src/unix/sound_sdl.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        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, Vaclav Slavik
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // for compilers that support precompilation, includes "wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #include "wx/setup.h"
  16
  17 #if defined(__BORLANDC__)
  18 #pragma hdrstop
  19 #endif
  20
  21 #if wxUSE_WAVE && wxUSE_LIBSDL
  22
  23 #include <SDL.h>
  24
  25 #ifndef WX_PRECOMP
  26     #include "wx/event.h"
  27     #include "wx/intl.h"
  28     #include "wx/log.h"
  29     #include "wx/utils.h"
  30 #endif
  31
  32 #include "wx/thread.h"
  33 #include "wx/module.h"
  34 #include "wx/sound.h"
  35
  36 // ----------------------------------------------------------------------------
  37 // wxSoundBackendSDL, for Unix with libSDL
  38 // ----------------------------------------------------------------------------
  39
  40 class wxSoundBackendSDLNotification : public wxEvent
  41 {
  42 public:
  43     DECLARE_DYNAMIC_CLASS(wxSoundBackendSDLNotification)
  44     wxSoundBackendSDLNotification();
  45         wxEvent *Clone() const { return new wxSoundBackendSDLNotification(*this); }
  46 };
  47
  48 typedef void (wxEvtHandler::*wxSoundBackendSDLNotificationFunction)
  49              (wxSoundBackendSDLNotification&);
  50
  51 BEGIN_DECLARE_EVENT_TYPES()
  52     DECLARE_LOCAL_EVENT_TYPE(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION, -1)
  53 END_DECLARE_EVENT_TYPES()
  54
  55 #define EVT_SOUND_BACKEND_SDL_NOTIFICATON(func) \
  56     DECLARE_EVENT_TABLE_ENTRY(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION, \
  57                               -1,                       \
  58                               -1,                       \
  59                               (wxObjectEventFunction)   \
  60                               (wxSoundBackendSDLNotificationFunction)& func, \
  61                               (wxObject *) NULL ),
  62
  63 IMPLEMENT_DYNAMIC_CLASS(wxSoundBackendSDLNotification, wxEvtHandler)
  64 DEFINE_EVENT_TYPE(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION)
  65
  66 wxSoundBackendSDLNotification::wxSoundBackendSDLNotification()
  67 {
  68     SetEventType(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION);
  69 }
  70
  71 class wxSoundBackendSDLEvtHandler;
  72
  73 class wxSoundBackendSDL : public wxSoundBackend
  74 {
  75 public:
  76     wxSoundBackendSDL()
  77         : m_initialized(false), m_playing(false), m_audioOpen(false),
  78           m_data(NULL), m_evtHandler(NULL) {}
  79     virtual ~wxSoundBackendSDL();
  80
  81     wxString GetName() const { return _T("Simple DirectMedia Layer"); }
  82     int GetPriority() const { return 9; }
  83     bool IsAvailable() const;
  84     bool HasNativeAsyncPlayback() const { return true; }
  85     bool Play(wxSoundData *data, unsigned flags);
  86
  87     void FillAudioBuffer(Uint8 *stream, int len);
  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->Stop();
 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 bool wxSoundBackendSDL::OpenAudio()
 195 {
 196     if (!m_audioOpen)
 197     {
 198         if (!m_evtHandler)
 199             m_evtHandler = new wxSoundBackendSDLEvtHandler(this);
 200
 201         m_spec.silence = 0;
 202         m_spec.samples = 4096;
 203         m_spec.size = 0;
 204         m_spec.callback = wx_sdl_audio_callback;
 205         m_spec.userdata = (void*)this;
 206
 207         wxLogTrace(_T("sound"), _T("opening SDL audio..."));
 208         if (SDL_OpenAudio(&m_spec, NULL) >= 0)
 209         {
 210 #if wxUSE_LOG_DEBUG
 211             char driver[256];
 212             SDL_AudioDriverName(driver, 256);
 213             wxLogTrace(_T("sound"), _T("opened audio, driver '%s'"),
 214                        wxString(driver, wxConvLocal).c_str());
 215 #endif
 216             m_audioOpen = true;
 217             return true;
 218         }
 219         else
 220         {
 221             wxString err(SDL_GetError(), wxConvLocal);
 222             wxLogError(_("Couldn't open audio: %s"), err.c_str());
 223             return false;
 224         }
 225     }
 226     return true;
 227 }
 228
 229 void wxSoundBackendSDL::CloseAudio()
 230 {
 231     if (m_audioOpen)
 232     {
 233         SDL_CloseAudio();
 234         wxLogTrace(_T("sound"), _T("closed audio"));
 235         m_audioOpen = false;
 236     }
 237 }
 238
 239 bool wxSoundBackendSDL::Play(wxSoundData *data, unsigned flags)
 240 {
 241     int format;
 242     if (data->m_bitsPerSample == 8)
 243         format = AUDIO_U8;
 244     else if (data->m_bitsPerSample == 16)
 245         format = AUDIO_S16LSB;
 246     else
 247         return false;
 248
 249     SDL_LockAudio();
 250
 251     bool needsOpen = true;
 252     if (m_audioOpen)
 253     {
 254         if (format == m_spec.format &&
 255             m_spec.freq == (int)data->m_samplingRate &&
 256             m_spec.channels == data->m_channels)
 257         {
 258             needsOpen = false;
 259         }
 260         else
 261         {
 262             CloseAudio();
 263         }
 264     }
 265
 266     Stop();
 267
 268     if (needsOpen)
 269     {
 270         m_spec.format = format;
 271         m_spec.freq = data->m_samplingRate;
 272         m_spec.channels = data->m_channels;
 273         if (!OpenAudio())
 274         {
 275             SDL_UnlockAudio();
 276             return false;
 277         }
 278     }
 279
 280     m_playing = true;
 281     m_pos = 0;
 282     m_loop = (flags & wxSOUND_LOOP);
 283     m_data = data;
 284     data->IncRef();
 285
 286     SDL_PauseAudio(0);
 287     SDL_UnlockAudio();
 288
 289     // wait until playback finishes if called in sync mode:
 290     if (!(flags & wxSOUND_ASYNC))
 291     {
 292         wxLogTrace(_T("sound"), _T("waiting for sample to finish"));
 293         while (m_playing)
 294         {
 295 #if wxUSE_THREADS
 296             // give the playback thread a chance to add event to pending
 297             // events queue, release GUI lock temporarily:
 298             if (wxThread::IsMain())
 299                 wxMutexGuiLeave();
 300 #endif
 301             wxUsleep(10);
 302 #if wxUSE_THREADS
 303             if (wxThread::IsMain())
 304                 wxMutexGuiEnter();
 305 #endif
 306         }
 307         wxLogTrace(_T("sound"), _T("sample finished"));
 308     }
 309
 310     return true;
 311 }
 312
 313 void wxSoundBackendSDL::Stop()
 314 {
 315     SDL_LockAudio();
 316     SDL_PauseAudio(1);
 317     if (m_data)
 318     {
 319         m_data->DecRef();
 320         m_data = NULL;
 321     }
 322     SDL_UnlockAudio();
 323 }
 324
 325 extern "C" wxSoundBackend *wxCreateSoundBackendSDL()
 326 {
 327     return new wxSoundBackendSDL();
 328 }
 329
 330 #endif // wxUSE_WAVE && wxUSE_LIBSDL