annotate base/AudioPlaySource.h @ 167:665342c6ec57

* Add a bit of resistance to pane dragging so as to make it harder to inadvertently drag in the other axis from the one you intended
author Chris Cannam
date Fri, 22 Sep 2006 16:46:10 +0000
parents d397ea0a79f5
children d3ac9f953ebf
rev   line source
Chris@49 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
Chris@0 2
Chris@0 3 /*
Chris@52 4 Sonic Visualiser
Chris@52 5 An audio file viewer and annotation editor.
Chris@52 6 Centre for Digital Music, Queen Mary, University of London.
Chris@52 7 This file copyright 2006 Chris Cannam.
Chris@0 8
Chris@52 9 This program is free software; you can redistribute it and/or
Chris@52 10 modify it under the terms of the GNU General Public License as
Chris@52 11 published by the Free Software Foundation; either version 2 of the
Chris@52 12 License, or (at your option) any later version. See the file
Chris@52 13 COPYING included with this distribution for more information.
Chris@0 14 */
Chris@0 15
Chris@0 16 #ifndef _AUDIO_PLAY_SOURCE_H_
Chris@0 17 #define _AUDIO_PLAY_SOURCE_H_
Chris@0 18
Chris@0 19 /**
Chris@0 20 * Simple interface for audio playback. This should be all that the
Chris@0 21 * ViewManager needs to know about to synchronise with playback by
Chris@0 22 * sample frame, but it doesn't provide enough to determine what is
Chris@0 23 * actually being played or how. See the audioio directory for a
Chris@0 24 * concrete subclass.
Chris@0 25 */
Chris@0 26
Chris@0 27 class AudioPlaySource
Chris@0 28 {
Chris@0 29 public:
Chris@27 30 virtual ~AudioPlaySource() { }
Chris@27 31
Chris@0 32 /**
Chris@0 33 * Start playing from the given frame. If playback is already
Chris@0 34 * under way, reseek to the given frame and continue.
Chris@0 35 */
Chris@0 36 virtual void play(size_t startFrame) = 0;
Chris@0 37
Chris@0 38 /**
Chris@0 39 * Stop playback.
Chris@0 40 */
Chris@0 41 virtual void stop() = 0;
Chris@0 42
Chris@0 43 /**
Chris@0 44 * Return whether playback is currently supposed to be happening.
Chris@0 45 */
Chris@0 46 virtual bool isPlaying() const = 0;
Chris@0 47
Chris@0 48 /**
Chris@0 49 * Return the frame number that is currently expected to be coming
Chris@0 50 * out of the speakers. (i.e. compensating for playback latency.)
Chris@0 51 */
Chris@0 52 virtual size_t getCurrentPlayingFrame() = 0;
Chris@0 53
Chris@0 54 /**
Chris@0 55 * Return the current (or thereabouts) output levels in the range
Chris@0 56 * 0.0 -> 1.0, for metering purposes.
Chris@0 57 */
Chris@0 58 virtual bool getOutputLevels(float &left, float &right) = 0;
Chris@40 59
Chris@40 60 /**
Chris@40 61 * Return the sample rate set by the target audio device (or the
Chris@40 62 * source sample rate if the target hasn't set one).
Chris@40 63 */
Chris@40 64 virtual size_t getTargetSampleRate() const = 0;
Chris@0 65 };
Chris@0 66
Chris@0 67 #endif