ISO/IEC 14496-8:2004

Overview

ISO/IEC 14496-8:2004 (MPEG‑4 Part 8) defines a framework for carrying ISO/IEC 14496 (MPEG‑4) contents over IP networks. It provides guidelines for designing RTP payload formats, rules for fragmentation and concatenation, SDP usage to convey MPEG‑4 Systems information, registrations of MIME types (including MP4), and considerations for RTP security and multicasting. The standard bridges MPEG‑4 Systems, audio and video elementary streams, and IP transport protocols to enable interoperable streaming and real‑time delivery.

Key topics and technical requirements

• RTP payload framework: Guidance to design RTP payload formats for MPEG‑4 content (audio, visual, systems). Payloads must map MPEG‑4 Synchronization Layer (SL) semantics into RTP and specify how SL packet headers and SLConfigDescriptor are derived.
• Timestamp and timescale mapping: RTP timestamps should correspond to MPEG‑4 presentation times (e.g., CTS). The MPEG‑4 timescale (timeStampResolution) is used as the RTP timescale and declared in SDP.
• Fragmentation and concatenation rules: Rules for splitting/combining Access Units (AUs) into RTP packets while preserving decoding and presentation order.
• SDP usage: Usage rules and attributes to advertise MPEG‑4 sessions in SDP (for example, a=mpeg4-iod [] to locate an InitialObjectDescriptor and a=mpeg4-esid for elementary stream identifiers). RTPMAP naming and media section recommendations are defined.
• MIME type registrations: Standard MIME types such as video/mp4, audio/mp4, application/mpeg4-iod and specific types for MPEG‑4 visual/audio elementary streams are specified for HTTP and other transports.
• QoS, security and multicasting: Analysis and recommendations on RTP security, multicast transport, and QoS mechanisms; pointers to IETF techniques (FEC, retransmission, etc.) and interoperability considerations.
• Interoperability baseline: Recommends supporting a generic payload mapping (per IETF drafts/RFCs, e.g., RFC 3016) as a baseline for receivers.

Applications

• Live and on‑demand streaming services (IPTV, VoD)
• Real‑time conferencing and multimedia collaboration
• Media server and client implementations (players, set‑top boxes, mobile apps)
• Network equipment and CDN vendors implementing RTP/RTSP/SDP support
• Developers creating RTP payload RFCs or integrating MPEG‑4 Systems with IP transport

Who uses this standard

• Multimedia system architects and protocol engineers
• Streaming platform and CDN implementers
• Device manufacturers (set‑top boxes, mobile devices, media players)
• Standards authors and IETF working groups creating RTP payload specifications

Related standards

• ISO/IEC 14496 family (Parts 1–16, especially Part 1 Systems, Part 2 Visual, Part 3 Audio, Part 12/14 MP4)
• IETF RFCs: RTP (RFC 1889/3550), SDP (RFC 2327), RTSP (RFC 2326), RFC 3016/3640 (MPEG‑4 RTP payloads)

Keywords: ISO/IEC 14496-8, MPEG‑4 over IP, RTP payload, SDP attributes, MIME types, MP4, RTP security, multicast, fragmentation, timescale.