opensles: move code from Start/Stop to Open/Close

These objects do not depend on the audio format

modules/audio_output/opensles_android.c

@@ -41,6 +41,17 @@
 #include <SLES/OpenSLES.h>
 #include <SLES/OpenSLES_Android.h>
 
+#define CHECK_OPENSL_ERROR( msg )                   \
+    if( unlikely( result != SL_RESULT_SUCCESS ) )   \
+    {                                               \
+        msg_Err( aout, msg" (%lu)", result );       \
+        goto error;                                 \
+    }
+
+typedef SLresult (*slCreateEngine_t)(
+        SLObjectItf*, SLuint32, const SLEngineOption*, SLuint32,
+        const SLInterfaceID*, const SLboolean* );
+
 #define Destroy(a) (*a)->Destroy(a);
 #define SetPlayState(a, b) (*a)->SetPlayState(a, b)
 #define RegisterCallback(a, b, c) (*a)->RegisterCallback(a, b, c)
@@ -69,7 +80,7 @@ struct aout_sys_t
     SLAndroidSimpleBufferQueueItf   playerBufferQueue;
     SLObjectItf                     playerObject;
     SLVolumeItf                     volumeItf;
-
+    SLEngineItf                     engineEngine;
     SLPlayItf                       playerPlay;
 
     vlc_mutex_t                     lock;
@@ -86,13 +97,21 @@ struct aout_sys_t
     block_t                       **pp_buffer_last;
 
     void                           *p_so_handle;
+
+    slCreateEngine_t                slCreateEnginePtr;
+    SLInterfaceID                   SL_IID_ENGINE;
+    SLInterfaceID                   SL_IID_ANDROIDSIMPLEBUFFERQUEUE;
+    SLInterfaceID                   SL_IID_VOLUME;
+    SLInterfaceID                   SL_IID_PLAY;
+
     audio_sample_format_t           format;
 };
 
 /*****************************************************************************
  * Local prototypes.
  *****************************************************************************/
-static int  Open        ( vlc_object_t * );
+static int  Open  (vlc_object_t *);
+static void Close (vlc_object_t *);
 
 /*****************************************************************************
  * Module descriptor
@@ -106,56 +125,41 @@ vlc_module_begin ()
 
     set_capability( "audio output", 170 )
     add_shortcut( "opensles", "android" )
-    set_callbacks( Open, NULL )
+    set_callbacks( Open, Close )
 vlc_module_end ()
 
 
-static void Clean( aout_sys_t *p_sys )
-{
-    if( p_sys->playerObject )
-        Destroy( p_sys->playerObject );
-    if( p_sys->outputMixObject )
-        Destroy( p_sys->outputMixObject );
-    if( p_sys->engineObject )
-        Destroy( p_sys->engineObject );
-
-    if( p_sys->p_so_handle )
-        dlclose( p_sys->p_so_handle );
-
-    free( p_sys );
-}
-
-static void Flush(audio_output_t *p_aout, bool drain)
+static void Flush(audio_output_t *aout, bool drain)
 {
-    aout_sys_t *p_sys = p_aout->sys;
+    aout_sys_t *sys = aout->sys;
 
     if (drain) {
         mtime_t delay;
-        vlc_mutex_lock( &p_sys->lock );
-        delay = p_sys->length;
-        vlc_mutex_unlock( &p_sys->lock );
+        vlc_mutex_lock( &sys->lock );
+        delay = sys->length;
+        vlc_mutex_unlock( &sys->lock );
         msleep(delay);
     } else {
-        vlc_mutex_lock( &p_sys->lock );
-        SetPlayState( p_sys->playerPlay, SL_PLAYSTATE_STOPPED );
-        Clear( p_sys->playerBufferQueue );
-        SetPlayState( p_sys->playerPlay, SL_PLAYSTATE_PLAYING );
+        vlc_mutex_lock( &sys->lock );
+        SetPlayState( sys->playerPlay, SL_PLAYSTATE_STOPPED );
+        Clear( sys->playerBufferQueue );
+        SetPlayState( sys->playerPlay, SL_PLAYSTATE_PLAYING );
 
