From 145364a8af6a1fec06556221e66d4b724a62fc9a Mon Sep 17 00:00:00 2001 From: tpearson Date: Mon, 1 Mar 2010 18:37:05 +0000 Subject: Added old abandoned KDE3 version of the RoseGarden MIDI tool git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/applications/rosegarden@1097595 283d02a7-25f6-0310-bc7c-ecb5cbfe19da --- src/base/AudioLevel.h | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 src/base/AudioLevel.h (limited to 'src/base/AudioLevel.h') diff --git a/src/base/AudioLevel.h b/src/base/AudioLevel.h new file mode 100644 index 0000000..2dc742d --- /dev/null +++ b/src/base/AudioLevel.h @@ -0,0 +1,67 @@ +// -*- c-basic-offset: 4 -*- + +/* + Rosegarden + A sequencer and musical notation editor. + + This program is Copyright 2000-2008 + Guillaume Laurent , + Chris Cannam , + Richard Bown + + The moral right of the authors to claim authorship of this work + has been asserted. + + 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. +*/ + +#ifndef _AUDIO_LEVEL_H_ +#define _AUDIO_LEVEL_H_ + +namespace Rosegarden { + +/** + * We need to represent audio levels in three different ways: as dB + * values; as a floating-point multiplier for gain; and as an integer + * on a scale for fader position and vu level. This class does the + * necessary conversions. + */ + +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 + + -- cgit v1.2.1