXTERNAL VARIABLES REFERENCES
    ----------------------------------------------------------------------------*/


    /*----------------------------------------------------------------------------
    ; SIMPLE TYPEDEF'S
    ----------------------------------------------------------------------------*/

    /*----------------------------------------------------------------------------
    ; ENUMERATED TYPEDEF'S
    ----------------------------------------------------------------------------*/

    enum Mode
    {
        MR475 = 0,/* 4.75 kbps */
        MR515,    /* 5.15 kbps */
        MR59,     /* 5.90 kbps */
        MR67,     /* 6.70 kbps */
        MR74,     /* 7.40 kbps */
        MR795,    /* 7.95 kbps */
        MR102,    /* 10.2 kbps */
        MR122,    /* 12.2 kbps */
        MRDTX,    /* DTX       */
        N_MODES   /* Not Used  */
    };

    enum Frame_Type_3GPP
    {
        AMR_475 = 0,        /* 4.75 kbps    */
        AMR_515,            /* 5.15 kbps    */
        AMR_59,             /* 5.9 kbps     */
        AMR_67,             /* 6.7 kbps     */
        AMR_74,             /* 7.4 kbps     */
        AMR_795,            /* 7.95 kbps    */
        AMR_102,            /* 10.2 kbps    */
        AMR_122,            /* 12.2 kbps    */
        AMR_SID,            /* GSM AMR DTX  */
        GSM_EFR_SID,        /* GSM EFR DTX  */
        TDMA_EFR_SID,       /* TDMA EFR DTX */
        PDC_EFR_SID,        /* PDC EFR DTX  */
        FOR_FUTURE_USE1,    /* Unused 1     */
        FOR_FUTURE_USE2,    /* Unused 2     */
        FOR_FUTURE_USE3,    /* Unused 3     */
        AMR_NO_DATA         /* No data      */
    };

    /*----------------------------------------------------------------------------
    ; STRUCTURES TYPEDEF'S
    ----------------------------------------------------------------------------*/
    /*----------------------------------------------------------------------------
    ; GLOBAL FUNCTION DEFINITIONS
    ----------------------------------------------------------------------------*/
    /* AMREncodeInit initializes the GSM AMR Encoder library by calling
     * GSMInitEncode and sid_sync_init. If initialization was successful,
     * init_status is set to zero, otherwise, it is set to -1.
    */
    int AMREncodeInit(
        void **pEncStructure,
        void **pSidSyncStructure,
        Flag dtx_enable);

    /* AMREncodeReset resets the state memory used by the Encoder and SID sync
     * function. If reset was successful, reset_status is set to zero, otherwise,
     * it is set to -1.
    */
    int AMREncodeReset(
        void *pEncStructure,
        void *pSidSyncStructure);

    /* AMREncodeExit frees up the state memory used by the Encoder and SID
     * synchronization function.
    */
    void AMREncodeExit(
        void **pEncStructure,
        void **pSidSyncStructure);

    /*
     * AMREncode is the entry point to the ETS Encoder library that encodes the raw
     * data speech bits and converts the encoded bitstream into either an IF2-
     * formatted bitstream, WMF-formatted bitstream, or ETS-formatted bitstream,
     * depending on the the value of output_format. A zero is returned on success.
     */
    int AMREncode(
        void *pEncState,
        void *pSidSyncState,
        enum Mode mode,
        Word16 *pEncInput,
        unsigned char *pEncOutput,
        enum Frame_Type_3GPP *p3gpp_frame_type,
        Word16 output_format
    );

#ifdef __cplusplus
}
#endif


#endif  /* _GSMAMR_DEC_H_ */