src/Audio/PCMPlayer.hpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #ifndef XCSOAR_AUDIO_PCM_PLAYER_HPP
  25 #define XCSOAR_AUDIO_PCM_PLAYER_HPP
  26
  27 #ifdef ANDROID
  28 #include "Thread/Mutex.hpp"
  29 #include "SLES/Object.hpp"
  30 #include "SLES/Play.hpp"
  31 #include "SLES/AndroidSimpleBufferQueue.hpp"
  32
  33 #include <stdint.h>
  34 #endif
  35
  36 #include <stddef.h>
  37
  38 class PCMSynthesiser;
  39
  40 /**
  41  * An audio player that plays synthesized 16 bit mono PCM data.  It is
  42  * being fed by a #PCMSynthesiser object that gets called when more
  43  * PCM samples are needed.
  44  */
  45 class PCMPlayer {
  46   unsigned sample_rate;
  47
  48   PCMSynthesiser *synthesiser;
  49
  50 #ifdef ANDROID
  51
  52   SLES::Object engine_object;
  53
  54   SLES::Object mix_object;
  55
  56   SLES::Object play_object;
  57   SLES::Play play;
  58   SLES::AndroidSimpleBufferQueue queue;
  59
  60   /**
  61    * This mutex protects the attributes "next" and "filled".  It is
  62    * only needed while playback is launched, when the initial buffers
  63    * are being enqueued in the caller thread, while another thread may
  64    * invoke the registered callback.
  65    */
  66   Mutex mutex;
  67
  68   /**
  69    * The index of the next buffer to be enqueued.
  70    */
  71   unsigned next;
  72
  73   /**
  74    * Does the "next" buffer already contain synthesised samples?  This
  75    * can happen when PCMSynthesiser::Synthesise() has been called, but
  76    * the OpenSL/ES buffer queue was full.  The buffer will then be
  77    * postponed.
  78    */
  79   bool filled;
  80
  81   /**
  82    * An array of buffers.  It's one more than being managed by
  83    * OpenSL/ES, and the one not enqueued (see attribute #next) will be
  84    * written to.
  85    */
  86   int16_t buffers[3][4096];
  87
  88 #elif defined(WIN32)
  89 #else
  90 #endif
  91
  92 public:
  93   PCMPlayer();
  94   ~PCMPlayer();
  95
  96   /**
  97    * Start playback.
  98    *
  99    * @param synthesiser a PCMSynthesiser instance that will be used to
 100    * generate sound; the caller is responsible for releasing it (not
 101    * before playback is stopped)
 102    */
 103   bool Start(PCMSynthesiser &synthesiser, unsigned sample_rate);
 104
 105   /**
 106    * Stop playback and close the audio device.  This method is
 107    * synchronous.
 108    */
 109   void Stop();
 110
 111 #ifdef ANDROID
 112   void Enqueue();
 113 #elif defined(WIN32)
 114 #else
 115   void Synthesise(void *buffer, size_t n);
 116 #endif
 117 };
 118
 119 #endif