videonode: imx6: Ensure the video node excludes padding pixels

Padding rows & columns are included in the video frame that is sent to
the VIV direct texture. Scale the UV coordinates to ensure the padding
pixels aren't shown.

Change-Id: I8b870a95ff786f9f80f42f0cc33f468b0c9c3863
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>

6 files changed, 90 insertions, 4 deletions

diff --git a/src/plugins/videonode/imx6/qsgvivantevideomaterial.cpp b/src/plugins/videonode/imx6/qsgvivantevideomaterial.cpp
index ab6bcd52a..2e2092be9 100644
--- a/src/plugins/videonode/imx6/qsgvivantevideomaterial.cpp
+++ b/src/plugins/videonode/imx6/qsgvivantevideomaterial.cpp
@@ -60,6 +60,8 @@ QSGVivanteVideoMaterial::QSGVivanteVideoMaterial() :
 #endif
 
     setFlag(Blending, false);
+
+    mShader = new QSGVivanteVideoMaterialShader;
 }
 
 QSGVivanteVideoMaterial::~QSGVivanteVideoMaterial()
@@ -73,7 +75,7 @@ QSGMaterialType *QSGVivanteVideoMaterial::type() const {
 }
 
 QSGMaterialShader *QSGVivanteVideoMaterial::createShader() const {
-    return new QSGVivanteVideoMaterialShader;
+    return mShader;
 }
 
 int QSGVivanteVideoMaterial::compare(const QSGMaterial *other) const {
@@ -175,18 +177,49 @@ GLuint QSGVivanteVideoMaterial::vivanteMapping(QVideoFrame vF)
                 glGenTextures(1, &tmpTexId);
                 mBitsToTextureMap.insert(vF.bits(), tmpTexId);
 
+                // Determine the full width & height. Full means: actual width/height plus extra padding pixels.
+                // The full width can be deduced from the bytesPerLine value. The full height is calculated
+                // by calculating the distance between the start of the first and second planes, and dividing
+                // it by the stride (= the bytesPerLine). If there is only one plane, we don't worry about
+                // extra padding rows, since there are no adjacent extra planes.
+                // XXX: This assumes the distance between bits(1) and bits(0) is exactly the size of the first
+                // plane (the Y plane in the case of YUV data). A better way would be to have a dedicated
+                // planeSize() or planeOffset() getter.
+                // Also, this assumes that planes are tightly packed, that is, there is no space between them.
+                // It is okay to assume this here though, because the Vivante direct textures also assume that.
+                // In other words, if the planes aren't tightly packed, then the direct textures won't be able
+                // to render the frame correctly anyway.
+                int fullWidth = vF.bytesPerLine() / QSGVivanteVideoNode::getBytesForPixelFormat(vF.pixelFormat());
+                int fullHeight = (vF.planeCount() > 1) ? ((vF.bits(1) - vF.bits(0)) / vF.bytesPerLine()) : vF.height();
+
+                // The uscale is the ratio of actual width to the full width (same for vscale and height).
+                // Since the vivante direct textures do not offer a way to explicitly specify the amount of padding
+                // columns and rows, we use a trick. We show the full frame - including the padding pixels - in the
+                // texture, but render only a subset of that texture. This subset goes from (0,0) to (uScale, vScale).
+                // In the shader, the texture coordinates (which go from (0.0, 0.0) to (1.0, 1.0)) are multiplied by
+                // the u/v scale values. Since 1.0 * x = x, this effectively limits the texture coordinates from
+                // (0.0, 0.0) - (1.0, 1.0) to (0.0, 0.0) - (uScale, vScale).
+                float uScale = float(vF.width()) / float(fullWidth);
+                float vScale = float(vF.height()) / float(fullHeight);
+                mShader->setUVScale(uScale, vScale);
+
                 const uchar *constBits = vF.bits();
                 void *bits = (void*)constBits;
 
