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Playback issues

Q:I can't play a certain video file

Read the rest of the FAQ. There may be a topic related to the file type that you are trying to play. Here is a list of general tips:

  • Click on the shortcut called "Reset to recommended settings" in the start menu.
  • Load the file in the MediaInfo tool. That can usually give you some useful information about the contents of the file.
  • Test the file in Media Player Classic. For two reasons:
    1) It is better able to play certain files than other players.
    2) It shows more helpful error messages.

If all fails, then try the VideoLAN player. This player doesn't use DirectShow filters to play files, but it's own plugins. It should be able to play almost anything.

Q:I am unable to play any files on Windows Vista even though I have all the proper codecs installed

First use the Codec Tweak Tool to check for any possible problems. Enable these fixes:

  1. Detect and remove broken ACM/VFW codecs
  2. Detect and remove broken DirectShow filters
  3. Re-register base DirectShow filters

If the above does not help, then the problem might be related to the User Account Control (UAC) functionality of Windows Vista/7/8. Disabling UAC can often cause weird problems. Uninstall the codec pack. Re-enable UAC and then re-install the codec pack.

Q:I am not able to play AVI files

If you are not able to play any AVI files at all, then the AVI source filter of Windows is probably broken.

You can fix it using:
Codec Tweak Tool -> Fixes -> Re-register base DirectShow filters

Or manually from an administrator command prompt with this command:
regsvr32 quartz.dll

If the problem only occurs with some AVI files, then the file is damaged/incomplete/fake or you are missing a codec. The MediaInfo tool can tell you what kind of video format the file contains.

If the file shows you a video message about a missing codec that you need to download, then you got a fake file. Do NOT download the codec it points to. It is likely to contain a virus or other malware.

Q:I have trouble playing certain MPEG files

Use the MediaInfo tool to get details about the file.

If the file contains MPEG-1 video, then try enabling MPEG-1 in LAV video decoder or ffdshow. By default Microsoft's own MPEG-1 decoder is used.

If the video looks all messed up or is completely black, and the file contains MPEG-2 video, and also the Chroma subsampling has value 4:2:2, then you should use a different MPEG-2 decoder.

If the file still fails to play, then try setting LAV Splitter as the preferred splitter with the Codec Tweak Tool.

Q:I can't play AVI files anymore after using WinAVI Video Converter

WinAVI sometimes breaks the AVI source filter of Windows.

You can fix it using:
Codec Tweak Tool -> Fixes -> Re-register base DirectShow filters

Or manually from an administrator command prompt with this command:
regsvr32 quartz.dll

Q:I can't play .avi files that contain H.264 video

Early versions of CoreAVC have trouble decoding H.264 video when the video is stored in the AVI container. We recommend using LAV Video decoder.

Q:I can't play .avi files downloaded from

Select LAV Splitter as source filter for AVI during installation of the codec pack. That splitter is better able to handle those files than the default AVI source filter that is part of Windows.

Q:AVI files containing H.264 video play upside down in BS.Player and WMP

This problem should only occur in combination with old versions of CoreAVC. We recommend using LAV Video decoder.

Q:Two audio tracks are being played simultaneously

This means that you are using a player that doesn't contain a stream switcher. If you play a file that contains multiple audio/video/subtitle streams, then your player is trying to play them all at once instead of just one of them.


  • Use a player with a built-in stream switcher. For example Media Player Classic.
  • Use a source filter that contains a built-in stream switcher. For example LAV Splitter or Haali Media Splitter contain that functionality. The K-Lite Codec Pack uses these splitters by default for most formats.
Q:The CPU usage is very high during video playback, any tips on how I can lower it?

Video playback can require a lot of processing power, certainly when the video has a high resolution (1080p/4K). Some video formats, such as HEVC, are very complex to decode.

