GetHLSStreamingSessionURL

Retrieves an HTTP Live Streaming (HLS) URL for the stream. You can then open the URL in a browser or media player to view the stream contents.

Both the StreamName and the StreamARN parameters are optional, but you must specify either the StreamName or the StreamARN when invoking this API operation.

An Amazon Kinesis video stream has the following requirements for providing data through HLS:

• Video playback track requirements.

• Data retention must be greater than 0.

• The video track of each fragment must contain codec private data in the Advanced Video Coding (AVC) for H.264 format or HEVC for H.265 format (MPEG-4 specification ISO/IEC 14496-15). For information about adapting stream data to a given format, see NAL Adaptation Flags.

• The audio track (if present) of each fragment must contain codec private data in the AAC format (AAC specification ISO/IEC 13818-7).

Kinesis Video Streams HLS sessions contain fragments in the fragmented MPEG-4 form (also called fMP4 or CMAF) or the MPEG-2 form (also called TS chunks, which the HLS specification also supports). For more information about HLS fragment types, see the HLS specification.

The following procedure shows how to use HLS with Kinesis Video Streams:

1. Call the GetDataEndpoint API to get an endpoint. Then send the GetHLSStreamingSessionURL requests to this endpoint using the --endpoint-url parameter.

2. Retrieve the HLS URL using GetHLSStreamingSessionURL. Kinesis Video Streams creates an HLS streaming session to be used for accessing content in a stream using the HLS protocol. GetHLSStreamingSessionURL returns an authenticated URL (that includes an encrypted session token) for the session's HLS master playlist (the root resource needed for streaming with HLS).

   Note

   Don't share or store this token where an unauthorized entity could access it. The token provides access to the content of the stream. Safeguard the token with the same measures that you would use with your AWS credentials.

   The media that is made available through the playlist consists only of the requested stream, time range, and format. No other media data (such as frames outside the requested window or alternate bitrates) is made available.

3. Provide the URL (containing the encrypted session token) for the HLS master playlist to a media player that supports the HLS protocol. Kinesis Video Streams makes the HLS media playlist, initialization fragment, and media fragments available through the master playlist URL. The initialization fragment contains the codec private data for the stream, and other data needed to set up the video or audio decoder and renderer. The media fragments contain H.264-encoded video frames or AAC-encoded audio samples.

4. The media player receives the authenticated URL and requests stream metadata and media data normally. When the media player requests data, it calls the following actions:

   • GetHLSMasterPlaylist: Retrieves an HLS master playlist, which contains a URL for the GetHLSMediaPlaylist action for each track, and additional metadata for the media player, including estimated bitrate and resolution.

   • GetHLSMediaPlaylist: Retrieves an HLS media playlist, which contains a URL to access the MP4 initialization fragment with the GetMP4InitFragment action, and URLs to access the MP4 media fragments with the GetMP4MediaFragment actions. The HLS media playlist also contains metadata about the stream that the player needs to play it, such as whether the PlaybackMode is LIVE or ON_DEMAND. The HLS media playlist is typically static for sessions with a PlaybackType of ON_DEMAND. The HLS media playlist is continually updated with new fragments for sessions with a PlaybackType of LIVE. There is a distinct HLS media playlist for the video track and the audio track (if applicable) that contains MP4 media URLs for the specific track.

   • GetMP4InitFragment: Retrieves the MP4 initialization fragment. The media player typically loads the initialization fragment before loading any media fragments. This fragment contains the "fytp" and "moov" MP4 atoms, and the child atoms that are needed to initialize the media player decoder.

     The initialization fragment does not correspond to a fragment in a Kinesis video stream. It contains only the codec private data for the stream and respective track, which the media player needs to decode the media frames.

   • GetMP4MediaFragment: Retrieves MP4 media fragments. These fragments contain the "moof" and "mdat" MP4 atoms and their child atoms, containing the encoded fragment's media frames and their timestamps.

     Note

     For the HLS streaming session, in-track codec private data (CPD) changes are supported. After the first media fragment is made available in a streaming session, fragments can contain CPD changes for each track. Therefore, the fragments in a session can have a different resolution, bit rate, or other information in the CPD without interrupting playback. However, any change made in the track number or track codec format can return an error when those different media fragments are loaded. For example, streaming will fail if the fragments in the stream change from having only video to having both audio and video, or if an AAC audio track is changed to an ALAW audio track. For each streaming session, only 500 CPD changes are allowed.

