VfW Decoder Configuration
Although little work is being done on codecs for the older VfW (Video for Windows) framework, that doesn't mean its not still important for playback. While MKV, MP4, MPG, and TS files may be the current standard, there are probably billions of AVI files on computers, CDs, and even DVDs around the world. Although you may be happier in the long run by (losslessly) copying from the AVI container to something newer like Matroska (MKV), if you prefer to keep them in AVI format you can use the ffvfw dialog to configure codec support.
FourCC1
In AVI files, the video is assigned a special code called a FourCC. The FourCC tells Windows what VfW decoder the video should be sent to for decoding. Different formats, and sometimes different decoders for the same format, have different FourCC codes. These codes are generally taken from the codec's name, such as DIVX and XVID. In most cases it's almost an abbreviation of the name, such as HFYU for HuffYUV. Although the VfW codec listing is essentially the same as the DirectShow list, the FourCCs for each are listed in the description.VfW Decoding
MPEG-4 AVC (H.264)2Since almost all AVC in Windows is created and played by DirectShow based tools its unlikely you'll ever need to decode it with ffvfw. |  |
MPEG-4 ASP3MPEG-4 ASP codecs like DivX and Xvid were once extremely popular among hobbyists and casual encoders alike. These are the files your most likely to require ffvfw to play for you. Since MPEG-4 ASP is a standard, rather than a particular codec, any decoder (including ffvfw) should be able to read any MPEG-4 ASP video. XviD, DivX, ffvfw, and a host of other decoders are all more or less equal in terms of features. The biggest advantage to ffvfw is in keeping the number of individual codecs you must maintain on your computer to a minimum. |  |
Lossless Compression4The open source lossless HuffYUV codec became popular for analog video capture, but due to relatively large file sizes didn't catch on among the general public. However, with several hundred Gigabyte hard drives being commonplace it's found a new niche as an intermediary format for CPU intensive editing using AviSynth. In addition to reducing the number of separate codecs on your computer by one, ffvfw's HuffYUV encoding (a subject for a future guide) is more advanced than the standalone codec. |   |
MJPEGMotion JPEG is similar to DV, although with less compression. At one time it was commonly for TV captures due to smaller file sizes than the lossless alternatives. Unless you're editing AVI files you probably won't need MJPEG support. |  |
DV5DV is the primary format used to encode standard definition digital camcorder footage. Many DV camcorders include a DV decoder. DV is somewhat unusual since there are several FourCCs for a single format. Each FourCC corresponds to one or more specific decoders, which give slightly different output. Unless you have a DV (standard definition) camcorder or analog capture device you shouldn't have any need for this decoder. |  |
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1More FourCC InformationYou can find detailed information about a number of common and uncommon FourCCs at the FourCC.org website.(Return) 2AVC in AVIAlthough there was some work early in the development of x.264 (an open source AVC codec) for using the AVI container and VfW framework, the switch to AVC has been accompanied by a move to the MP4 and MKV containers, both of which are better suited to modern video encoding. As a result most work with AVC video (in Windows) involves DirectShow, and not VfW.(Return) 3MPEG-4 ASP in AVIMPEG-4 ASP files encoded with the DivX and XviD codecs are probably the most common use of the AVI container. In recent years this has been replaced by encoding with DirectShow tools and using the MP4 or MKV container which have become standard for MPEG-4 AVC.(Return) 4Using Lossless CompressionAt one time lossless compression was highly prized for video capturing and editing, but not feasible for many people due to low compression (high file sizes). More recently hard drive space has become abundant, but analog capture is disappearing. However, there's still one area where lossless compression is still a viable solution. When using AviSynth to filter video you may end up with very slow running scripts. When encoded in 2 passes there may be many CPU intensive operations being performed twice (once for each pass), competing with the video encoder for precious CPU cycles. By saving the output of an AVS script to a lossless AVI you can apply all the filters first, giving the video encoder full access to your CPU.(Return) 5Decoding DV CorrectlyDespite the standardization of DV technology, different DV decoders will produce different picture quality from the same file. In addition to ffvfw, you can also use the free Codecida DV codec for advanced decoding options.(Return) Where to go from hereIntroduction to Haali Media Splitter
Using AviSynth 2.5
How to play MP4 files
How to play MKV files
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Version History
v1.0 2008.03.20 Original version by Rich "vurbal" Fiscus
previousAudio Decoder Configuration
Written by: Rich Fiscus
