shaka-player
Version:
DASH/EME video player library
202 lines (199 loc) • 8.35 kB
JavaScript
/*! @license
* Shaka Player
* Copyright 2016 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @fileoverview Externs for CMCD data.
* @see https://github.com/shaka-project/shaka-player/issues/3619
* @see https://cdn.cta.tech/cta/media/media/resources/standards/pdfs/cta-5004-final.pdf
*
* @externs
*/
/**
* @typedef {{
* br: (number|undefined),
* d: (number|undefined),
* ot: (string|undefined),
* tb: (number|undefined),
* bl: (number|undefined),
* dl: (number|undefined),
* mtp: (number|undefined),
* nor: (string|undefined),
* nrr: (string|undefined),
* su: (boolean|undefined),
* cid: (string|undefined),
* pr: (number|undefined),
* sf: (string|undefined),
* sid: (string|undefined),
* st: (string|undefined),
* v: (number|undefined),
* bs: (boolean|undefined),
* rtp: (number|undefined),
* msd: (number|undefined),
* ltc: (number|undefined),
* }}
*
* @description
* Client Media Common Data (CMCD) data.
*
* @property {number} br
* 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.
*
* @property {number} d
* 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.
*
* @property {string} ot
* 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.
*
* @property {number} tb
* The highest bitrate rendition in the manifest or playlist that the client
* is allowed to play, given current codec, licensing and sizing constraints.
*
* @property {number} bl
* 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’.
*
* @property {number} dl
* 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.
*
* @property {number} mtp
* 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.
*
* @property {string} nor
* 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.
*
* @property {string} nrr
* 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\>"`
*
* @property {boolean} su
* 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.
*
* @property {string} cid
* 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.
*
* @property {number} pr
* The playback rate. `1` if real-time, `2` if double speed, `0` if not
* playing. SHOULD only be sent if not equal to `1`.
*
* @property {string} sf
* 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.
*
* @property {string} sid
* 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.
*
* @property {string} st
* Stream type
* - `v` = all segments are available – e.g., VOD
* - `l` = segments become available over time – e.g., LIVE
*
* @property {number} v
* 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.
*
* @property {boolean} bs
* 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.
*
* @property {number} rtp
* 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.
*
* @property {number} msd
* The Media Start Delay represents in milliseconds the delay between the
* initiation of the playback request and the moment the first frame is
* rendered. This is sent only once when it is calculated.
*
* @property {number} ltc
* Live Stream Latency
*
* The time delta between when a given media timestamp was made available at
* the origin and when it was rendered by the client. The accuracy of this
* estimate is dependent on synchronization between the packager and the
* player clocks.
*/
var CmcdData;