Various techniques and tools for encoding and decoding (e.g., in a video
encoder/decoder) binary information (e.g., skipped macroblock
information) are described. In some embodiments, the binary information
is arranged in a bit plane, and the bit plane is coded at the
picture/frame layer. The encoder and decoder process the binary
information and, in some embodiments, switch coding modes. For example,
the encoder and decoder use normal, row-skip, column-skip, or
differential modes, or other and/or additional modes. In some
embodiments, the encoder and decoder define a skipped macroblock as a
predicted macroblock whose motion is equal to its causally predicted
motion and which has zero residual error. In some embodiments, the
encoder and decoder use a raw coding mode to allow for low-latency
applications.