     Data retrieved with this action is billable. For information, see Pricing.

   • GetTSFragment: Retrieves MPEG TS fragments containing both initialization and media data for all tracks in the stream.

     Note

     If the ContainerFormat is MPEG_TS, this API is used instead of GetMP4InitFragment and GetMP4MediaFragment to retrieve stream media.

     Data retrieved with this action is billable. For more information, see Kinesis Video Streams pricing.

A streaming session URL must not be shared between players. The service might throttle a session if multiple media players are sharing it. For connection limits, see Kinesis Video Streams Limits.

You can monitor the amount of data that the media player consumes by monitoring the GetMP4MediaFragment.OutgoingBytes Amazon CloudWatch metric. For information about using CloudWatch to monitor Kinesis Video Streams, see Monitoring Kinesis Video Streams. For pricing information, see Amazon Kinesis Video Streams Pricing and AWS Pricing. Charges for both HLS sessions and outgoing AWS data apply.

See the video playback examples in the documentation guide: Use the AWS CLI to retrieve an HLS streaming session URL and Example: Use HLS in HTML and JavaScript.

For more information about HLS, see HTTP Live Streaming on the Apple Developer site.

Important

If an error is thrown after invoking a Kinesis Video Streams archived media API, in addition to the HTTP status code and the response body, it includes the following pieces of information:

• x-amz-ErrorType HTTP header – contains a more specific error type in addition to what the HTTP status code provides.

• x-amz-RequestId HTTP header – if you want to report an issue to AWS, the support team can better diagnose the problem if given the Request Id.

Both the HTTP status code and the ErrorType header can be utilized to make programmatic decisions about whether errors are retry-able and under what conditions, as well as provide information on what actions the client programmer might need to take in order to successfully try again.

For more information, see the Errors section at the bottom of this topic, as well as Common Errors.

Request Syntax

POST /getHLSStreamingSessionURL HTTP/1.1
Content-type: application/json

{
   "ContainerFormat": "string",
   "DiscontinuityMode": "string",
   "DisplayFragmentTimestamp": "string",
   "Expires": number,
   "HLSFragmentSelector": { 
      "FragmentSelectorType": "string",
      "TimestampRange": { 
         "EndTimestamp": number,
         "StartTimestamp": number
      }
   },
   "MaxMediaPlaylistFragmentResults": number,
   "PlaybackMode": "string",
   "StreamARN": "string",
   "StreamName": "string"
}

URI Request Parameters

The request does not use any URI parameters.

Request Body

The request accepts the following data in JSON format.

ContainerFormat

Specifies which format should be used for packaging the media. Specifying the FRAGMENTED_MP4 container format packages the media into MP4 fragments (fMP4 or CMAF). This is the recommended packaging because there is minimal packaging overhead. The other container format option is MPEG_TS. HLS has supported MPEG TS chunks since it was released and is sometimes the only supported packaging on older HLS players. MPEG TS typically has a 5-25 percent packaging overhead. This means MPEG TS typically requires 5-25 percent more bandwidth and cost than fMP4.

The default is FRAGMENTED_MP4.

Type: String

Valid Values: FRAGMENTED_MP4 | MPEG_TS

Required: No

DiscontinuityMode

Specifies when flags marking discontinuities between fragments are added to the media playlists.

Media players typically build a timeline of media content to play, based on the timestamps of each fragment. This means that if there is any overlap or gap between fragments (as is typical if HLSFragmentSelector is set to SERVER_TIMESTAMP), the media player timeline will also have small gaps between fragments in some places, and will overwrite frames in other places. Gaps in the media player timeline can cause playback to stall and overlaps can cause playback to be jittery. When there are discontinuity flags between fragments, the media player is expected to reset the timeline, resulting in the next fragment being played immediately after the previous fragment.

The following modes are supported:

• ALWAYS: a discontinuity marker is placed between every fragment in the HLS media playlist. It is recommended to use a value of ALWAYS if the fragment timestamps are not accurate.

