1. A method for video encoding or decoding of frames, comprising: determining availability of neighboring blocks with respect to an intra block, the neighboring blocks including first and second adjacent blocks that are adjacent to the intra block and a diagonal block that is adjacent to the first and second adjacent blocks and diagonal to the intra block; in response to determining that one or more of the neighboring blocks are unavailable, accessing a DC default value for each unavailable neighboring block; in response to determining that one or more of the neighboring blocks are available, accessing a respective quantized DC block value for each available neighboring block; and determining a direction of change for the intra block using predictor values obtained from each DC default value and quantized DC block value; wherein the determining the direction of change includes: comparing a first absolute difference to a second absolute difference, wherein: the first absolute difference is between a DC value of the first adjacent block and a DC value of the diagonal block, and the second absolute difference is between the DC value of the diagonal block and a DC value of the second adjacent block; and in response to one of the first and second adjacent blocks and the diagonal block being unavailable, the DC value of the unavailable block is the DC default value, and each other of the DC values is the respective quantized DC block value.