Roku Developer Program

[manuelalvarez]

I am having a hard time with HLS. The Roku seems to stick to one particular bitrate stream and won't switch to a lower one even if the bandwidth available is not enough for continuous playback.

The Roku will just stop playing and the "Loading..." screen will come back on until it refills the buffer. It keeps doing this over and over.

Can someone from Roku Engineering assure me if the Roku is supposed to switch to a lower bitrate stream? How can I troubleshoot this? I am trying to play a live stream from a Wowza server.

[manuelalvarez]

Here is a test stream if anybody wants to try it out, it has four different bitrates. The SMIl file has the lowest as the first entry.

http://mek2.mekstream.com:1935/antenala ... ylist.m3u8

[RokuKevin]

The roku does do adaptive streaming in hls. It can switch on any segment boundary.

--Kevin

[manuelalvarez]

Thanks Kevin! Any idea why it would not be switching on my stream? I'd really appreciate some help with this.

Cheers,

Manuel.-

[RokuKevin]

It should switch. You can experiment with different streaming strategies using the new SwitchingStrategy content meta data parameter in v2.8. You could force a switch with a traffic shaping router or by removing one of the upcoming .ts files from the playing stream on your web server.

From the v2.8 Component Reference:

Possible strategy values:

“unaligned-segments”
This was the algorithm used in v2.7. This strategy does not require segments to align across variants. Also does not switch as often as full-adaptation.

“full-adaptation”
uses measured bandwidth and buffer fullness to determine when to switch. This strategy requires that segments align across variants as the HLS spec requires. This is the new default.

“minimum-adaptation”
Uses only measured bandwidth in determining switching strategy. This strategy requires that segments align across variants as the HLS spec requires.


--Kevin