rectalogic / webvfx

Video effects engine based on web technologies.

Overview

WebVfx is a video effects library that allows effects to be implemented using WebKit HTML or Qt QML. It is being developed for MacOS and Linux.

Prerequisites

You will need Qt installed (4.7.3 or later recommended). Qt includes QtWebKit and QML. For more interesting effects (e.g. using WebGL, CSS 3D etc.) you may want to build a more current QtWebKit. You may also want to build QtQuick3D - 3D extensions to QML. WebVfx includes support for QtQuick3D.

WebVfx includes an MLT service that exposes producers, filters and transitions implemented in WebVfx. Install MLT Framework 0.7.2 or greater to build the plugin.

Building

In the webvfx directory run qmake -r PREFIX=/usr/local and then make install. PREFIX determines where WebVfx will be installed. If MLT is installed in a non-standard location, you may need to set the PKG_CONFIG_PATH environment variable to where its pkgconfig file lives, e.g. PKG_CONFIG_PATH=/usr/local/lib/pkgconfig.

The MLT melt command will not work with WebVfx on MacOS because the Qt event loop must run on the main thread. If you set MLT_SOURCE to the root of your MLT source code directory, then a qmelt executable will be installed which behaves the same as melt but works with WebVfx on MacOS. e.g. qmake -r PREFIX=/usr/local MLT_SOURCE=~/Projects/mlt.

make doxydoc to generate the documentation using Doxygen. You can also make uninstall, make clean and make distclean.

Demos

See the documentation for examples.

License

Copyright (c) 2011 Hewlett-Packard Development Company, L.P. All rights reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

webvfx's Issues

html producer and transparency

i am using mlt for our community tv playout. i try now to use your really great plugin for dynamic real time overlays on our tv signal. the idea is to have a permanent (transparent) layer on top of the video signal and trigger showing elements using websockets.
the problem i am having now is that i find no way for the webvfx producer to give it a transparent backgrond.
css3 has support for that with background: rgba(255,255,255,0) but it seems when there is nothing to render at all webkit just returns white (which makes sense for usual browser usage)

do you think there is a way for your plugin to pass regions of frames that have nothing to show with transparency?
if this is not possible one could still set a backgound and do some keying on the output. but that has it's own drawbacks..

thanks for your answer
stefan

Qt version

Hi,

I want to check what version of QT should I use, because I get this error when running qmake:

Project ERROR: Unknown module(s) in QT: declarative webkit

this is the output of qmake -v:
QMake version 3.0
Using Qt version 5.0.2 in /usr/lib/x86_64-linux-gnu

Thanks!

compilation error: content_context.cpp:85:89: error: ‘class QString’ has no member named ‘toAscii’

pt -isystem /usr/include/qt5/QtCore -I../build/release/.moc/webvfx -I/usr/lib64/qt5/mkspecs/linux-g++ -o ../build/release/.obj/webvfx/content_context.o content_context.cpp
content_context.cpp: In member function ‘QUrl WebVfx::ContentContext::getImageUrl(const QString&)’:
content_context.cpp:85:89: error: ‘class QString’ has no member named ‘toAscii’
return QUrl::fromEncoded(QString("image://webvfx/%1/%2").arg(name).arg(renderCount).toAscii(),
^
Makefile.Release:344: recipe for target '../build/release/.obj/webvfx/content_context.o' failed
make[2]: *** [../build/release/.obj/webvfx/content_context.o] Error 1

How to start using webvfx

Good day!

I am an occasional kdenlive user. And I was always missing the ability to do some quick test animations and pseudo-3d transformations I had the experience doing in Sony Vegas before that. At the same time I do some web development stuff.

Now I've found webvfx and it kind of came together. I wish I could use it in my videos, but have no idea where and how to start. More to that, I've seen the deprecation disclaimer on the mltframework repo and that kind of bugs me.

So my question is this. Do you advise to start with webvfx now in 2021 and if so, how to do it?

Thanks in advance))

compilation error: content_context.cpp:85:89: error: ‘class QString’ has no member named ‘toAscii’

pt -isystem /usr/include/qt5/QtCore -I../build/release/.moc/webvfx -I/usr/lib64/qt5/mkspecs/linux-g++ -o ../build/release/.obj/webvfx/content_context.o content_context.cpp
content_context.cpp: In member function ‘QUrl WebVfx::ContentContext::getImageUrl(const QString&)’:
content_context.cpp:85:89: error: ‘class QString’ has no member named ‘toAscii’
return QUrl::fromEncoded(QString("image://webvfx/%1/%2").arg(name).arg(renderCount).toAscii(),
^
Makefile.Release:344: recipe for target '../build/release/.obj/webvfx/content_context.o' failed
make[2]: *** [../build/release/.obj/webvfx/content_context.o] Error 1