The BBC has initiated a trial to assess the effectiveness of its low-latency streaming approach in real-world viewer environments. For a few weeks, viewers on specific devices enrolled in iPlayer’s beta program will have the option to watch an experimental low-latency stream of BBC Two during live broadcasts.
In a blog post, Lead R&D engineer Chris Poole explained that although internet-streamed TV delays have significantly decreased, a 40-second lag still exists compared to traditional broadcasts. “For some content, viewers may not notice, but for live sport and for live events with a social media following, delays can detract from the viewing experience. We are aiming to address these delays whilst maintaining a high quality of experience through our work on ‘low latency streaming’,” he stated.
Latency remains a challenge for both commercial and public broadcasting. The BBC’s broadcast services currently have an 8-10 second delay. The BBC is employing Low Latency DASH technology with chunked CMAF segments. Data gathered from BBC Two trial sessions will be analyzed to compare quality and reliability with traditional live streaming across diverse home setups.
Poole noted ongoing discussions regarding handling potential rebuffering. “Should the stream just resume, leaving them further behind for the rest of the programme? Should the stream catch up, skipping a few seconds in the process?” The BBC’s solution for the trial is to slightly increase playback speed after a stall, aiming for low latency without viewers missing content. Due to limited device compatibility, the trial is initially restricted to devices supporting variable-speed playback, including the 3rd generation Amazon FireTV Stick, 2nd generation Amazon FireTV Stick 4K, and Samsung CU8000 and CU8500 TVs. The trial is limited to England and Scotland, running from 9 am to 5 pm daily.