RLE

Some ressource file in Realm Of The Haunting use a Run-length encoding (RLE) on some data.

A byte with the top 4 bits set indicates a RLE byte.

The low 4 bits indicate how many times to repeat the next byte.

RLE decode C pseudo-code

DestinationIndex = 0x00;
SourceIndex = 0x00;
while (DestinationIndex < DecodedSize) {
    if (EncodedData[SourceIndex] > 0xF0) {
        memset(DecodedData + DestinationIndex, EncodedData[SourceIndex + 1], EncodedData[SourceIndex] & 0x0F);
        DestinationIndex += EncodedData[SourceIndex] & 0x0F;
        SourceIndex += 2;
    }
    else {
        DecodedData[DestinationIndex++] = EncodedData[SourceIndex++];
    }
}