• NEVER: no discontinuity markers are placed anywhere. It is recommended to use a value of NEVER to ensure the media player timeline most accurately maps to the producer timestamps.

• ON_DISCONTINUITY: a discontinuity marker is placed between fragments that have a gap or overlap of more than 50 milliseconds. For most playback scenarios, it is recommended to use a value of ON_DISCONTINUITY so that the media player timeline is only reset when there is a significant issue with the media timeline (e.g. a missing fragment).

The default is ALWAYS when HLSFragmentSelector is set to SERVER_TIMESTAMP, and NEVER when it is set to PRODUCER_TIMESTAMP.

Type: String

Valid Values: ALWAYS | NEVER | ON_DISCONTINUITY

Required: No

DisplayFragmentTimestamp

Specifies when the fragment start timestamps should be included in the HLS media playlist. Typically, media players report the playhead position as a time relative to the start of the first fragment in the playback session. However, when the start timestamps are included in the HLS media playlist, some media players might report the current playhead as an absolute time based on the fragment timestamps. This can be useful for creating a playback experience that shows viewers the wall-clock time of the media.

The default is NEVER. When HLSFragmentSelector is SERVER_TIMESTAMP, the timestamps will be the server start timestamps. Similarly, when HLSFragmentSelector is PRODUCER_TIMESTAMP, the timestamps will be the producer start timestamps.

Type: String

Valid Values: ALWAYS | NEVER

Required: No

Expires

The time in seconds until the requested session expires. This value can be between 300 (5 minutes) and 43200 (12 hours).

When a session expires, no new calls to GetHLSMasterPlaylist, GetHLSMediaPlaylist, GetMP4InitFragment, GetMP4MediaFragment, or GetTSFragment can be made for that session.

The default is 300 (5 minutes).

Type: Integer

Valid Range: Minimum value of 300. Maximum value of 43200.

Required: No

HLSFragmentSelector

The time range of the requested fragment and the source of the timestamps.

This parameter is required if PlaybackMode is ON_DEMAND or LIVE_REPLAY. This parameter is optional if PlaybackMode is LIVE. If PlaybackMode is LIVE, the FragmentSelectorType can be set, but the TimestampRange should not be set. If PlaybackMode is ON_DEMAND or LIVE_REPLAY, both FragmentSelectorType and TimestampRange must be set.

Type: HLSFragmentSelector object

Required: No

MaxMediaPlaylistFragmentResults

The maximum number of fragments that are returned in the HLS media playlists.

When the PlaybackMode is LIVE, the most recent fragments are returned up to this value. When the PlaybackMode is ON_DEMAND, the oldest fragments are returned, up to this maximum number.

When there are a higher number of fragments available in a live HLS media playlist, video players often buffer content before starting playback. Increasing the buffer size increases the playback latency, but it decreases the likelihood that rebuffering will occur during playback. We recommend that a live HLS media playlist have a minimum of 3 fragments and a maximum of 10 fragments.

The default is 5 fragments if PlaybackMode is LIVE or LIVE_REPLAY, and 1,000 if PlaybackMode is ON_DEMAND.

The maximum value of 5,000 fragments corresponds to more than 80 minutes of video on streams with 1-second fragments, and more than 13 hours of video on streams with 10-second fragments.

Type: Long

Valid Range: Minimum value of 1. Maximum value of 5000.

Required: No

PlaybackMode

Whether to retrieve live, live replay, or archived, on-demand data.

Features of the three types of sessions include the following:

• LIVE : For sessions of this type, the HLS media playlist is continually updated with the latest fragments as they become available. We recommend that the media player retrieve a new playlist on a one-second interval. When this type of session is played in a media player, the user interface typically displays a "live" notification, with no scrubber control for choosing the position in the playback window to display.

  Note

  In LIVE mode, the newest available fragments are included in an HLS media playlist, even if there is a gap between fragments (that is, if a fragment is missing). A gap like this might cause a media player to halt or cause a jump in playback. In this mode, fragments are not added to the HLS media playlist if they are older than the newest fragment in the playlist. If the missing fragment becomes available after a subsequent fragment is added to the playlist, the older fragment is not added, and the gap is not filled.

