src/apps/cortex/addons/common/IAudioOp.h

   1 /*
   2  * Copyright (c) 1999-2000, Eric Moon.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions, and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions, and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  23  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  27  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31
  32 // IAudioOp.h
  33 // * PURPOSE
  34 //   Abstract audio-operation interface.  Each implementation
  35 //   of IAudioOp represents an algorithm for processing
  36 //   streaming media.
  37 //
  38 //   IAudioOp instances are returned by implementations of
  39 //   IAudioOpFactory, responsible for finding the
  40 //   appropriate algorithm for a given format combination.
  41 //
  42 // * NOTES
  43 //   7sep99:
  44 //   +++++ moving back towards a raw interface approach; the host node
  45 //         can provide the state/parameter/event-queue access.
  46 //         See IAudioOpHost for the operations that the host node needs
  47 //         to provide.
  48 //
  49 // * HISTORY
  50 //   e.moon             26aug99         Begun
  51
  52 #ifndef __IAudioOp_H__
  53 #define __IAudioOp_H__
  54
  55 #include "AudioBuffer.h"
  56
  57 class IAudioOpHost;
  58 class ParameterSet;
  59
  60 class IAudioOp {
  61
  62 public:                                                                                 // *** HOST (NODE)
  63         IAudioOpHost* const                             host;
  64
  65 public:                                                                                 // *** ctor/dtor
  66         IAudioOp(
  67                 IAudioOpHost*                                           _host) : host(_host) {}
  68
  69         virtual ~IAudioOp() {}
  70
  71 public:                                                                                 // *** REQUIRED INTERFACE
  72
  73         // Process a given source buffer to produce framesRequired
  74         // frames of output (this may differ from the number of frames
  75         // read from input if this is a resampling operation,
  76         // or if the operation requires some amount of 'lookahead'.)
  77         // The time at which the first destination frame should reach
  78         // its destination is given by performanceTime (this should help
  79         // wrt/ accurate parameter-change response.)
  80         //
  81         // Return the number of frames produced (if insufficient source
  82         // frames were available, this may be less than framesRequired;
  83         // it must never be greater.)
  84         // NOTE
  85         //   If the formats are identical, source and destination
  86         //   may reference the same buffer.
  87         //
  88         // ANOTHER NOTE
  89         //   This method may well be called multiple times in response to
  90         //   a single call to the functor method (operator()) if one or
  91         //   more events occur midway through the buffer.
  92         //
  93         virtual uint32 process(
  94                 const AudioBuffer&                      source,
  95                 AudioBuffer&                                            destination,
  96                 double&                                                                 sourceFrame,
  97                 uint32&                                                                 destinationFrame,
  98                 uint32                                                                  framesRequired,
  99                 bigtime_t                                                               performanceTime) =0;
 100
 101         // Replace the given filter operation (responsibility for deleting
 102         // it is yours, in case you want to keep it around for a while.)
 103         //
 104         virtual void replace(
 105                 IAudioOp*                                                               oldOp) =0;
 106
 107 public:                                                                                 // *** OPTIONAL INTERFACE
 108
 109         // Called when the host node is started, before any calls to
 110         // process().
 111
 112         virtual void init() {}
 113
 114         // Return the number of input frames required before an output
 115         // frame can be produced.
 116
 117         virtual uint32 bufferLatency() const { return 0; }
 118
 119 };
 120
 121 #endif /*__IAudioOp_H__*/