CMAF Livestreams with Subtitles

This page provides two live web streams with subtitles to demonstrate the advantages of the emerging Common Media Application Format (CMAF). CMAF aims at unifying the two leading adaptive streaming standards which currently are MPEG-DASH and Apple's HLS.

See below for the stream url's and more background information about the showcase.

BR Live Service as recorded loop

Note: Your Browser was not tested yet or does not meet the necessary requirements to play the stream in good quality. On Windows please try Firefox or Edge.

The stream shows content from the TV program of the public broadcaster Bayerischer Rundfunk (BR). The program was recorded and is played back in a loop but the encoding itself is done live.

Program Live Stream (Bayerischer Rundfunk)

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This stream shows the regular TV program of the Bavarian Public Broadcaster Bayerischer Rundfunk (BR).

Note: At certain times of the day the video may not be available. For legal reasons content may not be streamed or not be accessible everywhere. The broadcast content used as input may also have no subtitles or no Audio Description (AD). Alternatively please access the stream with the recorded content ("BR Live Service as recorded loop") which does not have regional constraints. This stream has always subtitles and AD.

About this showcase

For broadcasters the benefit of using CMAF for future OTT IP services lies in its efficiency: only one packaging system is required and only one set of media chunks needs to be built. Consequently, also less storage space is needed for non-linear services such as catch-up TV, leading to lower storage costs. The viewer benefits as well, because HTTP caches in the delivery network become much more efficient, thus decreasing the risk of network congestion.

CMAF also facilitates a better deployment of accessibility services. The sample streams contain deaf and hard of hearing subtitles in the IMSC1 format and can be extended by the alternative Web caption format WebVTT. This flexibility results in a better cross-platform support on mobile devices and Smart TVs.

Technical Background

Technically, with CMAF, both HLS playlists and DASH manifests are allowed to reference the same fragmented MP4 (fMP4) chunks, whereas currently these chunks must be duplicated for each streaming mechanism. This allows any DASH player on Windows or Android to playback the exact same media segments as recent Apple devices (iOS11, tvOS, MacOS). Smart TVs based on HbbTV 1.5 and onwards support DASH-based streaming; therefore, CMAF also provides an important step towards the harmonization of HbbTV and HLS platforms.

DASH URLs

Recorded Loop

https://irtdashreference-i.akamaihd.net/dash/live/901161/keepixo1/manifestBR2.mpd

BR Live

https://irtdashreference-i.akamaihd.net/dash/live/901161/keepixo1/manifestBR.mpd

HLS URLs

Recorded Loop

https://irtdashreference-i.akamaihd.net/dash/live/901161/keepixo1/playlistBR2.m3u8

BR Live

https://irtdashreference-i.akamaihd.net/dash/live/901161/keepixo1/playlistBR.m3u8

Cooperation between partners

BR (Bayerischer Rundfunk) is the content provider of the program streams, integrated the encoder in its operational streaming environment and provides both streams.

IRT coordinated the efforts and reviewed the sample streams.

Keepixo developed the multirate encoder and OTT packager for CMAF.

Contact: Andreas Tai, tai(at)irt.de