Changeset 245032 in webkit

Timestamp:

May 7, 2019 2:04:09 PM (5 years ago)

Author:

youenn@apple.com

Message:

getUserMedia framerate unusable under low light in iOS 12.2
​https://bugs.webkit.org/show_bug.cgi?id=196214
<rdar://problem/49232193>

Reviewed by Geoffrey Garen.

When setting the frame rate, set it to the exact value instead of a range.
Otherwise, the capture device might use the lowest frame rate according the light conditions
for best picture quality which is not what is expected by most web pages.

Move frame rate range computation to closer where actually used.
Since frame rate matching is fuzzy, add some checks in case the expected frame rate is slightly out of min/max range.

Manually tested on a real device.

• platform/mediastream/mac/AVVideoCaptureSource.mm:

(WebCore::AVVideoCaptureSource::setSizeAndFrameRateWithPreset):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/mediastream/mac/AVVideoCaptureSource.mm (modified) (3 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-05-07  Youenn Fablet  <youenn@apple.com>
+
+        getUserMedia framerate unusable under low light in iOS 12.2
+        https://bugs.webkit.org/show_bug.cgi?id=196214
+        <rdar://problem/49232193>
+
+        Reviewed by Geoffrey Garen.
+
+        When setting the frame rate, set it to the exact value instead of a range.
+        Otherwise, the capture device might use the lowest frame rate according the light conditions
+        for best picture quality which is not what is expected by most web pages.
+
+        Move frame rate range computation to closer where actually used.
+        Since frame rate matching is fuzzy, add some checks in case the expected frame rate is slightly out of min/max range.
+
+        Manually tested on a real device.
+
+        * platform/mediastream/mac/AVVideoCaptureSource.mm:
+        (WebCore::AVVideoCaptureSource::setSizeAndFrameRateWithPreset):
+
 2019-05-07  Robin Morisset  <rmorisset@apple.com>
 

trunk/Source/WebCore/platform/mediastream/mac/AVVideoCaptureSource.mm

@@ -300 +300 @@
     m_pendingFrameRate = 0;
 
-    auto* frameRateRange = frameDurationForFrameRate(requestedFrameRate);
-    ASSERT(frameRateRange);
-    if (!frameRateRange)
-        return;
-
     if (!avPreset)
         return;
@@ -316 +311 @@
             if (!m_currentPreset || ![m_currentPreset->format.get() isEqual:avPreset->format.get()]) {
                 [device() setActiveFormat:avPreset->format.get()];
-
-                frameRateRange = frameDurationForFrameRate(requestedFrameRate);
-                ASSERT(frameRateRange);
-                if (!frameRateRange)
-                    return;
 
 #if PLATFORM(MAC)
@@ -332 +322 @@
 #endif
             }
-
-            ALWAYS_LOG_IF(loggerPtr(), LOGIDENTIFIER, "setting frame rate ", CMTimeGetSeconds([frameRateRange minFrameDuration]), " .. ", CMTimeGetSeconds([frameRateRange maxFrameDuration]));
-            [device() setActiveVideoMinFrameDuration:[frameRateRange minFrameDuration]];
-            [device() setActiveVideoMaxFrameDuration:[frameRateRange maxFrameDuration]];
+            auto* frameRateRange = frameDurationForFrameRate(requestedFrameRate);
+            ASSERT(frameRateRange);
+            if (!frameRateRange)
+                return;
+
+            if (requestedFrameRate < frameRateRange.minFrameRate)
+                requestedFrameRate = frameRateRange.minFrameRate;
+            else if (requestedFrameRate > frameRateRange.maxFrameRate)
+                requestedFrameRate = frameRateRange.maxFrameRate;
+
+            ALWAYS_LOG_IF(loggerPtr(), LOGIDENTIFIER, "setting frame rate to ", requestedFrameRate);
+            [device() setActiveVideoMinFrameDuration: CMTimeMake(1, requestedFrameRate)];
+            [device() setActiveVideoMaxFrameDuration: CMTimeMake(1, requestedFrameRate)];
+
             [device() unlockForConfiguration];
         }