MPEGDASHHLS

MPEGDASHHLS is a term used to describe an interoperability approach intended to serve video content to both MPEG-DASH and Apple HLS clients using a unified delivery format. It is not an official standard, but rather a practical strategy employed by streaming providers to maximize compatibility across devices and platforms while sharing a common encoding and packaging workflow.

The core idea relies on the Common Media Application Format (CMAF) and fragmented MP4 (fMP4) segments. By encoding video and audio in standard codecs (for example H.264/AVC, H.265/HEVC, AAC, or the more recent AV1) and packaging them into CMAF segments, a single set of media assets can be referenced by both a DASH MPD manifest and an HLS M3U8 playlist. This often involves generating parallel manifests where DASH clients read a dynamic MPD while HLS clients read an M3U8, both pointing to the same CMAF-based segments. DRM using common encryption (CENC) is typically aligned across the two protocols to protect the content.

Advantages include reduced storage and encoding effort, faster turnaround for multi-platform releases, and simpler content pipelines. Limitations can arise from legacy players or devices with partial CMAF support, variations in segment duration handling, and DRM or timeline compatibility concerns. While CMAF-enabled workflows are widely supported in modern streaming environments, MPEGDASHHLS remains a descriptive concept rather than a formal specification, reflecting industry practices for cross-compatibility rather than a standalone standard.