 #ifdef QT_VIVANTE_VIDEO_DEBUG
-                qDebug() << Q_FUNC_INFO << "new texture, texId: " << tmpTexId << "; constBits: " << constBits;
+                qDebug() << Q_FUNC_INFO
+                         << "new texture, texId: " << tmpTexId
+                         << "; constBits: " << constBits
+                         << "; actual/full width: " << vF.width() << "/" << fullWidth
+                         << "; actual/full height: " << vF.height() << "/" << fullHeight
+                         << "; UV scale: U " << uScale << " V " << vScale;
 #endif
 
                 GLuint physical = ~0U;
 
                 glBindTexture(GL_TEXTURE_2D, tmpTexId);
                 glTexDirectVIVMap_LOCAL(GL_TEXTURE_2D,
-                                        vF.width(), vF.height(),
+                                        fullWidth, fullHeight,
                                         QSGVivanteVideoNode::getVideoFormat2GLFormatMap().value(vF.pixelFormat()),
                                         &bits, &physical);
 
diff --git a/src/plugins/videonode/imx6/qsgvivantevideomaterial.h b/src/plugins/videonode/imx6/qsgvivantevideomaterial.h
index faefa1c98..faf4e8d22 100644
--- a/src/plugins/videonode/imx6/qsgvivantevideomaterial.h
+++ b/src/plugins/videonode/imx6/qsgvivantevideomaterial.h
@@ -43,6 +43,8 @@
 
 #include <private/qsgvideonode_p.h>
 
+class QSGVivanteVideoMaterialShader;
+
 class QSGVivanteVideoMaterial : public QSGMaterial
 {
 public:
@@ -78,6 +80,8 @@ private:
 
     GLuint mTexDirectTexture;
     GLvoid *mTexDirectPlanes[3];
+
+    QSGVivanteVideoMaterialShader *mShader;
 };
 
 #endif // QSGVIDEOMATERIAL_VIVMAP_H
diff --git a/src/plugins/videonode/imx6/qsgvivantevideomaterialshader.cpp b/src/plugins/videonode/imx6/qsgvivantevideomaterialshader.cpp
index b51acfe62..a0a417736 100644
--- a/src/plugins/videonode/imx6/qsgvivantevideomaterialshader.cpp
+++ b/src/plugins/videonode/imx6/qsgvivantevideomaterialshader.cpp
@@ -35,6 +35,13 @@
 #include "qsgvivantevideonode.h"
 #include "qsgvivantevideomaterial.h"
 
+QSGVivanteVideoMaterialShader::QSGVivanteVideoMaterialShader() :
+    mUScale(1),
+    mVScale(1),
+    mNewUVScale(true)
+{
+}
+
 void QSGVivanteVideoMaterialShader::updateState(const RenderState &state,
                                                 QSGMaterial *newMaterial,
                                                 QSGMaterial *oldMaterial)
@@ -48,6 +55,10 @@ void QSGVivanteVideoMaterialShader::updateState(const RenderState &state,
         mat->setOpacity(state.opacity());
         program()->setUniformValue(mIdOpacity, state.opacity());
     }
+    if (mNewUVScale) {
+        program()->setUniformValue(mIdUVScale, mUScale, mVScale);
+        mNewUVScale = false;
+    }
     if (state.isMatrixDirty())
         program()->setUniformValue(mIdMatrix, state.combinedMatrix());
 }
@@ -61,6 +72,13 @@ const char * const *QSGVivanteVideoMaterialShader::attributeNames() const {
     return names;
 }
 
