Changeset 239387 in webkit

Timestamp:

Dec 19, 2018, 1:11:12 PM (8 years ago)

Author:

jer.noble@apple.com

Message:

Force synchronous decode in WebCoreDecompressionSession::decodeSampleSync()
​https://bugs.webkit.org/show_bug.cgi?id=192856
<rdar://problem/46843245>

Reviewed by Alex Christensen.

Some decoders exposed through VideoToolbox will decode asynchronously even when
kVTDecodeInfo_Asynchronous is not set. Force synchronous behavior with a Semaphore.

• platform/graphics/cocoa/WebCoreDecompressionSession.mm:

(WebCore::WebCoreDecompressionSession::decodeSampleSync):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/cocoa/WebCoreDecompressionSession.mm (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2018-12-19  Jer Noble  <jer.noble@apple.com>
+
+        Force synchronous decode in WebCoreDecompressionSession::decodeSampleSync()
+        https://bugs.webkit.org/show_bug.cgi?id=192856
+        <rdar://problem/46843245>
+
+        Reviewed by Alex Christensen.
+
+        Some decoders exposed through VideoToolbox will decode asynchronously even when 
+        kVTDecodeInfo_Asynchronous is not set. Force synchronous behavior with a Semaphore.
+
+        * platform/graphics/cocoa/WebCoreDecompressionSession.mm:
+        (WebCore::WebCoreDecompressionSession::decodeSampleSync):
+
 2018-12-19  Megan Gardner  <megan_gardner@apple.com>
 

trunk/Source/WebCore/platform/graphics/cocoa/WebCoreDecompressionSession.mm

@@ -40 +40 @@
 #import <wtf/StringPrintStream.h>
 #import <wtf/Vector.h>
+#import <wtf/WTFSemaphore.h>
 #import <wtf/cf/TypeCastsCF.h>
 
@@ -278 +279 @@
     RetainPtr<CVPixelBufferRef> pixelBuffer;
     VTDecodeInfoFlags flags { 0 };
+    WTF::Semaphore syncDecompressionOutputSemaphore { 0 };
     VTDecompressionSessionDecodeFrameWithOutputHandler(m_decompressionSession.get(), sample, flags, nullptr, [&] (OSStatus, VTDecodeInfoFlags, CVImageBufferRef imageBuffer, CMTime, CMTime) mutable {
         if (imageBuffer && CFGetTypeID(imageBuffer) == CVPixelBufferGetTypeID())
             pixelBuffer = (CVPixelBufferRef)imageBuffer;
+        syncDecompressionOutputSemaphore.signal();
     });
+    syncDecompressionOutputSemaphore.wait();
     return pixelBuffer;
 }