/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1993-2001 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#ifndef _MULTIMEDIA_AUDIOGAIN_H
#define _MULTIMEDIA_AUDIOGAIN_H

#include <AudioTypePcm.h>

#ifdef __cplusplus
extern "C" {
#endif

// Class to handle gain calculations

// Define bits for AudioGain::Process() type argument
#define AUDIO_GAIN_INSTANT      (1)             // Gain for level meter
#define AUDIO_GAIN_WEIGHTED     (2)             // Gain for agc


class AudioGain {
protected:

static const double     LoSigInstantRange;      // normalization constants
static const double     HiSigInstantRange;
static const double     NoSigWeight;
static const double     LoSigWeightRange;
static const double     HiSigWeightRange;
static const double     PeakSig;
static const double     DCtimeconstant;         // DC offset time constant

        AudioTypePcm    float_convert;          // used in signal processing
        unsigned        clipcnt;                // clip counter
        Double          DCaverage;              // weighted DC offset
        Double          instant_gain;           // current (instantaneous) gain
        Double          weighted_peaksum;       // peak weighted sum
        Double          weighted_sum;           // running sum of squares
        Double          weighted_avgsum;        // accumulated sums to averages
        unsigned        weighted_cnt;           // number of sums to average
        double          *gain_cache;            // weighted gains
        Double          gain_cache_size;        // number of cached gains

protected:
        // Internal processing methods

        // filter DC bias
        virtual void process_dcfilter(
            AudioBuffer*);
        // calculate instant gain
        virtual void process_instant(
            AudioBuffer*);
        // calculate weighted gain
        virtual void process_weighted(
            AudioBuffer*);

public:
                AudioGain();                    // Constructor
        virtual ~AudioGain();                   // Destructor

        // TRUE if conversion ok
        virtual Boolean CanConvert(
            const AudioHdr&) const;     // type to check against

        // Process new audio data
        virtual AudioError Process(
            AudioBuffer*, int);         // buffer destroyed if not referenced!
        virtual double InstantGain();   // Get most recent gain
        virtual double WeightedGain();  // Get current weighted gain
        virtual double WeightedPeak();  // Get peak weighted gain
        virtual Boolean Clipped();      // TRUE if peak since last check
        virtual void Flush();           // Reset state
};

#ifdef __cplusplus
}
#endif

#endif /* !_MULTIMEDIA_AUDIOGAIN_H */