Add new property to QVideoSurfaceFormat.

The 'mirrored' property indicates the QVideoFrames need to be mirrored
along their vertical axis. This is typically needed for video frames
coming from a front camera on a mobile device.

This is implemented as a string-based property. In Qt 5.6, this should
be replaced by a new public function.

Change-Id: Ideb7de81e83f66826f4efb5f2951c4beec13546b
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

4 files changed, 49 insertions, 15 deletions

diff --git a/src/multimedia/video/qvideosurfaceformat.cpp b/src/multimedia/video/qvideosurfaceformat.cpp
index 4c616b89..df6cbcfc 100644
--- a/src/multimedia/video/qvideosurfaceformat.cpp
+++ b/src/multimedia/video/qvideosurfaceformat.cpp
@@ -61,6 +61,7 @@ public:
         , pixelAspectRatio(1, 1)
         , ycbcrColorSpace(QVideoSurfaceFormat::YCbCr_Undefined)
         , frameRate(0.0)
+        , mirrored(false)
     {
     }
 
@@ -76,6 +77,7 @@ public:
         , ycbcrColorSpace(QVideoSurfaceFormat::YCbCr_Undefined)
         , viewport(QPoint(0, 0), size)
         , frameRate(0.0)
+        , mirrored(false)
     {
     }
 
@@ -89,6 +91,7 @@ public:
         , ycbcrColorSpace(other.ycbcrColorSpace)
         , viewport(other.viewport)
         , frameRate(other.frameRate)
+        , mirrored(other.mirrored)
         , propertyNames(other.propertyNames)
         , propertyValues(other.propertyValues)
     {
@@ -104,6 +107,7 @@ public:
             && viewport == other.viewport
             && frameRatesEqual(frameRate, other.frameRate)
             && ycbcrColorSpace == other.ycbcrColorSpace
+            && mirrored == other.mirrored
             && propertyNames.count() == other.propertyNames.count()) {
             for (int i = 0; i < propertyNames.count(); ++i) {
                 int j = other.propertyNames.indexOf(propertyNames.at(i));
@@ -130,6 +134,7 @@ public:
     QVideoSurfaceFormat::YCbCrColorSpace ycbcrColorSpace;
     QRect viewport;
     qreal frameRate;
+    bool mirrored;
     QList<QByteArray> propertyNames;
     QList<QVariant> propertyValues;
 };
@@ -468,7 +473,8 @@ QList<QByteArray> QVideoSurfaceFormat::propertyNames() const
             << "frameRate"
             << "pixelAspectRatio"
             << "sizeHint"
-            << "yCbCrColorSpace")
+            << "yCbCrColorSpace"
+            << "mirrored")
             + d->propertyNames;
 }
 
@@ -499,6 +505,8 @@ QVariant QVideoSurfaceFormat::property(const char *name) const
         return sizeHint();
     } else if (qstrcmp(name, "yCbCrColorSpace") == 0) {
         return qVariantFromValue(d->ycbcrColorSpace);
+    } else if (qstrcmp(name, "mirrored") == 0) {
+        return d->mirrored;
     } else {
         int id = 0;
         for (; id < d->propertyNames.count() && d->propertyNames.at(id) != name; ++id) {}
@@ -547,6 +555,9 @@ void QVideoSurfaceFormat::setProperty(const char *name, const QVariant &value)
     } else if (qstrcmp(name, "yCbCrColorSpace") == 0) {
           if (value.canConvert<YCbCrColorSpace>())
               d->ycbcrColorSpace = qvariant_cast<YCbCrColorSpace>(value);
+    } else if (qstrcmp(name, "mirrored") == 0) {
+        if (value.canConvert<bool>())
+            d->mirrored = qvariant_cast<bool>(value);
     } else {
         int id = 0;
         for (; id < d->propertyNames.count() && d->propertyNames.at(id) != name; ++id) {}
diff --git a/src/multimediawidgets/qpaintervideosurface.cpp b/src/multimediawidgets/qpaintervideosurface.cpp
index c9fa206a..5a8857b7 100644
--- a/src/multimediawidgets/qpaintervideosurface.cpp
+++ b/src/multimediawidgets/qpaintervideosurface.cpp
@@ -86,11 +86,13 @@ private:
     QSize m_imageSize;
     QImage::Format m_imageFormat;
     QVideoSurfaceFormat::Direction m_scanLineDirection;
+    bool m_mirrored;
 };
 
