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>

1 files changed, 29 insertions, 13 deletions

diff --git a/src/multimediawidgets/qpaintervideosurface.cpp b/src/multimediawidgets/qpaintervideosurface.cpp
index c9fa206a2..5a8857b78 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();