Category:Hardware-FAQ: Difference between revisions
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= | {{Delete|reason=Page not category. Also mostly not about hardware. Include as single block in [[Devices FAQ]] if relevant}} | ||
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[[Category:Devices]] | |||
==What is the difference between Qt 4.8.x and Qt 5?== | == What is the difference between Qt 4.8.x and Qt 5? == | ||
* 4.8: QtQuick1, Javascript core, | * 4.8: QtQuick1, Javascript core, QWS (good) and QPA (not good) | ||
* 5.0: QtQuick2, v8, | * 5.0: QtQuick2, v8, QPA, no QWS, QPA only supporting OpenGL and DirectFB backends | ||
==What is the difference between | == What is the difference between QPA and QWS and when should I use which? == | ||
* In general use | * In general use QWS on 4.8 and QPA on 5.0 | ||
* Depending on the use-case | * Depending on the use-case QPA on 4.8 is a valid choice as well. Some important limitations and requirements are necessary to consider: | ||
** | ** QPA on Qt4.8 only makes sense on OpenGL Hardware! If you don't have OpenGL HW there is absolutely no point in choosing Qt4.8-QPA over Qt4.8-QWS | ||
** If you have OpenGL HW, there are two distinct use-cases to consider: | ** If you have OpenGL HW, there are two distinct use-cases to consider: | ||
*** single-process: The features and limits of | *** single-process: The features and limits of QWS and QPA are similar. QWS is older, is therefor considered more stable. Arguments for QPA could be: | ||
**** you have to work on the graphcis/platform-plugin because your OpenGL implementation need special threadment, and(!): | **** you have to work on the graphcis/platform-plugin because your OpenGL implementation need special threadment, and(!): | ||
**** | **** you're thinking about moving to Qt5 | ||
*** multi-process: There is currently no officially supported embedded(!) OpenGL-multi-process offering in Qt4.8. Implementing a platform-plugin for | *** multi-process: There is currently no officially supported embedded(!) OpenGL-multi-process offering in Qt4.8. Implementing a platform-plugin for QPA is considered to be way simpler then writing QWS-graphics-plugins. Therefor Qt 4.8 QPA is the primary choice if you start your own platform-plugin or work on an existing platform plugin (e.g. the wayland-platform-plugin) | ||
==What are the technical differences between QtQuick 1 and QtQuick 2?== | == What are the technical differences between QtQuick 1 and QtQuick 2? == | ||
* QtQuick 1 is the only choice for Qt4.7 and Qt4.8 | * QtQuick 1 is the only choice for Qt4.7 and Qt4.8 | ||
| Line 23: | Line 25: | ||
* QtQuick 2 is based on a complete new and tailor made graphics stack called scenegraph. | * QtQuick 2 is based on a complete new and tailor made graphics stack called scenegraph. | ||
** This leads to rendering performance of QtQuick2 which is a multiple of the rendering performance of QtQuick1 | ** This leads to rendering performance of QtQuick2 which is a multiple of the rendering performance of QtQuick1 | ||
* Both use the same language ( | * Both use the same language (QML) to declare a user interface | ||
* Although the language is the same, QtQuick2 comes with more and improved UI-elements (e.g. a complete new particle-engine) | * Although the language is the same, QtQuick2 comes with more and improved UI-elements (e.g. a complete new particle-engine) | ||
==When should I use OpenGL, OpenVG, DirectFB versus software rendering?== | == When should I use OpenGL, OpenVG, DirectFB versus software rendering? == | ||
* Use OpenGL and DirectFB for hardware acceleration in 4.8 or 5.0. OpenVG only works on 4.8 ( | * Use OpenGL and DirectFB for hardware acceleration in 4.8 or 5.0. OpenVG only works on 4.8 (it's a graphics system only tested on Symbian). Be aware of the hardware acceleration capabilities of your device: if you do something it can't accelerate you will end up with software rendering (not great performance). | ||
==What is the difference between Webkit 1 and Webkit 2 and how are they supported on Qt 4 and Qt 5?== | == What is the difference between Webkit 1 and Webkit 2 and how are they supported on Qt 4 and Qt 5? == | ||
* Webkit 1 runs on both 4.8 and 5.0, Webkit2 only runs on 5.0. Qt Webkit2 is staying up to date with HTML5 features in webkit.org (Qt Webkit 1 is not). | * Webkit 1 runs on both 4.8 and 5.0, Webkit2 only runs on 5.0. Qt Webkit2 is staying up to date with HTML5 features in webkit.org (Qt Webkit 1 is not). | ||
==What are the options for implementing multimedia playback in Qt 4 and Qt 5?== | == What are the options for implementing multimedia playback in Qt 4 and Qt 5? == | ||
* The options are in-process and out-of-process. Most demos are using out-of-process today but if you implement in-process you can apply QtQuick effects to your media. (more from Bhooshan). | * The options are in-process and out-of-process. Most demos are using out-of-process today but if you implement in-process you can apply QtQuick effects to your media. (more from Bhooshan). | ||
==When should I use DirectFB versus Wayland?== | == When should I use DirectFB versus Wayland? == | ||
* In general this questions | * In general this questions shouldn't be answered by "Qt" but by the silicon-vender (which should also be the one providing the BSP) | ||
* The questions is only valid if you want to use OpenGL-HW-acceleration (and you need multi-process) | * The questions is only valid if you want to use OpenGL-HW-acceleration (and you need multi-process) | ||
* Qt has wayland-platform-plugins for Qt4.8 and Qt5 | * Qt has wayland-platform-plugins for Qt4.8 and Qt5 | ||
| Line 46: | Line 48: | ||
* [for holder: please comment the directfb-opengl state in Qt4/Qt5] | * [for holder: please comment the directfb-opengl state in Qt4/Qt5] | ||
== Is OpenVG supported in Qt5? == | |||
==Is OpenVG supported in Qt5?== | |||
* No (at least not unless you contribute it). | * No (at least not unless you contribute it). | ||
Latest revision as of 14:32, 15 September 2016
| This article is nominated for deletion. Reason: Page not category. Also mostly not about hardware. Include as single block in Devices FAQ if relevant Please raise your support/opposition to this nomination in the article's discussion page. |
What is the difference between Qt 4.8.x and Qt 5?
