DASH Overlays: Enabling Scalable, Real-Time Video Graphics with MPEG-DASH

Qualabs contributed to the advancement of video streaming by enabling client-side DASH overlays. Traditional approaches required overlays to be burned into the video or inserted at the server level, making updates complex and limiting scalability. By leveraging MPEG-DASH's event messaging system, Qualabs sought to create a more flexible solution that allowed dynamic, real-time overlays at the client level.

Challenge

The main issue with existing overlay insertion methods was the lack of flexibility. Modifying overlays required altering video files or processing streams on the server, which increased latency and operational costs. The industry needed a way to insert overlays (such as logos, alerts, or ads) without modifying the main video stream. Ensuring synchronization, maintaining playback quality, and supporting multiple overlay types were key challenges.

Process

Alex Giladi, a Comcast Fellow and editor of MPEG-DASH, presented the evolution of ad insertion technologies and their extension to client-side overlays at Demuxed Watch the talk. Qualabs collaborated with him by supporting the development and showcasing of a real-world demo that demonstrated how DASH overlays could be implemented in practice.

This collaboration involved implementing the proposed overlay system, testing its feasibility, and ensuring seamless integration with video players. The team designed a schema for embedding overlay instructions directly within the DASH manifest (MPD), ensuring that players could fetch and display overlays at the correct times. Contributions were made to open-source players like Shaka Player and dash.js to support this new functionality. Testing was conducted with various use cases, including:


The final step was presenting the demo at Demuxed, where the collaboration between Alex Giladi and Qualabs highlighted the potential of DASH-based overlays in practical applications.

Solution

The solution enabled video players to interpret overlay events from the DASH manifest and render graphics, images, or secondary video streams in real time. This approach removed the need for pre-processing, allowing overlays to be modified on-the-fly. The implementation supported multiple overlay types, including static logos, HTML elements, and interactive components. By integrating with widely-used streaming players, the solution ensured accessibility without requiring proprietary technology.

Results

The client-side DASH overlay system significantly improved efficiency and scalability. It eliminated the need to re-encode videos for overlay changes, reducing processing time and costs. Broadcasters and content providers could now deliver personalized and region-specific overlays without modifying the source video. The ability to insert and update overlays dynamically opened new possibilities for real-time ad insertion and audience engagement. By contributing to open-source projects and collaborating with industry experts, Qualabs played a key role in expanding the adoption of this technology and demonstrating its real-world applications in video streaming.