WIP

rectalogic · Nov 29, 2023 · 9d0e84f · 9d0e84f
1 parent 57ad5a0
commit 9d0e84f
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Showing 8 changed files with 28 additions and 17 deletions.
diff --git a/src/mediafx/image_clip.cpp b/src/mediafx/image_clip.cpp
@@ -47,7 +47,7 @@ void ImageClip::loadMedia(const QUrl& url)
     videoFrame.unmap();
 }
 
-bool ImageClip::prepareNextVideoFrame()
+bool ImageClip::prepareNextVideoFrame(const Interval& globalTime)
 {
     // XXX timestamp frame based on nextClipTime() ? (in microseconds, not milliseconds)
     setCurrentVideoFrame(videoFrame);

diff --git a/src/mediafx/image_clip.h b/src/mediafx/image_clip.h
@@ -35,7 +35,7 @@ class ImageClip : public VisualClip {
 protected:
     void loadMedia(const QUrl&) override;
 
-    bool prepareNextVideoFrame() override;
+    bool prepareNextVideoFrame(const Interval& globalTime) override;
 
     void stop() override;
 

diff --git a/src/mediafx/rate_control.cpp b/src/mediafx/rate_control.cpp
@@ -35,6 +35,8 @@
 
 // XXX need to keep buffer partially full, scale to keep 5 frames in buffer somehow
 
+// track frame enqueue time, and growth rate of buffer, and tweak playback to control growth relative to desired size?
+//
 /*XXX
 qint64 movingAverage(qint64 average, qint64 sample)
 {
@@ -44,24 +46,25 @@ qint64 movingAverage(qint64 average, qint64 sample)
     return average;
 }
 */
+const int desiredBufferSize = 5; // XXX make member - fold into rateScalar
 
 qreal RateControl::playbackRate() const
 {
-    qreal rate = 10.0;
-    if (isFrameRequiredTimerValid && isEnqueueTimerValid) {
+    qreal rate = desiredBufferSize;
+    if (!bufferedFrames.isEmpty() && timeSinceFrameLastRequired && isEnqueueTimerValid) {
         auto timeSinceLastEnqueued = enqueueTimer.durationElapsed().count();
-        auto timeSinceLastRequired = frameRequiredTimer.durationElapsed().count();
-        rate = (timeSinceLastEnqueued / (qreal)timeSinceLastRequired) * rateScalar;
-        qCritical() << "rateScalar" << rateScalar << "rate" << rate << "frames" << bufferedFrames.size() << "timeSinceLastEnqueued" << timeSinceLastEnqueued << "timeSinceLastRequired" << timeSinceLastRequired; // XXX
+        rate = (timeSinceLastEnqueued / (qreal)timeSinceFrameLastRequired)
+            * (desiredBufferSize / (qreal)bufferedFrames.size())
+            * rateScalar;
+        qCritical() << "rateScalar" << rateScalar << "rate" << rate << "frames" << bufferedFrames.size() << "timeSinceLastEnqueued" << timeSinceLastEnqueued << "timeSinceFrameLastRequired" << timeSinceFrameLastRequired; // XXX
     }
     return rate;
 }
 
 void RateControl::onVideoFrameRequired()
 {
-    // Valid when we are called the 2nd time
     if (frameRequiredTimer.isValid())
-        isFrameRequiredTimerValid = true;
+        timeSinceFrameLastRequired = frameRequiredTimer.durationElapsed().count();
     frameRequiredTimer.start();
 }
 