Some tips to lower the CPU usage are:

  • Use a hardware accelerated decoder. Options for hardware acceleration are shown during installation of the codec pack when your system is compatible.
    A hardware accelerated decoder offloads the video decoding to your graphics card (GPU), significantly reducing the workload of your CPU. Your graphics card needs to support this functionality, but practically every graphics card manufactured in the past ten years supports it for at least certain video formats, such as H.264. For more modern formats like HEVC/x265 you need a more recent graphics card.
  • Disable subtitles.
    If disabling subtitles helps, then try these subtitle tweaks for MPC-HC:
    MPC-HC options > Subtitles > Maximum texture resolution > Select "Video" or a low resolution
    MPC-HC options > Subtitles > Never animate the subtitles
  • Close other programs that are also running on your computer that use a lot of CPU cycles. For example BitTorrent and other downloading programs.
Q:The video stutters and does not play smoothly

This is sometimes caused by buggy graphics drivers. Make sure that you are using recent drivers. You can download the latest drivers on the website of the manufacturer of your graphics card or chip. That is in most cases AMD/ATI, NVIDIA, or Intel.

If you don't know what kind of graphics card you have, then the Codec Tweak Tool can help you out.
Codec Tweak Tool -> Generate Log
The system information section of the log contains details about your graphics card and current driver.

If you have a NVIDIA graphics card, then we recommend this setting adjustment:
NVIDIA control panel > Manage 3D settings > Global Settings > Power Management Mode > Select Adaptive

If you have an AMD graphics card, then you should disable Enhanced Sync and FreeSync in the global settings section of the driver settings. You should enable these options only for individual games that are compatible.

A common cause for stuttering are performance issues. If your computer is too slow to decode the video it will result in suttering and frame drops. Read the topic above with tips on how to lower the CPU usage.

Another common cause for playback to have some occasional stuttering is a difference in framerate of the video and the refreshrate of your monitor. Ideally the refreshrate is a multiple of the video framerate. The madVR renderer has the ability to change refreshrate (if your screen supports it). Alternatively it also has an option called "smooth motion" that uses frame blending technique to reduce stuttering.

Media Player Classic allows you to choose which video renderer is used. On older/slower computers, changing the renderer may sometimes help improve playback smoothness. See MPC Options -> Playback -> Output.
Recommended renderers for Vista/7 are: madVR (on high-end computers), EVR Custom Presenter, or EVR.
Recommended renderer for XP are: madVR (on high-end computers), VMR-9 (renderless), or VMR-7 (windowed).

If the problem only occurs with certain AVI files, then read this FAQ entry.

If the problem only occurs in MPC with certain WMV or M2TS files, then read this FAQ entry and this FAQ entry.

If you are using DXVA2 or CUVID hardware accelerated decoding, then try disabling that and using pure software decoding. That may sometimes help, certainly if you make use of PixelShaders in Media Player Classic. A high GPU load can give problems, just like a high CPU load can give problems.

Video playback is very sensitive to timing. Certain monitoring programs that run in the background can cause trouble if they make excessive use of timers. For example tools that measure CPU/GPU speed and temperature.

Q:The video is not synchronized with the audio

A typical cause for this problem is high CPU usage. The video can't be decoded fast enough to keep up with the audio. Read the topic with tips on how to lower the CPU usage.

Q:The video plays very slow and parts are skipped. It is like I am watching a slide show.

A typical cause for this problem is high CPU usage. The video can't be decoded fast enough and as a result frames get dropped. Read the topic with tips on how to lower the CPU usage.

Q:The video stutters a lot when I play it fullscreen

This can be a result of certain graphics card settings that you might have changed. Try changing the following settings in your graphics card control panel:

- Set FSAA to 'Let the application decide'
- Disable anisotopic filtering (AF)
- Disable antialiasing

Q:The audio volume is really low

This is a common problem that is usually caused by playing 5.1 channel audio on stereo speakers. Buggy or badly configured audio drivers may then output just two audio channels to your speakers. This means that the center channel, which usually contains the dialogs, is not outputted to your speakers.

