Improve Video Quality Transition Handling and Buffer Retention on Firefox Android
Overview
I would like Mozilla to explore browser-level improvements that could reduce playback interruptions when video quality changes occur on Firefox for Android.
One example of an effective quality-switching experience can be observed in the YouTube mobile app. When a user changes video quality, the already buffered content is often retained instead of being discarded immediately. The transition to the newly selected quality occurs later when playback naturally moves beyond the existing buffer or when the user performs a playback action such as seeking forward or backward.
I believe a similar approach, where technically possible, could improve the media playback experience in Firefox.
Example User Experience
1. Initial Playback
The user begins watching a video at a selected quality (for example, 240p).
Several seconds of video are already buffered to ensure uninterrupted playback.
2. Quality Change Selection
The user selects a different quality, either lower (240p → 144p) or higher (240p → 360p).
Instead of immediately discarding the already buffered content, playback continues using the existing buffer.
3. Continued Playback
The video keeps playing smoothly using the buffered segments from the original quality.
No unnecessary interruption or rebuffering occurs simply because the quality setting was changed.
4. Triggering the Transition
When the user performs a playback action such as:
- Seeking forward
- Seeking backward
- Skipping ahead
- Moving beyond the already buffered region
the player begins requesting segments using the newly selected quality.
5. Post-Transition
Playback continues using the newly selected quality while preserving a smooth viewing experience.
Potential Benefits
Seamless Viewing
Reduces interruptions caused by immediate buffer invalidation when changing quality settings.
Better Data Efficiency
Avoids discarding already downloaded content and reduces unnecessary rebuffering.
Improved Mobile Experience
Can be particularly beneficial on slower or unstable network connections where rebuilding the buffer may take time.
Smoother Quality Transitions
Provides a more natural transition between quality levels rather than forcing an immediate reload of media segments.
Notes
I understand that many aspects of video streaming and quality selection are controlled by individual websites and their media players.
This request is not intended to require Firefox to override website behavior. Instead, I am suggesting that Mozilla investigate whether browser-level media buffering, caching, or stream-transition handling can be optimized to support smoother quality changes where technically feasible.
The YouTube mobile app is provided only as an example of a user experience that demonstrates the concept.
