Before installation:

It is highly recommended to first uninstall other codec related packages before installing this package. This way your system stays clean and potential problems will be avoided. This installer is able to automatically detect a lot of codec packs and it will ask you if you want to uninstall them.
Close all multimedia applications (media players, video editors, browsers, filesharing tools, etc) before installing this pack.

Installation:

Below on this page you can find some information about all components included in this codec pack. Please read this information thoroughly. Leave all settings in the installer at their default values if you don't know exactly what you should install. Do NOT simply select all components because you think that more means better. In fact, less is better. Many components are not selected by default since it is very unlikely that you actually need them. Click on the 'Print' button to open this documentation in Wordpad. That way you can view it during the entire installation procedure.

After installation:

It is recommended to run the Reset to recommended settings shortcut after the first installation. This should be done on all user accounts, except for the administrator account that was used to perform the installation. This will make sure all filters are correctly configured.

Unattended installation:

An unattended installation is a silent installation that doesn't require any user interaction.
Run the setup with the command-line parameter -MakeUnattended to create an unattended setup. A wizard called "Unattended Install Maker" will appear. Follow the instructions given in the wizard.

Codecs explained

Most players use DirectShow for playback. DirectShow is a system that uses multiple DirectShow filters as building blocks to construct what is called a DirectShow graph. A file is a root of this graph and the audio and video renderers are the leaves of the graph. During playback data flows from the root to the leaves. Each filter in the graph performs a subtask of the whole process. Typical elements in the graph are a source filter, which is often also called a splitter or parser, and decoders for the audio and video. A source filter is responsible for reading the file format and feeding the data to the other filters downstream in the graph. During graph creation, if DirectShow finds multiple filters that are able to perform the same subtask, then it will typically select the filter that has the highest merit. The merit of a filter is simply a numerical value that indicates the preferability of the filter. Tools exist to alter the merit of a DS filter. Advanced players are often able to manipulate which filters are used in the graph, allowing for example to block or prefer certain filters. If no suitable DirectShow filter can be found to decode a certain audio/video format, then DirectShow is able to fall back to using VFW and ACM codecs (see below) through special wrapper filters.

It is a myth that filters can 'conflict' with each other. If something goes wrong it is simply because some filters in the graph are not performing their subtasks correctly. The filters in this pack are carefully selected to provide you with optimal functionality and a minimal chance of running into problems.

Codec is short for 'compressor-decompressor', a piece of software that is able to decode and encode a certain format. By this definition, a DirectShow filter is not a codec.

Two other systems are VFW (Video For Windows) and ACM (Audio Compression Manager). Components for these system are called codecs, because they are typically able to both encode and decode. These two types of codecs are required by most video editing applications, such as VirtualDub. Traditional video editing applications are not able to use DirectShow. More modern applications are sometimes capable of using DirectShow for decoding, but they usually still require VFW and ACM codecs for encoding.

Components:

#   means that ffdshow is able to decode the same format(s) as the marked component. So you don't necessarily need to install the marked component if you install ffdshow.
#   means that Media Player Classic is able to decode the same format(s) as the marked component. So you don't necessarily need to install the marked component if you install MPC and use it as your default player.

Player:

Media Player Classic [version 6.4.9.1 rev. 73]
This is a full-featured player which has internal decoding support for DVD, MPEG-1/2, MP3, MP2, AAC, AC3 and DTS. It also has internal support for opening MP4, Matroska and Ogg containers. Media Player Classic is also capable of playing QuickTime and RealMedia content if those codecs are installed.

ffdshow:

ffdshow [revision 2067]
ffdshow is a very powerful DirectShow filter that can decode many audio and video formats. It also contains lots of options for manipulation of the audio and video, such as resizing and post-processing. Examples of supported video formats are: DivX, Xvid, MPEG-4, H.264/AVC, MPEG-2, FLV1, FLV4, VP3, VP6, and MJPEG. Examples of supported audio formats are: MP3, AAC, AC3, DTS, LPCM, Vorbis, MP1, MP2, AMR, and IMA ADPCM.
ffdshow VFW interface
VFW decoder that supports many video formats.
VFW encoder for a few video formats: MPEG-4, DV, H.263, Theora, MPEG-2, MPEG-1, MJPEG and a couple more.
Extra plugins
Kernel and TomsMoComp deinterlacers. DScaler plugin.

