pica-client: callwindow layout, video resize

1 files changed, 40 insertions, 2 deletions

diff --git a/pica-client/videodevice.h b/pica-client/videodevice.h
index fe218ec..f65895d 100644
--- a/pica-client/videodevice.h
+++ b/pica-client/videodevice.h
@@ -26,6 +26,7 @@
 #include <QQueue>
 #include <QMutex>
 #include <QWaitCondition>
+#include <QSize>
 #include <QAtomicInt>
 
 // Reassembles the fragments of one encoded video frame, as carried by 0x77
@@ -155,12 +156,29 @@ public:
 	void setMaxFragmentSize(int size);
 
 	// Stops keeping decoded frames in GPU memory, for when the renderer that
-	// was to draw them turns out not to be able to: decoding carries on, but
+	// was to draw them turns out to not be able to: decoding carries on, but
 	// frames come back through system memory and are emitted by frameReady()
 	// from then on. Safe to call from any thread, and called directly rather
 	// than queued for the same reason enqueueFrame() is.
 	void disableHardwareRendering();
 
+	// The size of the area the decoded frames are going to be drawn in, so
+	// that Play() can produce them at that size directly. A decoded frame has
+	// to be resized to the window either way, and doing it inside the colour
+	// conversion the decode loop already runs costs far less than a second
+	// pass over the picture afterwards - between 1.1 and 4.6 times less over
+	// the whole pipeline, see tests/test_videoscaler.
+	//
+	// Frames keep their aspect ratio: this is the area to fit inside, not the
+	// size to produce. An empty size means the display size is not known and
+	// frames come back at their own resolution.
+	//
+	// Changes while a call is running, on every window resize, and is safe to
+	// call from any thread. Called directly rather than queued for the same
+	// reason enqueueFrame() is - the decode loop it affects is already
+	// running.
+	void setDisplaySize(QSize size);
+
 public slots:
 	// Blocking capture+encode loop: opens the configured camera, encodes
 	// captured frames, and emits packetReady() for each encoded frame, split
@@ -189,7 +207,16 @@ signals:
 	// onto the 0x77 sequence number's last fragment marker bit.
 	void packetReady(QByteArray data, bool isLastFragment);
 
-	// One decoded picture from the remote side, ready to be displayed.
+	// One decoded picture from the remote side, ready to be displayed, as a
+	// Format_RGB32 image - the format a widget draws without converting it
+	// first.
+	//
+	// Already scaled to fit the area last given to setDisplaySize(), keeping
+	// its aspect ratio, so the receiver can draw it as it stands. At the
+	// frame's own resolution while no display size has been set. A receiver
+	// still has to cope with the occasional frame at another size: the ones
+	// already decoded or in flight when the window is resized arrive at the
+	// size that was current when they were converted.
 	void frameReady(QImage frame);
 
 #ifdef HAVE_VAAPI
@@ -248,6 +275,13 @@ private:
 	// capture loop is running.
 	QAtomicInt m_maxFragmentSize;
 
+	// Likewise set from another thread, by setDisplaySize(), while the decode
+	// loop is running. Both dimensions live in the one atomic - width in the
+	// upper half, height in the lower - so that the decode loop cannot read a
+	// new width against an old height and scale one frame to a wrong aspect
+	// ratio. Zero means not known yet.
+	QAtomicInt m_displaySize;
+
 	QMutex m_queueMutex;
 	QWaitCondition m_queueCond;
 	QQueue<QByteArray> m_frameQueue;
@@ -272,6 +306,10 @@ private:
 	// packets, hence atomic.
 	QAtomicInt m_decoderStarted;
 
+	// What setDisplaySize() was last given, unpacked; an empty size if it has
+	// not been called. Read by the decode loop, once per frame.
+	QSize displaySize() const;
+
 	// Sends one encoded frame out as one or more protocol sized fragments.
 	void emitFragments(const unsigned char *data, int size);