Overview
ISO/IEC 23000-19:2024/Amd 2:2026 is an amendment to the MPEG-A Part 19 Common Media Application Format (CMAF), which is a widely adopted media container standard for segmented media delivery. This amendment introduces an additional structural CMAF brand profile, enhancing support for new track types and media profiles within the CMAF specification. The CMAF framework enables efficient streaming, editing, and packaging of multimedia content across a variety of platforms, ensuring interoperability and adaptive bitrate delivery for video, audio, and metadata.
Key Topics
- CMAF Brand Profiles: Introduction and definition of new structural CMAF brands such as
cmf1, which extends and restricts existing brands and explicitly allows carrying supplementary metadata tracks within the same media track as the primary audio, video, or audiovisual content.
- Track Structure Enhancements: Clarification and expansion of what constitutes a primary media track (carrying essential audio or video data) and the addition of supplementary metadata tracks for carrying related metadata, with strict associations to primary tracks.
- Media Track Types and Extensions: Support for new file extensions and internet media types for media, subtitles, and metadata, such as .cmfv for video and .cmfm for metadata.
- Multiview and Alpha Video Support: Specification of new media profiles for multi-view HEVC (MV-HEVC) content, including stereo video, alpha channel (opacity information), and stereo with alpha, supporting advanced features like stereoscopic video and transparency.
- Metadata Handling: Differentiation between timed metadata tracks (independent metadata streams) and supplementary metadata tracks (metadata tied directly to primary content), ensuring precise metadata application and seamless adaptive streaming.
Applications
Implementing the updates from this amendment into CMAF-based workflows brings multiple practical benefits and use cases:
- Advanced Streaming Services: Enables enhanced streaming scenarios such as 3D video (stereoscopic), video with transparency, and richer supplemental information for user experiences, making it ideal for immersive applications and interactive media.
- Content Packaging and Interoperability: Streamlines the creation and exchange of segmented media files compatible with a wide range of playback environments, content delivery networks, and digital rights management systems.
- Broadcast and OTT Platforms: Supports broadcasters and over-the-top (OTT) streaming providers in delivering segmented content that adapts seamlessly to varying network conditions and device capabilities, including support for stereo and multi-view video content.
- Metadata-Driven Experiences: Provides tools for synchronizing supplementary metadata (such as captions, timed program information, or geolocation data) with primary media, which is essential for accessibility, analytics, and enhanced presentation.
- Flexible Media Distribution: The improved structure and defined profiles ease the implementation of adaptive bitrate streaming, content personalization, and future-proofing against evolving codec standards.
Related Standards
- ISO/IEC 23000 (MPEG-A): The overarching series for multimedia application formats.
- ISO Base Media File Format (ISOBMFF) [ISO/IEC 14496-12]: The underlying container format upon which CMAF and its tracks are built.
- HEVC (High Efficiency Video Coding) [ISO/IEC 23008-2]: Video coding standard supported natively in CMAF, including multiview and auxiliary data profiles.
- IETF RFC 6381: Provides media type and codec parameter definitions for media streaming profiles.
- MPEG-DASH: Often used alongside CMAF for adaptive streaming delivery.
- Other CMAF Amendments: Updates for codec-specific and media profile constraints, such as LCEVC and MV-HEVC enhancements, ensure conformance and compatibility.
Keeping up to date with ISO/IEC 23000-19:2024/Amd 2:2026 and its related standards is crucial for developers, system architects, and service providers who require robust, scalable, and interoperable multimedia streaming solutions in today’s evolving digital media landscape.