Forum Discussion

RonaldH's avatar
RonaldH
Visitor
15 years ago

M3U8 Multi Bandwidth issue

I'm developing a Channel for Livestream, to test, but when we have multiple bandwidths enabled in the m3u8 it doesn't go to HD, when we only put up HD it will play it fine, bandwidth can't be an issue.

I modified the customvideoplayer example to accept the m3u8 of ours.

Specifications:
-Roku HD - Software version 2.9 build 1553
-Bandwidth to the city where the server is: http://www.speedtest.net/result/1274142669.png
-M3U8 URL: http://xhdmultibitratedemox.api.channel.livestream.com/3.0/playlist.m3u8

If more info is required, I could supply it.
Roku Developer Program

8 Replies

  • TheEndless's avatar
    TheEndless
    Channel Surfer
    15 years ago
    I'm not sure if this is what you're seeing or not, but with HLS, the Roku will start with a lower quality stream to get playback started faster. After a minute or so, you should see it switch to the higher stream(s).
  • RonaldH's avatar
    RonaldH
    Visitor
    15 years ago
    It will sometimes switch to HD, but will switch shortly after it to normal quality.
  • tensen's avatar
    tensen
    Visitor
    15 years ago
    I could be that it isn't able to sustain the higher bandwidth consistently. Can you put in an intermediary 720p HD in to catch a midpoint in your bandwidth utilization?
  • RonaldH's avatar
    RonaldH
    Visitor
    15 years ago
    I tried it, and it has the same issue.

    When having a stream up @ 6 Mbit/s just in HD quality, it will keep it streaming just fine, no glitches or any other problems.
  • RokuKevin's avatar
    RokuKevin
    Visitor
    15 years ago
    How did you come up with the 3096000 bandwidth value in the .m3u8 file??

    --Kevin
  • RonaldH's avatar
    RonaldH
    Visitor
    15 years ago
    The current stream is just mobile and high for the test.

    it's 3000 Kbit/s for video + 96 Kbit/s for audio * 1000

    On the HD + Meidum + Mobile it is

    #EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=198000
    #EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=52
    #EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=678000
    #EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2128000
  • RokuKevin's avatar
    RokuKevin
    Visitor
    15 years ago
    Because you've set the bandwidth artificially high, the Roku is trying to download that bandwidth but can't get it. Therefore, it drops down to the lower bandwidth.

    You should set the bandwidth to the actual average bitrate of your stream.

    --Kevin
  • RonaldH's avatar
    RonaldH
    Visitor
    15 years ago
    We will try to do so, but it isn't artificially high, we are actually streaming at that channel with a 3 Mbit downstream.

    What bandwidth work best with the roku device? what works best in your experience?



    The specifications of HTTP Live streaming says the following of of the bandwidth

    BANDWIDTH=<n>
    where n is an approximate upper bound of the stream bitrate, expressed as a number of bits per second.


    As a last note, we will try to lower the bandwidth tag, but the roku device is handling the constant streaming of the 3 Mbit one fine, when we have the four bandwidth one, it sometimes jumps to 2128000 and then sometimes jumps back to 678000. As you can see in the first post, the internet that we have can handle the speed fine.