-        p_sys->length = 0;
-        p_sys->buffers = 0;
+        sys->length = 0;
+        sys->buffers = 0;
 
         /* release audio data not yet written to opensles */
-        block_ChainRelease( p_sys->p_buffer_chain );
-        p_sys->p_buffer_chain = NULL;
-        p_sys->pp_buffer_last = &p_sys->p_buffer_chain;
+        block_ChainRelease( sys->p_buffer_chain );
+        sys->p_buffer_chain = NULL;
+        sys->pp_buffer_last = &sys->p_buffer_chain;
 
         /* release audio data written to opensles, but not yet
          * played on hardware */
-        block_ChainRelease( p_sys->p_chain );
-        p_sys->p_chain = NULL;
-        p_sys->pp_last = &p_sys->p_chain;
+        block_ChainRelease( sys->p_chain );
+        sys->p_chain = NULL;
+        sys->pp_last = &sys->p_chain;
 
-        vlc_mutex_unlock( &p_sys->lock );
+        vlc_mutex_unlock( &sys->lock );
     }
 }
 
@@ -181,26 +185,26 @@ static int MuteSet(audio_output_t *aout, bool mute)
     return (r == SL_RESULT_SUCCESS) ? 0 : -1;
 }
 
-static void Pause(audio_output_t *p_aout, bool pause, mtime_t date)
+static void Pause(audio_output_t *aout, bool pause, mtime_t date)
 {
     (void)date;
-    aout_sys_t *p_sys = p_aout->sys;
-    SetPlayState( p_sys->playerPlay,
+    aout_sys_t *sys = aout->sys;
+    SetPlayState( sys->playerPlay,
         pause ? SL_PLAYSTATE_PAUSED : SL_PLAYSTATE_PLAYING );
 }
 
-static int TimeGet(audio_output_t* p_aout, mtime_t* restrict drift)
+static int TimeGet(audio_output_t* aout, mtime_t* restrict drift)
 {
-    aout_sys_t *p_sys = p_aout->sys;
+    aout_sys_t *sys = aout->sys;
 
-    vlc_mutex_lock( &p_sys->lock );
-    mtime_t delay = p_sys->length;
-    vlc_mutex_unlock( &p_sys->lock );
+    vlc_mutex_lock( &sys->lock );
+    mtime_t delay = sys->length;
+    vlc_mutex_unlock( &sys->lock );
 
     SLAndroidSimpleBufferQueueState st;
-    SLresult res = GetState(p_sys->playerBufferQueue, &st);
+    SLresult res = GetState(sys->playerBufferQueue, &st);
     if (unlikely(res != SL_RESULT_SUCCESS)) {
-        msg_Err(p_aout, "Could not query buffer queue state in TimeGet (%lu)", res);
+        msg_Err(aout, "Could not query buffer queue state in TimeGet (%lu)", res);
         return -1;
     }
 
@@ -211,52 +215,52 @@ static int TimeGet(audio_output_t* p_aout, mtime_t* restrict drift)
     return 0;
 }
 
-static int WriteBuffer(audio_output_t *p_aout)
+static int WriteBuffer(audio_output_t *aout)
 {
-    aout_sys_t *p_sys = p_aout->sys;
+    aout_sys_t *sys = aout->sys;
 
-    block_t *b = p_sys->p_buffer_chain;
+    block_t *b = sys->p_buffer_chain;
     if (!b)
         return false;
 
     if (!b->i_length)
-        b->i_length = (mtime_t)(b->i_buffer / 2 / p_sys->format.i_channels) * CLOCK_FREQ / p_sys->format.i_rate;
+        b->i_length = (mtime_t)(b->i_buffer / 2 / sys->format.i_channels) * CLOCK_FREQ / sys->format.i_rate;
 