 QVideoSurfaceGenericPainter::QVideoSurfaceGenericPainter()
     : m_imageFormat(QImage::Format_Invalid)
     , m_scanLineDirection(QVideoSurfaceFormat::TopToBottom)
+    , m_mirrored(false)
 {
     m_imagePixelFormats << QVideoFrame::Format_RGB32;
 
@@ -137,6 +139,7 @@ QAbstractVideoSurface::Error QVideoSurfaceGenericPainter::start(const QVideoSurf
     m_imageFormat = QVideoFrame::imageFormatFromPixelFormat(format.pixelFormat());
     m_imageSize = format.frameSize();
     m_scanLineDirection = format.scanLineDirection();
+    m_mirrored = format.property("mirrored").toBool();
 
     const QAbstractVideoBuffer::HandleType t = format.handleType();
     if (t == QAbstractVideoBuffer::NoHandle) {
@@ -183,17 +186,22 @@ QAbstractVideoSurface::Error QVideoSurfaceGenericPainter::paint(
                 m_frame.bytesPerLine(),
                 m_imageFormat);
 
+        const QTransform oldTransform = painter->transform();
+        QTransform transform = oldTransform;
+        QRectF targetRect = target;
         if (m_scanLineDirection == QVideoSurfaceFormat::BottomToTop) {
-            const QTransform oldTransform = painter->transform();
-
-            painter->scale(1, -1);
-            painter->translate(0, -target.bottom());
-            painter->drawImage(
-                QRectF(target.x(), 0, target.width(), target.height()), image, source);
-            painter->setTransform(oldTransform);
-        } else {
-            painter->drawImage(target, image, source);
+            transform.scale(1, -1);
+            transform.translate(0, -target.bottom());
+            targetRect.setY(0);
+        }
+        if (m_mirrored) {
+            transform.scale(-1, 1);
+            transform.translate(-target.right(), 0);
+            targetRect.setX(0);
         }
+        painter->setTransform(transform);
+        painter->drawImage(targetRect, image, source);
+        painter->setTransform(oldTransform);
 
         m_frame.unmap();
     } else if (m_frame.isValid()) {
@@ -281,6 +289,7 @@ protected:
     QGLContext *m_context;
     QAbstractVideoBuffer::HandleType m_handleType;
     QVideoSurfaceFormat::Direction m_scanLineDirection;
+    bool m_mirrored;
     QVideoSurfaceFormat::YCbCrColorSpace m_colorSpace;
     GLenum m_textureFormat;
     GLuint m_textureInternalFormat;
@@ -299,6 +308,7 @@ QVideoSurfaceGLPainter::QVideoSurfaceGLPainter(QGLContext *context)
     : m_context(context)
     , m_handleType(QAbstractVideoBuffer::NoHandle)
     , m_scanLineDirection(QVideoSurfaceFormat::TopToBottom)
+    , m_mirrored(false)
     , m_colorSpace(QVideoSurfaceFormat::YCbCr_BT601)
     , m_textureFormat(0)
     , m_textureInternalFormat(0)
@@ -829,6 +839,7 @@ QAbstractVideoSurface::Error QVideoSurfaceArbFpPainter::start(const QVideoSurfac
             } else {
                 m_handleType = format.handleType();
                 m_scanLineDirection = format.scanLineDirection();
+                m_mirrored = format.property("mirrored").toBool();
                 m_frameSize = format.frameSize();
                 m_colorSpace = format.yCbCrColorSpace();
 
@@ -878,8 +889,10 @@ QAbstractVideoSurface::Error QVideoSurfaceArbFpPainter::paint(
         if (scissorTestEnabled)
             glEnable(GL_SCISSOR_TEST);
 
