Bitrate and playlist

• Confirm that the first line of the bitrate playlist files is #EXTM3U.
• Check that the bitrate playlist files contain the #EXT-X-TARGETDURATION and #EXT-X-MEDIA-SEQUENCE tags.
• Ensure that the tag EXT_X_MEDIA_SEQUENCE is consistent across playlists.

DNS lookups, upload retries, and timeouts

Encoders must perform DNS lookups whenever an error occurs. Any time there is an upload error, server abort, connection timeout, or HTTP timeout, encoders should perform a DNS lookup to ensure that they continue to be connected with the appropriate server. If the entry point sends a Connection=close header in the response, then the encoder needs to re-resolve the domain (for all formats including RTMP).

This table summarizes how the failure conditions are handled.

Extensions and mime types

This table provides mime type requirements for supported extensions.

IDR frame alignment

Stream encoders should produce IDR frame alignment across bitrates for the duration of the targeted segment. For example, if an encoder is generating maximum supported 10-second segments, then every 10 seconds there must be timestamp-aligned IDR frames across streams. There must be an IDR frame at the beginning of the segment; otherwise, the audio and video might deviate and drop out of synchronization. IDR frames must be at the very beginning of the segment, not in the middle or end of the segment.

Industry compliance

Marking playlists complete

At the end of a list stream, encoders should mark the stream (for HLS format) as complete by inserting the EXT-X-ENDLIST tag into the .m3u8 playlist file. This ensures that the device behaves appropriately when it comes to the end of the stream. The EXT-X-ENDLIST tag prevents unexpected playback issues when the device comes to the end of the stream. This tag ensures that viewers have a consistent and high-quality playback experience. It is also required for Live-to-VoD generation.

Publishing URL format

Encoders should be capable of using a POST URL with the entrypoint hostnames and pathnames in the format described in this table.

URL path for HLS: https://p-ep{stream_id}.i.akamaientrypoint.net/<stream_id>/<uniquesourcename>/<sessionID>/<bitrateID>/<OPTIONAL_PATH>/<somename>_<sequence#>.extension

https://p-ep{stream_id}.i.akamaientrypoint.net/<stream_id>/<uniquesourcename>/<sessionID>/<bitrateID>/<OPTIONAL_PATH>/segment_0001.ts
https://p-ep{stream_id}.i.akamaientrypoint.net/<stream_id>/<uniquesourcename>/<sessionID>/<bitrateID>/<OPTIONAL_PATH>/segment_0002.ts
https://p-ep{stream_id}.i.akamaientrypoint.net/<stream_id>/<uniquesourcename>/<sessionID>/<bitrateID>/<OPTIONAL_PATH>/segment_0003.ts

URL path for HDS, DASH, or CMAF: https://p-ep{stream_id}.i.akamaientrypoint.net/<format>/<stream_id>/<uniquesourcename> /<sessionID>/<bitrateID>/<OPTIONAL_PATH>/ <somename>_<sequence#>.extension

The playback URL format remains the same as previous MSL versions. For example, if the format is HLS it is: https://example-i.akamaized.net/hls/live/[stream_id]/[event_name]/[filename_.m3u8_or_.mpd]

PUT or POST request

Encoders should be capable of uploading generated content, video segments, and playlist/manifest files using multiple PUT or POST requests. Each segment should be uploaded in a separate request. Use a persistent connection for these requests.

Flexible segment numbering

All previous restrictions requiring sequential segment numbers have been lifted. However, fragment numbers must not repeat when an encoder restarts. To prevent this, derive fragment numbers from current epoch time. This results in always increasing fragment numbers and prevents overwriting data in the storage system.

The path and segment number are treated as one entity. Archived data gets corrupted when the encoder restarts and attempts to use the previous sequence number and path.

https://p-ep{stream_id}.i.akamaientrypoint.net/<stream_id>/<uniquesourcename>/<sessionID>/<bitrateID>/<OPTIONAL_PATH>/<somename>_<sequence#>.ts

https://p-ep{stream_id}.i.akamaientrypoint.net/<stream_id>/<uniquesourcename>/<sessionID>/<bitrateID>/<OPTIONAL_PATH>/segment_0001.ts
https://p-ep{stream_id}.i.akamaientrypoint.net/<stream_id>/<uniquesourcename>/<sessionID>/<bitrateID>/<OPTIONAL_PATH>/segment_0002.ts
https://p-ep{stream_id}.i.akamaientrypoint.net/<stream_id>/<uniquesourcename>/<sessionID>/<bitrateID>/<OPTIONAL_PATH>/segment_0003.ts

The segment number must be extractable from the upload URL using regex. Ensure that you separate the string and the numbers of a segment. Segment names can contain alphanumeric characters and the hyphen (-) as delimiters. Other special characters are not supported. You cannot use symbols, special characters, or alphabets. For example:

bitrate1000-00012.ts

<sessionId>/bitrateA_12.ts

<sessionId>/1-123.ts

<sessionId>_1_123.ts

<sessionId>/P2-2-1001.ts

The encoder must not introduce any other changing parameters such as frequently changing time stamps in the URL path. For example, if the URL path format was: eventname/sessionID/bitrateID/post-timestamp_sequence#.ts

Introducing the post-timestamp parameter creates another set of directories for each .ts file — a condition that would cause excess directories and possible timeouts over long periods of time.

User-Agent string

Encoders must include a User-Agent header (which provides information about brand name, version number, and build number in a readable format) in all posts. For example, Vendor Model Version#

URL configurability

Encoders should allow specification of a POST server address, also known as a POST URL, upload URL, or ingress URL. It's also recommended that encoders allow the specification of a playback address, also known as a playback URL or retrieval link. For details, see Primary and backup HLS stream URLs.

Use Live-to-VoD

The Live-to-VoD feature enables you to convert live streams to video-on-demand assets.

#EXT-X-PROGRAM-DATE-TIME:2017-01-19T08:04:00.624Z

The EXTINF tag is also mandatory for Live-to-VOD.

For DASH, Live-to-VoD is supported only for sequential segment indexing and not for time-base indexing.