# .avi Movies Lagging



## The Khaotik

Hi, I have a problem with some .avi movies lagging, I can play most without any problems but some of them have about 1 second long lags always at the same places, I have tried playing these files with VLC, DivX Plus Player, Windows Media Player and Media Player Classic but they lag no matter what I'm playing them in. Does anybody have any ideas what might be wrong with these movies? Is there any way to fix this?

By the way, only the video lags, there is no problem with the audio


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## Nanobyte

When you talk about lag, are you referring to the video stopping or slowing down then suddenly catching up?  Never catching up?  What pixel sizes are the videos and their bitrates and codecs (in Properties if you don't have a utility like Media Info or GSpot)?  How long are these lapses apart?

If the video falls behind the audio it's often because the PC cannot process the video fast enough.  However, if it's happening in the same places, it could be crappy video.


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## The Khaotik

It kinda stops and then suddenly catches up, the audio and video are not desynced, the time between the lags varies from a few seconds to several minutes.

Here are some information about two of the .avi movies.


Movie #1

Pixel Size: 640x368

Bitrate: 914 kbit/s for video and 129 kbit/s for audio

Video Codec: XVID Mpeg-4

Audio Codec: MPEG Layer 3



Movie #2

Pixel Size: 640x368

Bitrate: 866 kbit/s for video and 128 kbit/s for audio

Video Codec: XVID Mpeg-4

Audio Codec: MPEG Layer 3


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## linkin

Defrag your hard drive.


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## Nanobyte

The videos are nothing special in terms of the bitrate so any PC of the last 10 years could handle without issue.  When you burn a dvd you are transferring data at a minimum of 8MB/s off the hard drive.  Those videos are nothing.  Linkin's suggestion may help.  You did not mention your PC's age.

I'm not sure of the actual issue.  In the first post you say the audio is fine but video lags.  In your last post you say audio and video are not desynced.  Both cannot be true.

One way to tell if the video is the problem is to find one of the bad sections and play at slower speed.  The sound will be down in pitch but should stay in sync and the video should be at steady speed if the avi is OK.

I'm guessing the files have VBR audio.  I've yet to find one file of that type that will load in VirtualDub without an "Incorrect VBR audio encoding error" message.


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## The Khaotik

It's hard to explain how the lag is exactly, I uploaded a short clip showing some of the lag http://www.yourfilelink.com/get.php?fid=598663 (Lame site I know, but I don't know where else to upload it)

Thanks for the help so far


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## Nanobyte

Looks like poorly encoded video. It's not an avi, it's Windows Media Video 9 Pro.  The bitrate is a lot higher than you posted but that's often the case when reading from Properties. Edit:  Later noted that you posted info on xvids not wmv.

The picture is actually jumping back frames.  In this clip, at one point there are 9 frames that play and then it jumps back to the first of those frames and plays normally.  I see the audio is CBR.  This jumping behaviour though is exactly what I find when loading a VBR audio avi into something like Sony Vegas.

You may be able to find a common factor in all the bad videos you had - who did them and on what equipment. Mind you, even though most people don't use the wmv format, there is no reason it should give poor results.  I'm not familiar enough with the format.  Perhaps someone else is?  The movies may be repairable but only with proper editing and a lot of time.  Not worth the bother.

General
Complete name                    : Lag_M.wmv
Format                           : Windows Media
File size                        : 482 KiB
Duration                         : 2s 4ms
Overall bit rate mode            : Constant
Overall bit rate                 : 1 970 Kbps
Maximum Overall bit rate         : 3 017 Kbps
Encoded date                     : UTC 2011-01-05 17:06:46.541

Video
ID                               : 2
Format                           : VC-1
Format profile                   : MP@ML
Codec ID                         : WMV3
Codec ID/Info                    : Windows Media Video 9
Codec ID/Hint                    : WMV3
Description of the codec         : Windows Media Video 9 - Professional
Duration                         : 2s 0ms
Bit rate mode                    : Constant
Bit rate                         : 2 799 Kbps
Width                            : 640 pixels
Height                           : 480 pixels
Display aspect ratio             : 4/3
Frame rate                       : 29.970 fps
Resolution                       : 24 bits
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.304
Language                         : en-us

Audio
ID                               : 1
Format                           : WMA2
Format profile                   : L3
Codec ID                         : 161
Codec ID/Info                    : Windows Media Audio 2
Description of the codec         : Windows Media Audio 9.2 - 192 kbps, 48 kHz, stereo (A/V) 1-pass CBR
Duration                         : 2s 4ms
Bit rate mode                    : Constant
Bit rate                         : 192 Kbps
Channel(s)                       : 2 channels
Sampling rate                    : 48.0 KHz
Resolution                       : 16 bits
Language                         : en-us


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## The Khaotik

The original movie is an .avi, this clip is .wmv because I used Windows Movie Maker to clip out the rest.

I guess there is no simple way to fix this then, thanks for the help anyway


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## voyagerfan99

Try installing a good codec pack like K-lite.


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## Nanobyte

The Khaotik said:


> The original movie is an .avi, this clip is .wmv because I used Windows Movie Maker to clip out the rest.


That kind of defeats the purpose!  At least it illustrated the "lag".  I'm assuming the original avi looked similar to the wmv.

FYI if you want to produce a short sample, you can load in freeware VirtualDub, select the start and end using Home & End; Video - Direct Stream Copy; Save As.  As I mentioned if the original has VBR audio you will get an error on loading.


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