• LIVE_REPLAY : For sessions of this type, the HLS media playlist is updated similarly to how it is updated for LIVE mode except that it starts by including fragments from a given start time. Instead of fragments being added as they are ingested, fragments are added as the duration of the next fragment elapses. For example, if the fragments in the session are two seconds long, then a new fragment is added to the media playlist every two seconds. This mode is useful to be able to start playback from when an event is detected and continue live streaming media that has not yet been ingested as of the time of the session creation. This mode is also useful to stream previously archived media without being limited by the 1,000 fragment limit in the ON_DEMAND mode.

• ON_DEMAND : For sessions of this type, the HLS media playlist contains all the fragments for the session, up to the number that is specified in MaxMediaPlaylistFragmentResults. The playlist must be retrieved only once for each session. When this type of session is played in a media player, the user interface typically displays a scrubber control for choosing the position in the playback window to display.

In all playback modes, if FragmentSelectorType is PRODUCER_TIMESTAMP, and if there are multiple fragments with the same start timestamp, the fragment that has the largest fragment number (that is, the newest fragment) is included in the HLS media playlist. The other fragments are not included. Fragments that have different timestamps but have overlapping durations are still included in the HLS media playlist. This can lead to unexpected behavior in the media player.

The default is LIVE.

Type: String

Valid Values: LIVE | LIVE_REPLAY | ON_DEMAND

Required: No

StreamARN

The Amazon Resource Name (ARN) of the stream for which to retrieve the HLS master playlist URL.

You must specify either the StreamName or the StreamARN.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 1024.

Pattern: arn:[a-z\d-]+:kinesisvideo:[a-z0-9-]+:[0-9]+:[a-z]+/[a-zA-Z0-9_.-]+/[0-9]+

Required: No

StreamName

The name of the stream for which to retrieve the HLS master playlist URL.

You must specify either the StreamName or the StreamARN.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 256.

Pattern: [a-zA-Z0-9_.-]+

Required: No

Response Syntax

HTTP/1.1 200
Content-type: application/json

{
   "HLSStreamingSessionURL": "string"
}

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

HLSStreamingSessionURL

The URL (containing the session token) that a media player can use to retrieve the HLS master playlist.

Type: String

Errors

For information about the errors that are common to all actions, see Common Errors.

ClientLimitExceededException

Kinesis Video Streams has throttled the request because you have exceeded a limit. Try making the call later. For information about limits, see Kinesis Video Streams Limits.

HTTP Status Code: 400

InvalidArgumentException

A specified parameter exceeds its restrictions, is not supported, or can't be used.

HTTP Status Code: 400

InvalidCodecPrivateDataException

The codec private data in at least one of the tracks of the video stream is not valid for this operation.

HTTP Status Code: 400

MissingCodecPrivateDataException

No codec private data was found in at least one of tracks of the video stream.

HTTP Status Code: 400

NoDataRetentionException

GetImages was requested for a stream that does not retain data (that is, has a DataRetentionInHours of 0).

HTTP Status Code: 400

NotAuthorizedException

Status Code: 403, The caller is not authorized to perform an operation on the given stream, or the token has expired.

HTTP Status Code: 401

ResourceNotFoundException

GetImages will throw this error when Kinesis Video Streams can't find the stream that you specified.

GetHLSStreamingSessionURL and GetDASHStreamingSessionURL throw this error if a session with a PlaybackMode of ON_DEMAND or LIVE_REPLAY is requested for a stream that has no fragments within the requested time range, or if a session with a PlaybackMode of LIVE is requested for a stream that has no fragments within the last 30 seconds.

HTTP Status Code: 404

UnsupportedStreamMediaTypeException

The type of the media (for example, h.264 or h.265 video or AAC or G.711 audio) could not be determined from the codec IDs of the tracks in the first fragment for a playback session. The codec ID for track 1 should be V_MPEG/ISO/AVC and, optionally, the codec ID for track 2 should be A_AAC.

HTTP Status Code: 400

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following:

• AWS Command Line Interface

• AWS SDK for .NET

• AWS SDK for C++

• AWS SDK for Go v2

• AWS SDK for Java V2

• AWS SDK for JavaScript V3

• AWS SDK for PHP V3

• AWS SDK for Python

• AWS SDK for Ruby V3