Beta Placeshifter Excessive CPU and jerky

[brookb]

Hi,

I've noticed with the 6.5.13 beta (Placeshifter on main PC and SageTV on server PC in server mode) and with the previous few betas as well that when watching 720P material in full screen mode where Placeshifter has focus, on a dual core Intel processor, CPU time on the Placeshifter PC goes up approaches 50% on one core and a little less on the other (max is 50% on each core), and the video is jerky at times - especially at times when one of the cores saturates at 50%. However, if I'm watching NTSC or 1080i material, if Placeshifter is not in full screen mode, or if any other process window besides Placeshifter has 'focus', this does not occur. The CPU cores do not saturate.

Using process explorer to analyze what's going on, it appears that an MSVCR71.dll!endthreadx+0x31 sub-process of the SageTVPlaceshifter.exe task is the primary CPU hogging culprit. When Placeshifter is in focus, fullscreen, and 720P, the problem occurs, and MSVCR71 shows between 28 and 50% CPU time with over 2000 context switches (CSwitch Delta in Process Explorer) between samples. However, with 720P running full screen, but any other window on top with focus, the video runs smooth behind the window on top, and the MSVCR71 CPU time drops to between 8 and 20% usage with only 300-800 context switches per sample period.

It is obvious that the actual function of playing back the video and audio do not hog the CPU, because as I said before, if another window has focus, the video plays cleanly in the background. But this MSVCR71 sub-process pegs out and performance goes in the can when all of the afore-mentioned characteristics come into alignment. What is this sub-process doing, and why does it only do it under these particular circumstances?

My temporary solution is to open Firefox, drag its corners until its a tiny square, and place it in the corner of the screen on top of Placeshifter in full screen mode. Then the video is nice and smooth, and the CPU usage drops way down. My Placeshifter keyboard shortcuts don't work without ALT-TABing first to give Placeshifter focus, but at least the video is smooth.

Please advise if this can be fixed with settings, properties file entries, or if this is likely a 'bug' than needs to be resolved in the software.

BTW: I've tried the video_buffer_size=32000000 thing, and that doesn't help.

Thx!

Brook

[Narflex]

That's a very interesting problem....I have one idea of what might be related. First, if you have the bitrate statistics window open; close it (but if that's it, I'm sure you tried it). Second, if you have the bitrate statistics enabled on the title bar; then disable them (you can do that by right-clicking on the title bar). Let me know if that changes anything. Also, do you have 3D acceleration on in the Placeshifter? And does changing that option affect the issue at all?

[brookb]

Hi Narflex,

My Placeshifter settings were:
Enable Custom SageTV Title Bar: Enabled
Show streaming statistics in Title Bar: Enabled
Enable 3D acceleration: Enabled
Enable Video Post-Processing: Disabled

Media was being played back without transcoding on a wired 100BT network.

First, I tried disabling "Show Streaming Statistics in Title Bar". This did not help.

Next I disabled "Enable Custom SageTV Title Bar. This made a difference:
* First of all, an undesired standard windows 'Title bar' became always visible, even in full-screen mode. I'd like this to go away.
* However, the jerkiness disappeared. Finally the picture looks good!
* The CPU usage for MSVCR71 now stays the same (relatively low) regardless of which window has focus
* All in all, despite the undesired title bar, this is a far superior choice for clean video

Next, I re-enabled "Enable Custom SageTV Title Bar". But then I disabled the 3D accelleration. This made the following differences:
* The irritating title bar was now gone again
* The Jerkiness is gone as well
* The CPU usage for SageTVPlaceshifter and all of its sub-processes combined appears to have dropped down to around 1%. Excellent!

This is the best solution for my setup, and I'm now happy! Thanks much!!!

I would suggest a 'warning' on the Placeshifter settings window next to the 3D acceleration setting that tells folks that in some cases, enabling this will cause excessive CPU usage and jerkiness, and to leave it disabled unless needed. Or something like that. . .

[Wheemer]

Enabling that option should not have that kind of negative effect. So it would be better to fix the underlying problem than to place that warning.

[brookb]

I agree with Wheemer that if this is a bug, then fixing it is by far the best solution. But disabling 3D is a good option for at least some of us.

When I saw the latest 6.5.14 beta come out, I read the release notes and did see something about a 'focus' and 'performance' problem being fixed, and figured that perhaps this was a fix for the problem I had noted.

So I installed .14 SageTV and Placeshifter, re-enabled 3D in placeshifter and started it up. Performance is the same as before - for me anyway; jerky playback and high CPU usage. But as I said earlier, I just disable the 3D setting, and all is OK. But others may not have that luxury.

BTW: I'm running an up-to-date XP on a Core 2 Duo on an ASUS MB with an XFX NVidia GForce 7600, and Java(TM) Platform SE 6 U13 Version 6.0.130.3 if that information helps in figuring out what the problem is.

[DisturbedKT]

I've gotten more specific detail around this problem, as I have experienced it myself. In looking more closely at my "jerky placeshifter" problem, I noticed the key correlation was in the content being viewed rather than anything related to resource constraints (when operating in a jerky fashion, neither server or Placeshifter client are under load, both below 10% on any core at all times - save a short blip at streaming start-up)

What I did noticed when looking at my variety of content is this:

* All of my HD recording exhibit the unusably jerky playback behavior, however all of these are 1080i, PAFF-interlaced H.264 R5000 recordings with AC3 sound. Because these are R5000 recordings, they are all in MPEG2-TS containers.

* All of my SD recordings seem to work fine, though they are 480i MPEG-2 recordings with MP2 sound, though also in a MPEG2-TS container.

* Some video files I'd downloaded as samples from the internet are both HD and play flawlessly. One particularly good example is a 1hr clip which is a 720p H.264 video with AAC stereo audio in (what SageTV calls) a "Format: Quicktime" container.

Further, I will also specify that all of this testing was on a local LAN and therefore not using the dynamic transcoding or any other details to complicated the testing issue.

So, in summary, I think this might help get this subject adjusted a bit, as I think it's compelling anecdotal evidence that this jerky behavior may be more about the video format itself and how it moves through the Placeshifter transcoding process. Items worth considering:

- Could PAFF-interlacing be integral to the problem?
- Is there anything special about H.264 in MPEG2-TS containers?
- Could it be related to AC3 or AC3 in concert with MPEG2-TS containers?


To help this along, could any of you noting these problems look at "detailed info" on examples of jerky/unplayable files and see if we can draw any correlations? Can you also download or find some of your existing files in standard video formats which work fine and contribute similar attributes from them?

Let's see where this takes us, if we put together some good, hard data, I will be happy to put in a bug compiling it all, in hopes it will help the cause of getting this issue addressed for everyone.

-KT

[vikingisson]

I am seeing the same placeshifter issues. For me the problem is with mpeg2-ts files which is what I get from HD-PVR recordings or live. Turning 3D accel off only makes it worse and causes everything to be slow. My much higher res content at mpeg2-ds plays fine. There is something wrong in placeshifter with TS files.

Also, running placeshifter on the server has the same jerky playback. The server UI or windows client is ok, only the placeshiter gives me the problem. I've tried placeshifter on a variety of machines, Windows and Linux.

So for the time being my HD-PVR is useless to me except from the server UI.

Here's a new clue, I ran an HD-PVR recording through conversion and it plays ok. For some reason the latest beta will only convert to iPod format (which I don't need), other choices fail to convert. But it points to the TS encoding as the problem.