@@ -76,6 +79,7 @@ void RateControl::enqueue(const QVideoFrame& videoFrame)
         isEnqueueTimerValid = true;
     enqueueTimer.start();
     bufferedFrames.enqueue(videoFrame);
+    qCritical() << "enqueue" << bufferedFrames.size(); // XXX
 }
 
 void RateControl::reset()
@@ -84,4 +88,5 @@ void RateControl::reset()
     bufferedFrames.squeeze();
     frameRequiredTimer.invalidate();
     enqueueTimer.invalidate();
+    timeSinceFrameLastRequired = 0;
 }
diff --git a/src/mediafx/rate_control.h b/src/mediafx/rate_control.h
@@ -38,6 +38,7 @@ class RateControl : public QObject {
 
 private:
     QElapsedTimer frameRequiredTimer;
+    qint64 timeSinceFrameLastRequired = 0;
     bool isFrameRequiredTimerValid = false;
     QElapsedTimer enqueueTimer;
     bool isEnqueueTimerValid = false;

diff --git a/src/mediafx/video_clip.cpp b/src/mediafx/video_clip.cpp
@@ -51,7 +51,9 @@ void VideoClip::loadMedia(const QUrl& url)
 
 void VideoClip::onRateControl()
 {
-    mediaPlayer.setPlaybackRate(rateControl.playbackRate());
+    auto rate = rateControl.playbackRate();
+    qCritical() << "onRateControl" << rate; // XXX
+    mediaPlayer.setPlaybackRate(rate);
 }
 
 void VideoClip::onVideoFrameChanged(const QVideoFrame& frame)
@@ -69,7 +71,7 @@ void VideoClip::onVideoFrameChanged(const QVideoFrame& frame)
     QMetaObject::invokeMethod(this, &VideoClip::onRateControl, Qt::QueuedConnection);
 }
 
-bool VideoClip::prepareNextVideoFrame()
+bool VideoClip::prepareNextVideoFrame(const Interval& globalTime)
 {
     QMutexLocker locker(&mutex);
     auto nextFrameTime = nextClipTime();
@@ -81,9 +83,11 @@ bool VideoClip::prepareNextVideoFrame()
     if (videoFrame.isValid() && nextFrameTime.contains(videoFrame.startTime())) {
         return true;
     }
-    if (rateControl.isEmpty())
-        qCritical() << "prepareNextVideoFrame BUFFER EMPTY"; // XXX
-    rateControl.onVideoFrameRequired();
+    qCritical() << "prepareNextVideoFrame buffer empty" << rateControl.isEmpty(); // XXX
+    if (lastRequestedGlobalTime != globalTime) {
+        rateControl.onVideoFrameRequired();
+        lastRequestedGlobalTime = globalTime;
+    }
     while (!rateControl.isEmpty()) {
         videoFrame = rateControl.dequeue();
         if (nextFrameTime.contains(videoFrame.startTime())) {

diff --git a/src/mediafx/video_clip.h b/src/mediafx/video_clip.h
@@ -42,7 +42,7 @@ class VideoClip : public VisualClip {
 protected:
     void loadMedia(const QUrl&) override;
 
-    bool prepareNextVideoFrame() override;
+    bool prepareNextVideoFrame(const Interval& globalTime) override;
 
     void onActiveChanged(bool active) override;
 
@@ -59,4 +59,5 @@ private slots:
     QVideoSink mediaPlayerSink;
     QMutex mutex;
     RateControl rateControl;
+    Interval lastRequestedGlobalTime;
 };
diff --git a/src/mediafx/visual_clip.cpp b/src/mediafx/visual_clip.cpp
@@ -32,7 +32,7 @@ void VisualClip::setVideoSinks(const QList<QVideoSink*>& videoSinks)
 
 bool VisualClip::renderClip(const Interval& globalTime)
 {
-    if (!prepareNextVideoFrame())
+    if (!prepareNextVideoFrame(globalTime))
         return false;
     for (auto videoSink : videoSinks()) {
         videoSink->setVideoFrame(m_currentVideoFrame);

diff --git a/src/mediafx/visual_clip.h b/src/mediafx/visual_clip.h
@@ -40,7 +40,7 @@ class VisualClip : public Clip {
     void setVideoSinks(const QList<QVideoSink*>&);
 
     bool renderClip(const Interval& globalTime) override;
-    virtual bool prepareNextVideoFrame() = 0;
+    virtual bool prepareNextVideoFrame(const Interval& globalTime) = 0;
     QVideoFrame currentVideoFrame() const { return m_currentVideoFrame; };
     void setCurrentVideoFrame(const QVideoFrame& videoFrame) { m_currentVideoFrame = videoFrame; };