. A new exact-match integer 4x4 spatial block transform enables the H.264 encoder to select adaptively between a 4x4 and 8x8 transform block size for the integer transform operation. H.264 is a worthy successor to H.263 with an exhaustive catalog of improvements. Other enhancements include intra-frame coding from the edges of neighboring blocks for spatial prediction, context-adaptive binary arithmetic coding (CABAC) for lossless compression for syntax elements in the video stream through, context- adaptive variable-length coding (CAVLC) for the coding of quantized transform coefficient values, Exponential-Golomb (Exp-Golomb) code as the variable length coding (VLC) technique for many syntax elements not coded by CABAC or CAVLC, a secondary Hadamard transform on DC coefficients of the primary spatial transform to increase compression in smooth regions. H.264 enables an encoder to direct a decoder to enter into an ongoing video stream for video streaming bit rate switching via switching slices (SP or SI slices) with an exact match to the decoded pictures in the video stream at that location, even in the absence of reference pictures. H.264 includes additions such as picture parameter sets (PPS) and sequence parameter sets (SPS) to include a network abstraction layer (NAL) definition that provides for video syntax sharing in various network environments. One more feature of H.264 is picture order count, which isolates picture ordering and decoded picture value samples from timing information SO that timing information can be carried and manipulated by a separate system without affecting decoded picture content. H.264 already enjoys wide adoption in videoconferencing, and is likely to find its way into a broad array of products, including broadcast TV in the US. MPEG has integrated H.264 support MPEG-2 and MPEG-4 systems and the ISO media file format specification. The Republic of Korea and Japan have already announced support, as has the Motion Imagery Standards Board (MISB) of the United States Standards for Video