Transparency video stream bug with 5+ active streams

Bug
1

  • What is your operating system?

Windows 10 22H2 (same result with Ubuntu 24.04 LTS and the Appimage)

  • What is your Shotcut version (see Help > About Shotcut)?

25.08.16

  • Can you repeat the problem? If so, what are the steps?

100% Repeatable

As described in Transparency flicker with 5+ visible video tracks
once a fifth or sixth video stream is active on screen, ALL of them are no longer displayed properly in an exported video. At the time posting the question (see videos linked there), the video would start flickering, like one out of every four frames would show the transparency checkerboard pattern. In 25.08.16 and 25.07.26, this is no longer the case, instead the transparency pattern is shown for every frame until one of the streams is removed. Then all remaining streams are fully working again.

Current video output with 25.08.16 is like this: https://www.youtube.com/watch?v=lKCoofe_P6Q

vlcsnap-2025-05-27-22h52m19s075
vlcsnap-2025-05-27-22h52m19s0751920Ă—823 108 KB

vlcsnap-2025-05-27-22h51m03s899
vlcsnap-2025-05-27-22h51m03s8991920Ă—823 98 KB

log file

[Info ] Starting Shotcut version 25.08.16
[Info ] Windows version “10”
[Info ] number of logical cores = 32
[Info ] locale = QLocale::system()/* German, Latin, Germany */
[Info ] install dir = “C:/Program Files/Shotcut”
[Info ] ShotcutSettings::log language “en_GB”
[Info ] ShotcutSettings::log deinterlacer “onefield”
[Info ] ShotcutSettings::log external monitor “”
[Info ] ShotcutSettings::log GPU processing false
[Info ] ShotcutSettings::log interpolation “nearest”
[Info ] ShotcutSettings::log video mode “C:/Users/mb/AppData/Local/Meltytech/Shotcut/profiles/model s”
[Info ] ShotcutSettings::log realtime true
[Info ] ShotcutSettings::log audio channels 2
[Info ] ShotcutSettings::log audio driver “winmm”
[Debug ] MainWindow::changeTheme begin
[Debug ] MainWindow::changeTheme Available styles: QList(“windows11”, “windowsvista”, “Windows”, “Fusion”)
[Debug ] MainWindow::changeTheme end
[Debug ] MainWindow::MainWindow begin
[Info ] MainWindow::MainWindow device pixel ratio = 1
[Debug ] Mlt::Controller::Controller begin
[Info ] Mlt::Controller::resetLocale decimal point .
[Debug ] Mlt::Controller::Controller end
[Debug ] Mlt::VideoWidget::VideoWidget begin
[Debug ] Mlt::VideoWidget::VideoWidget end
[Debug ] MainWindow::setupSettingsMenu begin
[Warning] [consumer 0x17ade878950] The DeckLink drivers not installed.
[Debug ] MainWindow::setupSettingsMenu end
[Debug ] MainWindow::readPlayerSettings begin
[Debug ] MainWindow::setAudioChannels 2
[Debug ] Mlt::Controller::setAudioChannels 2
[Debug ] MainWindow::setPreviewScale 540
[Debug ] Mlt::Controller::setPreviewScale 676 x 540
[Debug ] MainWindow::readPlayerSettings end
[Debug ] MainWindow::configureVideoWidget begin
[Debug ] MainWindow::setProfile “C:/Users/mb/AppData/Local/Meltytech/Shotcut/profiles/model s”
[Debug ] Mlt::Controller::setProfile setting to profile “C:/Users/mb/AppData/Local/Meltytech/Shotcut/profiles/model s”
[Debug ] MainWindow::setAudioChannels 2
[Debug ] Mlt::Controller::setAudioChannels 2
[Debug ] MainWindow::configureVideoWidget end
[Debug ] ScopeController::ScopeController begin
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] AudioLoudnessScopeWidget::AudioLoudnessScopeWidget begin
[Debug ] AudioLoudnessScopeWidget::AudioLoudnessScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] AudioLoudnessScopeWidget::resetQview begin isSceneGraphInitialized false
[Debug ] AudioLoudnessScopeWidget::resetQview begin isSceneGraphInitialized false
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] AudioPeakMeterScopeWidget::AudioPeakMeterScopeWidget begin
