The VideoLAN Forums

I upgraded to Snow Leopard last Friday and have noticed some stuttering issues with VLC 1.0.1 in SL. It's mainly playing XviD files, at least that's all I usually view with VLC. I had one video that was constantly stuttering every 5-7 seconds. I took at look the VLC log file and it was constantly reiterating messages such as this:

mpgatofixed32 debug: libmad error: bad main_data_begin pointer
main warning: late picture skipped (45332 > -352)
main warning: late picture skipped (3623 > -352)
main warning: late picture skipped (87040 > -352)
main warning: late picture skipped (35160 > -383)
main warning: computed PTS is out of range (100925), clearing out
main warning: PTS is out of range (100938), dropping buffer
main warning: output PTS is out of range (135612), clearing out
main warning: PTS is out of range (76957), dropping buffer
main warning: PTS is out of range (52968), dropping buffer
main warning: PTS is out of range (28978), dropping buffer
main warning: PTS is out of range (4989), dropping buffer
main warning: PTS is out of range (-19001), dropping buffer
mpgatofixed32 debug: libmad error: bad main_data_begin pointer
main warning: computed PTS is out of range (92651), clearing out

I've never really looked at the logs in the years I've been using VLC since this is the first time I've really had any sort of performance issue.

Anyone else having the same problem? On my work iMac (Snow Leopard), there is a slight stuttering issue, but hardly noticeable.

though not as frequently as 5-7 seconds, the stutter does occur randomly with 1.0.x in leopard (10.5.x) as well.

long discussion about it here:
viewtopic.php?f=12&t=61848

Mores notes:

I've got one XviD that stutters every 3 seconds.

Both Snow Leopard installs on my personal 13" MacBook Pro and my work iMac were done from clean hard drives (not upgraded on top of existing 10.5 install).

Same issue here.. it's TONS worse in fullscreen mode on my 1080P display. Fullscreen in Snow Leopard skip frames like crazy.

- I had upgraded from 10.5.. Also 13" MacBook, Intel GMA integrated.
- Before the update, fullscreen plays on 10.5 with VLC 1.0.1 were very smooth. Same exact movies.
- Quicktime X, MplayerX fullscreen on Snow Leopard is smooth.

the CPU was not pegged at all.. I was going to try the Nightly build but it crashes as soon it launches.

I'm suffering the same problem as the topic starter, it's impossible for me to wacht and HD MKV files anymore. They stutter every few (3-6) seconds. And then freezes for a couple of seconds sometimes and gives a strange image after the stutter. The Macbook and iMac had no problems with displaying them under Leopard.

Info
Snow Leopard (everything was fine under Leopard) (10.6)
VLC (1.0.1)
iMac 3.06 intel core 2 duo 4GB ram NVIDEA Gforce 8800GS
Files: mostly 1080P and 720P .MKV files
VIDEO_TS folders play correctly without stutter
Installed Snow leopard on top of Leopard but other users on another forum report the same problems with a fresh install.

(also tested on a Alu Macbook 2.4 with Snow Leopard. Same problem)

The image:

What video codec is used by your mkv file?

How can you see on a MAC, one file is the picture below and with the other files i can't see. For the record, with all HD movies i have have the same problem in VLC.
I also downloaded Perian and opened the files with quicktime. In quicktime the files can be played without stuttering although quicktime produces high processor usage.

First file has 1080p.bluray.x264-hv.mkv in the filename
The second file vlc says this


If you show me how to get all the codec information i'll be sure to post it here.

I am getting similar results with any mkv file. VLC.app caps out at around 100% on C2D 2.4 4GB 8600M and there's plenty of idle cycles not being utilized as you can see in the screenshots. Although this seems like a normal problem with apps not coded for multi-cores.

Is there a build of VLC that supports multi-cores on OSX because this capping out at only 100% is really useless on today's CPUs.




http://i28.tinypic.com/1htv0g.png
http://i30.tinypic.com/r0s5dl.png

frame skips happen to all the files i could throw at it. Playback is smooth with QT X w/ Perian. It's the same VLC binary that I used to when my computer was running Leopard, and it ran like a champ then. I have logs for playing h264, mp4v, mpegv, wmv3, xvid i can send you.

Weird that your VLC always skips and mine only with HD. If i load a DVD VIDEO_TS file in vlc it works fine.

