[vlc-devel] [PATCH 2/4] coreaudio: notify when the output is silence

[Thomas Guillem]

It can be used as a hint to whether the buffer needs to be processed or
not.
---
 modules/audio_output/auhal.c            | 3 ++-
 modules/audio_output/coreaudio_common.c | 9 +++++++--
 modules/audio_output/coreaudio_common.h | 2 +-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/modules/audio_output/auhal.c b/modules/audio_output/auhal.c
index f99acfc27ec..739c857f851 100644
--- a/modules/audio_output/auhal.c
+++ b/modules/audio_output/auhal.c
@@ -981,7 +981,8 @@ RenderCallbackSPDIF(AudioDeviceID inDevice, const AudioTimeStamp * inNow,
     uint64_t i_host_time = (inOutputTime->mFlags & kAudioTimeStampHostTimeValid)
                          ? inOutputTime->mHostTime : 0;
 
-    ca_Render(p_aout, 0, i_host_time, p_output, i_size);
+    bool ignored;
+    ca_Render(p_aout, 0, i_host_time, p_output, i_size, &ignored);
 
     return noErr;
 }
diff --git a/modules/audio_output/coreaudio_common.c b/modules/audio_output/coreaudio_common.c
index 4c96a1ffbd6..dbeae522f97 100644
--- a/modules/audio_output/coreaudio_common.c
+++ b/modules/audio_output/coreaudio_common.c
@@ -126,7 +126,7 @@ ca_Open(audio_output_t *p_aout)
 /* Called from render callbacks. No lock, wait, and IO here */
 void
 ca_Render(audio_output_t *p_aout, uint32_t i_frames, uint64_t i_host_time,
-          uint8_t *p_output, size_t i_requested)
+          uint8_t *p_output, size_t i_requested, bool *is_silence)
 {
     struct aout_sys_common *p_sys = (struct aout_sys_common *) p_aout->sys;
 
@@ -224,11 +224,13 @@ ca_Render(audio_output_t *p_aout, uint32_t i_frames, uint64_t i_host_time,
         memset(p_output, 0, i_requested);
     }
 
+    *is_silence = p_sys->b_muted;
     lock_unlock(p_sys);
     return;
 
 drop:
     memset(p_output, 0, i_requested);
+    *is_silence = true;
     lock_unlock(p_sys);
 }
 
@@ -532,8 +534,11 @@ RenderCallback(void *p_data, AudioUnitRenderActionFlags *ioActionFlags,
     uint64_t i_host_time = (inTimeStamp->mFlags & kAudioTimeStampHostTimeValid)
                          ? inTimeStamp->mHostTime : 0;
 
+    bool is_silence;
     ca_Render(p_data, inNumberFrames, i_host_time, ioData->mBuffers[0].mData,
-              ioData->mBuffers[0].mDataByteSize);
+              ioData->mBuffers[0].mDataByteSize, &is_silence);
+    if (is_silence)
+        *ioActionFlags |= kAudioUnitRenderAction_OutputIsSilence;
 
     return noErr;
 }
diff --git a/modules/audio_output/coreaudio_common.h b/modules/audio_output/coreaudio_common.h
index faa3286e1d1..1a8f50c0898 100644
--- a/modules/audio_output/coreaudio_common.h
+++ b/modules/audio_output/coreaudio_common.h
@@ -88,7 +88,7 @@ struct aout_sys_common
 int ca_Open(audio_output_t *p_aout);
 
 void ca_Render(audio_output_t *p_aout, uint32_t i_nb_samples, uint64_t i_host_time,
-               uint8_t *p_output, size_t i_requested);
+               uint8_t *p_output, size_t i_requested, bool *is_silence);
 
 int  ca_TimeGet(audio_output_t *p_aout, vlc_tick_t *delay);
 
-- 
2.30.0