[Debug ] AudioPeakMeterScopeWidget::AudioPeakMeterScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] AudioSpectrumScopeWidget::AudioSpectrumScopeWidget begin
[Debug ] AudioSpectrumScopeWidget::AudioSpectrumScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] AudioSurroundScopeWidget::AudioSurroundScopeWidget begin
[Debug ] AudioSurroundScopeWidget::AudioSurroundScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] AudioVectorScopeWidget::AudioVectorScopeWidget begin
[Debug ] AudioVectorScopeWidget::AudioVectorScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] AudioWaveformScopeWidget::AudioWaveformScopeWidget begin
[Debug ] AudioWaveformScopeWidget::AudioWaveformScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] VideoHistogramScopeWidget::VideoHistogramScopeWidget begin
[Debug ] VideoHistogramScopeWidget::VideoHistogramScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] VideoRgbParadeScopeWidget::VideoRgbParadeScopeWidget begin
[Debug ] VideoRgbParadeScopeWidget::VideoRgbParadeScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] VideoRgbWaveformScopeWidget::VideoRgbWaveformScopeWidget begin
[Debug ] VideoRgbWaveformScopeWidget::VideoRgbWaveformScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] VideoVectorScopeWidget::VideoVectorScopeWidget begin
[Debug ] VideoVectorScopeWidget::profileChanged 709
[Debug ] VideoVectorScopeWidget::VideoVectorScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] VideoWaveformScopeWidget::VideoWaveformScopeWidget begin
[Debug ] VideoWaveformScopeWidget::VideoWaveformScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeWidget::ScopeWidget begin true
[Debug ] ScopeWidget::ScopeWidget end
[Debug ] VideoZoomWidget::VideoZoomWidget begin
[Debug ] VideoZoomWidget::VideoZoomWidget end
[Debug ] VideoZoomScopeWidget::VideoZoomScopeWidget begin
[Debug ] VideoZoomScopeWidget::VideoZoomScopeWidget end
[Debug ] ScopeDock::ScopeDock begin
[Debug ] ScopeDock::ScopeDock end
[Debug ] ScopeController::ScopeController end
[Debug ] RecentDock::RecentDock begin
[Debug ] RecentDock::RecentDock end
[Debug ] PlaylistDock::PlaylistDock begin
[Debug ] PlaylistProxyModel::setSmartBin 0
[Debug ] PlaylistDock::PlaylistDock end
[Debug ] FilesDock::FilesDock begin
[Debug ] FilesDock::FilesDock end
[Debug ] TimelineDock::TimelineDock begin
[Debug ] TimelineDock::TimelineDock end
[Debug ] FiltersDock::FiltersDock begin
[Debug ] FiltersDock::FiltersDock end
[Debug ] MarkersDock::MarkersDock begin
[Debug ] MarkersDock::MarkersDock end
[Debug ] KeyframesDock::KeyframesDock begin
[Debug ] KeyframesDock::KeyframesDock end
[Debug ] KeyframesDock::load begin true false
[Debug ] EncodeDock::EncodeDock begin
[Debug ] EncodeDock::EncodeDock end
[Debug ] JobsDock::JobsDock begin
[Debug ] JobsDock::JobsDock end
[Debug ] NotesDock::NotesDock begin
[Debug ] NotesDock::NotesDock end
[Debug ] SubtitlesDock::SubtitlesDock begin
[Debug ] SubtitlesDock::SubtitlesDock end
[Debug ] MainWindow::readWindowSettings begin
[Debug ] AudioLoudnessScopeWidget::resetQview begin isSceneGraphInitialized false
[Debug ] MainWindow::readWindowSettings end
[Debug ] MainWindow::MainWindow end
[Debug ] FiltersDock::load begin isVisible true qview.status QQuickWidget::Null
[Debug ] KeyframesDock::load begin false false
[Debug ] Mlt::VideoWidget::initialize begin
[Debug ] Mlt::VideoWidget::initialize end
[Debug ] NewProjectFolder::showEvent m_profile “C:/Users/mb/AppData/Local/Meltytech/Shotcut/profiles/model s” action.data “C:/Users/mb/AppData/Local/Meltytech/Shotcut/profiles/model s”
[Info ] Util::isMemoryLow available RAM = 60358272 KB
[Debug ] FilterController::loadFilterMetadata reading filter metadata “alpha_adjust” “meta.qml”
[Debug ] FilterController::loadFilterMetadata added filter “Alpha Channel: Adjust”

