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