Force bitrate switching?

Archived
1

Hey all:

I’d like to debug some keyframe issues in our proprietary HD encoders, and wondered if there’s a way to force roku to select a specific bitrate mid-stream in the debug console?

Thanks,
-t

2

I assume you’re talking about an HLS stream? There’s no debug command to do this, but you can omit some segments from the m3u8 for the high bitrate streams (using a DISCONTINUITY tag) and the player will switch to another stream that does contain that segment.

–Mark

3

Thanks, Mark - can you confirm/deny that it will hls bitrates midstream at all, or is it just a best-shot guess at stream startup? I’m not actually seeing it increase at all any more when I throw it in automatic mode.

4

If there are multiple variant streams defined by the top level m3u8 and they cover the same sequence numbers, then the player should switch between them based on bandwidth.

–Mark

5

ahhh i had been using different tags for the distinct bitrates of each stream. i’ll try the wowza smil method and see how it fares, thanks.

6

@peppert

Please report back, I am also interested in finding out if Roku switching midstream between the bitrates.

Regards,

Manuel.-

7

not particularly well yet, though it’s entirely possible that’s my fault. i should probably first mention that my test streams are a mix of the following:

720p (actual res 1248x702) 29.97fps ~1600kbps
1024x576 29.97fps ~1000kbps
480x270 29.97fps ~600kbps
480x270 29.97fps ~350kbps
480x270 29.97fps ~150kbps

my ipad, iphone, and quicktime are all able to switch between bitrates seamlessly but the Roku here seems to want to stick on one bitrate when playing my testing urls, e.g.:

http://10.0.22.104:1935/rtplive/smil:21 … ylist.m3u8

the smil file (on wowza) in question contains:

8

I am also new with the Roku, but I have seen the same behavior, the Roku seems to select a stream and if there is not enough bandwidth to maintain it, instead of switching to a lower bitrate stream, it will rebuffer the first selected.

I really hope this can be fixed. I am also using Wowza as the server.

9

i’m also using live streams, not that it should matter.

10

Same here.

11

I had done some tests with Roku and get same results as mentioned by Peppert.
About HLS standard Can we force client to always look for the highest bit rate defined in the manifest file? instead of looking for the lowest bit rate in the manifest file?
Suppose we have following bitrates in the manifest file 1mbps ,750kbps,500kbps,250kbps, is there a possibility whatever client requests we can force it to highest bitrate? or its mandatory to be at lowerst