Overview
ISO/IEC 14496-15:2022/Amd 1:2023 is an amendment to the international standard focused on the coding of audio-visual objects, specifically addressing the carriage of Network Abstraction Layer (NAL) unit structured video in the ISO Base Media File Format (ISOBMFF). This amendment introduces support for Low Complexity Enhancement Video Coding (LCEVC), as defined in ISO/IEC 23094-2:2021.
The update provides a standardized way to carry LCEVC-enhanced video streams within ISOBMFF files, enabling enhanced video compression efficiency by applying LCEVC as an enhancement layer over base video codecs like AVC, HEVC, EVC, or VVC.
Key Topics
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NAL Unit Structure: The amendment clarifies how NAL units for structured video, including LCEVC, are encapsulated and carried in ISOBMFF. It defines the syntax for LCEVC elementary streams as collections of NAL units, consistent with prior ISO/IEC 14496-15 specifications.
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LCEVC Elementary Streams: LCEVC streams function as enhancement layers that reference separate base codec streams. The amendment ensures that LCEVC tracks can be independently decoded or combined with their base layers for improved video quality.
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Parameter Sets:
- Defines sequence_configuration (SC), global_configuration (GC), and additional_info (AI) sets that represent static information used in streams.
- Specifies that these parameter sets must be available in sample entries or included with key frames (sync samples).
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Decoder Configuration:
- Introduces the LCEVCDecoderConfigurationRecord, detailing capabilities such as profile indication, level, chroma format, bit depth, and picture dimensions.
- This record ensures consistent decoding and interoperability across implementations.
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Sample Entry Names: The amendment registers the sample entry name 'lvc1' for LCEVC streams in ISOBMFF’s Sample Description Box (stsd), which must include the LCEVCConfigurationBox containing decoder configuration.
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Compatibility: LCEVC streams are designed to work with existing base video codec streams, enabling backward compatibility while adding enhancement layers.
Applications
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Streaming Media Services: Enables efficient delivery of enhanced video streams over networks by leveraging LCEVC's capabilities layered over traditional codecs.
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Video-on-Demand Platforms: Improves video quality at reduced bitrates by carrying enhancement streams alongside base video tracks, reducing bandwidth usage.
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Broadcasting and OTT: Facilitates backward-compatible video upgrades and adaptive streaming workflows through standard carriage of LCEVC streams.
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Media Storage and Archiving: Supports storage of enhanced video content in a standardized, interoperable container format, ensuring future-proof archiving.
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Decoder and Encoder Implementations: Provides guidelines and requirements for developers to implement proper encoding, packaging, and decoding of LCEVC-enhanced streams in ISOBMFF containers.
Related Standards
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ISO/IEC 23094-2:2021 – Defines the Low Complexity Enhancement Video Coding (LCEVC) codec itself and its bitstream syntax.
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ISO/IEC 14496-10 – Covers the coding of H.264/AVC video NAL units, referenced for NAL unit structure.
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ISO/IEC 14496-12 – Specifies the ISO Base Media File Format (ISOBMFF), providing the foundational container structure for audiovisual streams.
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RFC 6381 – Defines MIME media types and codec identifiers, relevant for the codecs parameter string for ISOBMFF media tracks including LCEVC.
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Interoperability: Standardized carriage of LCEVC streams ensures seamless interoperability between content providers, broadcasters, and device manufacturers.
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Enhanced Compression: By layering LCEVC as an enhancement over base codecs, content providers can achieve improved video compression efficiency while retaining compatibility.
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Flexibility: Separate LCEVC and base layers allow independent or combined decoding, supporting adaptive streaming and progressive enhancement.
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Future-Proofing: The amendment supports evolving video coding technologies, allowing integration of new codecs via LCEVC enhancement layers.
For organizations working with advanced video coding, streaming, or multimedia file packaging, adopting ISO/IEC 14496-15:2022/Amd 1:2023 ensures compliance with the latest standard for carrying LCEVC-enhanced video within ISO base media files. This facilitates higher quality streaming experiences and efficient media workflows across a wide range of applications.
Open preview (PDF)Information technology — Coding of audio-visual objects — Part 15: Carriage of network abstraction layer (NAL) unit structured video in the ISO base media file format — Amendment 1: Support for LCEVC
