Is it possible to use IIS Smooth Streaming for audio without any Video? If so, how do I encode it?

I downloaded Expression Encoder 4, but I can't get it to encode to audio. It's converting my audio files into video streams. I'd like it to have multiple bandwidths from 128Kbps stereo down to 16kbps mono and have it adapt the stream to the bandwidth, just like the video streams.

Is that possible with IIS Smooth Streaming, and do I encode with Expression Encoder or should I prepare the content differently?

1 Answer 1


I don't believe there is a way to do what you are looking for mostly because there isn't much of a practical reason for it. Pretty much any reasonably modern connection is going to handle streaming audio without buffering, so running multiple bitrates and trying to switch between them on the fly shouldn't be necessary. Also, changing from stereo to mono as bandwidth changes would likely have a negative impact on the overall listening experience.

Due to the extremely limited to non-existent need for such bandwidth scaling technology on audio only feeds, I'm not aware of any format or streaming server that supports this. That isn't to say there might not be one, but none of the major media servers I know of bother. 128Kbps is only a little over twice the speed of an old 56k modem. Even the most basic of DSL and cellular data connections exceed that.

Adaptive Bitrate Streaming is the term you are looking for if you want to do more digging to see if you can find something that does it for audio only that I have missed.

  • Probably true for most of the dense populated areas, some of our listeners live in Suriname though, where good bandwidth is a rare luxury. It's mainly speech so the listening experience would not be a big problem. Since the feature already exists in IIS without any extra cost, I'd like to make use of it. But maybe you are right and they just refer to "Media" when they mainly mean "video".
    – Louis Somers
    Commented Aug 14, 2013 at 7:21
  • @LouisSomers - in that case, making two separate streams is probably your best bet unfortunately. I do realize there are parts of the world with low bandwidth, but they haven't been a significant enough portion of the media market to justify building the rather complex software necessary to adaptively shift between different stream qualities on the fly.
    – AJ Henderson
    Commented Aug 14, 2013 at 13:02

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