Take the following steps to properly configure your speakers:

  1. Use the Codec Tweak Tool to configure your speaker settings. This will make sure that the audio decoders that are included in the pack downmix (or upmix) the audio to the appropriate number of audio channels.
    Note: These speakers settings are the same as those displayed during the installation of the codec pack.
  2. Go to the Sound settings in the Windows Control Panel and also check if the number of speakers is configured properly there.
Q:The volume of voices is very low compared to the background sounds and other sound effects

See the above topic for instructions on how to properly configure your speaker setup.

Even when the number of speakers is configured correctly, the volume of the voices can still be too low compared to the sound effects. This is simply how the movie studios have mixed the sound track.

Here are some way to boost the volume of the center channel that contains the voices:

  • When using ffdshow as audio decoder:
    ffdshow audio decoder configuration -> Volume -> enable Volume and Normalize
  • When using ffdshow as audio decoder:
    ffdshow audio decoder configuration -> Mixer -> increase Center slider to above 100%
  • When using AC3Filter as audio decoder:
    AC3Filter options -> Mixer -> Voice -> change value to for example 10
Q:The volume of voices is too high compared to the other sounds

Disable the "[AC3Filter] Boost voice/dialog volume" tweak during installation of the codec pack. This only applies in the situation where AC3Filter is installed.

It is also possible to manually disable this tweak. Go to AC3Filter options. On the 'Mixer' tab, set the 'Voice' slider to value 0.

Q:Vorbis audio in MP4 container does not play

Use LAV Splitter or Haali MP4 splitter instead of Gabest MP4 splitter. You can configure your preferred source filters with the Codec Tweak Tool.

Q:MP3 files play too fast in Windows Media Player

Go to AC3Filter settings. On the System tab, disable PCM.

Q:Video plays too fast in Windows Media Player

Go to AC3Filter settings. On the System tab, disable PCM.

Q:How can I play AVI files from Blizzard Games?

Videos belonging to games from Blizzard contain DivX video, but with a different FourCC, namely "BLZ0".

To play such videos you need to use ffdshow for decoding DivX video. The regular DivX decoder won't work (unless you manually change the FourCC).

Go to ffdshow video decoder configuration. On the Codecs page, set DivX 4/5/6 and Generic MPEG-4 to libavcodec.

Q:How can I make 6 channel Windows Media audio play properly on stereo speakers?

WMVHD files, typically created for playback on the XBOX360, can contain a 5.1 audio stream. If you play such a file on a computer that only has two speakers then you will only hear the sound from two of the six channels. This causes for example the voices (center channel) to be almost unhearable.

The solution is to downmix the 5.1 channels into 2 channels. There are two ways to do this. You can either use AC3Filter or ffdshow.

In ffdshow audio decoder configuration, go to the 'Codecs' page. Scroll down to the bottom of the list and set 'Uncompressed' to 'All supported'. Now go to the 'Mixer' page and set the speakers to '2/0 Stereo'. Also enable the checkbox in front of 'Mixer' to activate the mixer filter.

In AC3Filter options, go to the 'System' tab and enable 'PCM'. Configure the output setting to stereo speakers.

Q:Seeking within an AVI file has a delay of a few seconds in Winamp

Disable Gabest AVI splitter using the Codec Tweak Tool. Or select the Microsoft AVI splitter during installation of the codec pack.

Q:When using Vista Media Center the video freezes for a few seconds every few minutes

Updating your graphics driver to a recent version should fix this problem.

Q:I can't play WMV files.

You need to install the Windows Media Format Runtimes. These are also included with Windows Media Player.

Windows XP/2003/Vista:
Windows Media Format Runtimes v11
(Do NOT use this on Windows 7. It will not work!)

Windows 98/ME/2000:
Windows Media Format runtimes v9

If you remove WMP on Windows 7, then the windows media codecs are also removed. You need re-install WMP in order to get them back.

If you are using a special N or K edition of Windows 7, then you need to install this to get the Windows Media codecs: Media Format Feature Pack for Windows 7

Q:I can't open AVI files with WMV3 video in editing applications such as VirtualDub

You need to install WMV9VCM.

