[Bug]: Video disappears from editor after exporting (only background remains)

[cfinnberg]

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Describe the bug

Only a reminder that this bug is still present in version 1.5.0

Original bug: siddharthvaddem#585

After exporting, I can't see the video anymore in the editor/preview, only the background.

Expected behavior

To still see the video to be able to continue to work on it

To Reproduce

1. Record a video
2. Export the video
3. Confirm video is not visible anymore

Screenshots

No response

OS

Linux

OS Version

Manjaro

Other OS

No response

Browser

None

Browser Version

No response

Other Browser

No response

Device Type

Desktop

Other Device

No response

Additional context

OpenScreen v1.5.0

[EtienneLescot]

@cfinnberg I have a manjaro distro but only in a WSL2 context.
I will install a proper Manjaro VM to reproduce this. Unless someone else is winling to take a look in the meantime.

[cfinnberg]

In the original bug report, another user commented that it also happens in CachyOS. Maybe something related to ArchLinux and/or KDE. There was also a backlink from a fork, where this comment can be found:

After export completes, the editor preview shows only the wallpaper background — source video gone, can't continue editing. Likely the exporter tears down or invalidates a decoder/object URL shared with the preview. Verify against current merged pipeline; the source-copy fast path (joaothaira@1f5afa9) may also sidestep one trigger.

Not a clue if this is any help given that it seems to be AI generated.

[EtienneLescot]

@cfinnberg I setup a VM with Manjaro. But I was not able to reproduce :-(
Do you have more details?
Recording length.
Entire screen or windows.
Hardware.
Any relevant detail.

[cfinnberg]

I have two systems, one desktop computer with Nvidia graphics and one laptop with AMD graphics. Both exhibit the same behavior, as soon as I start exporting, I see how the video disappears from the preview window, showing only the background. I tested also in a VM and it worked fine.

So I don't really know what to tell you, I don't see what's in common in these systems other than the operating system and desktop environment. On the other hand the VM has the same OS and DE, but works fine.

Can we just maintain this open? maybe others with the same problem can say something more.

I appreciate the time you have dedicated to this @EtienneLescot. Thanks.

Edit: I forgot to say that other parameters don't seem to affect to the problem:

• Recording length: checked with recordings from 5 to 30 seconds.
• Entire screen or windows: Both and different screen sizes too.
• Hardware: Nvidia graphics desktop system with two monitors and AMD graphics laptop tested. No difference. Systems have also different processors and RAM.

[EtienneLescot]

@cfinnberg I made a PR with step by step for you to generate a complete diagnostic :
#11

If you have time for that, it would help me fix the issue.

[cfinnberg]

Hi @EtienneLescot, I just tested the instructions in your PR. Interestingly there is no [VideoEditor] lines in the output, only a bunch of [OpenH264] warnings. As the output is not very long and doesn't contain personal information, I copy it here, just in case:

