FastCodec is a free, fast lossless video codec designed for video capture. The main design goals are simplicity and speed. Compression algorithm is relatively simple.

The general scheme is:

- Each frame is compressed separately.
- Frame is divided into square blocks 4x4 or 8x4 pixels.
- Every block converted from RGB to YUV color space.
- Enumerative coding applayed to transformed block.

FastCodec has 2 working modes:

- Absolutely lossless compression: there is no difference between non coded and decoded movies. The codec doesn't add any distortions to video.
- Visually lossless compression: there is a small difference between non coded and decoded movies. Human eye can't see this difference but at the same time compression ratio greater than in the first case.
Also FastCodec supports logging. This feature added mostly for debug purposes. It's not recommended to use it during real time video capturing because of performance reducing.

Features of FastCodec 1.0 :

- Lossless and lossy compression.
- Decompression in preview mode.
- Frame size restrictions. Lossless compression requires that frame width and height must be a multiple of 4. Lossy compression requires that frame height is multiple of 4 but frame width is multiple of 8.
- Supported input and output formats: YUY2/YUNV/V422/YUYV, YVYU, UYVY/Y422/UYNV, RGB24, RGB32.
- Codec implemented as VFW driver, FOURCC is FCKK

Codec restrictions :

- Lossless compression requires that frame width and height should be a multiple of 4.
- Lossy comression also requires that frame height is multiple of 4 but width is multiple of 8.
- Supported input and output formats: RGB24, RGB32, YUY2. The next step is support several other YUV 4:2:2 formats.
- RGB compressed data can only be decompressed to RGB. YUY2 compressed data can only be decompressed to YUY2.
- Lossless and lossy compression in YUY2 are the same.

• FOURCC used by this codec: FCKK

Changes in FastCodec 1.0 beta :

- Internal video data format was changed (incompatible with previous versions)
- Added experimental "Preview" decompression mode
- Created installer with modern UI interface
- Options dialog was changed (added decompression options)
- Several bugs fixed