annotate base/AudioPlaySource.h @ 0:da6937383da8

initial import
author Chris Cannam
date Tue, 10 Jan 2006 16:33:16 +0000
parents
children d86891498eef
rev   line source
Chris@0 1 /* -*- c-basic-offset: 4 -*- vi:set ts=8 sts=4 sw=4: */
Chris@0 2
Chris@0 3 /*
Chris@0 4 A waveform viewer and audio annotation editor.
Chris@0 5 Chris Cannam, Queen Mary University of London, 2005
Chris@0 6
Chris@0 7 This is experimental software. Not for distribution.
Chris@0 8 */
Chris@0 9
Chris@0 10 #ifndef _AUDIO_PLAY_SOURCE_H_
Chris@0 11 #define _AUDIO_PLAY_SOURCE_H_
Chris@0 12
Chris@0 13 /**
Chris@0 14 * Simple interface for audio playback. This should be all that the
Chris@0 15 * ViewManager needs to know about to synchronise with playback by
Chris@0 16 * sample frame, but it doesn't provide enough to determine what is
Chris@0 17 * actually being played or how. See the audioio directory for a
Chris@0 18 * concrete subclass.
Chris@0 19 */
Chris@0 20
Chris@0 21 class AudioPlaySource
Chris@0 22 {
Chris@0 23 public:
Chris@0 24 /**
Chris@0 25 * Start playing from the given frame. If playback is already
Chris@0 26 * under way, reseek to the given frame and continue.
Chris@0 27 */
Chris@0 28 virtual void play(size_t startFrame) = 0;
Chris@0 29
Chris@0 30 /**
Chris@0 31 * Stop playback.
Chris@0 32 */
Chris@0 33 virtual void stop() = 0;
Chris@0 34
Chris@0 35 /**
Chris@0 36 * Return whether playback is currently supposed to be happening.
Chris@0 37 */
Chris@0 38 virtual bool isPlaying() const = 0;
Chris@0 39
Chris@0 40 /**
Chris@0 41 * Return the frame number that is currently expected to be coming
Chris@0 42 * out of the speakers. (i.e. compensating for playback latency.)
Chris@0 43 */
Chris@0 44 virtual size_t getCurrentPlayingFrame() = 0;
Chris@0 45
Chris@0 46 /**
Chris@0 47 * Return the current (or thereabouts) output levels in the range
Chris@0 48 * 0.0 -> 1.0, for metering purposes.
Chris@0 49 */
Chris@0 50 virtual bool getOutputLevels(float &left, float &right) = 0;
Chris@0 51 };
Chris@0 52
Chris@0 53 #endif