MPEG-2 Layer I, MPEG-4 AAC and many other audio coders. The methods of this codec are described in the IEEE paper: Real world performance issues MUSE had a four-field dot-interlacing cycle, meaning it took four fields to complete a single MUSE frame. Thus, only stationary images were transmitted at full resolution. However, as MUSE lowers the horizontal and vertical resolution of material that varies greatly from frame to frame, moving images were blurred. Because MUSE used motion-compensation, whole camera pans maintained full resolution, but individual moving elements could be reduced to only a quarter of the full frame resolution. Because the mix between motion and non-motion was encoded on a pixel-by-pixel basis, it wasn't as visible as most would think. Later, NHK came up with backwards compatible methods of MUSE encoding/decoding that greatly increased resolution in moving areas of the image as well as increasing the chroma resolution during motion. This so-called MUSE-III system was used for broadcasts starting in 1995 and a very few of the last Hi-Vision MUSE LaserDiscs used it ("A River Runs Through It" is one Hi-Vision LD that used it). During early demonstrations of the MUSE system, complaints were common about the decoder's large size, which led to the creation of a miniaturized decoder. Shadows and multipath still plague this analog frequency modulated transmission mode. Japan has since switched to a digital HDTV system based on ISDB, but the original MUSE-based BS Satellite channel 9 (NHK BS Hi-vision) was broadcast until September 30, 2007. Cultural and geopolitical impacts Internal reasons inside Japan that led to the creation of Hi-Vision (1940s): The NTSC standard (as a 525 line monochrome system) was imposed by the US occupation forces. (1950s-1960s): Unlike Canada (that could have switched to PAL), Japan was stuck with the US TV transmission standard regardless of circumstances. (1960s-1970s): By the late 1960s many parts of the modern Japanese electronics industry had gotten their start by fixing the transmission and storage problems inherent with NTSC's design. (1970s-1980s): By the 1980s there was spare engineering talent available in Japan that could design a better television system. MUSE, as the US public came to know it, was initially covered in the magazine Popular Science in the mid-1980s. The US television networks did not provide much coverage of MUSE until the late 1980s, as there were few public demonstrations of the system outside Japan. Because Japan had its own