[bobd76]

Before I launch into detailed debugging, please let me know if I'm crazy.

For several months now, I had a stable installation of XBMC on my newish HTPC. Now after some tweaking, I'm noticing something that is driving me mad.

I seem to be dropping frames, or skipping frames, or random frames are freezing for a fraction of a second. However, when I hit "o" on my keyboard, XBMC reports that I am not dropping any frames at all. I never noticed this until today.

Can anyone think of any situation which would result in video playback stuttering slightly while XBMC reports no dropped frames?

[boxterduke]

I had the same issue when I installed the new version of XBMC, what video card do you have?
Mine is an ATI and I went into CCC and put vsynch to always on and that resolved it for me.
Nvidia has an option as well.

[bobd76]

Thanks, boxterduke. But I don't think that is it. I have vsynch set to "always on" in both XBMC settings and my NVIDIA control panel. Plus, if it were a vsynch issue, I think I'd see tearing in the image. But that's not what I'm seeing.


I have some new info, a debug log, and a lot of detail. I hope someone can help.

Here's what is happening in more detail:

1. I open a 1080p MKV from my local hard drive--a file I've never had any trouble playing. As I begin to watch, I notice a strange frame rate issue.

2. I press "O" to bring up the XBMC OSD. I see that I am NOT dropping any frames. However, the file should be running at 24fps--more or less. Usually on a 24fps file, the fps readout will sometimes fluctuate a little--say 23.9 to 24.1. But now, it is fluctuating much more--as much as 22.X to 26.x. But as I said, XBMC says I'm not dropping frames.

3. Now, if I skip backwards with the arrow buttons and watch the same section of the file again, it runs at almost a rock-solid 24.0fps. But as soon as I get to a part of the file I haven't watched, the same fps issue begins again. I've tried restarting the file, and even closing and relaunching XBMC. As long as I don't restart the computer, the part of the file I've watched will play at 24fps. If I restart the PC, it all starts again. from scratch.

Here is my debug log. Please let me know if I did this incorrectly. The log shows what I just described. Launch XBMC, start file, fps issue, skip back and zero fps trouble, and as soon as I get to a new section, fps trouble begins again: http://pastebin.com/m1ed9e515

I see at least two warnings someone might comment on:

WARNING: CDVDVideoCodecFFmpeg:ecode - avcodec_decode_video didn't consume the full packet. size: 9244, consumed: 0

WARNING: CWin32DirectSound::GetSpace - buffer underrun - W:1920, P:2960, O:198144.

The problem began when I installed an extra hard drive yesterday. I had to try a few different SATA ports to get XP to seethe HD. Right after that, XBMC (an older Jester Atlantis release) would crash every time I tried to launch it, so I upgraded to Babylon 9.04.1-repack2. I've since tried my older stable release, and it makes no difference, so I went back to 9.04.1-repack2.

I've since completely disconnected the newer HD to make sure that wasn't the issue, but the problem persists.


Here's my current HTPC setup:

Here is my current HTPC configuration:

• GIGABYTE GA-E7AUM-DS2H with on-board NVIDIA GeForce 9400 (nvidia driver 185.85)
  
• Intel C2Duo E8400 @3.00GHz
  
• 4 GB Ram {Crucial Ballistix 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) running dual-channel}
  
• 2 SATA HD's (1TB + 1.5TB)
  
• LG BD / HD-DVD combo drive
  
• Antec New Solution NSK2480 MicroATX Desktop Computer Case 380W Power Supply
  
• WinXP Pro SP 3
  
• XBMC Babylon 9.04.1-repack2
  

Please help.

[midgetspy]

The obvious next step, IMO, is to try playing it with a different player like VLC. If playback still has problems it's obviously not an XBMC problem but something wrong with your PC.

[althekiller]

No, the obvious next step is to just pastebin the damn log and stop jerking people around.

[smcnally75]

No, the obvious next step is to just pastebin the damn log and stop jerking people around.

He did post the debug log in his second post

Here is my debug log. Please let me know if I did this incorrectly. The log shows what I just described. Launch XBMC, start file, fps issue, skip back and zero fps trouble, and as soon as I get to a new section, fps trouble begins again: http://pastebin.com/m1ed9e515

[fahrenheit]

I have the same problem.
http://forum.xbmc.org/showthread.php?tid=52513
Please try turning vsync off (in both XBMC and NVIDA control panel) and let me know if you get smooth frame rate, but terrible vsync tearing.

Hopefully we can find some commonality.

[tknice1]

No, the obvious next step is to just pastebin the damn log and stop jerking people around.

/sigh

[bobd76]

I have the same problem.
http://forum.xbmc.org/showthread.php?tid=52513
Please try turning vsync off (in both XBMC and NVIDA control panel) and let me know if you get smooth frame rate, but terrible vsync tearing.

Hopefully we can find some commonality.

I believe my issue may be related to a certain hard drive I'm using. I'll post more after I experiment further.

When you get choppy playback, does the OSD show that you are dropping frames or not?

[althekiller]

He did post the debug log in his second post

Hrm, so he did. Word to link ratio was too high for me.

[Fred-L]

I have the same problem since the implementation of new playback options.

[fahrenheit]

When you get choppy playback, does the OSD show that you are dropping frames or not?

Nope, its not dropping frames.

[bobd76]

Fred-L, can you confirm that your FPS is taking a hit while at the same time you are not dropping frames?

[Fred-L]

Fred-L, can you confirm that your FPS is taking a hit while at the same time you are not dropping frames?

I confirm

[Fred-L]

I installed XBMC Babylon 9.04.1 and video playback is smooth again
Unfortunately, Aeon skin doesn't fully work with this version