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Terrestrial-Digital Mobile (multimedia) Broadcasting (T-DMB) is a technology invented in Korea and Japan that is close to being adopted as a European standard to deliver video and other multimedia services to handheld devices.
The DMB service would become another type of service alongside the ones we have today (e.g. data & MOT) and be part of the overall DAB ensemble. The DMB data is decoded externally to the DAB decoder where it is unpacked from the MPEG-2 transport system and then it is presented to the DMB AV decoder where audio, video and data streams are extracted.
Now we have MPEG-4 compliant with highly efficient coding rates. The video content will be aimed at handheld devices so will only be displaying images of the order of 320x240 pixels. The audio encoding is much more interesting! DMB has adopted two MPEG-4 audio encoding schemes in addition to Musicam.
The first is AAC+, which is used in DRM and should deliver CD quality at 128kbps and FM quality at 48-64kbps. A new standard is Bit Sliced Arithmetic Coding (BSAC), which uses nearly all the elements of AAC and this one should deliver CD quality at 128Kbps and FM at 64-80kbps.
ETSI documents were issued in June 2005 detailing how video services could be delivered via DAB transport streams. The ETSI standard considers audio encoding techniques very similar to those in Digital Radio Mondiale where AAC sampling rates of 24 KHz are combined with Spectral Band Replication (SBR) and Parametric Stereo.
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