Audio Only not working for DASH

Wowza Streaming Engine
1

Hi,

If an audio only radio service is transcoded and the appropriate SMIL file is created an HLS m3u8 manifest can be got from the server, however it is not possible to get the DASH mpd one. If a video stream is added then it is possible to get the DASH mpd file from the server. DASH is enabled in the configuration.

Is this a bug or a feature that audio only can’t be streamed or is there some specific config for this? Has anybody else streamed audio only radio services using DASH?

Thanks,

Bob.

2

Hi,

Audio only should work.

Please describe your live streaming configuration, the live source encoder being used and the player used for listening.

If you play a single stream, instead of the smil presentation, does the audio then playback?

Daren

3

Bob, thank you for the detailed follow up. This will surly come in handy for others as well.

Regards,

Salvadore

4

Hi,

I have now got it working for audio only. It was already working for TV services.

The setup is a professional satellite receiver that outputs a DVB/MPEG multi program transport stream over IP in to the server running Wowza on Fedora.

The incoming TV services are MPEG2 video with MPEG1 Layer II audio and the radio services are MPEG1 Layer II audio that are transcoded. For the TV services the Fallback transcoder is used and a specific named one bfbsuk.stream for audio only. Appropriate smil files were created for the services that refer to the transcoded streams.

First of all for HLS this now appears to be a red herring:

:~> curl http://172.30.2.83/satlive/smil:bfbsuk.smil/playlist.m3u8

#EXTM3U

#EXT-X-VERSION:3

#EXT-X-STREAM-INF:BANDWIDTH=96000

chunklist_w16524389_b96000_ao_sleng.m3u8

Even though it returns the playlist it doesn’t actually play when tested with the the bitdash player that supports HLS. Digging down it was found that:

curl http://172.30.2.83:1935/satlive/smil:bfbsuk.smil/chunklist_w16524389_b96000_ao_sleng.m3u8

Does not work, nothing returned.

For DASH

:~> curl http://172.30.2.83:1935/satlive/bfbsuk.stream_aac/manifest.mpd

returned nothing.

What worked was referring to the transcoded stream directly and not using the SMIL file.

:~> curl http://172.30.2.83:1935/satlive/bfbsuk.stream_aac/playlist.m3u8

and

:~> curl http://172.30.2.83:1935/satlive/bfbsuk.stream_aac/manifest.mpd

These urls were used in the configuration for the bitdash player and it now works.

Thanks for your help.

Bob.