<snip for 32000 characters posting limit reasons>

[Debug ] FilterController::loadFilterMetadata reading filter metadata “vertigo” “meta.qml”
[Debug ] FilterController::loadFilterMetadata added filter “Vertigo”
[Debug ] FilterController::loadFilterMetadata reading filter metadata “vibrance” “meta.qml”
[Debug ] FilterController::loadFilterMetadata added filter “Vibrance”
[Debug ] FilterController::loadFilterMetadata reading filter metadata “video_autofade” “meta.qml”
[Debug ] QmlMetadata::isMltVersion MLT version: “2” Shotcut minimumVersion: “2”
[Debug ] FilterController::loadFilterMetadata added filter “Track Auto Fade Video”
[Debug ] FilterController::loadFilterMetadata reading filter metadata “vignette” “meta_movit.qml”
[Debug ] FilterController::loadFilterMetadata added filter “Vignette”
[Debug ] FilterController::loadFilterMetadata reading filter metadata “vignette” “meta_oldfilm.qml”
[Debug ] FilterController::loadFilterMetadata added filter “Vignette”
[Debug ] FilterController::loadFilterMetadata reading filter metadata “wave” “meta.qml”
[Debug ] FilterController::loadFilterMetadata added filter “Wave”
[Debug ] FilterController::loadFilterMetadata reading filter metadata “waveform” “meta.qml”
[Debug ] FilterController::loadFilterMetadata added filter “Audio Waveform Visualisation”
[Debug ] FilterController::loadFilterMetadata reading filter metadata “white” “meta_frei0r.qml”
[Debug ] FilterController::loadFilterMetadata added filter “White Balance”
[Debug ] FilterController::loadFilterMetadata reading filter metadata “white” “meta_movit.qml”
[Debug ] FilterController::loadFilterMetadata added filter “White Balance”
[Debug ] AudioLoudnessScopeWidget::resetQview begin isSceneGraphInitialized false
[Debug ] FiltersDock::load begin isVisible true qview.status QQuickWidget::Ready
[Info ] MainWindow::showStatusMessage “Checking for upgrade…”
[Debug ] MainWindow::open “C:/Users/mb/AppData/Local/Meltytech/Shotcut/untitled.mlt”
[Debug ] MltXmlChecker::check begin
[Debug ] MltXmlChecker::check “”
[Debug ] MltXmlChecker::check end “”
[Debug ] MainWindow::onUpgradeCheckFinished response: "{\n "version_number": 250816,\n "version_string": "25.08.16",\n "url": "https://shotcut.org/blog/new-release-250816/\“\n}\n”
[Info ] MainWindow::showStatusMessage “You are running the latest version of Shotcut.”
[Debug ] MainWindow::openVideo QFlagsQFileDialog::Option()
[Debug ] MainWindow::open “Y:/bug 6x/runde3.mlt”
[Info ] MainWindow::showStatusMessage “Opening Y:/bug 6x/runde3.mlt”
[Debug ] MltXmlChecker::check begin
[Info ] Mlt::Controller::resetLocale decimal point .
[Debug ] MltXmlChecker::check QList(“Shotcut”, “version”, “25.05.11”)
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/Red Planet 1-37-293 _ 0-54-2R _ 0-43-1 20250511203210 Gramschatzer Wald - Converted1.mkv”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/Red Planet 1-33-325 _ 0-49-8R _ 0-43-5 20250511203908 Gramschatzer Wald - Converted1.mkv”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/Red Planet 1-32-375 _ 0-47-4B _ 0-45-0 20250511205236 Gramschatzer Wald - Converted1.mkv”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/Red Planet 1-31-775 _ 0-48-2B _ 0-43-6 20250511211442 Gramschatzer Wald - Converted1.mkv”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/Red Planet 1-29-258 _ 0-45-1B _ 0-44-2 20250511212504 Gramschatzer Wald - Converted.mkv”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/Red Planet 1-29-258 _ 0-45-1B _ 0-44-2 20250511212504 Gramschatzer Wald - Converted1.mkv”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/Red Planet 1-33-754 _ 0-49-3S _ 0-44-5 00098 Hockenheim - Converted1.mkv”
