- Revision
- 294864
- Author
- [email protected]
- Date
- 2022-05-25 20:15:16 -0700 (Wed, 25 May 2022)
Log Message
Capturing a canvas that is not in the DOM can lead to erratic frame rates or no frame emission at all
https://bugs.webkit.org/show_bug.cgi?id=240380
Patch by Dan Glastonbury <[email protected]> on 2022-05-25
Reviewed by Simon Fraser.
* Source/WebCore/dom/Document.cpp:
(WebCore::Document::canvasChanged):
Schedule a rendering update whenever a canvas with out a rect needing display
preparation is added. This ensures that the prepareForDisplay is called on all
pending canvases, since this is handled in doAfterUpdateRendering.
* Source/WebCore/dom/Document.h:
Update size of RenderingUpdateState to accomodate PrepareCanvasesForDisplay.
* Source/WebCore/page/Page.cpp:
* Source/WebCore/page/Page.h:
Introduce new RenderingUpdateStep, PrepareCanvasesForDisplay, which signals that
prepareCanvasesForDisplayInNeeded() needs to be called from
doAfterRenderingUpdate(). Update size of RenderingUpdateState to accomodate
PrepareCanvasesForDisplay.
* LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-canvas-expected.txt: Added.
* LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-canvas.html:
Test that frame rate of captured video from out-of-DOM canvas is with in 25% of
the generating frame rate.
Canonical link: https://commits.webkit.org/250996@main
Modified Paths
Added Paths
Diff
Added: trunk/LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-canvas-expected.txt (0 => 294864)
--- trunk/LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-canvas-expected.txt (rev 0)
+++ trunk/LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-canvas-expected.txt 2022-05-26 03:15:16 UTC (rev 294864)
@@ -0,0 +1,4 @@
+
+
+PASS check frame of capture canvas is sufficient
+
Added: trunk/LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-canvas.html (0 => 294864)
--- trunk/LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-canvas.html (rev 0)
+++ trunk/LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-canvas.html 2022-05-26 03:15:16 UTC (rev 294864)
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<html>
+<head>
+ <meta charset="utf-8">
+ <title>Capture canvas to video track framerate</title>
+ <script src=""
+ <script src=""
+ <script src=""
+</head>
+<body>
+ <video id="video" autoplay playsInline controls width="200px"></video>
+ <script>
+promise_test(async (t) => {
+ const canvas = document.createElement('canvas');
+ canvas.width = 200;
+ canvas.height = 200;
+
+ const ctx = canvas.getContext('2d');
+
+ let frames = 0;
+ const loop = () => {
+ frames += 1;
+ ctx.fillStyle = (ctx.fillStyle !== '#ff0000') ? 'red' : 'green';
+ ctx.fillRect(0, 0, canvas.width, canvas.height);
+ setTimeout(loop, 1000/30);
+ }
+
+ loop();
+
+ const stream = canvas.captureStream();
+ video.srcObject = stream;
+ video.play();
+
+ const frameRate = await computeFrameRate(stream, video);
+
+ // If the test was unable to generate any frames then nothing meaningful can be determined. Our test only makes sense if we have sufficient fps.
+ if (frames <= 10)
+ return;
+
+ // Check that the difference in expected and observed frame rates is < 25%
+ const percentDiff = Math.abs(frameRate - frames) / frames * 100;
+ assert_less_than(percentDiff, 25, `frame rate difference between ${frames} & ${frameRate} is below 25%`);
+}, "check frame of capture canvas is sufficient");
+ </script>
+</body>
+</html>
\ No newline at end of file
Modified: trunk/LayoutTests/platform/win/TestExpectations (294863 => 294864)
--- trunk/LayoutTests/platform/win/TestExpectations 2022-05-26 02:56:49 UTC (rev 294863)
+++ trunk/LayoutTests/platform/win/TestExpectations 2022-05-26 03:15:16 UTC (rev 294864)
@@ -3704,6 +3704,8 @@
fast/events/webkit-media-key-events-constructor.html [ Failure ]
fast/forms/validation-message-maxLength.html [ Failure ]
fast/mediacapturefromelement/CanvasCaptureMediaStream-2d-events.html [ Failure ]
+# canvas.captureStream is not a function
+webkit.org/b/240380 fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-canvas.html [ Failure ]
fast/mediacapturefromelement/CanvasCaptureMediaStream-capture-out-of-DOM-element.html [ Failure ]
fast/mediacapturefromelement/CanvasCaptureMediaStream-clone-track.html [ Failure ]
fast/mediacapturefromelement/CanvasCaptureMediaStream-creation.html [ Failure ]
Modified: trunk/Source/WebCore/dom/Document.cpp (294863 => 294864)
--- trunk/Source/WebCore/dom/Document.cpp 2022-05-26 02:56:49 UTC (rev 294863)
+++ trunk/Source/WebCore/dom/Document.cpp 2022-05-26 03:15:16 UTC (rev 294864)
@@ -9095,13 +9095,20 @@
m_canvasesNeedingDisplayPreparation.remove(canvas);
}
-void Document::canvasChanged(CanvasBase& canvasBase, const std::optional<FloatRect>&)
+void Document::canvasChanged(CanvasBase& canvasBase, const std::optional<FloatRect>& changedRect)
{
if (!is<HTMLCanvasElement>(canvasBase))
return;
auto& canvas = downcast<HTMLCanvasElement>(canvasBase);
- if (canvas.needsPreparationForDisplay())
+ if (canvas.needsPreparationForDisplay()) {
m_canvasesNeedingDisplayPreparation.add(canvas);
+ // Schedule a rendering update to force handling of prepareForDisplay
+ // for any queued canvases. This is especially important for any canvas
+ // that is not in the DOM, as those don't have a rect to invalidate to
+ // trigger an update. <http://bugs.webkit.org/show_bug.cgi?id=240380>.
