Changeset 293664 in webkit

Timestamp:

May 2, 2022, 9:15:55 AM (4 years ago)

Author:

youenn@apple.com

Message:

VPIO requires the same sample rate for microphone and speaker formats
​https://bugs.webkit.org/show_bug.cgi?id=239956

Reviewed by Eric Carlson.

VPIO requires the speaker sample rate and microphone sample rate to be the same.
This is not guaranteed to be true : getUserMedia/applyConstraints may set the microphone sample rate to different values.
If audio rendering already started at capture start time, we use the audio rendering sample rate.
This is not strictly compliant, given required constraints but they are not widely used.
Applications that want to make sure to use a specific sample rate would need to pause audio rendering when starting to capture.
We reset exposed settings when starting to capture to expose the actual sample rate to JavaScript through MediaStreamTrack.getSettings().

Manually tested.

• platform/mediastream/mac/BaseAudioSharedUnit.h:
• platform/mediastream/mac/CoreAudioCaptureSource.cpp:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/mediastream/mac/BaseAudioSharedUnit.h (modified) (1 diff)
• platform/mediastream/mac/CoreAudioCaptureSource.cpp (modified) (14 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2022-05-02  Youenn Fablet  <youenn@apple.com>
+
+        VPIO requires the same sample rate for microphone and speaker formats
+        https://bugs.webkit.org/show_bug.cgi?id=239956
+
+        Reviewed by Eric Carlson.
+
+        VPIO requires the speaker sample rate and microphone sample rate to be the same.
+        This is not guaranteed to be true : getUserMedia/applyConstraints may set the microphone sample rate to different values.
+        If audio rendering already started at capture start time, we use the audio rendering sample rate.
+        This is not strictly compliant, given required constraints but they are not widely used.
+        Applications that want to make sure to use a specific sample rate would need to pause audio rendering when starting to capture.
+        We reset exposed settings when starting to capture to expose the actual sample rate to JavaScript through MediaStreamTrack.getSettings().
+
+        Manually tested.
+
+        * platform/mediastream/mac/BaseAudioSharedUnit.h:
+        * platform/mediastream/mac/CoreAudioCaptureSource.cpp:
+
 2022-05-01  Philippe Normand  <philn@igalia.com>
 

trunk/Source/WebCore/platform/mediastream/mac/BaseAudioSharedUnit.h

@@ -78 +78 @@
 
     virtual CapabilityValueOrRange sampleRateCapacities() const = 0;
+    virtual int actualSampleRate() const { return sampleRate(); }
 
     void devicesChanged(const Vector<CaptureDevice>&);

trunk/Source/WebCore/platform/mediastream/mac/CoreAudioCaptureSource.cpp

@@ -102 +102 @@
     void isProducingMicrophoneSamplesChanged() final;
     void validateOutputDevice(uint32_t deviceID) final;
-
-    OSStatus configureSpeakerProc();
-    OSStatus configureMicrophoneProc();
+    int actualSampleRate() const final;
+
+    OSStatus configureSpeakerProc(int sampleRate);
+    OSStatus configureMicrophoneProc(int sampleRate);
     OSStatus defaultOutputDevice(uint32_t*);
     OSStatus defaultInputDevice(uint32_t*);
@@ -150 +151 @@
 
     bool m_isReconfiguring { false };
-    Lock m_speakerSamplesProducerLock;
+    mutable Lock m_speakerSamplesProducerLock;
     CoreAudioSpeakerSamplesProducer* m_speakerSamplesProducer WTF_GUARDED_BY_LOCK(m_speakerSamplesProducerLock) { nullptr };
 };
@@ -259 +260 @@
 #endif
 
-    err = configureMicrophoneProc();
+    // FIXME: Add support for different speaker/microphone sample rates.
+    int actualSampleRate = this->actualSampleRate();
+    err = configureMicrophoneProc(actualSampleRate);
     if (err)
         return err;
 
-    err = configureSpeakerProc();
+    err = configureSpeakerProc(actualSampleRate);
     if (err)
         return err;
@@ -286 +289 @@
 }
 
-OSStatus CoreAudioSharedUnit::configureMicrophoneProc()
-{
+int CoreAudioSharedUnit::actualSampleRate() const
+{
+    Locker locker { m_speakerSamplesProducerLock };
+    return m_speakerSamplesProducer ? m_speakerSamplesProducer->format().streamDescription().mSampleRate : sampleRate();
+}
+
+OSStatus CoreAudioSharedUnit::configureMicrophoneProc(int sampleRate)
+{
+    ASSERT(isMainThread());
+
     if (!isProducingMicrophoneSamples())
         return noErr;
@@ -307 +318 @@
     }
 
-    microphoneProcFormat.mSampleRate = sampleRate();
+    microphoneProcFormat.mSampleRate = sampleRate;
     err = PAL::AudioUnitSetProperty(m_ioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, inputBus, &microphoneProcFormat, size);
     if (err) {
@@ -320 +331 @@
 }
 
-OSStatus CoreAudioSharedUnit::configureSpeakerProc()
-{
+OSStatus CoreAudioSharedUnit::configureSpeakerProc(int sampleRate)
+{
+    ASSERT(isMainThread());
+
     AURenderCallbackStruct callback = { speakerCallback, this };
     auto err = PAL::AudioUnitSetProperty(m_ioUnit, kAudioUnitProperty_SetRenderCallback, kAudioUnitScope_Input, outputBus, &callback, sizeof(callback));
@@ -333 +346 @@
     {
         Locker locker { m_speakerSamplesProducerLock };
-        if (m_speakerSamplesProducer)
+        if (m_speakerSamplesProducer) {
+            ASSERT(speakerProcFormat.mSampleRate == sampleRate);
             speakerProcFormat = m_speakerSamplesProducer->format().streamDescription();
-        else {
+        } else {
             err = PAL::AudioUnitGetProperty(m_ioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, outputBus, &speakerProcFormat, &size);
             if (err) {
@@ -341 +355 @@
                 return err;
             }
-            speakerProcFormat.mSampleRate = sampleRate();
         }
     }
+    speakerProcFormat.mSampleRate = sampleRate;
 
     err = PAL::AudioUnitSetProperty(m_ioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, outputBus, &speakerProcFormat, size);
@@ -494 +508 @@
 OSStatus CoreAudioSharedUnit::startInternal()
 {
+    ASSERT(isMainThread());
+
     setIsProducingMicrophoneSamples(true);
 
@@ -574 +590 @@
 void CoreAudioSharedUnit::stopInternal()
 {
+    ASSERT(isMainThread());
+
     m_verifyCapturingTimer.stop();
 
@@ -633 +651 @@
 void CoreAudioSharedUnit::registerSpeakerSamplesProducer(CoreAudioSpeakerSamplesProducer& producer)
 {
+    ASSERT(isMainThread());
+
     setIsRenderingAudio(true);
 
@@ -650 +670 @@
 void CoreAudioSharedUnit::unregisterSpeakerSamplesProducer(CoreAudioSpeakerSamplesProducer& producer)
 {
+    ASSERT(isMainThread());
+
     {
         Locker locker { m_speakerSamplesProducerLock };
@@ -820 +842 @@
     initializeToStartProducingData();
     unit().startProducingData();
+    m_currentSettings = { };
 }
 
@@ -846 +869 @@
         RealtimeMediaSourceSettings settings;
         settings.setVolume(volume());
-        settings.setSampleRate(sampleRate());
+        settings.setSampleRate(unit().actualSampleRate());
         settings.setDeviceId(hashedId());
         settings.setLabel(name());