Fix QSGVideoNode rendering of frames with stride != width.

Adjust texture coordinates to not render padding at the end of lines,
and better calculate the stride of UV planes.

Task-number: QTBUG-38218
Task-number: QTBUG-30447
Change-Id: I7b7577979719c48460b838f7dcc89b9d17741f79
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>

2 files changed, 73 insertions, 18 deletions

diff --git a/src/qtmultimediaquicktools/qsgvideonode_i420.cpp b/src/qtmultimediaquicktools/qsgvideonode_i420.cpp
index d7eb04863..2d84f6ed1 100644
--- a/src/qtmultimediaquicktools/qsgvideonode_i420.cpp
+++ b/src/qtmultimediaquicktools/qsgvideonode_i420.cpp
@@ -87,11 +87,15 @@ protected:
     virtual const char *vertexShader() const {
         const char *shader =
         "uniform highp mat4 qt_Matrix;                      \n"
+        "uniform highp float yWidth;                        \n"
+        "uniform highp float uvWidth;                       \n"
         "attribute highp vec4 qt_VertexPosition;            \n"
         "attribute highp vec2 qt_VertexTexCoord;            \n"
-        "varying highp vec2 qt_TexCoord;                    \n"
+        "varying highp vec2 yTexCoord;                      \n"
+        "varying highp vec2 uvTexCoord;                     \n"
         "void main() {                                      \n"
-        "    qt_TexCoord = qt_VertexTexCoord;               \n"
+        "    yTexCoord   = qt_VertexTexCoord * vec2(yWidth, 1);\n"
+        "    uvTexCoord  = qt_VertexTexCoord * vec2(uvWidth, 1);\n"
         "    gl_Position = qt_Matrix * qt_VertexPosition;   \n"
         "}";
         return shader;
@@ -105,13 +109,14 @@ protected:
         "uniform mediump mat4 colorMatrix;"
         "uniform lowp float opacity;"
         ""
-        "varying highp vec2 qt_TexCoord;"
+        "varying highp vec2 yTexCoord;"
+        "varying highp vec2 uvTexCoord;"
         ""
         "void main()"
         "{"
-        "    mediump float Y = texture2D(yTexture, qt_TexCoord).r;"
-        "    mediump float U = texture2D(uTexture, qt_TexCoord).r;"
-        "    mediump float V = texture2D(vTexture, qt_TexCoord).r;"
+        "    mediump float Y = texture2D(yTexture, yTexCoord).r;"
+        "    mediump float U = texture2D(uTexture, uvTexCoord).r;"
+        "    mediump float V = texture2D(vTexture, uvTexCoord).r;"
         "    mediump vec4 color = vec4(Y, U, V, 1.);"
         "    gl_FragColor = colorMatrix * color * opacity;"
         "}";
@@ -120,6 +125,8 @@ protected:
 
     virtual void initialize() {
         m_id_matrix = program()->uniformLocation("qt_Matrix");
+        m_id_yWidth = program()->uniformLocation("yWidth");
+        m_id_uvWidth = program()->uniformLocation("uvWidth");
         m_id_yTexture = program()->uniformLocation("yTexture");
         m_id_uTexture = program()->uniformLocation("uTexture");
         m_id_vTexture = program()->uniformLocation("vTexture");
@@ -128,6 +135,8 @@ protected:
     }
 
     int m_id_matrix;
+    int m_id_yWidth;
+    int m_id_uvWidth;
     int m_id_yTexture;
     int m_id_uTexture;
     int m_id_vTexture;
@@ -181,6 +190,8 @@ public:
     GLuint m_textureIds[Num_Texture_IDs];
 
     qreal m_opacity;
+    GLfloat m_yWidth;
+    GLfloat m_uvWidth;
     QMatrix4x4 m_colorMatrix;
 
     QVideoFrame m_frame;
@@ -189,7 +200,9 @@ public:
 
 QSGVideoMaterial_YUV420::QSGVideoMaterial_YUV420(const QVideoSurfaceFormat &format) :
     m_format(format),
-    m_opacity(1.0)
+    m_opacity(1.0),
+    m_yWidth(1.0),
+    m_uvWidth(1.0)
 {
     memset(m_textureIds, 0, sizeof(m_textureIds));
 
@@ -245,21 +258,34 @@ void QSGVideoMaterial_YUV420::bind()
             }
 
             const uchar *bits = m_frame.bits();
-            int bpl = m_frame.bytesPerLine();
-            int bpl2 = (bpl / 2 + 3) & ~3;
-            int offsetU = bpl * fh;
-            int offsetV = bpl * fh + bpl2 * fh / 2;
+            int yStride = m_frame.bytesPerLine();
+            // The UV stride is usually half the Y stride and is 32-bit aligned.
+            // However it's not always the case, at least on Windows where the
+            // UV planes are sometimes not aligned.
+            // We calculate the stride using the UV byte count to always
+            // have a correct stride.
+            int uvStride = (m_frame.mappedBytes() - yStride * fh) / fh;
+            int offsetU = yStride * fh;
+            int offsetV = yStride * fh + uvStride * fh / 2;
+
+            m_yWidth = qreal(fw) / yStride;
+            m_uvWidth = qreal(fw) /  (2 * uvStride);
 
             if (m_frame.pixelFormat() == QVideoFrame::Format_YV12)
                 qSwap(offsetU, offsetV);
 