RECORDINGS_DIR: /home/user/.config/openscreen/recordings
User Data Path: /home/user/.config/openscreen
Global shortcut registered: CommandOrControl+Shift+O
[13500:0620/115628.463925:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_manager.cc:277] Unable to set image transfer function.
[13500:0620/115628.463940:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_manager.cc:195] Failed to populate image description for color space {primaries:BT709, transfer:SRGB, matrix:RGB, range:FULL}
[13500:0620/115629.707691:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_manager.cc:277] Unable to set image transfer function.
[13500:0620/115629.707707:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_manager.cc:195] Failed to populate image description for color space {primaries:BT709, transfer:SRGB, matrix:RGB, range:FULL}
[13500:0620/115629.707713:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_management_surface.cc:64] Failed to get image description for color space.
[13500:0620/115724.266192:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_manager.cc:277] Unable to set image transfer function.
[13500:0620/115724.266231:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_manager.cc:195] Failed to populate image description for color space {primaries:BT709, transfer:SRGB, matrix:RGB, range:FULL}
[13500:0620/115724.521856:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_manager.cc:277] Unable to set image transfer function.
[13500:0620/115724.521871:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_manager.cc:195] Failed to populate image description for color space {primaries:BT709, transfer:SRGB, matrix:RGB, range:FULL}
[13500:0620/115724.521877:ERROR:ui/ozone/platform/wayland/host/wayland_wp_color_management_surface.cc:64] Failed to get image description for color space.
[OpenH264] this = 0x0x3afc03daae20, Warning:ParamValidationExt(), eSpsPpsIdStrategy setting (2) with iUsageType (1) not supported! eSpsPpsIdStrategy adjusted to CONSTANT_ID
[OpenH264] this = 0x0x3afc03daae20, Warning:ParamValidation(), AdaptiveQuant(1) is not supported yet for screen content, auto turned off
[OpenH264] this = 0x0x3afc03daae20, Warning:ParamValidation(), BackgroundDetection(1) is not supported yet for screen content, auto turned off
[OpenH264] this = 0x0x3afc03daae20, Warning:bEnableFrameSkip = 0,bitrate can't be controlled for RC_QUALITY_MODE,RC_BITRATE_MODE and RC_TIMESTAMP_MODE without enabling skip frame.
[OpenH264] this = 0x0x3afc03daae20, Warning:CWelsH264SVCEncoder::Initialize(), reinitialize, m_bInitialFlag= 1.
[OpenH264] this = 0x0x3afc03daae20, Warning:ParamValidationExt(), eSpsPpsIdStrategy setting (2) with iUsageType (1) not supported! eSpsPpsIdStrategy adjusted to CONSTANT_ID
[OpenH264] this = 0x0x3afc03daae20, Warning:ParamValidation(), AdaptiveQuant(1) is not supported yet for screen content, auto turned off
[OpenH264] this = 0x0x3afc03daae20, Warning:ParamValidation(), BackgroundDetection(1) is not supported yet for screen content, auto turned off
[OpenH264] this = 0x0x3afc03daae20, Warning:bEnableFrameSkip = 0,bitrate can't be controlled for RC_QUALITY_MODE,RC_BITRATE_MODE and RC_TIMESTAMP_MODE without enabling skip frame.
[OpenH264] this = 0x0x3afc03daae20, Warning:Actual input fLatestFrameRate = 28.171827 is quite different from framerate in setting 60.000000, please check setting or timestamp unit (ms), cur_Ts = 5005 start_Ts = 0
[OpenH264] this = 0x0x3afc03daae20, Warning:Actual input framerate 28.171827 is different from framerate in setting 60.000000, suggest to use other rate control modes
[OpenH264] this = 0x0x3afc06a3ca80, Warning:bEnableFrameSkip = 0,bitrate can't be controlled for RC_QUALITY_MODE,RC_BITRATE_MODE and RC_TIMESTAMP_MODE without enabling skip frame.
[OpenH264] this = 0x0x3afc063f15c0, Warning:bEnableFrameSkip = 0,bitrate can't be controlled for RC_QUALITY_MODE,RC_BITRATE_MODE and RC_TIMESTAMP_MODE without enabling skip frame.
[OpenH264] this = 0x0x3afc063f15c0, Warning:CWelsH264SVCEncoder::Initialize(), reinitialize, m_bInitialFlag= 1.
[OpenH264] this = 0x0x3afc063f15c0, Warning:bEnableFrameSkip = 0,bitrate can't be controlled for RC_QUALITY_MODE,RC_BITRATE_MODE and RC_TIMESTAMP_MODE without enabling skip frame.

I have checked I am on the right branch and your diagnostics code is there.

Just to be clear about the bug, these are the steps I do to reproduce the bug:

• Open OpenScreen
• Select source. Usually I select one of my screens, but it also fails if I select a window.
• Record a few seconds video (5-30 seconds)
• In the editor I don't change anything, just press the export button.
• Export format is MP4. In all resolutions the bug is present.
• Now I noticed that GIF export works fine and video doesn't disappear.

My system is Manjaro KDE with Wayland. The recordings in ~/.config/openscreen/recordings/ are .webm files.

[EtienneLescot]

Hey @cfinnberg thanks for the log. Two things.

1. The original PR [codex] Add export preview diagnostics #11 had a bug: the diagnostic object (second arg to console.info) was collapsing to [object Object] in the forwarded line, so even when [VideoEditor] did fire you couldn't see the actual payload. I just pushed a fix that inlines the JSON into the first arg. The branch is rebased on current main.

2. Could you pull and re-test? git pull on codex/export-preview-diagnostics, then npm ci && npm run dev. Even if [VideoEditor] still doesn't appear, paste any [renderer INFO/WARNING/ERROR] lines you do see.

Also worth trying PR #19 in parallel — it adds a webglcontextlost handler on the preview canvas that rebuilds the Pixi app with a fresh context. The wallpaper survives the loss (it's a 2D canvas in frameRenderer.ts:212), so this directly fixes the "wallpaper stays, video gone" symptom. If #19 makes the bug disappear on your machine, the missing logs are almost certainly a downstream effect of the same context loss wiping the console-message subscription.