aout: handle viewpoint change via audio filters

include/vlc_aout.h

@@ -388,6 +388,7 @@ VLC_API bool aout_FiltersAdjustResampling(aout_filters_t *, int);
 VLC_API block_t *aout_FiltersPlay(aout_filters_t *, block_t *, int rate);
 VLC_API block_t *aout_FiltersDrain(aout_filters_t *);
 VLC_API void     aout_FiltersFlush(aout_filters_t *);
+VLC_API void     aout_FiltersChangeViewpoint(aout_filters_t *, const vlc_viewpoint_t *vp);
 
 VLC_API vout_thread_t * aout_filter_RequestVout( filter_t *, vout_thread_t *p_vout, const video_format_t *p_fmt );
 

include/vlc_filter.h

@@ -118,6 +118,14 @@ struct filter_t
      */
     void (*pf_flush)( filter_t * );
 
+    /** Change viewpoint
+     *
+     * Pass a new viewpoint to audio filters. Filters like the spatialaudio one
+     * used for Ambisonics rendering will change its output according to this
+     * viewpoint.
+     */
+    void (*pf_change_viewpoint)( filter_t *, const vlc_viewpoint_t * );
+
     union
     {
         /** Filter mouse state (video filter).
@@ -171,6 +179,13 @@ static inline void filter_Flush( filter_t *p_filter )
         p_filter->pf_flush( p_filter );
 }
 
+static inline void filter_ChangeViewpoint( filter_t *p_filter,
+                                           const vlc_viewpoint_t *vp)
+{
+    if( p_filter->pf_change_viewpoint != NULL )
+        p_filter->pf_change_viewpoint( p_filter, vp );
+}
+
 /**
  * This function will drain, then flush an audio filter.
  */

src/audio_output/aout_internal.h

@@ -25,6 +25,7 @@
 # define LIBVLC_AOUT_INTERNAL_H 1
 
 # include <vlc_atomic.h>
+# include <vlc_vout.h> /* for vlc_viewpoint_t */
 
 /* Max input rate factor (1/4 -> 4) */
 # define AOUT_MAX_INPUT_RATE (4)
@@ -67,6 +68,13 @@ typedef struct
         unsigned count;
     } dev;
 
+    struct
+    {
+        atomic_bool update;
+        vlc_mutex_t lock;
+        vlc_viewpoint_t value;
+    } vp;
+
     struct
     {
         mtime_t end; /**< Last seen PTS */
@@ -170,4 +178,7 @@ static inline void aout_SetWavePhysicalChannels(audio_sample_format_t *fmt)
 /* From filters.c */
 bool aout_FiltersCanResample (aout_filters_t *filters);
 
+void aout_ChangeViewpoint(audio_output_t *aout,
+                          const vlc_viewpoint_t *p_viewpoint);
+
 #endif /* !LIBVLC_AOUT_INTERNAL_H */

src/audio_output/dec.c

@@ -112,6 +112,7 @@ error:
 
     atomic_init (&owner->buffers_lost, 0);
     atomic_init (&owner->buffers_played, 0);
+    atomic_init (&owner->vp.update, false);
     return 0;
 }
 
@@ -384,6 +385,13 @@ int aout_DecPlay (audio_output_t *aout, block_t *block, int input_rate)
     if (block->i_flags & BLOCK_FLAG_DISCONTINUITY)
         owner->sync.discontinuity = true;
 
+    if (atomic_exchange(&owner->vp.update, false))
+    {
+        vlc_mutex_lock (&owner->vp.lock);
+        aout_FiltersChangeViewpoint (owner->filters, &owner->vp.value);
+        vlc_mutex_unlock (&owner->vp.lock);
+    }
+
     block = aout_FiltersPlay (owner->filters, block, input_rate);
     if (block == NULL)
         goto lost;
@@ -456,3 +464,14 @@ void aout_DecFlush (audio_output_t *aout, bool wait)
     }
     aout_OutputUnlock (aout);
 }
+
+void aout_ChangeViewpoint(audio_output_t *aout,
+                          const vlc_viewpoint_t *p_viewpoint)
+{
+    aout_owner_t *owner = aout_owner (aout);
+
+    vlc_mutex_lock (&owner->vp.lock);
+    owner->vp.value = *p_viewpoint;
+    atomic_store(&owner->vp.update, true);
+    vlc_mutex_unlock (&owner->vp.lock);
+}

src/audio_output/filters.c

@@ -327,6 +327,13 @@ static void aout_FiltersPipelineFlush(filter_t *const *filters,
         filter_Flush (filters[i]);
 }
 
