At its 70th meeting in Palma de Mallorca, Spain last month, the Motion Pictures Expert Group (MPEG) evaluated four competing technologies for the efficient coding of spatial audio. This technology has the potential to produce high-quality surround sound from a stereo or mono stream.
MPEG said the goal is to add a small amount of data to the original signal in order to get a faithful spatial sound stage. The advantage of the used techniques is that the resulting signal is backward-compatible.
This means that an Advanced Audio Coding (AAC) device will still be able to decode the base signal even when spatial signal is present. MPEG has started to draft a standard that merges the best two of the competing proposals.
In parallel video work, MPEG has moved nearer to a new standard for scalable video coding. Designed to allow a single video codec to work across a wide range of bit rates without compromising quality, the new standard will be based on the Advanced Video Coding (AVC) standard and include new technologies such as motion-compensated temporal filtering, spatial upsampling prediction and progressively refined quantization.
Experimental work involving numerous MPEG members continues to refine this technology that is expected to find applications in fixed and mobile networks.
For more information, visit www.chiariglione.org/mpeg.