Video Stuttering = Annoying

[fixxer]

Have anyone found a way to correct the problem? Incrasing cache to 1-2 secs does not solve the problem. And it's stupid having it more than that.

[Guest]

No, this is occurring with AVI files.

The video plays normally, no distortion, but will freeze up for a second or 2 then play normally again and it happens every 30 seconds to a minute.

I have tried it with multiple files from multiple sources to make sure it's not the files that are the problem.

I have the same problem on a iMac G5 2.0Ghz with 1.5GB RAM.
Sometimes the avi files run just normal (all the files are stored on the local HDD), but very often I have those 1-3sec freezes during playback. In worst cases the movie freezes like every other minute.
Is there any way to prevent that behavior of vlc, or is it a known bug that maybe will be fixed in an upcoming release?

Any tips/help would be musch appreciated!!

Same for me except I only have 1GB RAM, it seems to happen less if i quit other open applications, it's also more of a problem in 0.8.4 (beta's and release) than 0.8.2 but it still exists. It happens on different .avi's all stored locally. They play fine on Mplayer, but in full screen that seems to have the menu stuck at the top... (and they don't play in Quicktime... I think they're X-vid but I cannot confirm...)

[Guest]

as of version 0.8.4 vlc has become much slower than before. now i'm experiencing much the same stuttering playback as described in this thread. my computer is a powermac g4/400 but so far it seems it has been able to cope with everything i throw at it.

most of the stuttering seems to be due to missed keyframes - the image freezes or turns into smudge - during which the audio is playing without trouble - until the next keyframe is properly decoded. i also experience regular stuttering playback during panning and fast motion.

now on to the strange things... i decided to revert to version 0.8.1 which i find for me to be the best working version so far. but something must have changed within the settings because now i'm starting to experience the dropped keyframes in 0.8.1 as well, though only about every 5 minutes or so (unless dimensions are really high like 720px or so). otherwise the video plays as good as before.

[Guest]

as of version 0.8.4 vlc has become much slower than before. now i'm experiencing much the same stuttering playback as described in this thread. my computer is a powermac g4/400 but so far it seems it has been able to cope with everything i throw at it.

most of the stuttering seems to be due to missed keyframes - the image freezes or turns into smudge - during which the audio is playing without trouble - until the next keyframe is properly decoded. i also experience regular stuttering playback during panning and fast motion.

now on to the strange things... i decided to revert to version 0.8.1 which i find for me to be the best working version so far. but something must have changed within the settings because now i'm starting to experience the dropped keyframes in 0.8.1 as well, though only about every 5 minutes or so (unless dimensions are really high like 720px or so). otherwise the video plays as good as before.

I concur. with previous versions of vlc i could watch dvd video just fine on my 800mhz g4 ibook. now i get quite a bit of stuttering and green or garbage blocks in the video output. anyone know what change may be causing this? has something made video decoding much more computationally intensive in the 0.8.4 build, or is this a buffer size issue of some sort? i have tried adjusting several of the settings with no perceptable effect on this behavior.

[fishmoose]

I encounter this problem too, quite regularly. When playing .avi files, the movie will freeze for a moment every couple minutes, then pick up a few seconds later. There is no audio or video during the freeze, then they pick up fine afterwards. Rewinding to that point and playing again doesn't experience the same problem.

The key thing I've found is that I get the error consistently while playing files from my internal (Serial ATA) drive, but never when playing from my external (ATA by Firewire) drive. My computer is a dual 2.0GHz desktop with 2.5GB RAM, lots of drive space and not much else running when the problems occur.

I will try increasing the cache size as someone mentioned. Thanks for the tip.

I have been experiencing the same thing on my iMac G5 2 GHz.
And with exactly the same kind of inconsistensy (plays fine on anything but the internal HD, like over network). I found one more condition for the problem to occur though, that might be of some use to the coders. The problem only occurs if I have skipped/forwarded in the current clip.
If I play it from the beginning without jumping in time, no audio/video-skips occur. Also, but I'm not 100% sure about this, I think the problem only concerns divx and xvid (or possibly all avi).
And this problem applies to all versions of VLC I have tested.

[plasmacutter]

Same here.. and this is a dual 2.7 ghz G5 with 2 gigs of ram and serial ata hard drive.

it's rediculous that such a well established video player should suddenly develop lagging due to i/o problems. (edit: of course VLC is not the only player which has developed this issue. the X.3 to X.4 transition has also seen quicktime become annoying and studdery as well.. is this an apple i/o api bug?)

EDIT: one solution i've found which works reliably well.
(check advanced in prefs for these)
prefs->video->output modules->switch from default to quartz (it seems to speed things up.. maybe default tries core video?)

prefs->input/codecs->access modules->files->up caching to 2000 milliseconds (this does not noticeably change response time.)

these 2 things have made the skipping seldom.. probably eliminated save for abnormal system loads..

further measures which may work:
prefs-> advanced->other there should be choices of memcpy .. i'll experiment with this one.

