Changelog
- Dynamic load QtAVWidgets in VideoOutput.
`QtAV::Widgets::registerRenderers()` and `QT  = avwidgets` is not
requred now.
- D3D11 decoder support. Not stable on Windows phone.
- DXVA refactor and bug fix.
- VA-API: fix memory leak when seeking
- OpenGL:
 * Fix PBO binding
 * Custom shader support (WIP)
 * Edit and apply custom shader when playing. Based on Qt property
system.
 * Optimize uniform update
 * GLSL filter support
 * Add `OpenGLVideo.beforeRendering/afterRendering`
- CUDA:
 * Direct copy is default for windows. Now Rendering CUDA decoded frames
is faster than any other players
 * 0-copy is default for linux.
 * Use new API (4.0)
- AVPlayer:
 * Add `AVPlayer.stoppedAt` signal
 * add `setTimeRange()`
 * setStart/StopPosition can be called at any time with any value
 * Ensure all threads are running when `started` is emitted
 * Support preload using `load()`. Now no reload in `play()`
- Fix build with QT_NAMESPACE
- Fix swscale color range
- Fix linux install destinations
- Add AVTranscoder.async, encoders are in individual threads
- Add FrameReader class
- Use FFmpeg 3.0 API
- QML:
 * Support filters, including sw filters from libavfilter, and GLSL
filter
 * Add `MediaPlayer/Video.audioBackends` property
 * Support autoLoad
 * Add `VideoOutput.mapTo/FromXXX` between source frame and item
 * Video EQ in VideoOutput/Video
 * Add `MediaPlayer.startPosition/stopPotion`
- QMLPlayer: Open video and subtitle at the same time. History view.
Zoom. Video EQ