aacdec.c

MP3 for ARM codec. [asm+C]

/* ***** BEGIN LICENSE BLOCK *****  
 * Source last modified: $Id: aacdec.c,v 1.1 2005/02/26 01:47:31 jrecker Exp $ 
 *   
 * Portions Copyright (c) 1995-2005 RealNetworks, Inc. All Rights Reserved.  
 *       
 * The contents of this file, and the files included with this file, 
 * are subject to the current version of the RealNetworks Public 
 * Source License (the "RPSL") available at 
 * http://www.helixcommunity.org/content/rpsl unless you have licensed 
 * the file under the current version of the RealNetworks Community 
 * Source License (the "RCSL") available at 
 * http://www.helixcommunity.org/content/rcsl, in which case the RCSL 
 * will apply. You may also obtain the license terms directly from 
 * RealNetworks.  You may not use this file except in compliance with 
 * the RPSL or, if you have a valid RCSL with RealNetworks applicable 
 * to this file, the RCSL.  Please see the applicable RPSL or RCSL for 
 * the rights, obligations and limitations governing use of the 
 * contents of the file. 
 *   
 * This file is part of the Helix DNA Technology. RealNetworks is the 
 * developer of the Original Code and owns the copyrights in the 
 * portions it created. 
 *   
 * This file, and the files included with this file, is distributed 
 * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY 
 * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS 
 * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES 
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET 
 * ENJOYMENT OR NON-INFRINGEMENT. 
 *  
 * Technology Compatibility Kit Test Suite(s) Location:  
 *    http://www.helixcommunity.org/content/tck  
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 * Contributor(s):  
 *   
 * ***** END LICENSE BLOCK ***** */  

/**************************************************************************************
 * Fixed-point HE-AAC decoder
 * Jon Recker ([e-mail]), Ken Cooke ([e-mail])
 * February 2005
 *
 * aacdec.c - platform-independent top level decoder API
 **************************************************************************************/

#include "aaccommon.h"

//#define PROFILE
#ifdef PROFILE
#include "systime.h"
#endif

/**************************************************************************************
 * Function:    AACInitDecoder
 *
 * Description: allocate memory for platform-specific data
 *              clear all the user-accessible fields
 *              initialize SBR decoder if enabled
 *
 * Inputs:      none
 *
 * Outputs:     none
 *
 * Return:      handle to AAC decoder instance, 0 if malloc fails
 **************************************************************************************/
HAACDecoder AACInitDecoder(void)
{
	AACDecInfo *aacDecInfo;

	aacDecInfo = AllocateBuffers();
	if (!aacDecInfo)
		return 0;

#ifdef AAC_ENABLE_SBR
	if (InitSBR(aacDecInfo)) {
		AACFreeDecoder(aacDecInfo);
		return 0;
	}
#endif

	return (HAACDecoder)aacDecInfo;
}

/**************************************************************************************
 * Function:    AACFreeDecoder
 *
 * Description: free platform-specific data allocated by AACInitDecoder
 *              free SBR decoder if enabled
 *
 * Inputs:      valid AAC decoder instance pointer (HAACDecoder)
 *
 * Outputs:     none
 *
 * Return:      none
 **************************************************************************************/
void AACFreeDecoder(HAACDecoder hAACDecoder)
{
	AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;

	if (!aacDecInfo)
		return;

#ifdef AAC_ENABLE_SBR
	FreeSBR(aacDecInfo);
#endif
	FreeBuffers(aacDecInfo);
}

/**************************************************************************************
 * Function:    AACFindSyncWord
 *
 * Description: locate the next byte-alinged sync word in the raw AAC stream
 *
 * Inputs:      buffer to search for sync word
 *              max number of bytes to search in buffer
 *
 * Outputs:     none
 *
 * Return:      offset to first sync word (bytes from start of buf)
 *              -1 if sync not found after searching nBytes
 **************************************************************************************/
int AACFindSyncWord(unsigned char *buf, int nBytes)
{
	int i;

