text: // Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
  //
  // 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.
  
  /*******************************************************************************
   *
   *  Filename:      btc_media.h
   *
   *  Description:   This is the audio module for the BTC system.
   *
   *******************************************************************************/
  
  #ifndef __BTC_MEDIA_H__
  #define __BTC_MEDIA_H__
  
  #include <stdbool.h>
  #include "bta_api.h"
  #include "btc_av_api.h"
  
  #if (BTA_AV_INCLUDED == TRUE)
  
  /*******************************************************************************
   **  Constants
   *******************************************************************************/
  #define BTC_SUCCESS                         (0)
  /**
   * AV (Audio Video source) Errors
   */
  #define BTC_ERROR_SRV_AV_NOT_ENABLED        700     /* AV is not enabled */
  #define BTC_ERROR_SRV_AV_FEEDING_NOT_SUPPORTED 701  /* Requested Feeding not supported */
  #define BTC_ERROR_SRV_AV_BUSY               702     /* Another operation ongoing */
  #define BTC_ERROR_SRV_AV_NOT_OPENED         703     /* No AV link opened */
  #define BTC_ERROR_SRV_AV_NOT_STARTED        704     /* AV is not started */
  #define BTC_ERROR_SRV_AV_CP_NOT_SUPPORTED   705     /* Content protection is not supported by all headsets */
  
  /* Transcoding definition for TxTranscoding and RxTranscoding */
  #define BTC_MEDIA_TRSCD_OFF             0
  #define BTC_MEDIA_TRSCD_PCM_2_SBC       1  /* Tx */
  
  
  /*******************************************************************************
   **  Data types
   *******************************************************************************/
  
  typedef int tBTC_STATUS;
  
  /* tBTC_MEDIA_INIT_AUDIO msg structure */
  typedef struct {
      BT_HDR hdr;
      UINT16 SamplingFreq; /* 16k, 32k, 44.1k or 48k*/
      UINT8 ChannelMode; /* mono, dual, stereo or joint stereo*/
      UINT8 NumOfSubBands; /* 4 or 8 */
      UINT8 NumOfBlocks; /* 4, 8, 12 or 16*/
      UINT8 AllocationMethod; /* loudness or SNR*/
      UINT16 MtuSize; /* peer mtu size */
  } tBTC_MEDIA_INIT_AUDIO;
  
  #if (BTA_AV_INCLUDED == TRUE)
  /* tBTC_MEDIA_UPDATE_AUDIO msg structure */
  typedef struct {
      BT_HDR hdr;
      UINT16 MinMtuSize; /* Minimum peer mtu size */
      UINT8 MaxBitPool; /* Maximum peer bitpool */
      UINT8 MinBitPool; /* Minimum peer bitpool */
  } tBTC_MEDIA_UPDATE_AUDIO;
  
  /* tBTC_MEDIA_INIT_AUDIO_FEEDING msg structure */
  typedef struct {
      BT_HDR hdr;
      tBTC_AV_FEEDING_MODE feeding_mode;
      tBTC_AV_MEDIA_FEEDINGS feeding;
  } tBTC_MEDIA_INIT_AUDIO_FEEDING;
  
  typedef struct {
      BT_HDR hdr;
      UINT8 codec_info[AVDT_CODEC_SIZE];
  } tBTC_MEDIA_SINK_CFG_UPDATE;
  #endif
  
  /*******************************************************************************
   **  Public functions
   *******************************************************************************/
  
  /*******************************************************************************
   **
   ** Function         btc_av_task
   **
   ** Description
   **
   ** Returns          void
   **
   *******************************************************************************/
  extern void btc_media_task(void);
  
  /*******************************************************************************
   **
   ** Function         btc_media_task_enc_init_req
   **
   ** Description      Request to initialize the media task encoder
   **
   ** Returns          TRUE is success
   **
   *******************************************************************************/
  extern BOOLEAN btc_media_task_enc_init_req(tBTC_MEDIA_INIT_AUDIO *p_msg);
  
  /*******************************************************************************
   **
   ** Function         btc_media_task_enc_update_req
   **
   ** Description      Request to update the media task encoder
   **
   ** Returns          TRUE is success
   **
   *******************************************************************************/
  #if (BTA_AV_INCLUDED == TRUE)
  extern BOOLEAN btc_media_task_enc_update_req(tBTC_MEDIA_UPDATE_AUDIO *p_msg);
  #endif
  
