[pmcgarr]

Hi,

I am new to XBMC and this community. I am a long time Windows Media Center user and like many others, very excited about the new PVR functionality in Frodo. I have a question that I searched the forums for an answer to without luck. In fact I searched outside the forum as well. It’s possible (probable) the answer is staring me right in the face though.

The symptom is live TV playback is jerky. It plays back fast and then slows to a crawl, only to speed up again and then slow down again. I see a buffering status periodically as this is happening, but it comes and goes. Sometimes when I change a channel everything will freeze and I will see that buffering status just sitting there stuck at 0% or 2%, etc. If I wait long enough, a handful of minutes, often it will resume, but still be suffering from the slow/fast behavior.

Recorded video plays back fine. By recorded video, I mean TV that was recorded by Windows Media Center, movies that were downloaded/ripped, etc. From what I can see, the only video that suffers is live TV.

I use NPVR backend and of course, the NPVR add in that was included with Frodo. I do not have this performance issue in NPVR or Windows Media Center, just XBMC so I am thinking that XBMC is the scope of my issue. Remember though, I am new to XBMC and not sure of the interactions of it with NPVR. I see a lot of reference to audio causing these types of issues. Is that accurate? Could I have an audio issue that affects live TV playback and just live TV playback? Seems strange to me, but that’s likely because I just don’t understand. Here are my system details, at least the ones I can think of:

Tuner: HD Homerun Prime
Network (connection to tuner): 100Mbit, this will be changing to 1000Mbit soon.
Frontend: XBMC Frodo
Backend: NextPVR 2.5.9 (installed patch recommended in XBMC wiki)
OS: Windows 7, 32 bit, current on all Windows Updates
Graphics: Intel 954GM

Memory and CPU show reasonable levels in System/Info. By reasonable I mean ~30% memory and ~20-40%CPU. Not sure if that is reasonable, but doesn’t appear to be anywhere near a maximum.

Any advice would be appreciated. I am glad to provide any information I can. I very much appreciate any help anyone can give me. I look forward to this XBMC experience, and I look forward to giving back once I get my feet wet.

Thank you,

Paul McGarr

[pmcgarr]

I made some progress last night with this. I still have the jerky playback, but it has improved. Also I resolved the buffering issue.

For the buffering issue, I think NPVR cumulative updates fixed it. I know I stated above that I installed the update recommended on the XBMC Wiki, but a second look showed that I installed just a single update, not the cumulative update. That, in combination with a setting in my tuner config I believe, resolved the buffering/freezing issue, at least for the short period I tested. I should ask this. My tuner config has a setting where I chose the system It will be used with. I can chose from NextPVR, XBMC, Windows Media Center, and others. Previously I had chosen NextPVR, but last night I tried XBMC. This is a guess because I don't understand how XBMC and NextPVR interact.

For the jerky live TV playback issue, which was totally unwatchable before last night, I was able to witness the influence of audio settings making a huge difference in the severity of this issue. I changed the Windows setting that allows XBMC to take complete control over the audio, and I played around with /system/settings/audio. Playback is better, but still jerky, suffering from the bursts of higher speed playback. I believe this is only a problem on HD channels.

I also noticed, after all the changes, that my CPU is higher than I thought. Memory is fine, but CPU as observed last night was 70-80% I can only assume this is bad. It played with the hardware decoding setting and it made no difference. I am unsure if my hardware supports it. I will look into that.

I am thinking about buying a new box so I can set this up on the side instead of on our in-service Media Center. I am tempted by the Acer Revo type off-the-shelf boxes. I think I will start a new thread about that as to not confuse this one.

Paul McGarr

[strifu]

I am having the same exact problem with live tv being choppy. The one difference I have is that I have a hdhomerun dual which I don't think matters. Have you made anymore progress on this issue?

[Frank_aspen]

I had a very similar issue, and was able to fix it by changing the mpeg2 codec being used. I run an hdhomerun connected to a virtual machine running npvr. I changed the codec on both (npvr and the htpc) and then changed the renderer on the VM.

[emveepee]

Placebo effect only as nextpvr codecs and renderers aren't used in recording or by xbmc.

Martin

[kinetik]

What codecs does everyone have NextPVR set to use?

[pmcgarr]

Just an update, I was pretty much stuck and decided to buy new hardware so I could give this a fair shot. I was unable to get things right on my Windows box, partly because it is Windows, but primarily because it is my current HTPC, and my family depends on it.

I have purchased new hardware to build a proper, but beginner, Linux HTPC. I will start a new thread on that because I am making mistakes and might be able to help others avoid the same ones.

Paul

[dj_siek]

Hey All, Similar issue for me...
My issue moves between Jerky TV (seems to be frame dropping) and the image slowing down and eventually stopping completely.

One Channel in partciular (Channel 10 - Melbourne Australia) is watchable but is always stuttering...), and other times, i have to switch to a channel 2-3 times before it will stay on, otherwise it just slows down and stops (audio continue's though)

I am using a Windows 7 Lenovo Laptop as my Tuner Server and have an Matricom Midnight MX2 as my front end (XBMC Frodo) connected via HDMI to TV

Setup Details:
Tuner: Kaiser Baas Dual DVB-T USB TV Tuner - plugged into USB port on Laptop
Network (connection to XBMC): 100Mbit, this will be changing to 1000Mbit soon.
Frontend: XBMC Frodo
Backend: NextPVR 2.6.2 (installed combination patches recommended in XBMC wiki)
Running on: Lenovo Thinkpad x1
OS: Windows 7, 64 bit, current on all Windows Updates
RAM: 4GB
CPU: Intel Core i5 2.5 Ghz

Has anyone had this same issue and been able to fix? I"m guessing it's my laptop not being powerful enough?