# Is TiVO artifically slowing down Stream transfers?



## Time_Lord (Jun 4, 2012)

I was looking at the Stream on my Roamio (http://<streamIP>:49152/sysinfo and randomly I was able to get an "Advanced" page to come up and found the bitrate set to 2240000, tried changing it but was unable to nor was I able to select the Override Bitrate see the (hopefully) attached image.


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## Dan203 (Apr 17, 2000)

I was able to look at the javascript code and see how to get to that page. I tried hacking it a bit but it seems to check in with the Stream itself first and only allows you to set them if the Stream is in the proper mode. I couldn't find any way to set the mode via Javascript, but I didn't look that hard. Although my guess is the mode is set by some switch on the headend.


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## moyekj (Jan 24, 2006)

Might be interesting to try turning off all HLS settings to see what results with a transfer. "Enable low power mode" setting also looks interesting to turn off. Most likely changing via http is not possible though without proper back end config as Dan mentioned.


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## Dan203 (Apr 17, 2000)

Has anyone really tried hacking a Stream? Like trying to break into it's Linux OS? I wonder if it has the same PROM protections as a full size TiVo?


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## Time_Lord (Jun 4, 2012)

Dan203 said:


> Has anyone really tried hacking a Stream? Like trying to break into it's Linux OS? I wonder if it has the same PROM protections as a full size TiVo?


Working for a hardware/appliance manufacturer in the IT world and seeing how they handle their new platforms and software I would suspect that TiVO would simply build on their existing knowledge of protecting the hardware from hacking. Simply put why change something that isn't broken?

-TL


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## tre74 (Nov 12, 2010)

I am transfering shows from my base Roamio to my iPad for the first time. Wow, is it slow! A one hour show is transfer in what seems like real time. It was never this slow with the Premiere. I am using the same Stream.


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## Dan203 (Apr 17, 2000)

tre74 said:


> I am transfering shows from my base Roamio to my iPad for the first time. Wow, is it slow! A one hour show is transfer in what seems like real time. It was never this slow with the Premiere. I am using the same Stream.


Is the Roamio connected to the network the same way as the Premiere? If the Roamio is using wifi and the Premiere is using Ethernet then that could explain the speed difference.


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## Time_Lord (Jun 4, 2012)

ok, I thought I'd look closer at the Stream's performance and I'm not sure if its the Stream that's the major bottleneck.

I'm downloading to an iPad Mini running iOS 6 (I don't have the courage to go to 7 yet)

I picked a 30 minute HD program and transferred it as "basic" quality, the iPad says the file is going to be 558.56 MBytes

according to my switch (nice thing about manageable switches) its averaging just over 6Mb/s, the throughput after about 5 minutes has dropped to just under 4Mb/s and a few minutes later dropped to 3.5Mb/s and appears to stay there.

A few things I do not know, how fast can the iPad transfer data, just because I have a quiet and rock solid 802.11g signal doesn't mean the iPad can accept data at full speed.

The second transfer I timed (didn't think to time the first one)...

while 216.8MB but as soon as it started transferring it went to 566.93MB for the size of the transfer. (why?)

It too ramped up quickly to 6Mb/s and at that speed should take about 12 minutes to transfer.

Half way through the transfer and the estimate remaining plus time used is about 13 minutes. After 8 minutes the transfer started to slow down to 4Mb/s, at 13 minutes its down to 3.6Mb/s and about 4 minutes to go, at 15 minutes I'm down to 3.2Mb/s and stayed between 2.9 and 3.2Mb/s for the remainder of the transfer. The transfer took 15 1/2 minutes.

I've got 2 questions

1) why is a "basic" quality going back to a "best" when its actually downloading?!?!?!
2) why is the speed dropping over time by half?

-TL


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## moyekj (Jan 24, 2006)

Time_Lord said:


> 2) why is the speed dropping over time by half?


 Following the theory that speed throttling is going into effect to reduce heat issues, maybe as download proceeds the Stream gets hotter and so throttling kicks in. If you are using Standalone Stream perhaps you can open the case and/or blow a fan on the Stream as it downloads to see if keeping the temperature down on the Stream has any effect. I believe the sysinfo Main page has temperature indicated so may be a good page to monitor regularly as well.


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## Time_Lord (Jun 4, 2012)

I think more importantly why it's the transfer f going back to best? 

Sent from my SPH-L710 using Tapatalk


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## Dan203 (Apr 17, 2000)

Are you sure that's not a display issue. You should check the free space available on your iPad before and after you transfer something and see if it goes down by the size of a Basic or Best transfer.


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## Time_Lord (Jun 4, 2012)

Dan203 said:


> Are you sure that's not a display issue. You should check the free space available on your iPad before and after you transfer something and see if it goes down by the size of a Basic or Best transfer.


positive its not a "display" issue, the amount of data to download goes back and matches the "best" download plus the amount of time it takes to download is correct for the filesize for "best" quality.

Sounds like a bug to me

-TL


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## Dan203 (Apr 17, 2000)

I just ran a test and I'm not seeing quite the same thing. I selected a 1 hour HD show and told it to download at Basic quality. The list said it would be 420MB. As soon as it started downloading the size jumped down to 320MB, but over the course of the download it climbed until eventually reaching a final size of 401MB.

