Abekas YUV is a raster image file format. Images use the YUV color space, and are subsampled.
It is a raw format, storing only the bitmap. It cannot be decoded unless you know, or can figure out, the image dimensions.
Note that there are other YUV image formats that also use the .yuv extension. The Diskus YUV format is apparently the same as the Abekas one, using only raw data for the three color layers and no headers. Apparently "qcif format" is one label for a family of YUV formats, but the format of a particular file can vary in the size of each of the layers and whether they are interlaced or progressive. Quantel raw uncompressed YCbCr (QNT) is another format label.
- Some example YUV files (qcif format), 6 frame animations