DirectShow video decoding filters:

Xvid [version 1.2 | build 2008-01-10] #
For decoding Xvid video. This is currently the most popular video format.
DivX [version 6.8.4] #
For decoding DivX video.
On2 VP6 [version 6.4.2.0]
For decoding VP6 video. This format is not very common.
On2 VP7 [version 7.0.10.0]
For decoding VP7 video. This format is not very common.
MPEG-2 (Cyberlink) [version 8.1.0.1608] # #
MPEG-2 (Gabest) [version 1.0.0.4] # #
For decoding MPEG-2 video.
Cyberlink also support playback of DVD video in Windows Media Player and Windows Media Center.
Windows Vista (Home Premium / Ultimate) already contains its own MPEG-2 and DVD decoder. So you don't need to install one of these, unless you prefer them over the MS decoder.
MPEG-1 (MainConcept) [version 1.0.0.78] # #
For decoding MPEG-1 video.
Windows already contains its own MPEG-1 decoder. So you don't need to install this, unless you prefer it over the MS decoder.

DirectShow audio decoding filters:

AC3/DTS/LPCM/MP1/MP2 (AC3Filter) [version 1.46] # #
For decoding AC3 and DTS audio. Also decodes DVD audio.
Vorbis (CoreVorbis) [version 1.1.0.79] #
For decoding Vorbis audio. This is the recommended Vorbis decoder.
AAC (MONOGRAM) [version 0.9.5.0] #
For decoding AAC audio.

DirectShow audio parsers:

MusePack (MONOGRAM) [version 0.9.1.2 / 0.3.1.2]
Source filter and decoding filter for MusePack audio files (.mpc).
WavPack (CoreWavPack) [version 1.1.1]
Source filter and decoding filter for WavPack audio files (.wv).
FLAC (madFLAC) [version 1.8]
Source filter and decoding filter for FLAC audio files (.flac).
Monkey's Audio (DCoder) [version 1.0]
Source filter with integrated decoder for Monkey's Audio files (.ape).
OptimFROG (RadLight) [version 1.0.0.1]
Source filter with integrated decoder for OptimFROG audio files (.ofr .ofs).
DC-Bass Source [version 1.1.1]
Source filter with integrated decoders for the following audio file types:
AAC (.aac .m4a)
ALAC (.alac)
Tracker (.it .mo3 .mod .mtm .s3m .umx .xm)
True Audio (.tta)
AC3/DTS Source (AC3File) [version 0.5b] #
Source filter for .ac3 and .dts files.
AMR (MONOGRAM) [version 1.0.1.0]
Source filter and decoding filter for AMR audio files (.amr).
This filter is also able to encode and mux AMR audio.

DirectShow source filters:

AVI splitter (Gabest) [version 1.0.0.9] #
AVI splitter (Haali Media Splitter) [version 1.8.122.18] #
For parsing the AVI container (.avi files).
MP4/3GP/MOV splitter (Haali Media Splitter) [version 1.8.122.18] #
MP4/3GP/MOV splitter (Gabest) [version 1.0.0.4] #
For parsing the MP4/MOV/3GP containers (.mp4 .m4v .hdmov .mov .3gp files).
Matroska splitter (Haali Media Splitter) [version 1.8.122.18] #
Matroska splitter (Gabest) [version 1.0.3.0] #
For parsing the Matroska container (.mkv .mka files).
Ogg splitter (Haali Media Splitter) [version 1.8.122.18] #
Ogg splitter (Gabest) [version 1.0.0.1] #
For parsing the Ogg container (.ogm .ogg files).
MPEG PS/TS splitter (Gabest) [version 1.0.0.5] #
MPEG PS/TS splitter (Haali Media Splitter) [version 1.8.122.18] #
For parsing the MPEG container (.mpeg .mpg .m1v .m2v .ts .m2ts files).
The Haali MPEG PS splitter also supports .evo files, but it does not always work properly for regular MPEG files.
FLV splitter (Gabest) [version 1.0.0.4] #
For parsing the FLV container (.flv files).
CDXA Reader (Gabest) [version 1.0.0.2] #
For reading VCD, SVCD and XCD discs.

