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, 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 #include "wx/setup.h"
  16
  17 #if defined(__BORLANDC__)
  18 #pragma hdrstop
  19 #endif
  20
  21 #if wxUSE_SOUND && 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)  wxStaticCastEvent( wxSoundBackendSDLNotificationFunction, & func ), \
  60                               (wxObject *) NULL ),
  61
  62 IMPLEMENT_DYNAMIC_CLASS(wxSoundBackendSDLNotification, wxEvtHandler)
  63 DEFINE_EVENT_TYPE(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION)
  64
  65 wxSoundBackendSDLNotification::wxSoundBackendSDLNotification()
  66 {
  67     SetEventType(wxEVT_SOUND_BACKEND_SDL_NOTIFICATION);
  68 }
  69
  70 class wxSoundBackendSDLEvtHandler;
  71
  72 class wxSoundBackendSDL : public wxSoundBackend
  73 {
  74 public:
  75     wxSoundBackendSDL()
  76         : m_initialized(false), m_playing(false), m_audioOpen(false),
  77           m_data(NULL), m_evtHandler(NULL) {}
  78     virtual ~wxSoundBackendSDL();
  79
  80     wxString GetName() const { return _T("Simple DirectMedia Layer"); }
  81     int GetPriority() const { return 9; }
  82     bool IsAvailable() const;
  83     bool HasNativeAsyncPlayback() const { return true; }
  84     bool Play(wxSoundData *data, unsigned flags,
  85               volatile wxSoundPlaybackStatus *status);
  86
  87     void FillAudioBuffer(Uint8 *stream, int len);
  88     void FinishedPlayback();
  89
  90     void Stop();
  91     bool IsPlaying() const { return m_playing; }
  92
  93 private:
  94     bool OpenAudio();
  95     void CloseAudio();
  96
  97     bool                        m_initialized;
  98     bool                        m_playing, m_audioOpen;
  99     // playback information:
 100     wxSoundData                 *m_data;
 101     unsigned                     m_pos;
 102     SDL_AudioSpec                m_spec;
 103     bool                         m_loop;
 104
 105     wxSoundBackendSDLEvtHandler *m_evtHandler;
 106 };
 107
 108 class wxSoundBackendSDLEvtHandler : public wxEvtHandler
 109 {
 110 public:
 111     wxSoundBackendSDLEvtHandler(wxSoundBackendSDL *bk) : m_backend(bk) {}
 112
 113 private:
 114     void OnNotify(wxSoundBackendSDLNotification& WXUNUSED(event))
 115     {
 116         wxLogTrace(_T("sound"),
 117                    _T("received playback status change notification"));
 118         m_backend->FinishedPlayback();
 119     }
 120     wxSoundBackendSDL *m_backend;
 121
 122     DECLARE_EVENT_TABLE()
 123 };
 124
 125 BEGIN_EVENT_TABLE(wxSoundBackendSDLEvtHandler, wxEvtHandler)
 126     EVT_SOUND_BACKEND_SDL_NOTIFICATON(wxSoundBackendSDLEvtHandler::OnNotify)
 127 END_EVENT_TABLE()
 128
 129 wxSoundBackendSDL::~wxSoundBackendSDL()
 130 {
 131     Stop();
 132     CloseAudio();
 133     delete m_evtHandler;
 134 }
 135
 136 bool wxSoundBackendSDL::IsAvailable() const
 137 {
 138     if (m_initialized)
 139         return true;
 140     if (SDL_WasInit(SDL_INIT_AUDIO) != SDL_INIT_AUDIO)
 141     {
 142         if (SDL_Init(SDL_INIT_AUDIO | SDL_INIT_NOPARACHUTE) == -1)
 143             return false;
 144     }
 145     wxConstCast(this, wxSoundBackendSDL)->m_initialized = true;
 146     wxLogTrace(_T("sound"), _T("initialized SDL audio subsystem"));
 147     return true;
 148 }
 149
 150 extern "C" void wx_sdl_audio_callback(void *userdata, Uint8 *stream, int len)
 151 {
 152     wxSoundBackendSDL *bk = (wxSoundBackendSDL*)userdata;
 153     bk->FillAudioBuffer(stream, len);
 154 }
 155
 156 void wxSoundBackendSDL::FillAudioBuffer(Uint8 *stream, int len)
 157 {
 158     if (m_playing)
 159     {
 160         // finished playing the sample
 161         if (m_pos == m_data->m_dataBytes)
 162         {
 163             m_playing = false;
 164             wxSoundBackendSDLNotification event;
 165             m_evtHandler->AddPendingEvent(event);
 166         }
 167         // still something to play
 168         else
 169         {
 170             unsigned size = ((len + m_pos) < m_data->m_dataBytes) ?
