QCC308x headset 做同时双向输出音频

/******************************************************************************

Copyright (c) 2014 - 2015 Qualcomm Technologies International, Ltd.

FILE NAME

    audio_output.h

DESCRIPTION

    Plugin that implements multichannel audio by utilising multiple hardware

    audio outputs (onboard DAC, I2S, etc...).

*/

/*!

@file    audio_output.h

@brief   Implements multichannel audio by utilising multiple hardware audio

         outputs (onboard DAC, I2S, etc...).

         This file provides documentation for the audio_output API.

         Plugin should be initialised with a suitable output mapping before

         being used, defined by the structures declared in this header file.

*/

#ifndef __AUDIO_OUTPUT_H__

#define __AUDIO_OUTPUT_H__

/*============================================================================*

 *  SDK Header Files

 *============================================================================*/

#include <csrtypes.h>

#include <stream.h>

/*============================================================================*

 *  Public Defintions

 *============================================================================*/

/* Turn audio output into a bitmask */

#define AudioOutputGetMask(audio_out) ((uint16)1 << audio_out)

/*============================================================================*

 *  Public Data Types

 *============================================================================*/

/*!

    @brief Audio Output Channel

    Allows identification of and looping through each output channel. The first

    output should always start at 0, and audio_output_max should always be last

    as it is also used to define arrays and loop bounds.

*/

typedef enum __audio_output

{

    audio_output_primary_left = 0,   /*! Left primary (filtered) output */

    audio_output_primary_right,      /*! Right primary (filtered) output */

    audio_output_secondary_left,     /*! Left secondary (filtered) output */

    audio_output_secondary_right,    /*! Right secondary (filtered) output */

    audio_output_wired_sub,          /*! Wired subwoofer (LP filter) output */

    audio_output_aux_left,           /*! Left auxiliary (full range) output */

    audio_output_aux_right,          /*! Right auxi