-        const float txLeft = source.left() / m_frameSize.width();
-        const float txRight = source.right() / m_frameSize.width();
+        const float txLeft = m_mirrored ? source.right() / m_frameSize.width()
+                                        : source.left() / m_frameSize.width();
+        const float txRight = m_mirrored ? source.left() / m_frameSize.width()
+                                         : source.right() / m_frameSize.width();
         const float txTop = m_scanLineDirection == QVideoSurfaceFormat::TopToBottom
                 ? source.top() / m_frameSize.height()
                 : source.bottom() / m_frameSize.height();
@@ -1188,6 +1201,7 @@ QAbstractVideoSurface::Error QVideoSurfaceGlslPainter::start(const QVideoSurface
     } else {
         m_handleType = format.handleType();
         m_scanLineDirection = format.scanLineDirection();
+        m_mirrored = format.property("mirrored").toBool();
         m_frameSize = format.frameSize();
         m_colorSpace = format.yCbCrColorSpace();
 
@@ -1276,8 +1290,10 @@ QAbstractVideoSurface::Error QVideoSurfaceGlslPainter::paint(
             GLfloat(target.right() + 1), GLfloat(target.top())
         };
 
-        const GLfloat txLeft = source.left() / m_frameSize.width();
-        const GLfloat txRight = source.right() / m_frameSize.width();
+        const GLfloat txLeft = m_mirrored ? source.right() / m_frameSize.width()
+                                          : source.left() / m_frameSize.width();
+        const GLfloat txRight = m_mirrored ? source.left() / m_frameSize.width()
+                                           : source.right() / m_frameSize.width();
         const GLfloat txTop = m_scanLineDirection == QVideoSurfaceFormat::TopToBottom
                 ? source.top() / m_frameSize.height()
                 : source.bottom() / m_frameSize.height();
diff --git a/src/qtmultimediaquicktools/qdeclarativevideooutput_render.cpp b/src/qtmultimediaquicktools/qdeclarativevideooutput_render.cpp
index de4cabfa..70d48dd9 100644
--- a/src/qtmultimediaquicktools/qdeclarativevideooutput_render.cpp
+++ b/src/qtmultimediaquicktools/qdeclarativevideooutput_render.cpp
@@ -255,6 +255,12 @@ void QDeclarativeVideoRendererBackend::updateGeometry()
         m_sourceTextureRect.setTop(m_sourceTextureRect.bottom());
         m_sourceTextureRect.setBottom(top);
     }
+
+    if (videoSurface()->surfaceFormat().property("mirrored").toBool()) {
+        qreal left = m_sourceTextureRect.left();
+        m_sourceTextureRect.setLeft(m_sourceTextureRect.right());
+        m_sourceTextureRect.setRight(left);
+    }
 }
 
 QSGNode *QDeclarativeVideoRendererBackend::updatePaintNode(QSGNode *oldNode,
diff --git a/tests/auto/unit/qvideosurfaceformat/tst_qvideosurfaceformat.cpp b/tests/auto/unit/qvideosurfaceformat/tst_qvideosurfaceformat.cpp
index 8e548d64..6ad87597 100644
--- a/tests/auto/unit/qvideosurfaceformat/tst_qvideosurfaceformat.cpp
+++ b/tests/auto/unit/qvideosurfaceformat/tst_qvideosurfaceformat.cpp
@@ -521,7 +521,8 @@ void tst_QVideoSurfaceFormat::staticPropertyNames()
     QVERIFY(propertyNames.contains("pixelAspectRatio"));
     QVERIFY(propertyNames.contains("yCbCrColorSpace"));
     QVERIFY(propertyNames.contains("sizeHint"));
-    QCOMPARE(propertyNames.count(), 10);
+    QVERIFY(propertyNames.contains("mirrored"));
+    QCOMPARE(propertyNames.count(), 11);
 }
 
 void tst_QVideoSurfaceFormat::dynamicProperty()