+void QSGVivanteVideoMaterialShader::setUVScale(float uScale, float vScale)
+{
+    mUScale = uScale;
+    mVScale = vScale;
+    mNewUVScale = true;
+}
+
 const char *QSGVivanteVideoMaterialShader::vertexShader() const {
     static const char *shader =
             "uniform highp mat4 qt_Matrix;                      \n"
@@ -78,12 +96,13 @@ const char *QSGVivanteVideoMaterialShader::fragmentShader() const {
     static const char *shader =
             "uniform sampler2D texture;"
             "uniform lowp float opacity;"
+            "uniform highp vec2 uvScale;"
             ""
             "varying highp vec2 qt_TexCoord;"
             ""
             "void main()"
             "{"
-            "  gl_FragColor = vec4(texture2D( texture, qt_TexCoord ).rgb, 1.0) * opacity;\n"
+            "  gl_FragColor = vec4(texture2D( texture, qt_TexCoord * uvScale ).rgb, 1.0) * opacity;\n"
             "}";
     return shader;
 }
@@ -93,4 +112,5 @@ void QSGVivanteVideoMaterialShader::initialize() {
     mIdMatrix = program()->uniformLocation("qt_Matrix");
     mIdTexture = program()->uniformLocation("texture");
     mIdOpacity = program()->uniformLocation("opacity");
+    mIdUVScale = program()->uniformLocation("uvScale");
 }
diff --git a/src/plugins/videonode/imx6/qsgvivantevideomaterialshader.h b/src/plugins/videonode/imx6/qsgvivantevideomaterialshader.h
index f902f763b..f6e707da4 100644
--- a/src/plugins/videonode/imx6/qsgvivantevideomaterialshader.h
+++ b/src/plugins/videonode/imx6/qsgvivantevideomaterialshader.h
@@ -39,9 +39,13 @@
 class QSGVivanteVideoMaterialShader : public QSGMaterialShader
 {
 public:
+    QSGVivanteVideoMaterialShader();
+
     void updateState(const RenderState &state, QSGMaterial *newMaterial, QSGMaterial *oldMaterial);
     virtual char const *const *attributeNames() const;
 
+    void setUVScale(float uScale, float vScale);
+
 protected:
     virtual const char *vertexShader() const;
     virtual const char *fragmentShader() const;
@@ -51,6 +55,11 @@ private:
     int mIdMatrix;
     int mIdTexture;
     int mIdOpacity;
+    int mIdUVScale;
+
+    float mUScale;
+    float mVScale;
+    bool mNewUVScale;
 };
 
 #endif // QSGVIDEOMATERIALSHADER_VIVANTE_H
diff --git a/src/plugins/videonode/imx6/qsgvivantevideonode.cpp b/src/plugins/videonode/imx6/qsgvivantevideonode.cpp
index 42058f1b1..229a69bc6 100644
--- a/src/plugins/videonode/imx6/qsgvivantevideonode.cpp
+++ b/src/plugins/videonode/imx6/qsgvivantevideonode.cpp
@@ -78,4 +78,23 @@ const QMap<QVideoFrame::PixelFormat, GLenum>& QSGVivanteVideoNode::getVideoForma
 }
 
 
+int QSGVivanteVideoNode::getBytesForPixelFormat(QVideoFrame::PixelFormat pixelformat)
+{
+    switch (pixelformat) {
+    case QVideoFrame::Format_YUV420P: return 1;
+    case QVideoFrame::Format_YV12: return 1;
+    case QVideoFrame::Format_NV12: return 1;
+    case QVideoFrame::Format_NV21: return 1;
+    case QVideoFrame::Format_UYVY: return 2;
+    case QVideoFrame::Format_YUYV: return 2;
+    case QVideoFrame::Format_RGB32: return 4;
+    case QVideoFrame::Format_ARGB32: return 4;
+    case QVideoFrame::Format_BGR32: return 4;
+    case QVideoFrame::Format_BGRA32: return 4;
+    case QVideoFrame::Format_RGB565: return 2;
+    default: return 1;
+    }
+}
+
+
 
diff --git a/src/plugins/videonode/imx6/qsgvivantevideonode.h b/src/plugins/videonode/imx6/qsgvivantevideonode.h
index ca088e21b..c65fc11ea 100644
--- a/src/plugins/videonode/imx6/qsgvivantevideonode.h
+++ b/src/plugins/videonode/imx6/qsgvivantevideonode.h
@@ -49,6 +49,7 @@ public:
     void setCurrentFrame(const QVideoFrame &frame, FrameFlags flags);
 
     static const QMap<QVideoFrame::PixelFormat, GLenum>& getVideoFormat2GLFormatMap();
+    static int getBytesForPixelFormat(QVideoFrame::PixelFormat pixelformat);
 
 private:
     QVideoSurfaceFormat mFormat;