[solved] Live TV stuttering after fixed amount of fps --> memory problem? (1 Viewer)

[mindm49907]

Hello to everyone,

I have been using MediaPortal (a. t. m. 1.7.1 with Windows 7 64 bit) for nearly one year from now, and would at first like to thank everybody involved in creating this great media center solution!

I appreciate MediaPortal very much, but there's one thing I never could get to work satisfactory:

When watching Live TV, the picture hangs once in a while, sometimes crackles while hanging, and after that, continues to work as normal. I analyzed this behaviour via "Shift+1" (I still don't know the name of this tool ), and I could figure out that this, when watching HD TV (ZDF HD from Germany), happens after every approx. 7000 frames.

When watching SD TV, the error (at least iI think of it as the same one) also sometimes appears, very rarely though, but more often if the quality of the TV stream is higher (e. g. the channels governed by public law in Germany have a higher quality than some others, and in my case, are causing stuttering more often).

This happens no matter if the refresh rate of the TV the HTPC is connected to matches the displayed media's frame rate or not. I am also able to record multiple programs simultaneuosly using my Silicondust HD Homerun Twin Tuner (I already did the troubleshooting recommended on their website), and also measured my network performance to exclude errors of that kind: everything is woking as expected. Also, playing HD videos from HDD never caused any problem.

This leads me to the question if my problem maybe memory-releated, or more precise: timeshift-memory-related. For timeshifting, I once bought a 16GB USB 3.0 Drive, since I didn't want to accidentally write my drives to death, especially not my system SSD.

But now, I do not really know how to move on, and how to further locate the error. Can someone of you please tell me how I can proceed troubleshooting, or - even better - give me a hint or even a (possible) solution to my problem? I would also like to provide logfiles if needed, but I don't know which ones would be helpful.

Thank you very much in advance!

Greetings, mindm49907

 

[mm1352000]

Hello and welcome mindm49907

Can someone of you please tell me how I can proceed troubleshooting, or - even better - give me a hint or even a (possible) solution to my problem?

The first step is to determine whether the problem is client side or server side.
When you see the problem occur, try to skip back 30 seconds and see if the video/audio shows artefacts again in the same place/time.

I would also like to provide logfiles if needed, but I don't know which ones would be helpful.

Yes, log files would be useful.
You should always provide all log files, and use the watchdog/debug-tool if possible:
http://wiki.team-mediaportal.com/1_MEDIAPORTAL_1/16_Support/3_Forums/2_Log_Files

Regards,
mm

 

[mindm49907]

Hello mm1352000,

The first step is to determine whether the problem is client side or server side.
When you see the problem occur, try to skip back 30 seconds and see if the video/audio shows artefacts again in the same place/time.

I'm sorry I forgot to mention this: the error is always at the same point, i can shift backwards multiple times and always get an fragmented screen at the same scene. And since my network does not seem to make any problems (i measured the transfer rates of every cable and network-device involved with iperf using a Debian system on both sides), some memory problem was the only thing left on my mind (maybe the beginning of a new timeshift-file or something?), since playing HD-media from HDD never made any problems.

But, of course, it's also possible that I am completely wrong

Yes, log files would be useful.

The zip-file produced using the watchdog/debug-tool is attached to this message. I waited till the error occured for the first time, and then closed MediaPortal shortly afterwads.

Thank you very much for your help!

Greetings, mindm49907

 

[mm1352000]

I'm sorry I forgot to mention this: the error is always at the same point, i can shift backwards multiple times and always get an fragmented screen at the same scene.

This means the error is server side.

The zip-file produced using the watchdog/debug-tool is attached to this message. I waited till the error occured for the first time, and then closed MediaProtal shortly afterwads.

