Roku has released an update to its operating system, Roku OS 15.1, introducing several improvements for developers of streaming applications. The update focuses on enhancing app performance, video playback precision, and development efficiency.
Enhanced Video Playback
One significant improvement relates to video seeking, which allows users to jump to specific points in a stream. For HLS video content, Roku OS 15.1 incorporates a new manifest mode for seeking.
This mode utilizes information from the HLS manifest, specifically the EXT-X-START tag, to determine the intended starting offset time.
When enabled, the video player automatically navigates to this exact position, aiming to provide precise video starting points and enhance the viewing experience by reducing delays or awkward starts.
Performance Tracing with Perfetto
Another addition is support for Perfetto, a tracing tool designed for Roku applications. Perfetto records detailed app activity, visualizing resource usage such as memory and processing demands on a timeline.
This feature allows developers to identify performance bottlenecks, such as slow loading or choppy playback, and optimize their applications.
Developers can use Perfetto by connecting to their Roku device via the External Control Protocol and a WebSocket client. The workflow involves launching an app, recording a trace, saving the data, and then loading it into Perfetto for interactive graphical analysis. The tool supports zooming, panning, and detailed event examination, including database-style queries.
Deprecated Functionality
Roku has marked the roString.AppendString function as deprecated. This function previously allowed developers to add text to a string with a specified length.
Developers are now advised to use the SetString function for string operations to ensure future compatibility.
These updates are intended to support Roku's developer community by offering advanced playback controls, performance diagnostics, and current best practices. The goal is to facilitate the creation of fast, responsive, and user-friendly streaming applications on Roku devices.