[fishmoose]

Thanks for your advice, but it doesn't help the problem entirely for me.
The Quartz thing doesn't seem to have any noticable effect for me. The buffer thing might, but everything becomes very irresponsive.
I think the buffering-code needs rewriting maybe... As it is now, when I pause, all video that is in the buffer is played before the movie stops, which shouldn't really be necessary I think. Also, the movie should be able to start without having the buffer all filled (to increase responsiveness when starting play) but fill the buffer continiously while playing.

[bmoctta]

It would be great to find a solution to this for the Macs. I have the same problem, only it is often with mpg vids. The audio can be very choppy, but the video fine, or it is a combination of both. Upping the file ms read didn't help any either. Any other clues? I have messed around with all the settings and can't get anything to work on it.

[gusax]

I got the same problem when vlc 0.8.0 was released.
Vlc 0.7.2 plays high definition files (.ts, 1080i) on my 2x2GHz with around 60% processor usage with interlace blend. With 0.8.0 that almost doubled to 100 - 110%. With 0.8.4 it jumped once more to consume even more resources.
It never lags or drops frames though but I can't for the life in me figure out what happened between 0.7.2 and 0.8.0 that eats up the processors.

I guess I have to run 0.8.4a now if the digital audio is fixed but it's annoying that something that used to take around 60% now requires anything from 100 - 200%.

[fishmoose]

Ok, I think this are different issues.
One is that vlc has become slower in recent versions if I understand this correctly. Personally I haven't noticed this so I can't comment on it much.

Then there's the problem with reading from local/system disc (if I am correct) on newer macs/systems (PM G5, imac g5? tiger?) that causes video skips at regular intervals (CPU is not the problem, vlc runs with maybe 30% cpu usage and then when it skips, CPU usage of the system drops to 0% as if vlc is waiting for file system or something). This problem can be resolved by increasing cache/buffer size but sadly this makes things very irresponsive.
So this "bug" could be "fixed" either by finding what's stalling the file system (except if problem is in tiger/hardware???) or by making a better buffer system, that doesn't cause irresponsiveness when playing local.

[fkuehne]

Well, the problem is that we can reproduce this behaviour neither on my iMac G5 (2 GHz) nor on our PowerMac G5 (Dual 1.8 GHz).
My usual response to any problems is the recommendation to delete VLC's preferences files. I'd suggest that here as well, but I doubt that this will help.

[fredericb]

Well, the problem is that we can reproduce this behaviour neither on my iMac G5 (2 GHz) nor on our PowerMac G5 (Dual 1.8 GHz).
My usual response to any problems is the recommendation to delete VLC's preferences files. I'd suggest that here as well, but I doubt that this will help.

First, I never meet problems described before when playing movie from local hard drive.

But now, I moved all my movies files on my network hard drive, Lacie Ethernet mini plugged to RJ45. My macs are all connected through Airport.

Now, movie steps every 5 seconds. I read all comments on this topic and found some tips to improve playing. I increased all buffer to 3'000 ms.

It seems to works correctly. I didn't experiment any missing frames.

[egon0119]

I've been having the problem as well. (Dual 2.3 GHz, 1GB ram)

I think Fishmoose is on the right track by suspecting the filesystem. I've noticed the same CPU % drop during pauses which on my box lasts from 1 to 10(!) seconds.

Is there any way to use the xvid codec as opposed to ffmpeg?
---
An additional note:

I'm also getting skips and pauses in Quicktime. However it has gotten better once I installed DivX 6. The long pauses are gone and the 1 second or so pauses that are left usually only affect the video and not so much the audio.

[poopie]

I have similar problems -- green blocks, stuttering -- especially with H.264 input, which would cause major stuttering and then a crash. I found a quick fix for dealing with H.264 files: Go to Preferences>Input/Codecs>Demuxers>H264 and lower the "framerate." Mine is set to 16 right now. It doesn't appear to actually lower the frame rate -- the audio plays at a normal rate and the video is much smoother and syncs up fine.

[Guest]

one solution i've found which works reliably well.
(check advanced in prefs for these)
prefs->video->output modules->switch from default to quartz (it seems to speed things up.. maybe default tries core video?)

prefs->input/codecs->access modules->files->up caching to 2000 milliseconds (this does not noticeably change response time.)

I was also experiencing these problems in my 2ghz iMac 2gb RAM with no other programs running. These fixed them, as far as I can tell.

Perhaps the number of responses can prompt VideoLAN to take some action for the OS X port?

[The DJ]

Perhaps the number of responses can prompt VideoLAN to take some action for the OS X port?

ROTFL...
We are not a commercial organization dude...
it's friends writing software. not for you. for themselves.

[scottmacd]

Trying to play any form of movie on a network share with VLC is a bad idea. Mac OS X handles the small reads that VLC does very badly. So far only NFS shares have worked for me. You can enlarge VLC's file cache to prevent hickups due to the slow response of the file reading, but this introduces delays in play/pause/stop commands.