  /*******************************************************************************
   **
   ** Function         btc_media_task_start_aa_req
   **
   ** Description      Request to start audio encoding task
   **
   ** Returns          TRUE is success
   **
   *******************************************************************************/
  extern BOOLEAN btc_media_task_start_aa_req(void);
  
  /*******************************************************************************
   **
   ** Function         btc_media_task_stop_aa_req
   **
   ** Description      Request to stop audio encoding task
   **
   ** Returns          TRUE is success
   **
   *******************************************************************************/
  extern BOOLEAN btc_media_task_stop_aa_req(void);
  
  /*******************************************************************************
   **
   ** Function         btc_media_task_aa_rx_flush_req
   **
   ** Description      Request to flush audio decoding pipe
   **
   ** Returns          TRUE is success
   **
   *******************************************************************************/
  extern BOOLEAN btc_media_task_aa_rx_flush_req(void);
  /*******************************************************************************
   **
   ** Function         btc_media_task_aa_tx_flush_req
   **
   ** Description      Request to flush audio encoding pipe
   **
   ** Returns          TRUE is success
   **
   *******************************************************************************/
  extern BOOLEAN btc_media_task_aa_tx_flush_req(void);
  
  /*******************************************************************************
   **
   ** Function         btc_media_aa_readbuf
   **
   ** Description      Read an audio buffer from the BTC media TX queue
   **
   ** Returns          pointer on a aa buffer ready to send
   **
   *******************************************************************************/
  extern BT_HDR *btc_media_aa_readbuf(void);
  
  /*******************************************************************************
   **
   ** Function         btc_media_sink_enque_buf
   **
   ** Description      This function is called by the av_co to fill A2DP Sink Queue
   **
   **
   ** Returns          size of the queue
   *******************************************************************************/
  UINT8 btc_media_sink_enque_buf(BT_HDR *p_buf);
  
  
  
  /*******************************************************************************
   **
   ** Function         btc_media_aa_writebuf
   **
   ** Description      Enqueue a Advance Audio media buffer to be processed by btc media task.
   **
   ** Returns          TRUE is success
   **
   *******************************************************************************/
  extern void btc_media_aa_writebuf(BT_HDR *pBuf, UINT32 timestamp, UINT16 seq_num);
  
  /*******************************************************************************
   **
   ** Function         btc_media_av_writebuf
   **
   ** Description      Enqueue a video media buffer to be processed by btc media task.
   **
   ** Returns          TRUE is success
   **
   *******************************************************************************/
  extern BOOLEAN btc_media_av_writebuf(UINT8 *p_media, UINT32 media_len,
                                       UINT32 timestamp, UINT16 seq_num);
  
  #if (BTA_AV_INCLUDED == TRUE)
  /*******************************************************************************
   **
   ** Function         btc_media_task_audio_feeding_init_req
   **
   ** Description      Request to initialize audio feeding
   **
   ** Returns          TRUE is success
   **
   *******************************************************************************/
  
  extern BOOLEAN btc_media_task_audio_feeding_init_req(tBTC_MEDIA_INIT_AUDIO_FEEDING *p_msg);
  #endif
  
  /*******************************************************************************
   **
   ** Function         dump_codec_info
   **
   ** Description      Decode and display codec_info (for debug)
   **
   ** Returns          void
   **
   *******************************************************************************/
  extern void dump_codec_info(unsigned char *p_codec);
  
  /**
   * Local adaptation helper functions between btc and media task
   */
  
  bool btc_a2dp_start_media_task(void);
  void btc_a2dp_stop_media_task(void);
  
  void btc_a2dp_on_init(void);
  void btc_a2dp_setup_codec(void);
  void btc_a2dp_on_idle(void);
  BOOLEAN btc_a2dp_on_started(tBTA_AV_START *p_av, BOOLEAN pending_start);
  void btc_a2dp_on_stop_req(void);
  void btc_a2dp_on_stopped(tBTA_AV_SUSPEND *p_av);
  void btc_a2dp_on_suspend(void);
  void btc_a2dp_on_suspended(tBTA_AV_SUSPEND *p_av);
  void btc_a2dp_set_rx_flush(BOOLEAN enable);
  void btc_media_check_iop_exceptions(UINT8 *peer_bda);
  void btc_reset_decoder(UINT8 *p_av);
  
  int btc_a2dp_get_track_frequency(UINT8 frequency);
  int btc_a2dp_get_track_channel_count(UINT8 channeltype);
  void btc_a2dp_set_peer_sep(UINT8 sep);
  #endif  ///BTA_AV_INCLUDED == TRUE
  #endif
  