+            GLint previousAlignment;
+            glGetIntegerv(GL_UNPACK_ALIGNMENT, &previousAlignment);
+            glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
             functions->glActiveTexture(GL_TEXTURE1);
-            bindTexture(m_textureIds[1], fw/2, fh / 2, bits + offsetU);
+            bindTexture(m_textureIds[1], uvStride, fh / 2, bits + offsetU);
             functions->glActiveTexture(GL_TEXTURE2);
-            bindTexture(m_textureIds[2], fw/2, fh / 2, bits + offsetV);
+            bindTexture(m_textureIds[2], uvStride, fh / 2, bits + offsetV);
             functions->glActiveTexture(GL_TEXTURE0); // Finish with 0 as default texture unit
-            bindTexture(m_textureIds[0], fw, fh, bits);
+            bindTexture(m_textureIds[0], yStride, fh, bits);
+
+            glPixelStorei(GL_UNPACK_ALIGNMENT, previousAlignment);
 
             m_frame.unmap();
         }
@@ -318,6 +344,8 @@ void QSGVideoMaterialShader_YUV420::updateState(const RenderState &state,
     mat->bind();
 
     program()->setUniformValue(m_id_colorMatrix, mat->m_colorMatrix);
+    program()->setUniformValue(m_id_yWidth, mat->m_yWidth);
+    program()->setUniformValue(m_id_uvWidth, mat->m_uvWidth);
     if (state.isOpacityDirty()) {
         mat->m_opacity = state.opacity();
         program()->setUniformValue(m_id_opacity, GLfloat(mat->m_opacity));
diff --git a/src/qtmultimediaquicktools/qsgvideonode_rgb.cpp b/src/qtmultimediaquicktools/qsgvideonode_rgb.cpp
index fbe60c9a7..ad01a08ae 100644
--- a/src/qtmultimediaquicktools/qsgvideonode_rgb.cpp
+++ b/src/qtmultimediaquicktools/qsgvideonode_rgb.cpp
@@ -79,6 +79,7 @@ public:
     QSGVideoMaterialShader_RGB(QVideoFrame::PixelFormat pixelFormat)
         : QSGMaterialShader(),
           m_id_matrix(-1),
+          m_id_width(-1),
           m_id_rgbTexture(-1),
           m_id_opacity(-1),
           m_pixelFormat(pixelFormat)
@@ -101,11 +102,12 @@ protected:
     virtual const char *vertexShader() const {
         const char *shader =
         "uniform highp mat4 qt_Matrix;                      \n"
+        "uniform highp float width;                         \n"
         "attribute highp vec4 qt_VertexPosition;            \n"
         "attribute highp vec2 qt_VertexTexCoord;            \n"
         "varying highp vec2 qt_TexCoord;                    \n"
         "void main() {                                      \n"
-        "    qt_TexCoord = qt_VertexTexCoord;               \n"
+        "    qt_TexCoord = qt_VertexTexCoord * vec2(width, 1);\n"
         "    gl_Position = qt_Matrix * qt_VertexPosition;   \n"
         "}";
         return shader;
@@ -146,11 +148,13 @@ protected:
 
     virtual void initialize() {
         m_id_matrix = program()->uniformLocation("qt_Matrix");
+        m_id_width = program()->uniformLocation("width");
         m_id_rgbTexture = program()->uniformLocation("rgbTexture");
         m_id_opacity = program()->uniformLocation("opacity");
     }
 
     int m_id_matrix;
+    int m_id_width;
     int m_id_rgbTexture;
     int m_id_opacity;
     QVideoFrame::PixelFormat m_pixelFormat;
@@ -163,7 +167,8 @@ public:
     QSGVideoMaterial_RGB(const QVideoSurfaceFormat &format) :
         m_format(format),
         m_textureId(0),
-        m_opacity(1.0)
+        m_opacity(1.0),
+        m_width(1.0)
     {
         setFlag(Blending, false);
     }
@@ -204,11 +209,25 @@ public:
         QMutexLocker lock(&m_frameMutex);
         if (m_frame.isValid()) {
             if (m_frame.map(QAbstractVideoBuffer::ReadOnly)) {
-                if (m_textureSize != m_frame.size()) {
+                QSize textureSize = m_frame.size();
+
+                int stride = m_frame.bytesPerLine();
+                switch (m_frame.pixelFormat()) {
+                case QVideoFrame::Format_RGB565:
+                    stride /= 2;
+                    break;
+                default:
+                    stride /= 4;
+                }
+
+                m_width = qreal(m_frame.width() / stride);
+                textureSize.setWidth(stride);
+
+                if (m_textureSize != textureSize) {
                     if (!m_textureSize.isEmpty())
                         glDeleteTextures(1, &m_textureId);
                     glGenTextures(1, &m_textureId);
-                    m_textureSize = m_frame.size();
+                    m_textureSize = textureSize;
                 }
 
                 GLint dataType = GL_UNSIGNED_BYTE;
@@ -219,12 +238,18 @@ public:
                     dataFormat = GL_RGB;
                 }
 
+                GLint previousAlignment;
+                glGetIntegerv(GL_UNPACK_ALIGNMENT, &previousAlignment);
+                glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+
                 functions->glActiveTexture(GL_TEXTURE0);
                 glBindTexture(GL_TEXTURE_2D, m_textureId);
                 glTexImage2D(GL_TEXTURE_2D, 0, dataFormat,
                              m_textureSize.width(), m_textureSize.height(),
                              0, dataFormat, dataType, m_frame.bits());
 
+                glPixelStorei(GL_UNPACK_ALIGNMENT, previousAlignment);
+
                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
@@ -245,6 +270,7 @@ public:
     QVideoSurfaceFormat m_format;
     GLuint m_textureId;
     qreal m_opacity;
+    GLfloat m_width;
 };
 
 
@@ -276,6 +302,7 @@ void QSGVideoMaterialShader_RGB::updateState(const RenderState &state,
 
     mat->bind();
 
+    program()->setUniformValue(m_id_width, mat->m_width);
     if (state.isOpacityDirty()) {
         mat->m_opacity = state.opacity();
         mat->updateBlending();