-offtopic-
Can you tell me what program you use to have all your comp stats like temp, upload/download on your menubar (or whatever it's called)
-/offtopic-

Weird that your VLC always skips and mine only with HD. If i load a DVD VIDEO_TS file in vlc it works fine.

-offtopic-
Can you tell me what program you use to have all your comp stats like temp, upload/download on your menubar (or whatever it's called)
-/offtopic-

VLC doesn't always skip. Just whenever it plays stuff like this 7GB HD file that needs more CPU but is only using 1 core.

Stats are from istat menus: http://www.islayer.com/apps/.

There are some problems with MKV files including subtitles on Snow Leopard, which might explain your playback issues. We hope to have this fixed for VLC 1.0.2 along with some other Snow Leopard improvements.

VLC will always use 1 core only for video decoding (audio decoding and playback management may be processed on another one), as its decoders are not multi-threaded yet, while VLC itself strongly is (there are about 20 threads running when playing a single video file). This is something we hope to be able to include later this year, but we're depending on the progress of the decoder developers here. This is a difficult task, which will take time.

Weird that your VLC always skips and mine only with HD. If i load a DVD VIDEO_TS file in vlc it works fine.

-offtopic-
Can you tell me what program you use to have all your comp stats like temp, upload/download on your menubar (or whatever it's called)
-/offtopic-

VLC doesn't always skip. Just whenever it plays stuff like this 7GB HD file that needs more CPU but is only using 1 core.

Stats are from istat menus: http://www.islayer.com/apps/.

hi pooprscooper,
its off the topic again.... but can't resist ..
i loved the way finder on your mac shows the folder-path-flow graphically this way ->>> "OSXL-Users-user-Desktop" ** "mmmm_ok"
how can i do it...

thanks

its off the topic again.... but can't resist ..
i loved the way finder on your mac shows the folder-path-flow graphically this way ->>> "OSXL-Users-user-Desktop" ** "mmmm_ok"
how can i do it...

thanks

That's Path Finder http://cocoatech.com/ 10.6 version is still in beta (5.1.7). You can actually add that one feature to Finder on 10.6 with dropdown menu "View >> Show Path Bar"
Check out http://www.usingmac.com/2009/6/19/20-fr ... ps-for-mac and view some of the other pages listing more tools on that site. It took me forever to figure out which apps to have on my mac and I just so happend to find that site yesterday; could've used it a year ago
I use most the stuff on that site.

There are some problems with MKV files including subtitles on Snow Leopard, which might explain your playback issues. We hope to have this fixed for VLC 1.0.2 along with some other Snow Leopard improvements.

Looking forward to the new version then. Any ETA on it?

When it's done

Seriously, within a month, I'd say.

Just another follow-up to my original post. I haven't replicated this issue on my work computer, a 2.4GHz iMac (Core 2 Duo). Same OS as my 13" MBP, Snow Leopard from clean hard drive.

Just a tip:
I was having the same problems and it seems to have pretty much stopped when I went to "Input & Codecs" preference tab and set "Skip the loop filter for H.264 decoding" to "All"...
Won't hurt to try!

Good luck
~Levi F

Just a tip:
I was having the same problems and it seems to have pretty much stopped when I went to "Input & Codecs" preference tab and set "Skip the loop filter for H.264 decoding" to "All"...
Won't hurt to try!

Good luck
~Levi F

Sorry, which exact setting is that?

Sorry, which exact setting is that?

Here is a screenshot:


Hope it helps!
~Levi F

Thanks. the thing that helped most to fix the skipping was to activate the mmap feature.

Set settings to show "all".

Input/Codecs -> Access Modules -> MMAP -> Tick "Use File Memory Mapping"

Save.

Just setting that H.264 thing to see if it makes things even better.

Thanks. the thing that helped most to fix the skipping was to activate the mmap feature.

Set settings to show "all".

Input/Codecs -> Access Modules -> MMAP -> Tick "Use File Memory Mapping"

Save.

Just setting that H.264 thing to see if it makes things even better.

Oh nice, I'll try that too! The setting I pointed out made a world's difference to me though!! But, as always, your mileage may vary...

UPDATE: Those settings (Mmap) really degraded the quality on mine and decreased the FPS.. :S Keeping "Use File Memory Mapping" *un-ticked* really improves overall image quality and fluidity. :S

Cheers
~Levi F

How strange. Exactly the opposite for me.

How strange. Exactly the opposite for me.

Wow, that is weird!
On another note, VLC 64-bit is out and I did notice some performance improvements! Try that!

Good luck,
~Levi F