DirectShow subtitle filter:

DirectVobSub (a.k.a. VSFilter) [version 2.39] # #
DirectVobSub (a.k.a. VSFilter) [version 2.33] # #
DirectVobSub is a filter for displaying subtitles (ssa/ass, srt and vobsub). Your subtitle file(s) should have the same filename as your video file (for example: MovieName.avi + MovieName.idx + MovieName.sub) and should be in the same folder as your video file. Then the subtitles will automatically be displayed in most players.

Other filters:

Haali Video Renderer [version 1.8.122.18]
Excellent video renderer that can be used as an alternative for the video renderers that Windows offers.
Requires a modern graphics card with PixelShader 1.4 or higher.

VFW video codecs:

Xvid [version 1.2 | build 2008-01-10]
For encoding video in the Xvid format.
DivX [version 6.8.4]
For encoding video in the DivX format.
x264 [revision 913]
For encoding video in the H.264 format.
We don't recommend using the VFW system to encode H.264 video. It is better to use a CLI based solution, such as MeGUI.
On2 VP6 [version 6.4.2.0]
For encoding video in the VP6 format.
On2 VP7 [version 7.0.10.0]
For encoding video in the VP7 format.
Intel Indeo 4 [version 4.51.16.2]
For decoding Indeo 4 video.
For encoding video in the Indeo 4 format.
Intel Indeo 5 [version 5.2562.15.54]
For decoding Indeo 5 video.
For encoding video in the Indeo 5 format.
Intel I.263 [version 2.55.1.16]
For decoding I.263 video.
For encoding video in the I.263 format.
huffyuv [version 2.1.1 CCE Patch 0.2.5]
For decoding huffyuv video.
For encoding video in the huffyuv format.
huffyuv is a lossless (no quality loss) video compression format.
YV12 (Helix) [version 1.2]
For decoding from and encoding in the YV12 format.

ACM audio codecs:

MP3 (Fraunhofer) [version 3.4.0.0]
For decoding and encoding MP3 audio in applications like VirtualDub.
MP3 (LAME) [version 3.98]
For encoding MP3 audio in applications like VirtualDub.
AC3ACM [version 1.4]
For decoding and encoding AC3 audio in applications like VirtualDub.
Vorbis [version 0.0.3.6]
Required for playing AVI files that contain Vorbis audio. These files are very uncommon.
DivX ;) Audio [version 4.2.0.0]
Some old DivX 3.11 videos use this audio codec.

Tools:

K-Lite Codec Tweak Tool [version 2.2.9]
With this multi-functional tool you can (1) detect and fix some common problems (2) generate a detailed list of all installed codecs and filters (3) reset settings (4) backup/restore settings (5) manage the installed codecs and filters.
MediaInfo Lite [version 0.7.7.4]
This tool can analyze a media file and show detailed information about it.
GSpot Codec Information Appliance [version 2.70a]
GSpot is a tool that can analyze AVI, MPEG and MP4 files and tell you which audio and video formats it contains. It can also perform a render test that shows you which filters are being used to play the file.
VobSubStrip [version 0.11]
With this tool you can strip languages from VobSub subtitle files (.idx and .sub files).
GraphEdit [build 061102]
GraphEdit is a visual tool for building and testing DirectShow filter graphs.
Haali Muxer
Tool for (re-)muxing audio and video into Matroska container.
FourCC Changer
The FourCC (Four Character Code) Changer is a program for changing the FourCC of a video file, which is used to identify which codec should be used to decode the file. This tool is for expert users only.
Bitrate Calculator
This can be used to calculate the bitrate to use when encoding a movie.