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/*----------------------------------------------------------------------------
 *
 * File: 
 * eas_pcmdata.h
 *
 * Contents and purpose:
 * Data declarations for the PCM engine
 *
 *
 * Copyright Sonic Network Inc. 2005

 * 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.
 *
 *----------------------------------------------------------------------------
 * Revision Control:
 *   $Revision: 847 $
 *   $Date: 2007-08-27 21:30:08 -0700 (Mon, 27 Aug 2007) $
 *----------------------------------------------------------------------------
*/

#ifndef _EAS_PCMDATA_H
#define _EAS_PCMDATA_H

/* sets the maximum number of simultaneous PCM streams */
#ifndef MAX_PCM_STREAMS
#define MAX_PCM_STREAMS				16
#define PCM_STREAM_THRESHOLD		(MAX_PCM_STREAMS - 4)
#endif

/* coefficents for high-pass filter in ADPCM */
#define INTEGRATOR_COEFFICIENT		100		/* coefficient for leaky integrator */

/* additional flags in S_PCM_STATE.flags used internal to module */
#define PCM_FLAGS_EMPTY				0x01000000	/* unsigned format */

/*----------------------------------------------------------------------------
 * S_PCM_STATE
 *
 * Retains state information for PCM streams.
 *----------------------------------------------------------------------------
*/
typedef struct s_decoder_state_tag
{
	EAS_I32				output;				/* last output for DC offset filter */
	EAS_I32				acc;				/* accumulator for DC offset filter */
	EAS_I32				step;				/* current ADPCM step size */
	EAS_PCM				x1;					/* current generated sample */
	EAS_PCM				x0;					/* previous generated sample */
} S_DECODER_STATE;

typedef enum
{
	PCM_ENV_START = 0,
	PCM_ENV_ATTACK,
	PCM_ENV_DECAY,
	PCM_ENV_SUSTAIN,
	PCM_ENV_RELEASE,
	PCM_ENV_END
} E_PCM_ENV_STATE;

typedef struct s_pcm_state_tag
{
#ifdef _CHECKED_BUILD
	EAS_U32				handleCheck;		/* signature check for checked build */
#endif
	EAS_FILE_HANDLE		fileHandle;			/* pointer to input file */
	EAS_PCM_CALLBACK 	pCallback;			/* pointer to callback function */
	EAS_VOID_PTR		cbInstData;			/* instance data for callback function */
	struct s_decoder_interface_tag EAS_CONST * pDecoder;	/* pointer to decoder interface */
	EAS_STATE			state;				/* stream state */
	EAS_I32				time;				/* media time */
	EAS_I32				startPos;			/* start of PCM stream */
	EAS_I32				loopLocation;		/* file location where loop starts */
	EAS_I32				byteCount;			/* size of file */
	EAS_U32				loopStart;			/* loop start, offset in samples from startPos */
											/* NOTE: For CMF, we use this to store total sample size */
	EAS_U32				loopSamples;		/* total loop length, in samples, 0 means no loop */
											/* NOTE: For CMF, non-zero means looped */
	EAS_U32				samplesInLoop;		/* samples left in the loop to play back */
	EAS_I32				samplesTilLoop;		/* samples left to play until top of loop */
	EAS_I32				bytesLeft;			/* count of bytes left in stream */
	EAS_I32				bytesLeftLoop;		/* count of bytes left in stream, value at start of loop */
	EAS_U32				phase;				/* current phase for interpolator */
	EAS_U32				basefreq;			/* frequency multiplier */
	EAS_U32				flags;				/* stream flags */
	EAS_U32				envData;			/* envelope data (and LFO data) */
	EAS_U32				envValue;			/* current envelope value */
	EAS_U32				envScale;			/* current envelope scale */
	EAS_U32				startOrder;			/* start order index, first is 0, next is 1, etc. */
	S_DECODER_STATE		decoderL;			/* left (mono) ADPCM state */
	S_DECODER_STATE		decoderR;			/* right ADPCM state */
	S_DECODER_STATE		decoderLLoop;		/* left (mono) ADPCM state, value at start of loop */
	S_DECODER_STATE		decoderRLoop;		/* right ADPCM state, value at start of loop */
	E_PCM_ENV_STATE		envState;			/* current envelope state */
	EAS_I16				volume;				/* volume for stream */
	EAS_I16				pitch;				/* relative pitch in cents - zero is unity playback */
	EAS_I16				gainLeft;			/* requested gain */
	EAS_I16				gainRight;			/* requested gain */
	EAS_I16				currentGainLeft;	/* current gain for anti-zipper filter */
	EAS_I16				currentGainRight;	/* current gain for anti-zipper filter */
	EAS_U16				blockSize;			/* block size for ADPCM decoder */
	EAS_U16				blockCount;			/* block counter for ADPCM decoder */
	EAS_U16				sampleRate;			/* input sample rate */
	EAS_U8				srcByte;			/* source byte */
	EAS_U8				msBitCount;			/* count keeps track of MS bits */
	EAS_U8				msBitMask;			/* mask keeps track of MS bits */
	EAS_U8				msBitValue;			/* value keeps track of MS bits */
	EAS_U8				msBitCountLoop;		/* count keeps track of MS bits, value at loop start */
	EAS_U8				msBitMaskLoop;		/* mask keeps track of MS bits, value at loop start */
	EAS_U8				msBitValueLoop;		/* value keeps track of MS bits, value at loop start */
	EAS_BOOL8			hiNibble;			/* indicates high/low nibble is next */
	EAS_BOOL8			hiNibbleLoop;		/* indicates high/low nibble is next, value loop start */
	EAS_U8				rateShift;			/* for playback rate greater than 1.0 */
} S_PCM_STATE;

/*----------------------------------------------------------------------------
 * S_DECODER_INTERFACE
 *
 * Generic interface for audio decoders
 *----------------------------------------------------------------------------
*/
typedef struct s_decoder_interface_tag
{
	EAS_RESULT (* EAS_CONST pfInit)(EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState);
	EAS_RESULT (* EAS_CONST pfDecodeSample)(EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState);
	EAS_RESULT (* EAS_CONST pfLocate)(EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState, EAS_I32 time);
} S_DECODER_INTERFACE;


/* header chunk for SMAF ADPCM */
#define TAG_YAMAHA_ADPCM 	0x4d776100
#define TAG_MASK			0xffffff00
#define TAG_RIFF_FILE		0x52494646
#define TAG_WAVE_CHUNK		0x57415645
#define TAG_FMT_CHUNK		0x666d7420

/*----------------------------------------------------------------------------
 * EAS_PESeek
 *----------------------------------------------------------------------------
 * Purpose: 
 * Locate to a particular byte in a PCM stream
 *----------------------------------------------------------------------------
*/
EAS_RESULT EAS_PESeek (EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState, EAS_I32 *pLocation);

#endif /* _EAS_PCMDATA_H */