     /* If something bad happens, we must remove this buffer from the FIFO */
-    block_t **pp_last_saved = p_sys->pp_last;
+    block_t **pp_last_saved = sys->pp_last;
     block_t *p_last_saved = *pp_last_saved;
     block_t *next_saved = b->p_next;
     b->p_next = NULL;
 
     /* Put this block in the list of audio already written to opensles */
-    block_ChainLastAppend( &p_sys->pp_last, b );
+    block_ChainLastAppend( &sys->pp_last, b );
 
     mtime_t len = b->i_length;
-    p_sys->length += len;
+    sys->length += len;
     block_t *next = b->p_next;
 
-    vlc_mutex_unlock( &p_sys->lock );
-    SLresult r = Enqueue( p_sys->playerBufferQueue, b->p_buffer, b->i_buffer );
-    vlc_mutex_lock( &p_sys->lock );
+    vlc_mutex_unlock( &sys->lock );
+    SLresult r = Enqueue( sys->playerBufferQueue, b->p_buffer, b->i_buffer );
+    vlc_mutex_lock( &sys->lock );
 
     if (r == SL_RESULT_SUCCESS) {
         /* Remove that block from the list of audio not yet written */
-        p_sys->buffers++;
-        p_sys->p_buffer_chain = next;
-        if (!p_sys->p_buffer_chain)
-            p_sys->pp_buffer_last = &p_sys->p_buffer_chain;
+        sys->buffers++;
+        sys->p_buffer_chain = next;
+        if (!sys->p_buffer_chain)
+            sys->pp_buffer_last = &sys->p_buffer_chain;
     } else {
         /* Remove that block from the list of audio already written */
-        msg_Err( p_aout, "error %lu when writing %d bytes, %d/255 buffers occupied %s",
-                r, b->i_buffer, p_sys->buffers,
+        msg_Err( aout, "error %lu when writing %d bytes, %d/255 buffers occupied %s",
+                r, b->i_buffer, sys->buffers,
                 (r == SL_RESULT_BUFFER_INSUFFICIENT) ? " (buffer insufficient)" : "");
 
-        p_sys->pp_last = pp_last_saved;
+        sys->pp_last = pp_last_saved;
         *pp_last_saved = p_last_saved;
 
         b->p_next = next_saved;
 
-        p_sys->length -= len;
+        sys->length -= len;
         next = NULL; /* We'll try again next time */
     }
 
@@ -266,123 +270,63 @@ static int WriteBuffer(audio_output_t *p_aout)
 /*****************************************************************************
  * Play: play a sound
  *****************************************************************************/
-static void Play( audio_output_t *p_aout, block_t *p_buffer )
+static void Play( audio_output_t *aout, block_t *p_buffer )
 {
-    aout_sys_t *p_sys = p_aout->sys;
+    aout_sys_t *sys = aout->sys;
 
     p_buffer->p_next = NULL; /* Make sur our linked list doesn't use old references */
-    vlc_mutex_lock(&p_sys->lock);
-    block_ChainLastAppend( &p_sys->pp_buffer_last, p_buffer );
-    while (WriteBuffer(p_aout))
+    vlc_mutex_lock(&sys->lock);
+    block_ChainLastAppend( &sys->pp_buffer_last, p_buffer );
+    while (WriteBuffer(aout))
         ;
-    vlc_mutex_unlock( &p_sys->lock );
+    vlc_mutex_unlock( &sys->lock );
 }
 
 static void PlayedCallback (SLAndroidSimpleBufferQueueItf caller, void *pContext )
 {
     (void)caller;
     block_t *p_block;
-    audio_output_t *p_aout = pContext;
-    aout_sys_t *p_sys = p_aout->sys;
+    audio_output_t *aout = pContext;
+    aout_sys_t *sys = aout->sys;
 
