[vlc-commits] [Git][videolan/vlc][master] 2 commits: qml: implement six pass blurring in `DualKawaseBlur`
Steve Lhomme (@robUx4)
gitlab at videolan.org
Tue Jun 23 19:59:03 UTC 2026
Steve Lhomme pushed to branch master at VideoLAN / VLC
Commits:
33260dbb by Fatih Uzunoglu at 2026-06-23T19:09:25+00:00
qml: implement six pass blurring in `DualKawaseBlur`
Six pass dual kawase blur produces better visual
quality than four pass, at the expense of using
more video memory. For that reason, it is advised
to use this mode only with static sources, when
`live` can be unset where in that case higher
passes become virtually free (the initialization
will take more time, but that can be considered
negligible).
Using six pass also makes blockiness less likely,
which is especially noticable with source image
that has sharp edges (like text).
- - - - -
f1c72b79 by Fatih Uzunoglu at 2026-06-23T19:09:25+00:00
qml: use six pass blur mode in `Player`
- - - - -
2 changed files:
- modules/gui/qt/player/qml/Player.qml
- modules/gui/qt/widgets/qml/DualKawaseBlur.qml
Changes:
=====================================
modules/gui/qt/player/qml/Player.qml
=====================================
@@ -309,7 +309,10 @@ FocusScope {
Widgets.DualKawaseBlur {
id: blurredBackground
- radius: 3
+ // Six pass is free here since we release the intermediate layers
+ // through unsetting `live` (see `liveTimer`):
+ mode: Widgets.DualKawaseBlur.Mode.SixPass
+ radius: 2
live: false
=====================================
modules/gui/qt/widgets/qml/DualKawaseBlur.qml
=====================================
@@ -41,7 +41,12 @@ Item {
enum Mode {
FourPass, // 2 downsample + 2 upsamples (3 layers/buffers)
- TwoPass // 1 downsample + 1 upsample (1 layer/buffer)
+ TwoPass, // 1 downsample + 1 upsample (1 layer/buffer)
+ // NOTE: Due to high count of layers, it is recommended to use six pass only with
+ // static sources with `live: false` to prevent consuming high video memory.
+ // Note that in such a case, using six (or higher) passes will consume no
+ // additional memory, which means it is effectively free:
+ SixPass // 3 downsample + 3 upsamples (5 layers/buffers)
}
property int mode: DualKawaseBlur.Mode.FourPass
@@ -213,6 +218,8 @@ Item {
if (live) {
ds1layer.parent = root
ds2layer.inhibitParent = false
+ ds3layer.inhibitParent = false
+ us0layer.inhibitParent = false
if (root._queuedScheduledUpdate) {
console.debug(root, "scheduleUpdate(): `live` is turned on, canceling the scheduled update.")
@@ -326,7 +333,7 @@ Item {
if (root._window) {
// In four pass mode, we can release the two intermediate layers:
- if (root.mode === DualKawaseBlur.Mode.FourPass) {
+ if (root.mode !== DualKawaseBlur.Mode.TwoPass) {
// Scheduling update must be done sequentially for each layer in
// a chain. It seems that each layer needs one frame for it to be
// used as a source in another layer, so we can not schedule
@@ -347,7 +354,7 @@ Item {
height: ds1.height / 2
Binding on tpObserver.notifyAllChanges {
- when: (root.mode !== DualKawaseBlur.Mode.FourPass)
+ when: (root.mode === DualKawaseBlur.Mode.TwoPass)
value: false
}
@@ -362,7 +369,7 @@ Item {
// This is mainly relevant for switching the mode case, as initially if this was
// never visible and was never used as texture provider, it should have never allocated
// resources to begin with.