The reason for this is that the file is being transcoded on the fly and they are using a variable bitrate encoder. So the size in the list is just a guess based on the average bitrate and the length of the program. However I know from experience that with VBR encoders the size vary can quite a bit depending on the amount of action in the video. A simple talking head type video may end up smaller then the target and a high action movie may end up bigger. This is probably what you're seeing.

That being said it did take quite a long time to download given it's final size. The 30 minute SD show I transferred at Best, which was 598MB, only took 13 minutes but the hour long HD show I did at Basic took nearly 40 minutes. I wonder if the amount of compression being used for Basic is slowing down the process? Or if because it's HD it was slower? I'm going to try downloading the same show as Best and see if it happens any faster.


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## moyekj (Jan 24, 2006)

Just got my iPad Air today. 30 min HD show @best took over 20 minutes to transfer for me. I watched the temperature under Stream sysinfo during transfer and it climbed from 40 C all the way to 68 C, so looks to me like heat is a factor.


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## Dan203 (Apr 17, 2000)

Same exact show at Best took exactly the same amount of time as at Basic. That's not normal even if they are mucking with the clock to reduce heat. Typically a higher resolution, higher bitrate, encode will take longer then a lower bitrate, lower resolution, encode all other factors being equal. That says to me that either the decoding is the limiting factor or the transfer from the TiVo to the Stream is being throttled. I could actually see them throttling the stream from the TiVo to the Stream since that might effect the performance of the TiVo for other duties, such as streaming to Minis, if it's just reading the file from the disk as fast as it possibly can. It would also explain why an SD show, which is only ~3.5Mbps would transcode faster then an HD show that is ~13.5Mbps. I'm running another test now on a lower bitrate show to see if it takes less time. Still HD, but only 720P so the bitrate is about 8Mbps.


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## Dan203 (Apr 17, 2000)

Weird. The 720p file only took 24 minutes so I thought I was on to something with my theory, but then I tried to download an SD file that was only about 5Mbps and it too 32 minutes. So I have no idea what's happening here. These times make no sense.


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## moyekj (Jan 24, 2006)

I'm dissappointed with the transfer speeds. For occasional transfers it will be ok, but for transferring several shows at once I'll stick to TTG methods and a wireless transfer app to copy encoded shows to the iPad since all that can be more easily automated.


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## jdmass (Dec 1, 2002)

Time_Lord said:


> I was looking at the Stream on my Roamio (http://<streamIP>:49152/sysinfo and randomly I was able to get an "Advanced" page to come up and found the bitrate set to 2240000, tried changing it but was unable to nor was I able to select the Override Bitrate see the (hopefully) attached image.


How were you able to get to the Advanced page? When i go the URL, I see the Advanced and Logs button flash briefly and then disappear -- the Javascript code is hiding them.


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## Dan203 (Apr 17, 2000)

I was able to redisplay them by using the debug console in Firefox. One line of JS code. But all the functionality requires a request to the server (i.e. The Stream) so you can't actually do anything.


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## Sixto (Sep 16, 2005)

Similar results here, about 40 minutes for one hour HD. Roamio Plus.


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## Dan203 (Apr 17, 2000)

I saw as low as 22 minutes for a 720p show an as high as about 38 for 1080i and 480i. Maybe it's the scaling and deinterlacing. The shows end up being 720p for the iPad so a 720p source would require the least amount of processing.


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## moyekj (Jan 24, 2006)

jdmass said:


> How were you able to get to the Advanced page? When i go the URL, I see the Advanced and Logs button flash briefly and then disappear -- the Javascript code is hiding them.


 You can see the values using this URL (returns data in JSON format):
http://<streamIP>:49152/sysinfo/json/advinfo
(As Dan mentioned, you can't change them, just view them).


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## mattack (Apr 9, 2001)

Dan203 said:


> Same exact show at Best took exactly the same amount of time as at Basic. That's not normal even if they are mucking with the clock to reduce heat. Typically a higher resolution, higher bitrate, encode will take longer then a lower bitrate, lower resolution, encode all other factors being equal.


But other factors aren't being equal. AFAIK, the whole 'reason' for the stream is that the *hardware* is doing the reencoding, not a general purpose CPU.


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## Dan203 (Apr 17, 2000)

Yes but even special purpose chips like this should vary based on bitrate. I think the bottleneck is the image processing. Shows that need to be deinterlaced and resized seem to take longer then shows that are already 720p.


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## Time_Lord (Jun 4, 2012)

What I don't know is what is the realistic download speed of an iPad? I'm using an iPad Mini. A 500 MB file transmitting at constant 5Mb/s rate will take about 15 minutes to transfer.


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## Dan203 (Apr 17, 2000)

The download speed is irrelevant. This isn't like TiVoToGo where the show is being downloaded at it's original quality and the bottleneck is the network speed. These shows are being decoded, deinterlaced, scaled and then recoded to H.264 on the fly. Even on a high end PC that process can take 20-30 minutes per hour of content. The Stream can do that to 4 shows simultaneously.


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