src/unix/sound_sdl.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/unix/sound_sdl.cpp
   3 // Purpose:     wxSound backend using SDL
   4 // Author:      Vaclav Slavik
   5 // Modified by:
   6 // Created:     2004/01/31
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2004, Open Source Applications Foundation
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // for compilers that support precompilation, includes "wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #if defined(__BORLANDC__)
  16 #pragma hdrstop
  17 #endif
  18
  19 #if wxUSE_SOUND && wxUSE_LIBSDL
  20
  21 #include <SDL.h>
  22
  23 #ifndef WX_PRECOMP
  24     #include "wx/event.h"
  25     #include "wx/intl.h"
  26     #include "wx/log.h"
  27     #include "wx/utils.h"
  28 #endif
  29
  30 #include "wx/thread.h"
  31 #include "wx/module.h"
  32 #include "wx/sound.h"
  33
  34 // ----------------------------------------------------------------------------
  35 // wxSoundBackendSDL, for Unix with libSDL
  36 // ----------------------------------------------------------------------------
  37
  38 class wxSoundBackendSDLNotification : public wxEvent
  39 {
  40 public:
  41     DECLARE_DYNAMIC_CLASS(wxSoundBackendSDLNotification)
  42     wxSoundBackendSDLNotification();
  43     wxEvent *Clone() const { return new wxSoundBackendSDLNotification(*this); }
  44 };
  45
  46 typedef void (wxEvtHandler::*wxSoundBackendSDLNotificationFunction)
  47              (wxSoundBackendSDLNotification&);
  48
  49 BEGIN_DECLARE_EVENT_TYPES()
  50     DECLARE_LOCAL_EVENT_TYPE(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION, -1)
  51 END_DECLARE_EVENT_TYPES()
  52
  53 #define EVT_SOUND_BACKEND_SDL_NOTIFICATON(func) \
  54     DECLARE_EVENT_TABLE_ENTRY(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION, \
  55                               -1,                       \
  56                               -1,                       \
  57                               (wxObjectEventFunction)  wxStaticCastEvent( wxSoundBackendSDLNotificationFunction, & func ), \
  58                               (wxObject *) NULL ),
  59
  60 IMPLEMENT_DYNAMIC_CLASS(wxSoundBackendSDLNotification, wxEvtHandler)
  61 DEFINE_EVENT_TYPE(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION)
  62
  63 wxSoundBackendSDLNotification::wxSoundBackendSDLNotification()
  64 {
  65     SetEventType(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION);
  66 }
  67
  68 class wxSoundBackendSDLEvtHandler;
  69
  70 class wxSoundBackendSDL : public wxSoundBackend
  71 {
  72 public:
  73     wxSoundBackendSDL()
  74         : m_initialized(false), m_playing(false), m_audioOpen(false),
  75           m_data(NULL), m_evtHandler(NULL) {}
  76     virtual ~wxSoundBackendSDL();
  77
  78     wxString GetName() const { return _T("Simple DirectMedia Layer"); }
  79     int GetPriority() const { return 9; }
  80     bool IsAvailable() const;
  81     bool HasNativeAsyncPlayback() const { return true; }
  82     bool Play(wxSoundData *data, unsigned flags,
  83               volatile wxSoundPlaybackStatus *status);
  84
  85     void FillAudioBuffer(Uint8 *stream, int len);
  86     void FinishedPlayback();
  87
  88     void Stop();
  89     bool IsPlaying() const { return m_playing; }
  90
  91 private:
  92     bool OpenAudio();
  93     void CloseAudio();
  94
  95     bool                        m_initialized;
  96     bool                        m_playing, m_audioOpen;
  97     // playback information:
