Roku - Bitrate Menu

I was testing the Roku hidden Bitrate menu by pressing Home 5x, RW 3x, FF 2x. Auto is set by default. Towards the bottom is Enable Debug Playback. I clicked ok on this to enable it and ran a stream from my Tablo. It stated it was a 1.5 mbps stream on 40 mbps network. I have Tablo set to HD 720p ( the high of the two 720p choices ). Both Roku 3 and tablo hard wired with Powerline adapters. This is strange that Tablo is sending a 1.5 mbps stream. So I went back in the menu and set the bitrate to 3.5 which is the highest. After that, the stream appeared a lot better quality and football tonight was great to watch. Tablo, why would the Roku register a 1.5 mbps stream from the Tablo?

Just tried this and i do see a difference.

This is very interesting

The Tablo only records 1 stream and does not dynamically adjust the bitrate, it is not possible for any bitrate setting on the roku to affect the quality of the video being sent from the Tablo.

@Davidvr when Roku is set to automatic and debugging is enabled and you start a stream from tablo it shows 1.5 mbps stream being delivered from the Tablo to the Roku. So either the Tablo is sending it as 1.5 or the Roku is determining the best Bitrate itself when set to automatic. I have been switching back and forth between auto and 3.5 max Bitrate and I notice an overall better picture quality when the Roku is forced to 3.5

@guck that’s nice that the roku says one thing or another, but I’m trying to tell you it’s techinically impossible for that setting on the roku to change the bitrate the roku is receiving from the tablo.

From what I was reading, the Roku automatic Bitrate setting uses an algorithm that takes the last X connection speeds across all channels and determines the best Bitrate/connection speed for you on your Roku with respect to your Network. This could explain the 1.5 mbps stream from Tablo and why forcing the Roku to connect at 3.5 max speed results is a better picture. @TabloTV @TabloSupport can you confirm the Tablo connection speed for Roku? And why the Roku would be reporting 1.5 mbps stream from the Tablo server when the default automatic is selected? ( FYI when the Roku is rebooted or power cycled the Bitrate setting defaults back to Automatic )

@Davidvr, wondering why you are saying it is technically impossible?? Is there some throttling that Tablo is doing for Roku that you know of?

I do an ffmpeg from my Tablo and I see bitrates in excess of 5MB

frame= 1367 fps= 30 q=-1.0 Lsize=   28767kB time=00:00:45.61 bitrate=5166.7kbits/s   

And that is lower than the highest I see

@jestep the tablo only has one stream at one bitrate , there is no way for the roku to get any other bitrate then what it was originally recorded at

I just pulled down a single .ts file and looked at it and here is what I see, so not sure why you are saying that.

Stream: 00001.ts
Path: ~/Downloads/00001.ts
Type: MPEG transport stream

Duration: 0:00:09
Data Size: 3.83 MB
Bit Rate: 3.23 Mbps

Video Tracks:
49 MPEG-1

Audio Tracks:
52 MP1 mono (joint), 48 kHz, 416 kbps

Stream Files:
00001.ts (3.83 MB)

@TabloSupport, can we get a response from you guys on this?

I am seeing 3mb+ Bitrate and @Davidvr is saying 1.5

I assume this is different based on the channel as I noticed a lower bitrate on a low res channel. Am I crazy here?

@jestep I never said 1.5 , I said the tablo will always provide the bitrate the program was recorded at . If it was recorded at 5 Mbps, that is what the roku will play it at

@Davidvr gotcha, I must have misunderstood… Sorry, early for me :stuck_out_tongue:

So back to @guck11 comment on changing the bitrate on Roku, if it is set to a lower bitrate (via Automatic) I am wondering does the roku transcode on the fly a higer bitrate down to a lower bitrate???

I should have mentioned I saw the 1.5 on the Roku on the files where I saw the 3mb+ ts files via the Automatic setting

@Jestep I’m trying to explain is that the Roku may be requesting a 1.5 Mbps stream but the tablo will provide whatever bitrate the TS stream is. 

Also keep in mind the bitrate of the ts file depends on what resolution the channel is. 
a 480 channel might be 1.5 Mbps 
a 720p channel might be 5 Mbps 
a 1080 channel might be 8 Mbps 

There is no way for changing that setting on the roku itself in the hidden menu to change the actual ts bitrate being sent to the roku.

@Davidvr, I understand what you are saying, but even on my 3mb+ files I was seeing 1.5mb bitrate. So I am trying to figure out why Roku would display 1.5 for the 3mb bitrate file.

@Jestep The bitrate may be variable in the recordings (where lower motion parts have a lower bitrate) or that screen may just not be accurate 

@Davidvr, that is my worry that the Roku is just showing 1.5 but may not be the valid value. Since the bitrate of my files are 3mb+ bitrate on the specific show I am looking at the Roku with.

Yea, I just went in and played a few different shows at different quality and they all show 1.5mb bitrate on the debug screen. I don’t trust that value at all

Found this comment, "The debugging screen is an engineering tool left over from the early days of Roku testing. It doesn’t work with adaptive bitrate streams, like Netflix, or live streaming. "