[Debug ] MltXmlChecker::check “Y:/bug 6x/shotcut-zJSedu.mlt”
[Debug ] MltXmlChecker::check end “”
[Debug ] MainWindow::openVideo QFlagsQFileDialog::Option()
[Debug ] MainWindow::open “Y:/bug 6x/test ultrawide 2nd round 2025-05-24T17-34-19.mlt”
[Info ] MainWindow::showStatusMessage “Opening Y:/bug 6x/test ultrawide 2nd round 2025-05-24T17-34-19.mlt”
[Debug ] MltXmlChecker::check begin
[Info ] Mlt::Controller::resetLocale decimal point .
[Debug ] MltXmlChecker::check QList(“Shotcut”, “version”, “25.05.11”)
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/bug 6x/kopien weghauen/Red Planet 1-32-375 _ 0-47-4B _ 0-45-0 20250511205236 Gramschatzer Wald.MTS”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/bug 6x/kopien weghauen/Red Planet 1-29-258 _ 0-45-1B _ 0-44-2 20250511212504 Gramschatzer Wald.MTS”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/bug 6x/kopien weghauen/Red Planet 1-37-293 _ 0-54-2R _ 0-43-1 20250511203210 Gramschatzer Wald.MTS”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/bug 6x/kopien weghauen/Red Planet 1-33-754 _ 0-49-3S _ 0-44-5 00098 Hockenheim.MTS”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/bug 6x/kopien weghauen/Red Planet 1-33-325 _ 0-49-8R _ 0-43-5 20250511203908 Gramschatzer Wald.MTS”
[Error ] MltXmlChecker::checkUnlinkedFile file not found: “Y:/bug 6x/kopien weghauen/Red Planet 1-31-775 _ 0-48-2B _ 0-43-6 20250511211442 Gramschatzer Wald.MTS”
[Debug ] MltXmlChecker::check “Y:/bug 6x/shotcut-EDJvjV.mlt”
[Debug ] MltXmlChecker::check end “”
[Info ] Util::isMemoryLow available RAM = 60385992 KB
[Debug ] UnlinkedFilesDialog::lookInDir “Y:/bug 6x”
[Debug ] MltXmlChecker::check begin
[Info ] Mlt::Controller::resetLocale decimal point .
[Debug ] MltXmlChecker::check QList(“Shotcut”, “version”, “25.05.11”)
[Debug ] MltXmlChecker::check “Y:/bug 6x/shotcut-zUfeQB.mlt”
[Debug ] MltXmlChecker::check end “”
[Info ] MainWindow::saveRepairedXmlFile repaired MLT XML file name “Y:/bug 6x/test ultrawide 09-2025.mlt”
[Debug ] Mlt::Controller::setPreviewScale 1290 x 540
[Debug ] MainWindow::setAudioChannels 2
[Debug ] Mlt::Controller::setAudioChannels 2
[Debug ] Mlt::Controller::setProjectFolder project folder “Y:/bug 6x”
[Debug ] PlaylistModel::refreshThumbnails true
[Debug ] Player::setIn in -1 out -1
[Debug ] Player::setOut in -1 out -1
[Debug ] TimelineDock::setSelection Changing selection to QList() trackIndex -1 isMultitrack true
[Debug ] TimelineDock::setSelection Changing selection to QList() trackIndex -1 isMultitrack false
[Debug ] VideoVectorScopeWidget::profileChanged 709
[Info ] MainWindow::open “Y:/bug 6x/test ultrawide 09-2025.mlt”
[Info ] MainWindow::showStatusMessage “Click in rectangle + hold Shift to drag”
[Info ] [consumer sdl2_audio] Audio Opened: driver=winmm channels=2 frequency=48000
[Debug ] MltXmlChecker::check begin
[Info ] Mlt::Controller::resetLocale decimal point .
[Debug ] MltXmlChecker::check QList(“Shotcut”, “version”, “25.08.16”)
[Debug ] MltXmlChecker::check “Y:/bug 6x/shotcut-QydNiW.mlt”
[Debug ] MltXmlChecker::check end “”