+ if (!changedRect)
+ scheduleRenderingUpdate(RenderingUpdateStep::PrepareCanvasesForDisplay);
+ }
}
void Document::canvasDestroyed(CanvasBase& canvasBase)
Modified: trunk/Source/WebCore/dom/Document.h (294863 => 294864)
--- trunk/Source/WebCore/dom/Document.h 2022-05-26 02:56:49 UTC (rev 294863)
+++ trunk/Source/WebCore/dom/Document.h 2022-05-26 03:15:16 UTC (rev 294864)
@@ -265,7 +265,7 @@
enum class MediaProducerMutedState : uint8_t;
enum class RouteSharingPolicy : uint8_t;
enum class ShouldOpenExternalURLsPolicy : uint8_t;
-enum class RenderingUpdateStep : uint16_t;
+enum class RenderingUpdateStep : uint32_t;
enum class StyleColorOptions : uint8_t;
enum class MutationObserverOptionType : uint8_t;
Modified: trunk/Source/WebCore/page/Page.cpp (294863 => 294864)
--- trunk/Source/WebCore/page/Page.cpp 2022-05-26 02:56:49 UTC (rev 294863)
+++ trunk/Source/WebCore/page/Page.cpp 2022-05-26 03:15:16 UTC (rev 294864)
@@ -1793,6 +1793,8 @@
DebugPageOverlays::doAfterUpdateRendering(*this);
+ m_renderingUpdateRemainingSteps.last().remove(RenderingUpdateStep::PrepareCanvasesForDisplay);
+
forEachDocument([] (Document& document) {
document.prepareCanvasesForDisplayIfNeeded();
});
@@ -3836,6 +3838,7 @@
case RenderingUpdateStep::ScrollingTreeUpdate: ts << "ScrollingTreeUpdate"; break;
#endif
case RenderingUpdateStep::VideoFrameCallbacks: ts << "VideoFrameCallbacks"; break;
+ case RenderingUpdateStep::PrepareCanvasesForDisplay: ts << "PrepareCanvasesForDisplay"; break;
}
return ts;
}
Modified: trunk/Source/WebCore/page/Page.h (294863 => 294864)
--- trunk/Source/WebCore/page/Page.h 2022-05-26 02:56:49 UTC (rev 294863)
+++ trunk/Source/WebCore/page/Page.h 2022-05-26 03:15:16 UTC (rev 294864)
@@ -208,7 +208,7 @@
InvalidateImagesWithAsyncDecodes = 1 << 1,
};
-enum class RenderingUpdateStep : uint16_t {
+enum class RenderingUpdateStep : uint32_t {
Resize = 1 << 0,
Scroll = 1 << 1,
MediaQueryEvaluation = 1 << 2,
@@ -227,6 +227,7 @@
#endif
FlushAutofocusCandidates = 1 << 14,
VideoFrameCallbacks = 1 << 15,
+ PrepareCanvasesForDisplay = 1 << 16,
};
constexpr OptionSet<RenderingUpdateStep> updateRenderingSteps = {
@@ -243,6 +244,7 @@
RenderingUpdateStep::WheelEventMonitorCallbacks,
RenderingUpdateStep::CursorUpdate,
RenderingUpdateStep::EventRegionUpdate,
+ RenderingUpdateStep::PrepareCanvasesForDisplay,
};
constexpr auto allRenderingUpdateSteps = updateRenderingSteps | OptionSet<RenderingUpdateStep> {
