mltframework · ddennedy · Jan 3, 2026 · Dec 21, 2025 · Jan 3, 2026
diff --git a/.github/workflows/build-distros.yml b/.github/workflows/build-distros.yml
@@ -34,7 +34,7 @@ jobs:
               sed -i 's/^Types: deb/Types: deb deb-src/' /etc/apt/sources.list.d/ubuntu.sources
               DEBIAN_FRONTEND=noninteractive apt-get -qq update
               DEBIAN_FRONTEND=noninteractive apt-get -yqq build-dep mlt
-              DEBIAN_FRONTEND=noninteractive apt-get -yqq install cmake qt6-base-dev libqt6svg6-dev libqt6core5compat6-dev
+              DEBIAN_FRONTEND=noninteractive apt-get -yqq install cmake qt6-base-dev libqt6svg6-dev
           - name: ubuntu-22.04
             image: ubuntu:22.04
             setup_script: |
@@ -54,15 +54,15 @@ jobs:
               echo 'deb-src http://deb.debian.org/debian testing main' >> /etc/apt/sources.list
               apt-get -qq update
               apt-get -yqq build-dep mlt
-              apt-get -yqq install cmake qt6-base-dev libqt6svg6-dev libqt6core5compat6-dev
+              apt-get -yqq install cmake qt6-base-dev libqt6svg6-dev
           - name: debian-stable
             image: debian:stable
             setup_script: |
               echo 'deb-src http://deb.debian.org/debian stable main\ndeb-src http://deb.debian.org/debian stable-updates main' >> /etc/apt/sources.list
               echo 'deb http://deb.debian.org/debian bookworm-backports main' >> /etc/apt/sources.list
               apt-get -qq update
               apt-get -yqq build-dep mlt
-              apt-get -yqq install cmake qt6-base-dev libqt6svg6-dev libqt6core5compat6-dev
+              apt-get -yqq install cmake qt6-base-dev libqt6svg6-dev
           - name: fedora-42
             image: fedora:42
             setup_script: |
@@ -71,7 +71,7 @@ jobs:
                 yasm gavl-devel libsamplerate-devel libxml2-devel \
                 ladspa-devel jack-audio-connection-kit-devel sox-devel \
                 SDL2-devel fftw-devel frei0r-devel gtk2-devel libexif-devel \
-                qt6-qtbase-devel qt6-qt5compat-devel qt6-qtsvg-devel \
+                qt6-qtbase-devel qt6-qtsvg-devel \
                 libtheora-devel libvorbis-devel libvdpau-devel \
                 libsoup-devel liboil-devel python-devel alsa-lib \
                 pulseaudio-libs-devel gcc-c++ cmake ffmpeg-free-devel \
@@ -84,7 +84,7 @@ jobs:
                 yasm gavl-devel libsamplerate-devel libxml2-devel \
                 ladspa-devel jack-audio-connection-kit-devel sox-devel \
                 SDL2-devel fftw-devel frei0r-devel gtk2-devel libexif-devel \
-                qt6-qtbase-devel qt6-qt5compat-devel qt6-qtsvg-devel \
+                qt6-qtbase-devel qt6-qtsvg-devel \
                 libtheora-devel libvorbis-devel libvdpau-devel \
                 libsoup-devel liboil-devel python-devel alsa-lib \
                 pulseaudio-libs-devel gcc-c++ cmake ffmpeg-free-devel \

diff --git a/.github/workflows/build-msys2-mingw64.yml b/.github/workflows/build-msys2-mingw64.yml
@@ -49,7 +49,6 @@ jobs:
             mingw-w64-x86_64-potrace
             mingw-w64-x86_64-python-pip
             mingw-w64-x86_64-qt5-base
-            mingw-w64-x86_64-qt6-5compat
             mingw-w64-x86_64-qt6-base
             mingw-w64-x86_64-qt6-svg
             mingw-w64-x86_64-rubberband