Q:I get some message about acquiring a license when I play certain media files

That means that the file is DRM protected. DRM is a copyright protection method. You generally need to get (read: buy) a license to be able to play the file. Our advice: shift+delete.

Q:I am having trouble playing .mkv files that contain "720p" or "1080p" or "x264" in their filename

This are high resolution videos in the H.264 format. Playing such files requires a lot of processing power. High CPU usage can cause various problems. Video will stutter, frames will be dropped, and audio goes out of sync.

Read the FAQ entry tips on how to lower the CPU usage.

Q:I am unable to play .vob files in Windows Media Player

This is caused by a bug in Windows Media Player. Simply renaming your .vob file to .mpg will make it playable in WMP.

Media Player Classic has no problems with playing .vob files.

Q:Audio stutters on Windows Vista

Open the Control Panel and click on the Sound applet. Select your output device in the list that appears. It is usually called "Speakers". Right-click on the device and in the context menu click on Properties. Click on the Enhancements TAB. Enable "Disable all enhancements".

Q:There is a long loading delay when you open an .mkv file

Matroska files have the ability to link several related files together. The delay is caused by Haali Media Splitter looking for linked files. This can result in a significant delay if there are many .mkv files in the same directory.

The solution is to disallow Haali Media Splitter to search for linked files.

Haali Media Splitter options -> Input -> set "Try to open linked files" to No.

Q:How do I play M2TS files that have been ripped from a Bluray disc?

You must set the preferred source filter (a.k.a. splitter) for M2TS files to LAV Splitter or Gabest splitter. You can configure your preferred source filters with the Codec Tweak Tool.

Be aware that the content protection of the Blu-ray disc must be removed before you can play the files. You can do that with a tool such as AnyDVD HD.

Q:AVI files with Xvid or DivX video stutter in Windows Media Player or Media Center on Windows 7

Windows 7 contains its own decoder for MPEG-4 video (DivX, Xvid, etc). Some people are having problems with that decoder, such as stuttering and bad visual quality.

Windows Media Player and Windows Media Center will default to using Microsofts own decoders. Changing the preferred decoders is possible with the Codec Tweak Tool that is included in the codec pack.

Tweaks that you should try (in this order):

  1. CTT > Win7DSFilterTweaker > Preferred Decoders:
    Change preferred DIVX/XVID/MP4V decoder to Use Merit
  2. CTT > Win7DSFilterTweaker > MS Codec Tweaks:
    Disable Mpeg4s Decoder DMO and Mpeg43 Decoder DMO
  3. CTT > Win7DSFilterTweaker > Preferred Decoders:
    Change preferred MP3 decoder to LAV Audio.
Q:MP4 files play without video in Winamp on Windows 7

Codec Tweak Tool > Win7DSFilterTweaker > Preferred Decoders:
Set H.264 to USE MERIT

Also enable H.264 in either LAV or ffdshow video decoder settings.

The codec pack already uses the correct settings by default. files recorded with Hauppauge software are out-of-sync during playback

Disable "MPEG-TS (Haali)" with the Codec Tweak Tool.

Q:How do I play WAV files that contains DTS audio?

The recommended solution is to rename the file from .wav to .dts. Then it will be parsed by the AC3File source filter, which will properly recognize the contents as DTS audio. AC3File is included in the Full/Mega/64bit packs.

An alternative solution is to enable decoding of both DTS and Uncompressed audio in ffdshow audio decoder.

Q:M2TS files that contain VC-1 video play with just a black screen in Windows Media Player on Windows 7

The standard Microsoft codecs used by WMP on Windows 7 do not support VC-1 video inside M2TS files.

Codec Tweak Tool > Win7DSFilterTweaker > MS Codec Tweaks:
Disable Media Foundation

Q:Some DVD rips created by AXXO give a black screen during playback

This happens because those videos have a width that is not a multiple of 8. That causes compatibility problems with some video renderers.

Assuming that you are using ffdshow for decoding the video, there is a workaround to properly play such video files. In ffdshow video decoder configuration, you should enable the "Resize & Aspect" filter. Select the setting called "Expand to next multiple of: 16".

