audio.h

1. 8623L平台

/*
 *
 * Copyright (c) 2001-2007 Sigma Designs, Inc. 
 * All Rights Reserved. Proprietary and Confidential.
 *
 */

/**
	@file   audio.h
	@brief  functions to set up the emhwlib audio passthrough (no external chip interaction)
	
	@author Christian Wolff Sean.Sekwon.Choi
*/

#ifndef __AUDIO_H__
#define __AUDIO_H__

struct cap_audio_instance;

/*
enum audio_state {
	audio_state_off,     // no audio present
	audio_state_request, // request audio, wait up to 200 mSec for stable clock
	audio_state_on       // audio is running
};
*/

/* parameter for the audio capture */
struct cap_audio_setup {
	RMuint32 AudioEngineID;        // index of the emhwlib module AudioEngine
	RMuint32 AudioCaptureID;       // index of the emhwlib module AudioCapture
	RMuint32 AudioDecoderID;       // index of the emhwlib module AudioDecoder
	RMuint32 VideoCaptureModuleID; // emhwlib module ID of the video/graphic input
	RMuint32 STCTimerNumber;       // STC timer to be used
	RMuint32 BitsPerSample;        // for PCM, 16 or 24 bits per sample
	RMuint32 SampleRate;           // nominal sample rate of the captured audio
	RMuint32 CaptureSource;        // 0=I2S, 1=SPDIF 2=SPDIF from I2S pin
	RMuint32 CaptureBitstream;     // selected bit stream number in the SPDIF header
	RMuint32 CaptureType;          // PCM or compressed ??? (unused)
	RMuint32 CaptureDelay;         // delay between the audio capture and playback, in units of 90 kHz
	RMbool ExternalClk;            // FALSE: use internallly generated clock to play back captured audio, TRUE: use external clock from RClkIn0 pin
	RMuint32 ExternalClkFreq;      // If ExternalClk==TRUE, nominal frequency of the clock at RClkIn0 pin
 	RMbool AudioInTandem;          // TODO: If TRUE, play back captured audio on both audio engines (not yet implemented)
 	RMuint32 AudioInAlign;         // I2S bit alignment for the capture (0..31)
 	RMbool AudioInLSBfirst;        // I2S bit order (FALSE: MSB first, TRUE: LSB first)
 	RMbool AudioInFrameInvert;     // I2S sample order (FALSE: left sample on low LRClk, TRUE: left sample on high)
 	RMbool AudioInSClkNegEdge;     // I2S clock polarity (FALSE: bit sampled on rising edge, TRUE: bit sampled on falling edge)
	RMbool audio_free_run;         // TRUE: don't syncronize audio playback to the PTS's of the capture, rely on the audio clock coherency instead
};

/* create the audio instace */
RMstatus cap_audio_open(
	struct RUA *pRUA, 
	struct DCC *pDCC, 
	struct rmcapture_options *cap_opt, 
	struct cap_audio_instance **ppAudio);

/* destroy the audio instance, close open capture */
RMstatus cap_audio_close(
	struct cap_audio_instance *pAudio);

/* provide setup info to the audio capture */
RMstatus cap_audio_setup(
	struct cap_audio_instance *pAudio, 
	struct cap_audio_setup *pSetup);  // necessary info for the audio capture

/* retreive current SPDIF channel status and payload header info from em8xxx */
RMstatus cap_audio_get_spdif_channel_status(
	struct cap_audio_instance *pAudio, 
	struct AudioEngine_InputSPDIFStatus_type *pStat);

/* Stops capture */
RMstatus cap_audio_stop_capture(
	struct cap_audio_instance *pAudio);

/* Initializes and starts capture */
RMstatus cap_audio_start_capture(
	struct cap_audio_instance *pAudio);

void cap_audio_print_bitstream_fifo_info(
	struct cap_audio_instance *pAudio, 
	RMuint32 threshold);

/* Stops capture, and playback of captured audio */
RMstatus cap_audio_stop_passthrough(
	struct cap_audio_instance *pAudio);

/* Initializes and starts capture, and playback of captured audio */
/* This function needs audio_opt for the audio playback */
/* If your application is using a different method to set up the audio decoder, follow this example for the passthrough */
RMstatus cap_audio_start_passthrough(
	struct cap_audio_instance *pAudio);

/**
  Detetct audio codec from 86xx SI channel status and from Pc/Pe values parsed by audio uCode
  Input:
    stat->ChannelStatus
    stat->Pc
    stat->Pe
    pAudio->Setup.BitsPerSample (capture 16 or 24 bit from I2S)
  Fills in:
    pAudio->auto_detect_codec (TRUE: codec could not be determined)
    pAudio->audio_opt->Codec
    pAudio->audio_opt optional values for that codec
    pAudio->audio_opt->OutputChannels (PCM only)
*/
/* This function needs audio_opt for the audio playback */
RMstatus cap_audio_get_codec_from_spdif_info(
	struct cap_audio_instance *pAudio, 
	struct AudioEngine_InputSPDIFStatus_type *stat);

/**
  set up auto-detection of audio codec.
  if capturing from SPDIF, start audio passthrough 
  to enable parsing of Pc/Pd values from stream
 */
/* This function needs audio_opt for the audio playback */
RMstatus start_detect_audio(
	struct cap_audio_instance *pAudio);

/* transition to a new audio state, and perform the necessary actions of that transition */
RMstatus cap_audio_set_state(
	struct cap_audio_instance *pAudio, 
	enum audio_state audio_state);

/* handle steps of the audio state machine */
RMstatus cap_audio_check_state(
	struct cap_audio_instance *pAudio);

#endif // __AUDIO_H__