src/types/cmcd.ts
/**
* CMCD spec version
*/
export const CMCDVersion = 1;
/**
* CMCD Object Type
*/
export enum CMCDObjectType {
MANIFEST = 'm',
AUDIO = 'a',
VIDEO = 'v',
MUXED = 'av',
INIT = 'i',
CAPTION = 'c',
TIMED_TEXT = 'tt',
KEY = 'k',
OTHER = 'o',
}
/**
* CMCD Streaming Format
*/
export enum CMCDStreamingFormat {
DASH = 'd',
HLS = 'h',
SMOOTH = 's',
OTHER = 'o',
}
/**
* CMCD Streaming Type
*/
export enum CMCDStreamType {
VOD = 'v',
LIVE = 'l',
}
/**
* CMCD Headers
*/
export interface CMCDHeaders {
'CMCD-Object': string;
'CMCD-Request': string;
'CMCD-Session': string;
'CMCD-Status': string;
}
/**
* CMCD
*/
export interface CMCD {
/////////////////
// CMCD Object //
/////////////////
/**
* Encoded bitrate
*
* The encoded bitrate of the audio or video object being requested. This may not be known precisely by the player; however,
* it MAY be estimated based upon playlist/manifest declarations. If the playlist declares both peak and average bitrate values,
* the peak value should be transmitted.
*
* Integer kbps
*/
br?: number;
/**
* Object duration
*
* The playback duration in milliseconds of the object being requested. If a partial segment is being requested, then this value
* MUST indicate the playback duration of that part and not that of its parent segment. This value can be an approximation of the
* estimated duration if the explicit value is not known.
*
* Integer milliseconds
*/
d?: number;
/**
* Object type
*
* The media type of the current object being requested:
* - `m` = text file, such as a 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` = cryptographic key, license or certificate.
* - `o` = other
*
* If the object type being requested is unknown, then this key MUST NOT be used.
*/
ot?: CMCDObjectType;
/**
* Top bitrate
*
* The highest bitrate rendition in the manifest or playlist that the client is allowed to play, given current codec, licensing and
* sizing constraints.
*
* Integer Kbps
*/
tb?: number;
//////////////////
// CMCD Request //
//////////////////
/**
* Buffer length
*
* The buffer length associated with the media object being requested. This value MUST be rounded to the nearest 100 ms. This key SHOULD only be
* sent with an object type of ‘a’, ‘v’ or ‘av’.
*
* Integer milliseconds
*/
bl?: number;
/**
* Deadline
*
* Deadline from the request time until the first sample of this Segment/Object needs to be available in order to not create a buffer underrun or
* any other playback problems. This value MUST be rounded to the nearest 100ms. For a playback rate of 1, this may be equivalent to the player’s
* remaining buffer length.
*
* Integer milliseconds
*/
dl?: number;
/**
* Measured mtp CMCD throughput
*
* The throughput between client and server, as measured by the client and MUST be rounded to the nearest 100 kbps. This value, however derived,
* SHOULD be the value that the client is using to make its next Adaptive Bitrate switching decision. If the client is connected to multiple
* servers concurrently, it must take care to report only the throughput measured against the receiving server. If the client has multiple concurrent
* connections to the server, then the intent is that this value communicates the aggregate throughput the client sees across all those connections.
*
* Integer kbps
*/
mtp?: number;
/**
* Next object request
*
* Relative path of the next object to be requested. This can be used to trigger pre-fetching by the CDN. This MUST be a path relative to the current
* request. This string MUST be URLEncoded. The client SHOULD NOT depend upon any pre-fetch action being taken - it is merely a request for such a
* pre-fetch to take place.
*
* String
*/
nor?: string;
/**
* Next range request
*
* If the next request will be a partial object request, then this string denotes the byte range to be requested. If the ‘nor’ field is not set, then the
* object is assumed to match the object currently being requested. The client SHOULD NOT depend upon any pre-fetch action being taken – it is merely a
* request for such a pre-fetch to take place. Formatting is similar to the HTTP Range header, except that the unit MUST be ‘byte’, the ‘Range:’ prefix is
* NOT required and specifying multiple ranges is NOT allowed. Valid combinations are:
*
* - `"\<range-start\>-"`
* - `"\<range-start\>-\<range-end\>"`
* - `"-\<suffix-length\>"`
*
* String
*/
nrr?: string;
/**
* Startup
*
* Key is included without a value if the object is needed urgently due to startup, seeking or recovery after a buffer-empty event. The media SHOULD not be
* rendering when this request is made. This key MUST not be sent if it is FALSE.
*
* Boolean
*/
su?: boolean;
//////////////////
// CMCD Session //
//////////////////
/**
* Content ID
*
* A unique string identifying the current content. Maximum length is 64 characters. This value is consistent across multiple different
* sessions and devices and is defined and updated at the discretion of the service provider.
*
* String
*/
cid?: string;
/**
* Playback rate
*
* `1` if real-time, `2` if double speed, `0` if not playing. SHOULD only be sent if not equal to `1`.
*
* Decimal
*/
pr?: number;
/**
* Streaming format
*
* The streaming format that defines the current request.
*
* - `d` = MPEG DASH
* - `h` = HTTP Live Streaming (HLS)
* - `s` = Smooth Streaming
* - `o` = other
*
* If the streaming format being requested is unknown, then this key MUST NOT be used.
*/
sf?: CMCDStreamingFormat;
/**
* Session ID
*
* A GUID identifying the current playback session. A playback session typically ties together segments belonging to a single media asset.
* Maximum length is 64 characters. It is RECOMMENDED to conform to the UUID specification.
*
* String
*/
sid?: string;
/**
* Stream type
* - `v` = all segments are available – e.g., VOD
* - `l` = segments become available over time – e.g., LIVE
*/
st?: CMCDStreamType;
/**
* CMCD version
*
* The version of this specification used for interpreting the defined key names and values. If this key is omitted, the client and server MUST
* interpret the values as being defined by version 1. Client SHOULD omit this field if the version is 1.
*
* Integer
*/
v?: number;
/////////////////
// CMCD Status //
/////////////////
/**
* Buffer starvation
*
* Key is included without a value if the buffer was starved at some point between the prior request and this object request,
* resulting in the player being in a rebuffering state and the video or audio playback being stalled. This key MUST NOT be
* sent if the buffer was not starved since the prior request.
*
* If the object type `ot` key is sent along with this key, then the `bs` key refers to the buffer associated with the particular
* object type. If no object type is communicated, then the buffer state applies to the current session.
*
* Boolean
*/
bs?: boolean;
/**
* Requested maximum throughput
*
* The requested maximum throughput that the client considers sufficient for delivery of the asset. Values MUST be rounded to the
* nearest 100kbps. For example, a client would indicate that the current segment, encoded at 2Mbps, is to be delivered at no more
* than 10Mbps, by using rtp=10000.
*
* Note: This can benefit clients by preventing buffer saturation through over-delivery and can also deliver a community benefit
* through fair-share delivery. The concept is that each client receives the throughput necessary for great performance, but no more.
* The CDN may not support the rtp feature.
*
* Integer kbps
*/
rtp?: number;
}