-    assert (caller == p_sys->playerBufferQueue);
+    assert (caller == sys->playerBufferQueue);
 
-    vlc_mutex_lock( &p_sys->lock );
-    p_sys->buffers--;
+    vlc_mutex_lock( &sys->lock );
+    sys->buffers--;
 
-    p_block = p_sys->p_chain;
+    p_block = sys->p_chain;
     assert( p_block );
 
-    p_sys->p_chain = p_sys->p_chain->p_next;
+    sys->p_chain = sys->p_chain->p_next;
     /* if we exhausted our fifo, we must reset the pointer to the last
      * appended block */
-    if (!p_sys->p_chain)
-        p_sys->pp_last = &p_sys->p_chain;
+    if (!sys->p_chain)
+        sys->pp_last = &sys->p_chain;
 
-    p_sys->length -= p_block->i_length;
+    sys->length -= p_block->i_length;
 
-    vlc_mutex_unlock( &p_sys->lock );
+    vlc_mutex_unlock( &sys->lock );
 
     block_Release( p_block );
 }
 /*****************************************************************************
- * Open
+ *
  *****************************************************************************/
-static int Start( audio_output_t *p_aout, audio_sample_format_t *restrict fmt )
+static void Clean( aout_sys_t *sys )
 {
-    SLresult       result;
-    SLEngineItf    engineEngine;
-
-    /* Allocate structure */
-    p_aout->sys = calloc( 1, sizeof( aout_sys_t ) );
-    if( unlikely( p_aout->sys == NULL ) )
-        return VLC_ENOMEM;
-
-    aout_sys_t *p_sys = p_aout->sys;
-
-    //Acquiring LibOpenSLES symbols :
-    p_sys->p_so_handle = dlopen( "libOpenSLES.so", RTLD_NOW );
-    if( p_sys->p_so_handle == NULL )
-    {
-        msg_Err( p_aout, "Failed to load libOpenSLES" );
-        goto error;
-    }
-
-    typedef SLresult (*slCreateEngine_t)(
-            SLObjectItf*, SLuint32, const SLEngineOption*, SLuint32,
-            const SLInterfaceID*, const SLboolean* );
-    slCreateEngine_t    slCreateEnginePtr = NULL;
-
-    SLInterfaceID *SL_IID_ENGINE;
-    SLInterfaceID *SL_IID_ANDROIDSIMPLEBUFFERQUEUE;
-    SLInterfaceID *SL_IID_VOLUME;
-    SLInterfaceID *SL_IID_PLAY;
-
-#define OPENSL_DLSYM( dest, handle, name )                   \
-    dest = dlsym( handle, name );                            \
-    if( dest == NULL )                                       \
-    {                                                        \
-        msg_Err( p_aout, "Failed to load symbol %s", name ); \
-        goto error;                                          \
-    }
-
-    OPENSL_DLSYM( slCreateEnginePtr, p_sys->p_so_handle, "slCreateEngine" );
-    OPENSL_DLSYM( SL_IID_ANDROIDSIMPLEBUFFERQUEUE, p_sys->p_so_handle,
-                 "SL_IID_ANDROIDSIMPLEBUFFERQUEUE" );
-    OPENSL_DLSYM( SL_IID_ENGINE, p_sys->p_so_handle, "SL_IID_ENGINE" );
-    OPENSL_DLSYM( SL_IID_PLAY, p_sys->p_so_handle, "SL_IID_PLAY" );
-    OPENSL_DLSYM( SL_IID_VOLUME, p_sys->p_so_handle, "SL_IID_VOLUME" );
-
-
-#define CHECK_OPENSL_ERROR( msg )                   \
-    if( unlikely( result != SL_RESULT_SUCCESS ) )   \
-    {                                               \
-        msg_Err( p_aout, msg" (%lu)", result );     \
-        goto error;                                 \
-    }
-
-    // create engine
-    result = slCreateEnginePtr( &p_sys->engineObject, 0, NULL, 0, NULL, NULL );
-    CHECK_OPENSL_ERROR( "Failed to create engine" );
-
-    // realize the engine in synchronous mode
-    result = Realize( p_sys->engineObject, SL_BOOLEAN_FALSE );
-    CHECK_OPENSL_ERROR( "Failed to realize engine" );
-
-    // get the engine interface, needed to create other objects
-    result = GetInterface( p_sys->engineObject, *SL_IID_ENGINE, &engineEngine );
-    CHECK_OPENSL_ERROR( "Failed to get the engine interface" );
-
-    // create output mix, with environmental reverb specified as a non-required interface
-    const SLInterfaceID ids1[] = { *SL_IID_VOLUME };
-    const SLboolean req1[] = { SL_BOOLEAN_FALSE };
-    result = CreateOutputMix( engineEngine, &p_sys->outputMixObject, 1, ids1, req1 );
-    CHECK_OPENSL_ERROR( "Failed to create output mix" );
+    if( sys->playerObject )
+        Destroy( sys->playerObject );
+    if( sys->outputMixObject )
+        Destroy( sys->outputMixObject );
+    if( sys->engineObject )
+        Destroy( sys->engineObject );
+}
 