- 4.8: QtQuick1, Javascript core, QWS (good) and QPA (not good)
- 5.0: QtQuick2, v8, QPA, no QWS, QPA only supporting OpenGL and DirectFB backends
What is the difference between QPA and QWS and when should I use which?
- In general use QWS on 4.8 and QPA on 5.0
- Depending on the use-case QPA on 4.8 is a valid choice as well. Some important limitations and requirements are necessary to consider:
- QPA on Qt4.8 only makes sense on OpenGL Hardware! If you don't have OpenGL HW there is absolutely no point in choosing Qt4.8-QPA over Qt4.8-QWS
- If you have OpenGL HW, there are two distinct use-cases to consider:
- single-process: The features and limits of QWS and QPA are similar. QWS is older, is therefor considered more stable. Arguments for QPA could be:
- you have to work on the graphcis/platform-plugin because your OpenGL implementation need special threadment, and(!):
- you're thinking about moving to Qt5
- multi-process: There is currently no officially supported embedded(!) OpenGL-multi-process offering in Qt4.8. Implementing a platform-plugin for QPA is considered to be way simpler then writing QWS-graphics-plugins. Therefor Qt 4.8 QPA is the primary choice if you start your own platform-plugin or work on an existing platform plugin (e.g. the wayland-platform-plugin)
- single-process: The features and limits of QWS and QPA are similar. QWS is older, is therefor considered more stable. Arguments for QPA could be:
What are the technical differences between QtQuick 1 and QtQuick 2?
- QtQuick 1 is the only choice for Qt4.7 and Qt4.8
- QtQuick 2 comes with and is the primary choice for Qt5.x
- QtQuick 2 is based on a complete new and tailor made graphics stack called scenegraph.
- This leads to rendering performance of QtQuick2 which is a multiple of the rendering performance of QtQuick1
- Both use the same language (QML) to declare a user interface
- Although the language is the same, QtQuick2 comes with more and improved UI-elements (e.g. a complete new particle-engine)
When should I use OpenGL, OpenVG, DirectFB versus software rendering?
- Use OpenGL and DirectFB for hardware acceleration in 4.8 or 5.0. OpenVG only works on 4.8 (it's a graphics system only tested on Symbian). Be aware of the hardware acceleration capabilities of your device: if you do something it can't accelerate you will end up with software rendering (not great performance).
What is the difference between Webkit 1 and Webkit 2 and how are they supported on Qt 4 and Qt 5?
- Webkit 1 runs on both 4.8 and 5.0, Webkit2 only runs on 5.0. Qt Webkit2 is staying up to date with HTML5 features in webkit.org (Qt Webkit 1 is not).
What are the options for implementing multimedia playback in Qt 4 and Qt 5?
- The options are in-process and out-of-process. Most demos are using out-of-process today but if you implement in-process you can apply QtQuick effects to your media. (more from Bhooshan).
When should I use DirectFB versus Wayland?
- In general this questions shouldn't be answered by "Qt" but by the silicon-vender (which should also be the one providing the BSP)
- The questions is only valid if you want to use OpenGL-HW-acceleration (and you need multi-process)
- Qt has wayland-platform-plugins for Qt4.8 and Qt5
- The Qt5-wayland-plugin get more attention (then the one for Qt4.8) and should be on a par with wayland-development
- [for holder: please comment the directfb-opengl state in Qt4/Qt5]
Is OpenVG supported in Qt5?
- No (at least not unless you contribute it).
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