 171                             len :
 172                             (m_data->m_dataBytes - m_pos);
 173             memcpy(stream, m_data->m_data + m_pos, size);
 174             m_pos += size;
 175             len -= size;
 176             stream += size;
 177         }
 178     }
 179     // the sample doesn't play, fill the buffer with silence and wait for
 180     // the main thread to shut the playback down:
 181     if (len > 0)
 182     {
 183         if (m_loop)
 184         {
 185             m_pos = 0;
 186             FillAudioBuffer(stream, len);
 187             return;
 188         }
 189         else
 190         {
 191             memset(stream, m_spec.silence, len);
 192         }
 193     }
 194 }
 195
 196 void wxSoundBackendSDL::FinishedPlayback()
 197 {
 198     if (!m_playing)
 199         Stop();
 200 }
 201
 202 bool wxSoundBackendSDL::OpenAudio()
 203 {
 204     if (!m_audioOpen)
 205     {
 206         if (!m_evtHandler)
 207             m_evtHandler = new wxSoundBackendSDLEvtHandler(this);
 208
 209         m_spec.silence = 0;
 210         m_spec.samples = 4096;
 211         m_spec.size = 0;
 212         m_spec.callback = wx_sdl_audio_callback;
 213         m_spec.userdata = (void*)this;
 214
 215         wxLogTrace(_T("sound"), _T("opening SDL audio..."));
 216         if (SDL_OpenAudio(&m_spec, NULL) >= 0)
 217         {
 218 #if wxUSE_LOG_DEBUG
 219             char driver[256];
 220             SDL_AudioDriverName(driver, 256);
 221             wxLogTrace(_T("sound"), _T("opened audio, driver '%s'"),
 222                        wxString(driver, wxConvLocal).c_str());
 223 #endif
 224             m_audioOpen = true;
 225             return true;
 226         }
 227         else
 228         {
 229             wxString err(SDL_GetError(), wxConvLocal);
 230             wxLogError(_("Couldn't open audio: %s"), err.c_str());
 231             return false;
 232         }
 233     }
 234     return true;
 235 }
 236
 237 void wxSoundBackendSDL::CloseAudio()
 238 {
 239     if (m_audioOpen)
 240     {
 241         SDL_CloseAudio();
 242         wxLogTrace(_T("sound"), _T("closed audio"));
 243         m_audioOpen = false;
 244     }
 245 }
 246
 247 bool wxSoundBackendSDL::Play(wxSoundData *data, unsigned flags,
 248                              volatile wxSoundPlaybackStatus *WXUNUSED(status))
 249 {
 250     Stop();
 251
 252     int format;
 253     if (data->m_bitsPerSample == 8)
 254         format = AUDIO_U8;
 255     else if (data->m_bitsPerSample == 16)
 256         format = AUDIO_S16LSB;
 257     else
 258         return false;
 259
 260     bool needsOpen = true;
 261     if (m_audioOpen)
 262     {
 263         if (format == m_spec.format &&
 264             m_spec.freq == (int)data->m_samplingRate &&
 265             m_spec.channels == data->m_channels)
 266         {
 267             needsOpen = false;
 268         }
 269         else
 270         {
 271             CloseAudio();
 272         }
 273     }
 274
 275     if (needsOpen)
 276     {
 277         m_spec.format = format;
 278         m_spec.freq = data->m_samplingRate;
 279         m_spec.channels = data->m_channels;
 280         if (!OpenAudio())
 281             return false;
 282     }
 283
 284     SDL_LockAudio();
 285     wxLogTrace(_T("sound"), _T("playing new sound"));
 286     m_playing = true;
 287     m_pos = 0;
 288     m_loop = (flags & wxSOUND_LOOP);
 289     m_data = data;
 290     data->IncRef();
 291     SDL_UnlockAudio();
 292
 293     SDL_PauseAudio(0);
 294
 295     // wait until playback finishes if called in sync mode:
 296     if (!(flags & wxSOUND_ASYNC))
 297     {
 298         wxLogTrace(_T("sound"), _T("waiting for sample to finish"));
 299         while (m_playing && m_data == data)
 300         {
 301 #if wxUSE_THREADS
 302             // give the playback thread a chance to add event to pending
 303             // events queue, release GUI lock temporarily:
 304             if (wxThread::IsMain())
 305                 wxMutexGuiLeave();
 306 #endif
 307             wxUsleep(10);
 308 #if wxUSE_THREADS
 309             if (wxThread::IsMain())
 310                 wxMutexGuiEnter();
 311 #endif
 312         }
 313         wxLogTrace(_T("sound"), _T("sample finished"));
 314     }
 315
 316     return true;
 317 }
 318
 319 void wxSoundBackendSDL::Stop()
 320 {
 321     SDL_LockAudio();
 322     SDL_PauseAudio(1);
 323     m_playing = false;
 324     if (m_data)
 325     {
 326         m_data->DecRef();
 327         m_data = NULL;
 328     }
 329     SDL_UnlockAudio();
 330 }
 331
 332 extern "C" wxSoundBackend *wxCreateSoundBackendSDL()
 333 {
 334     return new wxSoundBackendSDL();
 335 }
 336
 337 #endif // wxUSE_SOUND && wxUSE_LIBSDL