SMPTE 2110

From Wikipedia, the free encyclopedia

SMPTE 2110 is a suite of standards from the Society of Motion Picture and Television Engineers (SMPTE) that describes how to send digital media over an IP network.[1]

SMPTE 2110 is intended to be used within broadcast production and distribution facilities where quality and flexibility are more important than bandwidth efficiency.[2]

History[edit]

SMPTE 2110 was based on the TR-03[3] and TR-04[4] work published by the Video Services Forum on 12 November 2015. The first four parts of SMPTE 2110, -10, -20, -21 and -30, were published by SMPTE on 27 November 2017. Other parts, including recommended practices, were added later, and several parts were updated in 2022.

Standard[edit]

SMPTE 2110 is specified in several parts:[5]

  • ST 2110-10 - System architecture and synchronization: essences, RTP, SDP and PTP[6]
  • ST 2110-20 - Uncompressed video transport, based on SMPTE 2022-6
  • ST 2110-21 - Traffic shaping and network delivery timing
  • ST 2110-22 - Constant Bit-Rate Compressed Video transport[7]
  • ST 2110-30 - Audio transport, based on AES67[8]
  • ST 2110-31 - Transport of AES3 formatted audio
  • ST 2110-40 - Transport of ancillary data[9]
  • ST 2110-43 - Transport of Timed Text Markup Language for captions and subtitles in systems conforming to SMPTE ST 2110-10.[10]

ST 2110-10: System architecture and synchronization[edit]

There are several important features of ST 2110-10:[11]

  • Individual audio, video and ancillary data tracks or clips are carried as separate individual streams. These streams are referred to as "essences", e.g., a 5.1 JPEG mp4 clip could have 9 essences: a video essence, 6 separate audio essences, and two closed caption essences, English and Chinese.
  • Real-time Transport Protocol (RTP) is used to transmit streaming essences.
  • Session Initiation Protocol (SIP) is used to manage the connection and distribution of RTP streams including IP multicast one-to-many distribution.
  • Precision Time Protocol (PTP) provides global microsecond accuracy timing of all essences. Synchronization is based on SMPTE 2059.

ST 2110-20: Uncompressed video transport[edit]

SMPTE 2110-20 defines the key requirements for transporting uncompressed video essence and is built on the IETF RFC 4175, RTP Payload Format for Uncompressed Video. [12]

ST 2110-21: Transmission timing[edit]

SMPTE 2110-21 defines three classes of devices based on their transmission timing behavior: NL (for Narrow Linear), N (for Narrow), and W (for Wide). NL senders transmit at a constant bit rate. N senders may suspend transmission during the vertical blanking interval. W senders are intended to support software implementations of 2110 and adhere to less rigorous transmission timing requirements. A type W receiver should be able to receive from any type of sender.[13]

ST 2110-22: Constant bit-rate compressed video transport[edit]

SMPTE 2110-22 defines the key requirements for transporting compressed video essence. The compression standard needs to provide a constant bitrate, a defined RTP payload and low latency to satisfy the needs of Live production. The majority of the SMPTE 2110-22 implementations uses the JPEG XS lightweight low latency compression standard [14] created by the Joint Photographic Experts Group to answer the requirements of the SMPTE 2110 standard. The JPEG XS codec has only a few video lines of latency in software and hardware implementations,[15] which is less than 1 millisecond. SMPTE 2110-22 is used as an alternative to uncompressed video (SMPTE 2110-20) in live production environment. SMPTE 2110-22 is indeed very suitable to use less bandwidth in local live IP production, remote production, contribution or cloud-based production.[16]

Recommended practices[edit]

The 2110 suite also includes SMPTE Recommeded Practices:

References[edit]