Hello Mozilla Support,
I have an issue with video playback in Firefox on YouTube.
When I play HDR test videos such as “OLED / Black Level Test - Demo | HDR | 4K”, the dark transitions between black and gray appear blurry, blocky, and heavily pixelated. The gradients are not smooth.
However, when I play the exact same video in Google Chrome, the image quality is correct and the dark gradients look smooth without artifacts.
This makes me think the issue may be related to Firefox video decoding, HDR handling, color processing, or hardware acceleration.
My system configuration:
- GPU: NVIDIA GeForce RTX 5090
- Monitor: 27" Dell Alienware AW2725DF
- Connection: DisplayPort (DP)
- Resolution: QHD
- Refresh rate: 240 Hz
- Color depth: 8-bit
- Operating system: Windows 11
- Browser: Firefox
Issue details:
- Video source: YouTube HDR videos
- Problem: black and dark gray gradients are blocky/pixelated only in Firefox
- Google Chrome displays the same video correctly on the same system and settings
Could you please help me identify what may be causing this issue and whether there is a known fix or setting adjustment?
Thank you.
