CanvasCaptureMediaStreamTrack.cpp [plain text]
#include "config.h"
#include "CanvasCaptureMediaStreamTrack.h"
#include "GraphicsContext.h"
#include "HTMLCanvasElement.h"
#include "WebGLRenderingContextBase.h"
#if ENABLE(MEDIA_STREAM)
namespace WebCore {
Ref<CanvasCaptureMediaStreamTrack> CanvasCaptureMediaStreamTrack::create(ScriptExecutionContext& context, Ref<HTMLCanvasElement>&& canvas, Optional<double>&& frameRequestRate)
{
auto source = CanvasCaptureMediaStreamTrack::Source::create(canvas.get(), WTFMove(frameRequestRate));
return adoptRef(*new CanvasCaptureMediaStreamTrack(context, WTFMove(canvas), WTFMove(source)));
}
CanvasCaptureMediaStreamTrack::CanvasCaptureMediaStreamTrack(ScriptExecutionContext& context, Ref<HTMLCanvasElement>&& canvas, Ref<CanvasCaptureMediaStreamTrack::Source>&& source)
: MediaStreamTrack(context, MediaStreamTrackPrivate::create(source.copyRef()))
, m_canvas(WTFMove(canvas))
{
}
CanvasCaptureMediaStreamTrack::CanvasCaptureMediaStreamTrack(ScriptExecutionContext& context, Ref<HTMLCanvasElement>&& canvas, Ref<MediaStreamTrackPrivate>&& privateTrack)
: MediaStreamTrack(context, WTFMove(privateTrack))
, m_canvas(WTFMove(canvas))
{
}
Ref<CanvasCaptureMediaStreamTrack::Source> CanvasCaptureMediaStreamTrack::Source::create(HTMLCanvasElement& canvas, Optional<double>&& frameRequestRate)
{
auto source = adoptRef(*new Source(canvas, WTFMove(frameRequestRate)));
source->start();
callOnMainThread([source = source.copyRef()] {
if (!source->m_canvas)
return;
source->captureCanvas();
});
return source;
}
CanvasCaptureMediaStreamTrack::Source::Source(HTMLCanvasElement& canvas, Optional<double>&& frameRequestRate)
: RealtimeMediaSource(Type::Video, "CanvasCaptureMediaStreamTrack"_s)
, m_frameRequestRate(WTFMove(frameRequestRate))
, m_requestFrameTimer(*this, &Source::requestFrameTimerFired)
, m_canvasChangedTimer(*this, &Source::captureCanvas)
, m_canvas(&canvas)
{
}
void CanvasCaptureMediaStreamTrack::Source::startProducingData()
{
if (!m_canvas)
return;
m_canvas->addObserver(*this);
if (!m_frameRequestRate)
return;
if (m_frameRequestRate.value())
m_requestFrameTimer.startRepeating(1_s / m_frameRequestRate.value());
}
void CanvasCaptureMediaStreamTrack::Source::stopProducingData()
{
m_requestFrameTimer.stop();
if (!m_canvas)
return;
m_canvas->removeObserver(*this);
}
void CanvasCaptureMediaStreamTrack::Source::requestFrameTimerFired()
{
requestFrame();
}
void CanvasCaptureMediaStreamTrack::Source::canvasDestroyed(CanvasBase& canvas)
{
ASSERT_UNUSED(canvas, m_canvas == &canvas);
stop();
m_canvas = nullptr;
}
const RealtimeMediaSourceSettings& CanvasCaptureMediaStreamTrack::Source::settings()
{
if (m_currentSettings)
return m_currentSettings.value();
RealtimeMediaSourceSupportedConstraints constraints;
constraints.setSupportsWidth(true);
constraints.setSupportsHeight(true);
RealtimeMediaSourceSettings settings;
settings.setWidth(m_canvas->width());
settings.setHeight(m_canvas->height());
settings.setSupportedConstraints(constraints);
m_currentSettings = WTFMove(settings);
return m_currentSettings.value();
}
void CanvasCaptureMediaStreamTrack::Source::settingsDidChange(OptionSet<RealtimeMediaSourceSettings::Flag> settings)
{
if (settings.containsAny({ RealtimeMediaSourceSettings::Flag::Width, RealtimeMediaSourceSettings::Flag::Height }))
m_currentSettings = WTF::nullopt;
}
void CanvasCaptureMediaStreamTrack::Source::canvasResized(CanvasBase& canvas)
{
ASSERT_UNUSED(canvas, m_canvas == &canvas);
setSize(IntSize(m_canvas->width(), m_canvas->height()));
}
void CanvasCaptureMediaStreamTrack::Source::canvasChanged(CanvasBase& canvas, const FloatRect&)
{
ASSERT_UNUSED(canvas, m_canvas == &canvas);
#if ENABLE(WEBGL)
if (is<WebGLRenderingContextBase>(canvas.renderingContext())) {
auto& context = downcast<WebGLRenderingContextBase>(*canvas.renderingContext());
if (!context.isPreservingDrawingBuffer()) {
canvas.scriptExecutionContext()->addConsoleMessage(MessageSource::JS, MessageLevel::Warning, "Turning drawing buffer preservation for the WebGL canvas being captured"_s);
context.setPreserveDrawingBuffer(true);
}
}
#endif
if (m_canvasChangedTimer.isActive())
return;
m_canvasChangedTimer.startOneShot(0_s);
}
void CanvasCaptureMediaStreamTrack::Source::captureCanvas()
{
ASSERT(m_canvas);
if (!isProducingData())
return;
if (m_frameRequestRate) {
if (!m_shouldEmitFrame)
return;
m_shouldEmitFrame = false;
}
if (!m_canvas->originClean())
return;
auto sample = m_canvas->toMediaSample();
if (!sample)
return;
videoSampleAvailable(*sample);
}
RefPtr<MediaStreamTrack> CanvasCaptureMediaStreamTrack::clone()
{
if (!scriptExecutionContext())
return nullptr;
return adoptRef(*new CanvasCaptureMediaStreamTrack(*scriptExecutionContext(), m_canvas.copyRef(), m_private->clone()));
}
}
#endif // ENABLE(MEDIA_STREAM)