CMSD headers from AWS Elemental MediaPackage - AWS Elemental MediaPackage
Common CMSD keysAWS custom CMSD keys

CMSD headers from AWS Elemental MediaPackage

AWS Elemental MediaPackage uses Common Media Server Data (CMSD) HTTP response headers to provide downstream systems with information about content coming from an endpoint. These headers are defined by the Consumer Technology Association's CTA-5006 specification that establishes a uniform method for media servers and services to communicate data about media objects.

Media servers such as AWS Elemental MediaPackage use CMSD headers in responses to content requests. The headers can include data about the content, such as the type of content, playback duration, and quality scores. Servers receiving these headers can use the information for things like input switching and logging analysis.

The following sections describe keys that MediaPackage uses in CMSD headers.

Common CMSD keys

The following table describes common CMSD keys that MediaPackage uses. For a full of list of keys, see the Consumer Technology Association's Common Media Server Data CTA-5006 specification.

Key name Value CMSD header example
n The identifier for the MediaPackage origin endpoint of this object. CMSD-Static: n="MediaPackage:<region>:<channelGroup>:<channel>:<endpoint>"
st The type of content being returned. Supported values are:

  • l = live content

  • v = VOD content

 CMSD-Static: st=l
sf The streaming format of the response. Supported values are:

  • d h = MP4

  • h = TS

 CMSD-Static: sf=(d h)
ot

The media role of the object being returned. Supported values are:

  • m = text file (manifest or playlist)

  • a = audio only

  • v = video only

  • av = muxed audio and video

  • i = init segment

  • c = caption or subtitle

  • tt = ISOBMFF timed text track

  • k = crytographic key, license, or certificate

  • o = other

 CMSD-Static: ot=v
br The average encoded bitrate of the object. CMSD-Static: br=1000000
ht

The amount of time that MediaPackage waited to send this response to CloudFront.

Measured in milliseconds.		 CMSD-Static: ht=1000
d

The playback duration of the object.

Measured in milliseconds.		 CMSD-Static: d=2000
at The wallclock time that the first byte of this object became available to the server.

Measured in integer milliseconds since the Unix Epoch.

 CMSD-Static: at=1656703938470

AWS custom CMSD keys

The following table describes custom AWS keys that MediaPackage uses.

AWS custom key name Value CMSD header example
com.amazonaws-mqcs The media quality confidence score (MQCS) rating for the segment. CMSD-Static: com.amazonaws-mqcs="90"
com.amazonaws-mqcs-seq

The aggregate of MQCS ratings for all segments in the sequence.

Value is from 1-100.

 CMSD-Static: com.amazonaws-mqcs-seq="100"
com.amazonaws-mqcs-seq-tracks

The aggregate of MQCS ratings for all segments in the sequence, by object type.

Value is from 1-100.

 CMSD-Static: com.amazonaws-mqcs-seq-tracks="v:100;a:90;s:50;m:60"