Mercurial > hg > svcore
view base/AudioLevel.h @ 283:7336fe3a7caa
* Fix failure to properly load from text files with old-style Mac line endings
author | Chris Cannam |
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date | Thu, 09 Aug 2007 10:06:02 +0000 |
parents | d397ea0a79f5 |
children | cc27f35aa75c |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ /* This is a modified version of a source file from the Rosegarden MIDI and audio sequencer and notation editor. This file copyright 2000-2006 Chris Cannam. */ #ifndef _AUDIO_LEVEL_H_ #define _AUDIO_LEVEL_H_ /** * AudioLevel converts audio sample levels between various scales: * * - dB values (-inf -> 0dB) * - floating-point values (-1.0 -> 1.0) such as used for a * multiplier for gain or in floating-point WAV files * - integer values intended to correspond to pixels on a fader * or vu level scale. */ class AudioLevel { public: static const float DB_FLOOR; enum FaderType { ShortFader = 0, // -40 -> +6 dB LongFader = 1, // -70 -> +10 dB IEC268Meter = 2, // -70 -> 0 dB IEC268LongMeter = 3, // -70 -> +10 dB (0dB aligns with LongFader) PreviewLevel = 4 }; static float multiplier_to_dB(float multiplier); static float dB_to_multiplier(float dB); static float fader_to_dB(int level, int maxLevel, FaderType type); static int dB_to_fader(float dB, int maxFaderLevel, FaderType type); static float fader_to_multiplier(int level, int maxLevel, FaderType type); static int multiplier_to_fader(float multiplier, int maxFaderLevel, FaderType type); // fast if "levels" doesn't change often -- for audio segment previews static int multiplier_to_preview(float multiplier, int levels); static float preview_to_multiplier(int level, int levels); }; #endif