+static void aout_FiltersPipelineChangeViewpoint(filter_t *const *filters,
+                                                unsigned count,
+                                                const vlc_viewpoint_t *vp)
+{
+    for (unsigned i = 0; i < count; i++)
+        filter_ChangeViewpoint (filters[i], vp);
+}
 
 #define AOUT_MAX_FILTERS 10
 
@@ -760,3 +767,9 @@ void aout_FiltersFlush (aout_filters_t *filters)
     if (filters->resampler != NULL)
         aout_FiltersPipelineFlush (&filters->resampler, 1);
 }
+
+void aout_FiltersChangeViewpoint (aout_filters_t *filters,
+                                  const vlc_viewpoint_t *vp)
+{
+    aout_FiltersPipelineChangeViewpoint (filters->tab, filters->count, vp);
+}

src/audio_output/output.c

@@ -181,6 +181,15 @@ static int StereoModeCallback (vlc_object_t *obj, const char *varname,
     return 0;
 }
 
+static int ViewpointCallback (vlc_object_t *obj, const char *var,
+                              vlc_value_t prev, vlc_value_t cur, void *data)
+{
+    if( cur.p_address != NULL )
+        aout_ChangeViewpoint((audio_output_t *)obj, cur.p_address );
+    (void) var; (void) data; (void) prev;
+    return VLC_SUCCESS;
+}
+
 #undef aout_New
 /**
  * Creates an audio output object and initializes an output module.
@@ -199,6 +208,7 @@ audio_output_t *aout_New (vlc_object_t *parent)
     vlc_mutex_init (&owner->lock);
     vlc_mutex_init (&owner->req.lock);
     vlc_mutex_init (&owner->dev.lock);
+    vlc_mutex_init (&owner->vp.lock);
     owner->req.device = (char *)unset_str;
     owner->req.volume = -1.f;
     owner->req.mute = -1;
@@ -300,6 +310,8 @@ audio_output_t *aout_New (vlc_object_t *parent)
     text.psz_string = _("Audio filters");
     var_Change (aout, "audio-filter", VLC_VAR_SETTEXT, &text, NULL);
 
+    var_Create (aout, "viewpoint", VLC_VAR_ADDRESS  | VLC_VAR_DOINHERIT);
+    var_AddCallback (aout, "viewpoint", ViewpointCallback, NULL);
 
     var_Create (aout, "audio-visual", VLC_VAR_STRING | VLC_VAR_DOINHERIT);
     text.psz_string = _("Audio visualizations");
@@ -350,6 +362,7 @@ void aout_Destroy (audio_output_t *aout)
     aout->device_select = NULL;
     aout_OutputUnlock (aout);
 
+    var_DelCallback (aout, "viewpoint", ViewpointCallback, NULL);
     var_DelCallback (aout, "audio-filter", FilterCallback, NULL);
     var_DelCallback (aout, "device", var_CopyDevice, aout->obj.parent);
     var_DelCallback (aout, "mute", var_Copy, aout->obj.parent);
@@ -376,6 +389,7 @@ static void aout_Destructor (vlc_object_t *obj)
     }
 
     assert (owner->req.device == unset_str);
+    vlc_mutex_destroy (&owner->vp.lock);
     vlc_mutex_destroy (&owner->req.lock);
     vlc_mutex_destroy (&owner->lock);
 }

src/libvlccore.sym

@@ -23,6 +23,7 @@ aout_DeviceGet
 aout_DeviceSet
 aout_DevicesList
 aout_FiltersNew
+aout_FiltersChangeViewpoint
 aout_FiltersDelete
 aout_FiltersDrain
 aout_FiltersFlush