Arithyuv is a lossless video codec designed for video capturing.

Features of Arithyuv 1.1.1 :

- It only supports YUY2 colorspace.
- Codec settings can be changed during compression.
- Speed consideration: Huffyuv is becoming too fast. I mean that there are many CPU cycles that could be used to improve compression. However, the Lagarith codec is a little too slow for my PC. Arithyuv only uses median prediction (huffyuv implementation) and an assembly-optimized implementation of arithmetic coding.
- Compression consideration: Compression is better than Huffyuv, even when adaptive huffman tables are used (it's a ffdshow improvement). For interlaced sources, Arithyuv even give better results than Lagarith since Lagarith lacks the ability to treat the contents as interlaced video. However, Lagarith compression is generally better for progressive frames.
- Size consideration: Compression isn't the only factor to reduce the file size. The possibility to change settings during the capture allows you to optimize them without knowing in advance the format of the video. For example, cropping to remove black borders is generally unsafe. Anyway, not all capture applications allows you to crop the video. Also, discarding frames temporarily can be less problematic than stopping and restarting the capture.

How to install Arithyuv codec :

- Right-click on arithyuv.inf and choose "Install".
- You must have administrative privileges to install this software.

Changes in Arithyuv 1.1.1 :

- (bug) Fixed RGB output (decompression).
- Added a TODO list.