[Debug ] EncodeDock::convertReframe Found Reframe 3440 x 1440 “C:/Users/mb/AppData/Local/Temp/Shotcut.yjdhtw”
[Debug ] EncodeDock::convertReframe reframe profile 3440 x 1440
[Debug ] MeltJob::start “C:/Program Files/Shotcut/melt -verbose -progress2 -abort xml:C%3A%2FUsers%2Fmb%2FAppData%2FLocal%2FTemp%2Fshotcut-XibYTC.mlt”
[Info ] MainWindow::showStatusMessage “Checking for upgrade…”
[Debug ] MainWindow::onUpgradeCheckFinished response: "{\n "version_number": 250816,\n "version_string": "25.08.16",\n "url": "https://shotcut.org/blog/new-release-250816/\“\n}\n”
[Info ] MainWindow::showStatusMessage “You are running the latest version of Shotcut.”
[Info ] Util::isMemoryLow available RAM = 59991016 KB
[Info ] Util::isMemoryLow available RAM = 52215520 KB
[Info ] Util::isMemoryLow available RAM = 51797524 KB
[Info ] Util::isMemoryLow available RAM = 51417232 KB
[Info ] Util::isMemoryLow available RAM = 51405708 KB
[Info ] Util::isMemoryLow available RAM = 51406624 KB
[Info ] Util::isMemoryLow available RAM = 51409652 KB
[Info ] Util::isMemoryLow available RAM = 51402724 KB
[Info ] Util::isMemoryLow available RAM = 51555564 KB
[Info ] Util::isMemoryLow available RAM = 51481488 KB
[Info ] Util::isMemoryLow available RAM = 51464924 KB
[Info ] Util::isMemoryLow available RAM = 51475740 KB
[Info ] Util::isMemoryLow available RAM = 51450624 KB
[Info ] Util::isMemoryLow available RAM = 50268660 KB
[Info ] Util::isMemoryLow available RAM = 50247852 KB
[Info ] Util::isMemoryLow available RAM = 50265460 KB
[Info ] Util::isMemoryLow available RAM = 50254020 KB
[Info ] Util::isMemoryLow available RAM = 49873716 KB
[Info ] Util::isMemoryLow available RAM = 49763280 KB
[Info ] Util::isMemoryLow available RAM = 48529788 KB
[Info ] AbstractJob::onFinished job succeeeded
[Info ] Util::isMemoryLow available RAM = 59736208 KB
[Info ] Util::isMemoryLow available RAM = 59740812 KB
[Info ] Util::isMemoryLow available RAM = 59745948 KB
[Info ] Util::isMemoryLow available RAM = 59748760 KB
[Info ] Util::isMemoryLow available RAM = 59748484 KB
[Info ] Util::isMemoryLow available RAM = 59752640 KB
[Info ] Util::isMemoryLow available RAM = 59753732 KB
[Info ] Util::isMemoryLow available RAM = 59600228 KB

2

This looks like a hint. Maybe your project did not repair correctly?

Also, in the other thread Dan speculated that maybe your files are not seekable. .MTS files are transport stream files and are not edit friendly at all. You might have better luck if you convert them to an edit friendly format. I would suggest trying Convert to Edit-friendly Dialog on a couple of clips as a test. If that reduces the problem, then that might be a solution.

2 Likes
3

No, I just moved the files around a bunch over the last months - once I pointed to the correct directory for one, they all lit up in green. Besides, this bug project only exists because it never worked for a real project that had its files moved into directly and was never repaired. It also does not matter if the files exist locally (Linux) or on a remote SMB share (Windows). All projects with 4 or less streams visible at any time render perfectly fine. Once number 5 comes in, all transparency hell breaks loose.

As per the suggestion, I also converted these and the results were the same. They’re now just 10x bigger than before and it takes extra time to make them in the first place.