[1] Blizzard used this format for the cinematic videos seen in its games Warcraft II, StarCraft and Diablo I.
[4][5][6] A non-commercial SourceForge project libsmacker released an open source decoder in 2013.
[2] While being a palette-based format, which is inherently limited to having not more than 256 colors in each frame, Smacker videos may still contain more colors in total due to "palette rotation", whereby the palette is updated on a per-frame basis.
[citation needed] In Smacker video, a frame is split into 4×4 blocks in raster-scan order.
Each mode can be signaled for multiple blocks in a run-length encoding scheme.
In skip mode, the current block is copied from the previous frame in a conditional replenishment fashion.
[2] The mono mode can be interpreted as vector quantization, where a three-dimensional vector with the components red, green, and blue is quantized using an adaptive codebook with two entries.
[2] In the original full mode, 16 colors are transmitted, one for each pixel, equivalent to raw uncompressed PCM.