  98     wxSoundData                 *m_data;
  99     unsigned                     m_pos;
 100     SDL_AudioSpec                m_spec;
 101     bool                         m_loop;
 102
 103     wxSoundBackendSDLEvtHandler *m_evtHandler;
 104 };
 105
 106 class wxSoundBackendSDLEvtHandler : public wxEvtHandler
 107 {
 108 public:
 109     wxSoundBackendSDLEvtHandler(wxSoundBackendSDL *bk) : m_backend(bk) {}
 110
 111 private:
 112     void OnNotify(wxSoundBackendSDLNotification& WXUNUSED(event))
 113     {
 114         wxLogTrace(_T("sound"),
 115                    _T("received playback status change notification"));
 116         m_backend->FinishedPlayback();
 117     }
 118     wxSoundBackendSDL *m_backend;
 119
 120     DECLARE_EVENT_TABLE()
 121 };
 122
 123 BEGIN_EVENT_TABLE(wxSoundBackendSDLEvtHandler, wxEvtHandler)
 124     EVT_SOUND_BACKEND_SDL_NOTIFICATON(wxSoundBackendSDLEvtHandler::OnNotify)
 125 END_EVENT_TABLE()
 126
 127 wxSoundBackendSDL::~wxSoundBackendSDL()
 128 {
 129     Stop();
 130     CloseAudio();
 131     delete m_evtHandler;
 132 }
 133
 134 bool wxSoundBackendSDL::IsAvailable() const
 135 {
 136     if (m_initialized)
 137         return true;
 138     if (SDL_WasInit(SDL_INIT_AUDIO) != SDL_INIT_AUDIO)
 139     {
 140         if (SDL_Init(SDL_INIT_AUDIO | SDL_INIT_NOPARACHUTE) == -1)
 141             return false;
 142     }
 143     wxConstCast(this, wxSoundBackendSDL)->m_initialized = true;
 144     wxLogTrace(_T("sound"), _T("initialized SDL audio subsystem"));
 145     return true;
 146 }
 147
 148 extern "C" void wx_sdl_audio_callback(void *userdata, Uint8 *stream, int len)
 149 {
 150     wxSoundBackendSDL *bk = (wxSoundBackendSDL*)userdata;
 151     bk->FillAudioBuffer(stream, len);
 152 }
 153
 154 void wxSoundBackendSDL::FillAudioBuffer(Uint8 *stream, int len)
 155 {
 156     if (m_playing)
 157     {
 158         // finished playing the sample
 159         if (m_pos == m_data->m_dataBytes)
 160         {
 161             m_playing = false;
 162             wxSoundBackendSDLNotification event;
 163             m_evtHandler->AddPendingEvent(event);
 164         }
 165         // still something to play
 166         else
 167         {
 168             unsigned size = ((len + m_pos) < m_data->m_dataBytes) ?
 169                             len :
 170                             (m_data->m_dataBytes - m_pos);
 171             memcpy(stream, m_data->m_data + m_pos, size);
 172             m_pos += size;
 173             len -= size;
 174             stream += size;
 175         }
 176     }
 177     // the sample doesn't play, fill the buffer with silence and wait for
 178     // the main thread to shut the playback down:
 179     if (len > 0)
 180     {
 181         if (m_loop)
 182         {
 183             m_pos = 0;
 184             FillAudioBuffer(stream, len);
 185             return;
 186         }
 187         else
 188         {
 189             memset(stream, m_spec.silence, len);
 190         }
 191     }
 192 }
 193
 194 void wxSoundBackendSDL::FinishedPlayback()
 195 {
 196     if (!m_playing)
 197         Stop();
 198 }
 199
 200 bool wxSoundBackendSDL::OpenAudio()
 201 {
 202     if (!m_audioOpen)
 203     {
 204         if (!m_evtHandler)
 205             m_evtHandler = new wxSoundBackendSDLEvtHandler(this);
 206
 207         m_spec.silence = 0;
 208         m_spec.samples = 4096;
 209         m_spec.size = 0;
 210         m_spec.callback = wx_sdl_audio_callback;
 211         m_spec.userdata = (void*)this;
