limiter.h

linux下的一款播放器

/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: limiter.h,v 1.2.38.1 2004/07/09 02:00:38 hubbe Exp $
 * 
 * Portions Copyright (c) 1995-2004 RealNetworks, Inc. All Rights Reserved.
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 * the file under the current version of the RealNetworks Community
 * Source License (the "RCSL") available at
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 * ***** END LICENSE BLOCK ***** */

/* structure definitions and prototypes for audio limiter */

#ifndef _LIMITER_H_
#define _LIMITER_H_

#ifdef __cplusplus
extern "C" {
#endif

typedef struct LIMSTATE {
	/* settings */
	int samprate;
	int channels;
	int headroom;
	double dbgain;
	/* derived */
	unsigned int threshold;
	int reltc;
	int rmsatktc;
	int rmsreltc;
	int outfract;
	int outshift;
	/* state */
	int idx;
	int peak_z;
	int rms_z;
	int acc1;
	int acc2;
	unsigned int randsave;
	int delay[512];
	/* release tables */
	int peaktab[256];
	int rmstab[256];
} LIMSTATE;

LIMSTATE *LimiterInit(int samprate, int channels, int headroom);
void LimiterFree(LIMSTATE *lim);

void LimiterProcess(int *pcmbuf, int nsamples, LIMSTATE *lim);
void LimiterOutput16(int *pcmbuf, short *outbuf, int nsamples, LIMSTATE *lim);

void LimiterSetGain(double dbgain, LIMSTATE *lim);
void LimiterSetRelease(double release, LIMSTATE *lim);

/* delay in sample frames */
int LimiterGetDelay(LIMSTATE *lim);
double LimiterGetAtten(LIMSTATE *lim);

#ifdef __cplusplus
/*extern "C"*/ }
#endif

#endif /* _LIMITER_H_ */