[vlc-devel] Bug-Report

[Steve Lhomme]

Hello,

Can you report your issue here ? 
https://code.videolan.org/videolan/vlc/-/work_items
Reports sent it will not be handled and forgotten.

Thanks in advance.

On 19/07/2026 13:49, Winfried Wacker via vlc-devel wrote:
> Hello VLC developers,
> 
> I would like to report what appears to be a reproducible issue with AV1 
> playback.
> 
> **Environment**
> 
> * VLC version: 3.0.23 Vetinari (64-bit)
> * Operating System: Windows 11 Home
> * GPU: NVIDIA GeForce GTX 1050 Ti (Pascal, no AV1 hardware decoding)
> * Monitor: Standard SDR display
> 
> **Issue**
> When opening any AV1-encoded video, the entire video output flashes 
> black exactly three times before playback starts.
> 
> The flashing only occurs at the beginning of playback. After the third 
> flash, the video plays normally without any further issues.
> 
> **Expected behavior**
> Playback should begin immediately without any black flashes.
> 
> **Observed behavior**
> The whole video output briefly turns black three times in rapid 
> succession immediately before the first frame is displayed.
> 
> **Additional observations**
> 
> * The issue occurs with every AV1 file I have tested.
> * H.264 and H.265 videos do not show this behavior.
> * Enabling or disabling hardware-accelerated decoding makes no difference.
> * Trying different VLC video output modules also makes no difference.
> * The same AV1 files play normally in mpv on the same computer without 
> any flashing.
> 
> Because mpv does not exhibit this behavior with the same files and 
> hardware, I suspect this may be related to VLC's AV1 playback path or 
> video renderer initialization.
> 
> If required, I can provide sample files or additional debug logs.
> 
> Thank you for your work on VLC.
> 
> -- 
> Gruß Winfried
> 
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