- sourceItem: (root.mode === DualKawaseBlur.Mode.FourPass) ? ds2 : null
+ sourceItem: (root.mode !== DualKawaseBlur.Mode.TwoPass) ? ds2 : null
parent: (!inhibitParent && sourceItem) ? root : null // necessary to release resources even if `sourceItem` becomes null (non-live case)
property bool inhibitParent: false
@@ -388,6 +395,118 @@ Item {
ds2layer.inhibitParent = false
ds2layer.scheduleUpdate()
+ if (root._window) {
+ if (root.mode === DualKawaseBlur.Mode.FourPass)
+ root._window.afterAnimating.connect(us1layer, us1layer.scheduleChainedUpdate)
+ else if (root.mode === DualKawaseBlur.Mode.SixPass)
+ root._window.afterAnimating.connect(ds3layer, ds3layer.scheduleChainedUpdate)
+ }
+ }
+ }
+
+ DownsamplerShaderEffect {
+ id: ds3
+
+ // When downsampled, we can decrease the size here so that the layer occupies less VRAM:
+ width: ds2.width / 2
+ height: ds2.height / 2
+
+ Binding on tpObserver.notifyAllChanges {
+ when: (root.mode !== DualKawaseBlur.Mode.SixPass)
+ value: false
+ }
+
+ // Qt uses reference counting, otherwise ds2layer may not be released, even if it has no parent (see `QQuickItemPrivate::derefWindow()`):
+ source: ((root.mode !== DualKawaseBlur.Mode.SixPass) || !ds2layer.parent) ? null : ds2layer
+ }
+
+ DefaultShaderEffectSource {
+ id: ds3layer
+
+ // So that if the mode is two pass (this is not used), the buffer is released:
+ // This is mainly relevant for switching the mode case, as initially if this was
+ // never visible and was never used as texture provider, it should have never allocated
+ // resources to begin with.
+ sourceItem: (root.mode === DualKawaseBlur.Mode.SixPass) ? ds3 : null
+ parent: (!inhibitParent && sourceItem) ? root : null // necessary to release resources even if `sourceItem` becomes null (non-live case)
+
+ property bool inhibitParent: false
+
+ function scheduleChainedUpdate() {
+ if (!ds3layer) // context is lost, Qt bug (reproduced with 6.2)
+ return
+
+ if (root._window) {
+ root._window.afterAnimating.disconnect(ds3layer, ds3layer.scheduleChainedUpdate)
+ }
+
+ // If `live` is turned on during a chained update, we do not need to continue:
+ if (root.live) {
+ root._window = null
+ return
+ }
+
+ ds3.sourceTextureSize = ds3.tpObserver.nativeTextureSize
+ if (ds3.ensurePolished)
+ ds3.ensurePolished()
+
+ ds3layer.inhibitParent = false
+ ds3layer.scheduleUpdate()
+
+ if (root._window) {
+ root._window.afterAnimating.connect(us0layer, us0layer.scheduleChainedUpdate)
+ }
+ }
+ }
+
+ UpsamplerShaderEffect {
+ id: us0
+
+ width: ds3.width * 2
+ height: ds3.height * 2
+
+ Binding on tpObserver.notifyAllChanges {
+ when: (root.mode !== DualKawaseBlur.Mode.SixPass)
+ value: false
+ }
+
+ // Qt uses reference counting, otherwise ds3layer may not be released, even if it has no parent (see `QQuickItemPrivate::derefWindow()`):
+ source: ((root.mode !== DualKawaseBlur.Mode.SixPass) || !ds3layer.parent) ? null : ds3layer
+ }
+
+ DefaultShaderEffectSource {
+ id: us0layer
+
+ // So that if the mode is two pass (this is not used), the buffer is released:
+ // This is mainly relevant for switching the mode case, as initially if this was
+ // never visible and was never used as texture provider, it should have never allocated
+ // resources to begin with.
