Changeset 264966 in webkit

Timestamp:

Jul 28, 2020 1:01:20 AM (4 years ago)

Author:

youenn@apple.com

Message:

Disable low latency code path for H264 constrained baseline
​https://bugs.webkit.org/show_bug.cgi?id=214830

Reviewed by Eric Carlson.

Source/ThirdParty/libwebrtc:

In case of baseline profile, use straight VTB encoder.
In case of high profile, use low latency code path if enabled.
In case of MacOS software code path, enable low latency code path as straight VTB encoder buffers frames.

• Source/webrtc/sdk/objc/components/video_codec/RTCVideoEncoderH264.mm:

(-[RTCVideoEncoderH264 initWithCodecInfo:]):
(-[RTCVideoEncoderH264 resetCompressionSessionWithPixelFormat:]):

Source/WebKit:

Enable low latency code path on iOS.
Manually tested.

• Shared/WebPreferences.yaml:
• Shared/WebPreferencesDefaultValues.cpp:

(WebKit::defaultWebRTCH264LowLatencyEncoderEnabled):

• Shared/WebPreferencesDefaultValues.h:

Location:

trunk/Source

Files:

• ThirdParty/libwebrtc/ChangeLog (modified) (1 diff)
• ThirdParty/libwebrtc/Source/webrtc/sdk/objc/components/video_codec/RTCVideoEncoderH264.mm (modified) (4 diffs)
• WebKit/ChangeLog (modified) (1 diff)
• WebKit/Shared/WebPreferences.yaml (modified) (1 diff)
• WebKit/Shared/WebPreferencesDefaultValues.cpp (modified) (1 diff)
• WebKit/Shared/WebPreferencesDefaultValues.h (modified) (1 diff)

trunk/Source/ThirdParty/libwebrtc/ChangeLog

@@ +1 @@
+2020-07-28  Youenn Fablet  <youenn@apple.com>
+
+        Disable low latency code path for H264 constrained baseline
+        https://bugs.webkit.org/show_bug.cgi?id=214830
+
+        Reviewed by Eric Carlson.
+
+        In case of baseline profile, use straight VTB encoder.
+        In case of high profile, use low latency code path if enabled.
+        In case of MacOS software code path, enable low latency code path as straight VTB encoder buffers frames.
+
+        * Source/webrtc/sdk/objc/components/video_codec/RTCVideoEncoderH264.mm:
+        (-[RTCVideoEncoderH264 initWithCodecInfo:]):
+        (-[RTCVideoEncoderH264 resetCompressionSessionWithPixelFormat:]):
+
 2020-07-26  Michael Catanzaro  <mcatanzaro@gnome.org>
 

trunk/Source/ThirdParty/libwebrtc/Source/webrtc/sdk/objc/components/video_codec/RTCVideoEncoderH264.mm

@@ -365 +365 @@
     _profile_level_id =
         webrtc::H264::ParseSdpProfileLevelId([codecInfo nativeSdpVideoFormat].parameters);
-#if ENABLE_VCP_VTB_ENCODER
     if (_profile_level_id) {
       auto profile = ExtractProfile(*_profile_level_id);
@@ -372 +371 @@
       _useVCP = false;
     }
-#else
-    _useVCP = false;
-#endif
     RTC_DCHECK(_profile_level_id);
     RTC_LOG(LS_INFO) << "Using profile " << CFStringToString(ExtractProfile(*_profile_level_id));
@@ -701 +697 @@
   }
 #elif HAVE_VTB_REQUIREDLOWLATENCY
-  if (webrtc::isH264LowLatencyEncoderEnabled())
+  if (webrtc::isH264LowLatencyEncoderEnabled() && _useVCP)
     CFDictionarySetValue(encoderSpecs, kVTVideoEncoderSpecification_RequiredLowLatency, kCFBooleanTrue);
 #endif
@@ -750 +746 @@
                                &_vcpCompressionSession);
   }
-#elif !HAVE_VTB_REQUIREDLOWLATENCY
+#elif HAVE_VTB_REQUIREDLOWLATENCY
+  // In case VCP is disabled, we will use it anyway if using software encoder.
+  if (webrtc::isH264LowLatencyEncoderEnabled() && !_useVCP) {
+    CFBooleanRef hwaccl_enabled = nullptr;
+    if (status == noErr) {
+      status = VTSessionCopyProperty(_vtCompressionSession,
+                               kVTCompressionPropertyKey_UsingHardwareAcceleratedVideoEncoder,
+                               nullptr,
+                               &hwaccl_enabled);
+    }
+    if (status == noErr && (CFBooleanGetValue(hwaccl_enabled))) {
+      RTC_LOG(LS_INFO) << "Compression session created with hw accl enabled";
+    } else {
+      [self destroyCompressionSession];
+      CFDictionarySetValue(encoderSpecs, kVTVideoEncoderSpecification_RequiredLowLatency, kCFBooleanTrue);
+      status = VTCompressionSessionCreate(nullptr,  // use default allocator
+                                 _width,
+                                 _height,
+                                 kCMVideoCodecType_H264,
+                                 encoderSpecs,  // use hardware accelerated encoder if available
+                                 sourceAttributes,
+                                 nullptr,  // use default compressed data allocator
+                                 compressionOutputCallback,
+                                 nullptr,
+                                 &_vtCompressionSession);
+    }
+  }
+#else
   if (status != noErr) {
     if (encoderSpecs) {

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2020-07-28  Youenn Fablet  <youenn@apple.com>
+
+        Disable low latency code path for H264 constrained baseline
+        https://bugs.webkit.org/show_bug.cgi?id=214830
+
+        Reviewed by Eric Carlson.
+
+        Enable low latency code path on iOS.
+        Manually tested.
+
+        * Shared/WebPreferences.yaml:
+        * Shared/WebPreferencesDefaultValues.cpp:
+        (WebKit::defaultWebRTCH264LowLatencyEncoderEnabled):
+        * Shared/WebPreferencesDefaultValues.h:
+
 2020-07-27  Kate Cheney  <katherine_cheney@apple.com>
 

trunk/Source/WebKit/Shared/WebPreferences.yaml

@@ -600 +600 @@
 WebRTCH264LowLatencyEncoderEnabled:
   type: bool
-  defaultValue: false
+  defaultValue: defaultWebRTCH264LowLatencyEncoderEnabled()
   webcoreBinding: RuntimeEnabledFeatures
   condition: ENABLE(WEB_RTC)

trunk/Source/WebKit/Shared/WebPreferencesDefaultValues.cpp

@@ -266 +266 @@
 #endif
 
+#if ENABLE(WEB_RTC)
+bool defaultWebRTCH264LowLatencyEncoderEnabled()
+{
+#if PLATFORM(IOS_FAMILY)
+    return true;
+#else
+    return false;
+#endif
+}
+#endif
+
 } // namespace WebKit

trunk/Source/WebKit/Shared/WebPreferencesDefaultValues.h

@@ -371 +371 @@
 #endif
 
+#if ENABLE(WEB_RTC)
+bool defaultWebRTCH264LowLatencyEncoderEnabled();
+#endif
+
 } // namespace WebKit