 212
 213         wxLogTrace(_T("sound"), _T("opening SDL audio..."));
 214         if (SDL_OpenAudio(&m_spec, NULL) >= 0)
 215         {
 216 #if wxUSE_LOG_DEBUG
 217             char driver[256];
 218             SDL_AudioDriverName(driver, 256);
 219             wxLogTrace(_T("sound"), _T("opened audio, driver '%s'"),
 220                        wxString(driver, wxConvLocal).c_str());
 221 #endif
 222             m_audioOpen = true;
 223             return true;
 224         }
 225         else
 226         {
 227             wxString err(SDL_GetError(), wxConvLocal);
 228             wxLogError(_("Couldn't open audio: %s"), err.c_str());
 229             return false;
 230         }
 231     }
 232     return true;
 233 }
 234
 235 void wxSoundBackendSDL::CloseAudio()
 236 {
 237     if (m_audioOpen)
 238     {
 239         SDL_CloseAudio();
 240         wxLogTrace(_T("sound"), _T("closed audio"));
 241         m_audioOpen = false;
 242     }
 243 }
 244
 245 bool wxSoundBackendSDL::Play(wxSoundData *data, unsigned flags,
 246                              volatile wxSoundPlaybackStatus *WXUNUSED(status))
 247 {
 248     Stop();
 249
 250     int format;
 251     if (data->m_bitsPerSample == 8)
 252         format = AUDIO_U8;
 253     else if (data->m_bitsPerSample == 16)
 254         format = AUDIO_S16LSB;
 255     else
 256         return false;
 257
 258     bool needsOpen = true;
 259     if (m_audioOpen)
 260     {
 261         if (format == m_spec.format &&
 262             m_spec.freq == (int)data->m_samplingRate &&
 263             m_spec.channels == data->m_channels)
 264         {
 265             needsOpen = false;
 266         }
 267         else
 268         {
 269             CloseAudio();
 270         }
 271     }
 272
 273     if (needsOpen)
 274     {
 275         m_spec.format = format;
 276         m_spec.freq = data->m_samplingRate;
 277         m_spec.channels = data->m_channels;
 278         if (!OpenAudio())
 279             return false;
 280     }
 281
 282     SDL_LockAudio();
 283     wxLogTrace(_T("sound"), _T("playing new sound"));
 284     m_playing = true;
 285     m_pos = 0;
 286     m_loop = (flags & wxSOUND_LOOP);
 287     m_data = data;
 288     data->IncRef();
 289     SDL_UnlockAudio();
 290
 291     SDL_PauseAudio(0);
 292
 293     // wait until playback finishes if called in sync mode:
 294     if (!(flags & wxSOUND_ASYNC))
 295     {
 296         wxLogTrace(_T("sound"), _T("waiting for sample to finish"));
 297         while (m_playing && m_data == data)
 298         {
 299 #if wxUSE_THREADS
 300             // give the playback thread a chance to add event to pending
 301             // events queue, release GUI lock temporarily:
 302             if (wxThread::IsMain())
 303                 wxMutexGuiLeave();
 304 #endif
 305             wxMilliSleep(10);
 306 #if wxUSE_THREADS
 307             if (wxThread::IsMain())
 308                 wxMutexGuiEnter();
 309 #endif
 310         }
 311         wxLogTrace(_T("sound"), _T("sample finished"));
 312     }
 313
 314     return true;
 315 }
 316
 317 void wxSoundBackendSDL::Stop()
 318 {
 319     SDL_LockAudio();
 320     SDL_PauseAudio(1);
 321     m_playing = false;
 322     if (m_data)
 323     {
 324         m_data->DecRef();
 325         m_data = NULL;
 326     }
 327     SDL_UnlockAudio();
 328 }
 329
 330 extern "C" wxSoundBackend *wxCreateSoundBackendSDL()
 331 {
 332     return new wxSoundBackendSDL();
 333 }
 334
 335 #endif // wxUSE_SOUND && wxUSE_LIBSDL