Q:My player freezes during file opening when S/PDIF is enabled in ffdshow

ffdshow audio decoder configuration -> Output -> uncheck "Connect as PCM first"

Q:MKV files with DTS-MA audio give audio stutters/pops/crackles during playback

This is a known problem with Haali Media Splitter. It is related to the way the file was created. That problem has been fixed in MkvToolnix, so re-muxing the file can help.

The recommended solution is to fix the file. This can be done relatively easy:

  1. Download MKVToolNix.
  2. Open Mkvmerge Gui and select Header Editor from the File menu.
  3. Open your mkv file
  4. Under default duration for the audio track(s), click on Add Element and enter the value 10666666 (for DTS-MA) or 833333 (for TrueHD).

Another solution is to use a different source filter for .mkv files. You can change the preferred source filter with the Codec Tweak Tool, assuming you have a secondary splitter installed.

Q:I have problems playing certain RealMedia files

Update to the latest version of the codec pack. That uses the LAV Filters for playback of RealMedia Files. That works pretty good. Previously the Gabest RealMedia Splitter and ffdshow were used. That combination worked less good and could give problems such as: stuttering video, audio problems, and thumbnail problems.

If you want to use an externally installed version of MPC in combination with the LAV Filters, then you should disable its internal RealMedia source filter and decoders. The MPC included in the codec pack is configured properly automatically.

If LAV Filters do not give you satisfactory results, then you could try VLC player instead.

Q:Seeking in RealMedia files sometimes results in a loss of audio or audio distortion

RMVB files that contain AAC audio may give problems after seeking when using ffdshow or LAV Audio decoder. Seeking again may sometimes restore sound.

Such RMVB files work better when using one of the following AAC decoders:

  • AC3Filter (included in Mega and 64bit pack)
  • Monogram AAC decoder (included in Full and Mega pack)
  • Microsoft DTV-DVD Audio decoder. This decoder is included with Windows 7. To use it simply disable AAC in both ffdshow and LAV Audio decoders (or uncheck AAC during installation of the pack).
Q:Karaoke files on a VCD (.dat / .mpg) with dual mono MP2 audio play as stereo

To play these files correctly you must use the MPEG splitter and MPEG audio decoder from Microsoft.

Change the following settings:

  1. Disable MP2 format in the settings of LAV audio decoder
  2. Disable MP2 format in the settings of ffdhow audio decoder (if you also have that installed)
  3. Disable MPEG-PS input format in the settings of LAV Splitter
  4. If you want to use MPC-HC as player:
    MPC-HC options > Internal Filters > disable MPEG PS source filter and MPEG Audio transform filter

You can test playback with the GraphStudioNext tool or with MPC-HC.

Look at: MPC-HC menu > Play > Filters
This should show "MPEG-I Stream Splitter" and "MPEG Audio Decoder". Click on "MPEG Audio Decoder" to open its settings. There you can choose between First/Second/Both. First is left audio channel, and secondis the right audio channel.

Q:MP4 files that contain video with a variable frame rate play at the wrong speed

Use the Codec Tweak Tool to change the preferred splitter. LAV works better in this case than Haali.

Q:Files with DTS audio give stuttering playback

ffdshow audio decoder -> Decoder settings -> uncheck "Enable jitter correction"

Q:I am having SPDIF problems with ffdshow

One setting in ffdshow that may help is "Connect as PCM". Try with that setting disabled.

If that doesn't help, then you should try LAV Audio Decoder or AC3Filter instead of ffdshow.

Q:Sound only works in one application at a time

Windows has a setting that allows applications to gain exclusive access to the sound output. Disable that.

Windows Control Panel > Sound > Speakers > Properties > Advanced > Exclusive mode

Q:The screen goes black for a few seconds when starting a video

This can happen because of a setting in NVIDIA graphics driver.

NVIDIA control panel > "Adjust desktop color settings"

At the bottom of that page, change the option "Content type reported to the display" from "Auto-select (recommended)" to "Desktop programs".


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