Seamlessly Multiplexed Embedded Codec (SMEC)
JPEG 2000 and recent work in scalable video coding achieves multiple aspect scalability. The compressed bitstream can be flexibly reorganized to another bitstream of different bitrate, resolution, spatial region of interest (ROI), resolution, or a combination of any of the above. Such flexibility is achieved by multiplexing the compressed bitstream pieces of multiple code-blocks together into a combined bitstream, with the length of the code-block bitstream piece (LOCB) embedded in the combined bitstream. The LOCB serves both to reorganize the bitstream, and to decode the bitstream. It represents a significant overhead, especially since there is no correlation between the neighbor LOCBs. In the seamlessly multiplexed embedded codec, we introduce seamless multiplexing, and separate the information needed for the reorganization, i.e., the LOCB, from the com-pressed bitstream itself by using the decoder pointer to multiplex the bitstream pieces. As a result, the compressed bitstream consists of code-block bitstream pieces seamlessly concatenated to each other. With seamless multiplexing, only the compressed bitstream (without LOCB) needs to be delivered to the receiving client. It results in better compression performance and higher granularity of access. Another benefit of seamless multiplexing is that the relative coding orders of the code-blocks are preserved in the bitstream reorganization. As a result, the seamlessly multi-plexed embedded codec (SMEC) may utilize the dependencies among the code-blocks in the coding, thus further boost the com-pression performance.
For more information of the seamlessly multiplexed embedded codec (SMEC), please refer to the published paper:
©Copyright by Jin Li, Nov. 23, 2004