+ sourceItem: (root.mode === DualKawaseBlur.Mode.SixPass) ? us0 : null
+ parent: (!inhibitParent && sourceItem) ? root : null // necessary to release resources even if `sourceItem` becomes null (non-live case)
+
+ property bool inhibitParent: false
+
+ function scheduleChainedUpdate() {
+ if (!us0layer) // context is lost, Qt bug (reproduced with 6.2)
+ return
+
+ if (root._window) {
+ root._window.afterAnimating.disconnect(us0layer, us0layer.scheduleChainedUpdate)
+ }
+
+ // If `live` is turned on during a chained update, we do not need to continue:
+ if (root.live) {
+ root._window = null
+ return
+ }
+
+ us0.sourceTextureSize = us0.tpObserver.nativeTextureSize
+ if (us0.ensurePolished)
+ us0.ensurePolished()
+
+ us0layer.inhibitParent = false
+ us0layer.scheduleUpdate()
+
if (root._window) {
root._window.afterAnimating.connect(us1layer, us1layer.scheduleChainedUpdate)
}
@@ -397,16 +516,44 @@ Item {
UpsamplerShaderEffect {
id: us1
- width: ds2.width * 2
- height: ds2.height * 2
+ width: ((sourceShaderEffect?.width ?? 0.0) * 2)
+ height: ((sourceShaderEffect?.height ?? 0.0) * 2)
+
+ readonly property ShaderEffect sourceShaderEffect: {
+ switch (root.mode) {
+ case DualKawaseBlur.Mode.FourPass:
+ return ds2
+ case DualKawaseBlur.Mode.SixPass:
+ return us0
+ case DualKawaseBlur.Mode.TwoPass:
+ default:
+ return null
+ }
+ }
Binding on tpObserver.notifyAllChanges {
- when: (root.mode !== DualKawaseBlur.Mode.FourPass)
+ when: (root.mode === DualKawaseBlur.Mode.TwoPass)
value: false
}
// Qt uses reference counting, otherwise ds2layer may not be released, even if it has no parent (see `QQuickItemPrivate::derefWindow()`):
- source: ((root.mode === DualKawaseBlur.Mode.TwoPass) || !ds2layer.parent) ? null : ds2layer
+ source: {
+ switch (root.mode) {
+ case DualKawaseBlur.Mode.FourPass:
+ if (ds2layer.parent)
+ return ds2layer
+ else
+ return null
+ case DualKawaseBlur.Mode.SixPass:
+ if (us0layer.parent)
+ return us0layer
+ else
+ return null
+ case DualKawaseBlur.Mode.TwoPass:
+ default:
+ return null
+ }
+ }
}
DefaultShaderEffectSource {
@@ -416,13 +563,13 @@ Item {
// This is mainly relevant for switching the mode case, as initially if this was
// never visible and was never used as texture provider, it should have never allocated
// resources to begin with.
- sourceItem: (root.mode === DualKawaseBlur.Mode.FourPass) ? us1 : null
+ sourceItem: (root.mode !== DualKawaseBlur.Mode.TwoPass) ? us1 : null
// Last layer for four pass mode, so use the viewport rect:
// No need to check for the mode because this layer is not used in two pass mode anyway.
sourceRect: root._localViewportRect
- wrapMode: (root.mode === DualKawaseBlur.Mode.FourPass) ? root.visualWrapMode : ShaderEffectSource.ClampToEdge
+ wrapMode: (root.mode !== DualKawaseBlur.Mode.TwoPass) ? root.visualWrapMode : ShaderEffectSource.ClampToEdge
function scheduleChainedUpdate() {
if (!us1layer) // context is lost, Qt bug (reproduced with 6.2)
@@ -474,6 +621,8 @@ Item {
// https://doc.qt.io/qt-6/qquickitem.html#graphics-resource-handling
ds1layer.parent = null
ds2layer.inhibitParent = true
+ ds3layer.inhibitParent = true
+ us0layer.inhibitParent = true
if (root._queuedScheduledUpdate) {
// Tried calling `scheduleUpdate()` before the ongoing chained updates completed.
View it on GitLab: https://code.videolan.org/videolan/vlc/-/compare/6f3408b87f612e4ebca2d88e2324d7e075b80023...f1c72b79f2e89b58e4a8ba70ed8915340cf67596
--
View it on GitLab: https://code.videolan.org/videolan/vlc/-/compare/6f3408b87f612e4ebca2d88e2324d7e075b80023...f1c72b79f2e89b58e4a8ba70ed8915340cf67596
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