usr/src/cmd/audio/include/AudioGain.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 1993-2001 by Sun Microsystems, Inc.
  24  * All rights reserved.
  25  */
  26
  27 #ifndef _MULTIMEDIA_AUDIOGAIN_H
  28 #define _MULTIMEDIA_AUDIOGAIN_H
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include <AudioTypePcm.h>
  33
  34 #ifdef __cplusplus
  35 extern "C" {
  36 #endif
  37
  38 // Class to handle gain calculations
  39
  40 // Define bits for AudioGain::Process() type argument
  41 #define AUDIO_GAIN_INSTANT      (1)             // Gain for level meter
  42 #define AUDIO_GAIN_WEIGHTED     (2)             // Gain for agc
  43
  44
  45 class AudioGain {
  46 protected:
  47
  48 static const double     LoSigInstantRange;      // normalization constants
  49 static const double     HiSigInstantRange;
  50 static const double     NoSigWeight;
  51 static const double     LoSigWeightRange;
  52 static const double     HiSigWeightRange;
  53 static const double     PeakSig;
  54 static const double     DCtimeconstant;         // DC offset time constant
  55
  56         AudioTypePcm    float_convert;          // used in signal processing
  57         unsigned        clipcnt;                // clip counter
  58         Double          DCaverage;              // weighted DC offset
  59         Double          instant_gain;           // current (instantaneous) gain
  60         Double          weighted_peaksum;       // peak weighted sum
  61         Double          weighted_sum;           // running sum of squares
  62         Double          weighted_avgsum;        // accumulated sums to averages
  63         unsigned        weighted_cnt;           // number of sums to average
  64         double          *gain_cache;            // weighted gains
  65         Double          gain_cache_size;        // number of cached gains
  66
  67 protected:
  68         // Internal processing methods
  69
  70         // filter DC bias
  71         virtual void process_dcfilter(
  72             AudioBuffer*);
  73         // calculate instant gain
  74         virtual void process_instant(
  75             AudioBuffer*);
  76         // calculate weighted gain
  77         virtual void process_weighted(
  78             AudioBuffer*);
  79
  80 public:
  81                 AudioGain();                    // Constructor
  82         virtual ~AudioGain();                   // Destructor
  83
  84         // TRUE if conversion ok
  85         virtual Boolean CanConvert(
  86             const AudioHdr&) const;     // type to check against
  87
  88         // Process new audio data
  89         virtual AudioError Process(
  90             AudioBuffer*, int);         // buffer destroyed if not referenced!
  91         virtual double InstantGain();   // Get most recent gain
  92         virtual double WeightedGain();  // Get current weighted gain
  93         virtual double WeightedPeak();  // Get peak weighted gain
  94         virtual Boolean Clipped();      // TRUE if peak since last check
  95         virtual void Flush();           // Reset state
  96 };
  97
  98 #ifdef __cplusplus
  99 }
 100 #endif
 101
 102 #endif /* !_MULTIMEDIA_AUDIOGAIN_H */