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -306,7 +306,10 @@ endif()
 # It is necessary to look for Qt6 before Qt5, otherwise there will
 # be a conflict with the targets in case both are enabled
 if(MOD_QT6)
-  find_package(Qt6 REQUIRED COMPONENTS Core Gui Xml SvgWidgets Core5Compat)
+  find_package(Qt6 REQUIRED COMPONENTS Core Gui Xml SvgWidgets)
+  if(Qt6_VERSION VERSION_LESS 6.4.0)
+    find_package(Qt6 REQUIRED COMPONENTS Core5Compat)
+  endif()
   list(APPEND MLT_SUPPORTED_COMPONENTS qt6)
 endif()
 

diff --git a/Dockerfile b/Dockerfile
@@ -11,7 +11,7 @@ FROM base AS build
 RUN apt-get install -yqq wget git automake autoconf libtool intltool g++ yasm nasm \
   swig libgavl-dev libsamplerate0-dev libxml2-dev ladspa-sdk libjack-dev \
   libsox-dev libsdl2-dev libgtk2.0-dev libsoup2.4-dev \
-  qt6-base-dev qt6-5compat-dev qt6-svg-dev libarchive-dev libmp3lame-dev \
+  qt6-base-dev qt6-svg-dev libarchive-dev libmp3lame-dev \
   libexif-dev libtheora-dev libvorbis-dev python3-dev cmake xutils-dev \
   libegl1-mesa-dev libeigen3-dev libfftw3-dev libvdpau-dev meson ninja-build
 
@@ -29,7 +29,7 @@ FROM base
 RUN apt-get install -yqq dumb-init \
   libsamplerate0 libxml2 libjack0 \
   libsdl2-2.0-0 libgtk2.0-0 libsoup2.4-1 \
-  libqt6core5compat6 libqt6svgwidgets6 libqt6xml6 qt6-image-formats-plugins libarchive13 \
+  libqt6svgwidgets6 libqt6xml6 qt6-image-formats-plugins libarchive13 \
   libtheora0 libvorbis0a python3 \
   libegl1 libfftw3-double3 libvdpau1 \
   # Additional runtime libs \

diff --git a/src/modules/qt/CMakeLists.txt b/src/modules/qt/CMakeLists.txt
@@ -68,8 +68,12 @@ function(mlt_add_qt_module ARG_TARGET)
     if(ARG_QT_VERSION EQUAL 6)
       target_link_libraries(${ARG_TARGET} PRIVATE
         Qt6::SvgWidgets
-        Qt6::Core5Compat
       )
+      if(Qt6Core5Compat_FOUND)
+        target_link_libraries(${ARG_TARGET} PRIVATE
+          Qt6::Core5Compat
+        )
+      endif()
     else()
       target_link_libraries(${ARG_TARGET} PRIVATE
         Qt${ARG_QT_VERSION}::Svg

diff --git a/src/modules/qt/filter_qtext.cpp b/src/modules/qt/filter_qtext.cpp
@@ -27,8 +27,10 @@
 #include <QTextDocument>
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
 #include <QTextCodec>
-#else
+#elif QT_VERSION < QT_VERSION_CHECK(6, 4, 0)
 #include <QtCore5Compat/QTextCodec>
+#else
+#include <QStringDecoder>
 #endif
 
 #include "typewriter.h"
@@ -394,10 +396,15 @@ static QTextDocument *get_rich_text(mlt_properties properties, double width, dou
         QFile file(resource);
         if (file.open(QFile::ReadOnly)) {
             QByteArray data = file.readAll();
-            QTextCodec *codec = QTextCodec::codecForHtml(data);
             doc = new QTextDocument;
             doc->setPageSize(QSizeF(width, height));
+#if QT_VERSION < QT_VERSION_CHECK(6, 4, 0)
+            QTextCodec *codec = QTextCodec::codecForHtml(data);
             doc->setHtml(codec->toUnicode(data));
+#else
+            QStringDecoder decoder = QStringDecoder::decoderForHtml(data);
+            doc->setHtml(decoder(data));
+#endif
             mlt_properties_set_data(properties,
                                     "QTextDocument",
                                     doc,

diff --git a/src/modules/qt/producer_qtext.cpp b/src/modules/qt/producer_qtext.cpp
@@ -32,8 +32,7 @@
 #include <QTextCodec>
 #include <QTextDecoder>
 #else
-#include <QtCore5Compat/QTextCodec>
-#include <QtCore5Compat/QTextDecoder>
+#include <QStringDecoder>
 #endif
 
 static void close_qimg(void *qimg)
@@ -161,12 +160,16 @@ static void generate_qpath(mlt_properties producer_properties)
     // Make the path empty
     *qPath = QPainterPath();
     qPath->setFillRule(Qt::WindingFill);
-
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     // Get the strings to display
     QTextCodec *codec = QTextCodec::codecForName(encoding);
     QTextDecoder *decoder = codec->makeDecoder();
     QString s = decoder->toUnicode(text);
     delete decoder;
+#else
+    auto decoder = QStringDecoder(encoding);
+    QString s = decoder(text);
+#endif
     QStringList lines = s.split("\n");
 
     // Configure the font