-    // realize the output mix in synchronous mode
-    result = Realize( p_sys->outputMixObject, SL_BOOLEAN_FALSE );
-    CHECK_OPENSL_ERROR( "Failed to realize output mix" );
+static int Start( audio_output_t *aout, audio_sample_format_t *restrict fmt )
+{
+    SLresult       result;
 
+    aout_sys_t *sys = aout->sys;
 
     // configure audio source - this defines the number of samples you can enqueue.
     SLDataLocator_AndroidSimpleBufferQueue loc_bufq = {
@@ -404,89 +348,166 @@ static int Start( audio_output_t *p_aout, audio_sample_format_t *restrict fmt )
     // configure audio sink
     SLDataLocator_OutputMix loc_outmix = {
         SL_DATALOCATOR_OUTPUTMIX,
-        p_sys->outputMixObject
+        sys->outputMixObject
     };
     SLDataSink audioSnk = {&loc_outmix, NULL};
 
     //create audio player
-    const SLInterfaceID ids2[] = { *SL_IID_ANDROIDSIMPLEBUFFERQUEUE, *SL_IID_VOLUME };
+    const SLInterfaceID ids2[] = { sys->SL_IID_ANDROIDSIMPLEBUFFERQUEUE, sys->SL_IID_VOLUME };
     static const SLboolean req2[] = { SL_BOOLEAN_TRUE, SL_BOOLEAN_TRUE };
-    result = CreateAudioPlayer( engineEngine, &p_sys->playerObject, &audioSrc,
+    result = CreateAudioPlayer( sys->engineEngine, &sys->playerObject, &audioSrc,
                                     &audioSnk, sizeof( ids2 ) / sizeof( *ids2 ),
                                     ids2, req2 );
     CHECK_OPENSL_ERROR( "Failed to create audio player" );
 
-    result = Realize( p_sys->playerObject, SL_BOOLEAN_FALSE );
+    result = Realize( sys->playerObject, SL_BOOLEAN_FALSE );
     CHECK_OPENSL_ERROR( "Failed to realize player object." );
 
-    result = GetInterface( p_sys->playerObject, *SL_IID_PLAY, &p_sys->playerPlay );
+    result = GetInterface( sys->playerObject, sys->SL_IID_PLAY, &sys->playerPlay );
     CHECK_OPENSL_ERROR( "Failed to get player interface." );
 
-    result = GetInterface( p_sys->playerObject, *SL_IID_VOLUME, &p_sys->volumeItf );
+    result = GetInterface( sys->playerObject, sys->SL_IID_VOLUME, &sys->volumeItf );
     CHECK_OPENSL_ERROR( "failed to get volume interface." );
 