	/* find byte-aligned syncword (12 bits = 0xFFF) */
	for (i = 0; i < nBytes - 1; i++) {
		if ( (buf[i+0] & SYNCWORDH) == SYNCWORDH && (buf[i+1] & SYNCWORDL) == SYNCWORDL )
			return i;
	}
	
	return -1;
}

/**************************************************************************************
 * Function:    AACGetLastFrameInfo
 *
 * Description: get info about last AAC frame decoded (number of samples decoded, 
 *                sample rate, bit rate, etc.)
 *
 * Inputs:      valid AAC decoder instance pointer (HAACDecoder)
 *              pointer to AACFrameInfo struct
 *
 * Outputs:     filled-in AACFrameInfo struct
 *
 * Return:      none
 *
 * Notes:       call this right after calling AACDecode()
 **************************************************************************************/
void AACGetLastFrameInfo(HAACDecoder hAACDecoder, AACFrameInfo *aacFrameInfo)
{
	AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;

	if (!aacDecInfo) {
		aacFrameInfo->bitRate =       0;
		aacFrameInfo->nChans =        0;
		aacFrameInfo->sampRateCore =  0;
		aacFrameInfo->sampRateOut =   0;
		aacFrameInfo->bitsPerSample = 0;
		aacFrameInfo->outputSamps =   0;
		aacFrameInfo->profile =       0;
		aacFrameInfo->tnsUsed =       0;
		aacFrameInfo->pnsUsed =       0;
	} else {
		aacFrameInfo->bitRate =       aacDecInfo->bitRate;
		aacFrameInfo->nChans =        aacDecInfo->nChans;
		aacFrameInfo->sampRateCore =  aacDecInfo->sampRate;
		aacFrameInfo->sampRateOut =   aacDecInfo->sampRate * (aacDecInfo->sbrEnabled ? 2 : 1);
		aacFrameInfo->bitsPerSample = 16;
		aacFrameInfo->outputSamps =   aacDecInfo->nChans * AAC_MAX_NSAMPS * (aacDecInfo->sbrEnabled ? 2 : 1);
		aacFrameInfo->profile =       aacDecInfo->profile;
		aacFrameInfo->tnsUsed =       aacDecInfo->tnsUsed;
		aacFrameInfo->pnsUsed =       aacDecInfo->pnsUsed;
	}
}

/**************************************************************************************
 * Function:    AACSetRawBlockParams
 *
 * Description: set internal state variables for decoding a stream of raw data blocks
 *
 * Inputs:      valid AAC decoder instance pointer (HAACDecoder)
 *              flag indicating source of parameters
 *              AACFrameInfo struct, with the members nChans, sampRate, and profile
 *                optionally filled-in
 *
 * Outputs:     updated codec state 
 *
 * Return:      0 if successful, error code (< 0) if error
 *
 * Notes:       if copyLast == 1, then the codec sets up its internal state (for 
 *                decoding raw blocks) based on previously-decoded ADTS header info
 *              if copyLast == 0, then the codec uses the values passed in
 *                aacFrameInfo to configure its internal state (useful when the
 *                source is MP4 format, for example)
 **************************************************************************************/
int AACSetRawBlockParams(HAACDecoder hAACDecoder, int copyLast, AACFrameInfo *aacFrameInfo)
{
	AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;

	if (!aacDecInfo)
		return ERR_AAC_NULL_POINTER;

	aacDecInfo->format = AAC_FF_RAW;
	if (copyLast)
		return SetRawBlockParams(aacDecInfo, 1, 0, 0, 0);
	else
		return SetRawBlockParams(aacDecInfo, 0, aacFrameInfo->nChans, aacFrameInfo->sampRateCore, aacFrameInfo->profile);
}

/**************************************************************************************
 * Function:    AACFlushCodec
 *
 * Description: flush internal codec state (after seeking, for example)
 *
 * Inputs:      valid AAC decoder instance pointer (HAACDecoder)
 *
 * Outputs:     updated state variables in aacDecInfo
 *
 * Return:      0 if successful, error code (< 0) if error
 **************************************************************************************/
int AACFlushCodec(HAACDecoder hAACDecoder)
{
	int ch;
	AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;

	if (!aacDecInfo)
		return ERR_AAC_NULL_POINTER;

	/* reset common state variables which change per-frame
	 * don't touch state variables which are (usually) constant for entire clip 
	 *   (nChans, sampRate, profile, format, sbrEnabled)
	 */
	aacDecInfo->prevBlockID = AAC_ID_INVALID;
	aacDecInfo->currBlockID = AAC_ID_INVALID;
	aacDecInfo->currInstTag = -1;
	for (ch = 0; ch < MAX_NCHANS_ELEM; ch++)
		aacDecInfo->sbDeinterleaveReqd[ch] = 0;
	aacDecInfo->adtsBlocksLeft = 0;
	aacDecInfo->tnsUsed = 0;
	aacDecInfo->pnsUsed = 0;

	/* reset internal codec state (flush overlap buffers, etc.) */
	FlushCodec(aacDecInfo);
#ifdef AAC_ENABLE_SBR