At the time the error occurred I see this in the TsWriter log file:

[2014-06-28 15:16:56,432] [7bb9a50] [c78] - Recorderid 17de Continuity error... 9 ( prev f ) - bad signal?
[2014-06-28 15:16:56,444] [7bb9a50] [c78] - Recorderid 17e8 Continuity error... a ( prev c ) - bad signal?
[2014-06-28 15:16:56,444] [7bb9a50] [c78] - Recorderid 17ea Continuity error... d ( prev 4 ) - bad signal?
[2014-06-28 15:16:56,444] [7bb9a50] [c78] - Recorderid 17f2 Continuity error... 8 ( prev 8 ) - bad signal?
[2014-06-28 15:16:56,444] [7bb9a50] [c78] - Recorderid 17e9 Continuity error... 9 ( prev e ) - bad signal?
[2014-06-28 15:16:56,444] [7bb9a50] [c78] - Recorderid 17eb Continuity error... 8 ( prev c ) - bad signal?
[2014-06-28 15:16:56,450] [7bb9a50] [c78] - Recorderid 17de Continuity error... d ( prev d ) - bad signal?
[2014-06-28 15:16:56,451] [7bb9a50] [c78] - Recorderid 17eb Continuity error... 4 ( prev c ) - bad signal?
[2014-06-28 15:16:56,451] [7bb9a50] [c78] - Recorderid 17f2 Continuity error... b ( prev 2 ) - bad signal?
[2014-06-28 15:16:56,451] [7bb9a50] [c78] - Recorderid 17e8 Continuity error... a ( prev 0 ) - bad signal?
[2014-06-28 15:16:56,451] [7bb9a50] [c78] - Recorderid 17ea Continuity error... 9 ( prev 9 ) - bad signal?
[2014-06-28 15:16:56,451] [7bb9a50] [c78] - Recorderid 17e9 Continuity error... 6 ( prev d ) - bad signal?
[2014-06-28 15:16:56,457] [7bb9a50] [c78] - Recorderid 17de Continuity error... 3 ( prev 7 ) - bad signal?
[2014-06-28 15:16:56,458] [7bb9a50] [c78] - Recorderid 17e9 Continuity error... 2 ( prev a ) - bad signal?

Continuity errors usually mean either:

1. Signal strength/quality issues.
2. HDD stress.

If you're certain that your signal quality is okay (don't rely on the tuner 100% strength/quality readings - these are not reliable) then consider if there are any HDD-intensive processes (eg. virus or spyware scans, EPG updates) running on your server. Especially any security software scanning the MP or TV Server program, log, timeshift or recording folders.

mm

 

[mindm49907]

Hello again mm1352000,

I searched for leftovers, and disabled everything left running that wasn't supposed to: I deactivated Windows Defender (Windows Firewall was already turned off, no antivirus is installed) and deactivated the options to grab EPG for both cards (I am using WebEPG, anyway), since the EPG-grabber was somehow always using tuners, and switching between them (he was also trying some encryted channels), which might also led to the errors you just figured out(?).

I am now able to watch live HD live TV with HDHomeRun QuickTV (the program that comes with the tuner, which I also updated now, including the firmware of the tuner) without any stuttering.

But still, when using MediaPortal, I got the crackling every ~7000 frames. This is at about every 2:20 mins. I then watched 10 mins of live TV using QuickTV to make sure, nothing's crackling there. And, to avoid a classic, I also restarted my machine (which is a single-seat-setup btw.) after every change I made, and also checked if the changes persistet after rebooting.

I then tried to use one of my HDDs (not the SSD) for timeshifting, and - tada :-/ - the error didn't occur, not even after 60000 frames. I then tried another USB-stick, and tried formatting fat32 and ntfs, and tried different USB-ports... long story short: the error always occured every ~7000 frames.

Do you have any ideas for this? New log files are attached. Can you have another look at them?

Grettings, and thank you very much for your support!

mindm49907

 

[RonD]

I then tried to use one of my HDDs (not the SSD) for timeshifting, and - tada :-/ - the error didn't occur, not even after 60000 frames. I then tried another USB-stick, and tried formatting fat32 and ntfs, and tried different USB-ports... long story short: the error always occured every ~7000 frames.