-    result = GetInterface( p_sys->playerObject, *SL_IID_ANDROIDSIMPLEBUFFERQUEUE,
-                                                  &p_sys->playerBufferQueue );
+    result = GetInterface( sys->playerObject, sys->SL_IID_ANDROIDSIMPLEBUFFERQUEUE,
+                                                  &sys->playerBufferQueue );
     CHECK_OPENSL_ERROR( "Failed to get buff queue interface" );
 
-    result = RegisterCallback( p_sys->playerBufferQueue, PlayedCallback,
-                                   (void*)p_aout);
+    result = RegisterCallback( sys->playerBufferQueue, PlayedCallback,
+                                   (void*)aout);
     CHECK_OPENSL_ERROR( "Failed to register buff queue callback." );
 
     // set the player's state to playing
-    result = SetPlayState( p_sys->playerPlay, SL_PLAYSTATE_PLAYING );
+    result = SetPlayState( sys->playerPlay, SL_PLAYSTATE_PLAYING );
     CHECK_OPENSL_ERROR( "Failed to switch to playing state" );
 
-    vlc_mutex_init( &p_sys->lock );
-    p_sys->p_chain = NULL;
-    p_sys->pp_last = &p_sys->p_chain;
-    p_sys->p_buffer_chain = NULL;
-    p_sys->pp_buffer_last = &p_sys->p_buffer_chain;
+    sys->p_chain = NULL;
+    sys->pp_last = &sys->p_chain;
+    sys->p_buffer_chain = NULL;
+    sys->pp_buffer_last = &sys->p_buffer_chain;
 
     // we want 16bit signed data native endian.
     fmt->i_format              = VLC_CODEC_S16N;
     fmt->i_physical_channels   = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
-    p_aout->play               = Play;
-    p_aout->pause              = Pause;
-    p_aout->flush              = Flush;
-    p_aout->mute_set           = MuteSet;
-    p_aout->volume_set         = VolumeSet;
 
-    SetPositionUpdatePeriod( p_sys->playerPlay, AOUT_MIN_PREPARE_TIME * 1000 / CLOCK_FREQ);
+    SetPositionUpdatePeriod( sys->playerPlay, AOUT_MIN_PREPARE_TIME * 1000 / CLOCK_FREQ);
 
     aout_FormatPrepare( fmt );
 
-    p_sys->format = *fmt;
+    sys->format = *fmt;
 
     return VLC_SUCCESS;
+
 error:
-    Clean( p_sys );
+    Clean(sys);
     return VLC_EGENERIC;
 }
 
+static void Stop( audio_output_t *aout )
+{
+    aout_sys_t *sys = aout->sys;
+
+    SetPlayState( sys->playerPlay, SL_PLAYSTATE_STOPPED );
+    //Flush remaining buffers if any.
+    Clear( sys->playerBufferQueue );
+    block_ChainRelease( sys->p_chain );
+    block_ChainRelease( sys->p_buffer_chain);
+}
+
 /*****************************************************************************
- * Close
+ *
  *****************************************************************************/
-static void Stop( audio_output_t *p_aout )
+static void Close(vlc_object_t *obj)
 {
-    aout_sys_t     *p_sys = p_aout->sys;
+    audio_output_t *aout = (audio_output_t *)obj;
+    aout_sys_t *sys = aout->sys;
 