I have had some success using samba by adding the following [global]'s to smb.conf:

socket options = TCP_NODELAY
read raw = yes
write raw = yes
oplocks = yes
max xmit = 65535
dead time = 15
getwd cache = yes
lpq = 30
large readwrite = no

samba 3.0.22,1 running on FreeBSD 6.1-release (1.2GHz AMD, 512RAM)
client is OSX 10.4.6

hope this helps someone.

--Scott

[Pinay Goddess]

I have similar problems -- green blocks, stuttering -- especially with H.264 input, which would cause major stuttering and then a crash. I found a quick fix for dealing with H.264 files: Go to Preferences>Input/Codecs>Demuxers>H264 and lower the "framerate." Mine is set to 16 right now. It doesn't appear to actually lower the frame rate -- the audio plays at a normal rate and the video is much smoother and syncs up fine.

Thanxalot poopie! mine is working well now..Happy viewing to all!

[tones12]

Apart from all the moaning, I've found this thread really interesting and helpful. I am temporarily using g5 I-Mac (2g, 512RAM), and at first I really struggled watching even avi's. Augmenting the cache to 6000 ms sorted it out completely (never could find the preferences>modules>ffmpg>hurry up...).

I'm more of a PC man myself... But it seems that OS X (or maybe Macs in general) interrupts certain progams when other kicks in. For example, in Safari, if I click on the slide bar, all the animations on a website freeze...

I think a lot of the 'freezing' mentioned on this thread has in many cases got nothing to do with CPU or RAM, and have just got to do with basic settings within the preferences, many of them mentioned here.

And thanks to the developpers, this is an awsome piece of software (freeware, whatever you wanna call it).

[Guest (Timo)]

I always had this problem on my Dual G5 (2x2,3Ghz) with 4,5 GB RAM !!

I just found the tip with the cache increasing, and now I will gonna test it...

[Guest]

I am with similar settings, G5 2G DP
4G rams
and play 1080 ts file
VLC always skip frames,

really a shame, because on a PC, 1G P3 are able to play back 1080 ts file with no problem

I got the same problem when <b style="color:black;background-color:#99ff99">vlc</b> 0.8.0 was released.
<b style="color:black;background-color:#99ff99">Vlc</b> 0.7.2 plays high definition files (.<b style="color:black;background-color:#a0ffff">ts</b>, 1080i) on my 2x2GHz with around 60% processor usage with interlace blend. With 0.8.0 that almost doubled to 100 - 110%. With 0.8.4 it jumped once more to consume even more resources.
It never lags or drops frames though but I can't for the life in me figure out what happened between 0.7.2 and 0.8.0 that eats up the processors.

I guess I have to run 0.8.4a now if the digital audio is fixed but it's annoying that something that used to take around 60% now requires anything from 100 - 200%.

[The DJ]

Some ppl seem to be using network shares.
For the last time, the latency of network shares on OSX is so high, that playing files from them is annoying as hell. It's a well known issue, and without VLC downloading a couple MB in advance of the playback it cannot be solved.

Unfortunately this so called "prebuffering" is not possible in VLC at the moment.

[karakal]

In my case, the additional parameters in the smb.conf from scottmacd did the trick. I can now play my files from my smb-Server with Linux on my Mac Mini PPC without any audio-stuttering.

And I don't think, Mac OSX has the problems (why can Quicktime play the same files from the same network locations without problems?) but there is some problem in the VLC code.

The solution with the buffer-settings to 3000ms and more is not useful, because of the delays in reacting to any action in VLC.

And for "The DJ": Many people are using network shares. This is, what a mediacenter and a videoserver is all about....

[The DJ]

The difference is that QuickTime immediatly reads large amounts of data from the share and is not time critical, whereas VLC reads small amounts of data very often, and is time critical.

This makes it much more suited for streaming, but not for file sharing.
What you do when you change those settings on the server, is actually increasing the buffers on the serverside, allowing the server to respond faster to small reads.

[kenny_garlic]

Sorry to pull this ancient thread up again, but I have just bought my first home-NAS and moved my movies there.

I soon found out that movies played back stutter-free with QuickTime yet had hiccups every 4-5 seconds with VLC.

Of course I don´t want to stop using my favorite video player ;) So I set the file-buffering time to 5000ms and voila - instant solution. A 5 second reaction time does not really annoy me, I´d rather have glitchfree playback.

I assume that the caching technique QuickTime uses is not easily applicable to VLC.

However, what could "solve" this issue (or at least, reduce the questions/complaints) could be the simple addition of a simple and "apple-like" cache-parameter that is not hidden in the expert settings but instead presents this setting upfront, e.g. "optimized for local playback" or "optimized for network/share playback". This parameter could set cache times or whatever other useful parameters in the background.

Kenny