Most USB sticks/thumb drives do not have good write performance. For MePo recordings or timeshift I suggest using a real HDD. You might google for thumb drive performance benchmarks and see what kind of write performance your thumb drive has. One example is the following link, lots of benchmarks on the web http://www.userbenchmark.com/

A SSD designed to be a "windows system drive" has more sophisticated control logic than a thumb drive and better support for typical windows and application write traffic. Both SSD and thumb drives with flash memory have an "endurance" problem and lots of write/erase traffic will eventually wear out the drive.

 

[mm1352000]

I then tried to use one of my HDDs (not the SSD) for timeshifting, and - tada :-/ - the error didn't occur, not even after 60000 frames. I then tried another USB-stick, and tried formatting fat32 and ntfs, and tried different USB-ports... long story short: the error always occured every ~7000 frames.

Ahhhh, you didn't say you were still using a USB drive for timeshifting. My experience with USB is not good for the reasons RonD described. Also the drivers can be poorly written => DPC latency issues. The simplest solution is to use a proper HDD.

 

[mindm49907]

Hello RonD, hello mm1352000,

I once read through several posts in the MediaPortal forum where people mentioned USB drives with 3.0 speed would work well, but didn't think of possible device specific problems when it comes to USB drives (never been so wrong ).

I like the concept of using a USB drive for timeshifting, since I do not want to stress my hard drives all the time, and the USB drive - of course - makes significantly less noise than my hard drives that turn off after 10 mins without usage, which is especially usefull when you're watching TV in bed in a rather small student's appartment ...

Yesterday, I stumbled about the possibility to use a RAMdisk (didn't hear of that before) for timeshiffing (http://wiki.team-mediaportal.com/1_MEDIAPORTAL_1/15_Customization/TV-Server/Ramdisk_for_Timeshifting), and I gave it a try this morning. It seems to work really good (no stuttering or crackling, fast jumping back and forth, ...), and since I have another free slot on my mainboard, I'll just get myself another 4GB of RAM to the 4GB that are already in there, and mark this thread as solved

I want to thank you very much for your help, and for pointing me to the right direction (e. g. also with the EPG-thing)! Keep up your good work!

Greetings, mindm49907

edit: ehm, how exactly can I mark a thread as solved?

 

[RonD]

to beat this thread to death, a few more comments, I divide "disks" into 3 main groups

1. HDD (Hard Disk Drive). Normal drives in use for years with 1 or more spinning platters. HDD can be internal using a SATA interface. They can be external using a USB interface but are really the same HDD. The USB interface adds some overhead so they typically use a bit more CPU horsepower and may be a little slower.

2. SSD (Solid State Disk Drive). Use flash memory for storage with special control logic to provide a high speed replacement for HDD. Can be used as the main "Windows Drive" with higher performance. The flash memory causes 2 problems. You need to do an erase before you can do a write. The control logic tries to optimize the erase/write performance, but writes of lots small files can cause performance problems. Flash also has an "endurance" wearout problem if you erase/write the same flash location many times, so the controller tries to spread writes over the entire flash memory to avoid hot spots. Most SDD are internal with SATA/mSATA interfaces. There are some external USB SSDs, for example the following, I did not know about these until I started looking.

http://www.amazon.com/Seagate-256GB-Portable-External-STCM240100/dp/B00I6CVPVC/ref=sr_1_3?s=pc&ie=UTF8&qid=1404068634&sr=1-3&keywords=ssd external hard drive

http://www.amazon.com/MyDigitalSSD-SuperSpeed-Portable-External-Storage/dp/B00EZ2FRVQ/ref=sr_1_2?s=pc&ie=UTF8&qid=1404068634&sr=1-2&keywords=ssd external hard drive

3. Thumb/Stick USB drives. Also use flash memory for storage but typically have slower write performance than SSDs. I view these as a 2014 version of a floppy drive. A good way copy files between computers that do not have an easy network connection.