-    SetPlayState( p_sys->playerPlay, SL_PLAYSTATE_STOPPED );
-    //Flush remaining buffers if any.
-    Clear( p_sys->playerBufferQueue );
-    block_ChainRelease( p_sys->p_chain );
-    block_ChainRelease( p_sys->p_buffer_chain);
-    vlc_mutex_destroy( &p_sys->lock );
-    Clean( p_sys );
+    Clean(sys);
+    dlclose(sys->p_so_handle);
+    vlc_mutex_destroy(&sys->lock);
+    free(sys);
 }
 
 static int Open (vlc_object_t *obj)
 {
     audio_output_t *aout = (audio_output_t *)obj;
+    aout_sys_t *sys;
+    SLresult result;
+
+    aout->sys = sys = calloc(1, sizeof(*sys));
+    if (unlikely(sys == NULL))
+        return VLC_ENOMEM;
+
+    sys->p_so_handle = dlopen("libOpenSLES.so", RTLD_NOW);
+    if (sys->p_so_handle == NULL)
+    {
+        msg_Err(aout, "Failed to load libOpenSLES");
+        goto error;
+    }
+
+    sys->slCreateEnginePtr = dlsym(sys->p_so_handle, "slCreateEngine");
+    if (unlikely(sys->slCreateEnginePtr == NULL))
+    {
+        msg_Err(aout, "Failed to load symbol slCreateEngine");
+        goto error;
+    }
+
+#define OPENSL_DLSYM(dest, name)                       \
+    do {                                                       \
+        const SLInterfaceID *sym = dlsym(sys->p_so_handle, "SL_IID_"name);        \
+        if (unlikely(sym == NULL))                             \
+        {                                                      \
+            msg_Err(aout, "Failed to load symbol SL_IID_"name); \
+            goto error;                                        \
+        }                                                      \
+        sys->dest = *sym;                                           \
+    } while(0)
+
+    OPENSL_DLSYM( SL_IID_ANDROIDSIMPLEBUFFERQUEUE, "ANDROIDSIMPLEBUFFERQUEUE" );
+    OPENSL_DLSYM( SL_IID_ENGINE, "ENGINE" );
+    OPENSL_DLSYM( SL_IID_PLAY, "PLAY" );
+    OPENSL_DLSYM( SL_IID_VOLUME, "VOLUME" );
+#undef OPENSL_DLSYM
+
+    // create engine
+    result = sys->slCreateEnginePtr( &sys->engineObject, 0, NULL, 0, NULL, NULL );
+    CHECK_OPENSL_ERROR( "Failed to create engine" );
+
+    // realize the engine in synchronous mode
+    result = Realize( sys->engineObject, SL_BOOLEAN_FALSE );
+    CHECK_OPENSL_ERROR( "Failed to realize engine" );
+
+    // get the engine interface, needed to create other objects
+    result = GetInterface( sys->engineObject, sys->SL_IID_ENGINE, &sys->engineEngine );
+    CHECK_OPENSL_ERROR( "Failed to get the engine interface" );
+
+    // create output mix, with environmental reverb specified as a non-required interface
+    const SLInterfaceID ids1[] = { sys->SL_IID_VOLUME };
+    const SLboolean req1[] = { SL_BOOLEAN_FALSE };
+    result = CreateOutputMix( sys->engineEngine, &sys->outputMixObject, 1, ids1, req1 );
+    CHECK_OPENSL_ERROR( "Failed to create output mix" );
+
+    // realize the output mix in synchronous mode
+    result = Realize( sys->outputMixObject, SL_BOOLEAN_FALSE );
+    CHECK_OPENSL_ERROR( "Failed to realize output mix" );
+
+    vlc_mutex_init( &sys->lock );
+
+    aout->start      = Start;
+    aout->stop       = Stop;
+    aout->time_get   = TimeGet;
+    aout->play       = Play;
+    aout->pause      = Pause;
+    aout->flush      = Flush;
+    aout->mute_set   = MuteSet;
+    aout->volume_set = VolumeSet;
 
-    /* FIXME: set volume/mute here */
-    aout->start = Start;
-    aout->stop = Stop;
-    aout->time_get = TimeGet;
     return VLC_SUCCESS;
+
+error:
+    Clean(sys);
+    if (sys->p_so_handle)
+        dlclose(sys->p_so_handle);
+    free(sys);
+    return VLC_EGENERIC;
 }