Adaptive Multi-Rate audio codec

About: Adaptive Multi-Rate audio codec is a research topic. Over the lifetime, 1467 publications have been published within this topic receiving 19736 citations. The topic is also known as: AMR & Adaptive Multi-Rate.

Media codec devices providing universality for encoded signal origination and decided signal distribution

Abstract: A media codec device includes an input port that receives media signals from service providers and also receives power for the media codec device, and a decoder that stores decoder keys associated with the service providers. The decoder applies the decoder keys to decode the media signals. The media codec device operates to direct at a first time a decoded first media signal to a first output device and a decoded second media signal to a second output device, and to direct at a second time the decoded first media signal to the second output device and the decoded second media signal to the first output device.

MPEG-4 ALS - The Standard for Lossless Audio Coding

Abstract: The MPEG-4 Audio Lossless Coding (ALS) standard belongs to the family MPEG-4 audio coding standards. In contrast to lossy codecs such as AAC, which merely strive to preserve the subjective audio quality, lossless coding preserves every single bit of the original audio data. The ALS core codec is based on forward-adaptive linear prediction, which combines remarkable compression with low complexity. Additional features include long-term prediction, multichannel coding, and compression of floating-point audio material. This paper describes the basic elements of the ALS codec with a focus on prediction, entropy coding, and related tools and points out the most important applications of this standardized lossless audio format.

Enhanced Principal Component Using Polar Coordinate PCA for Stereo Audio Coding

Abstract: High efficiency audio compression is the basic technology in audio involved multimedia application. Down mixing and parametric coding are efficient coding scheme with widely applications in some up to date audio codecs such as PS in EAAC+ and MPEG-Surround, and PCA stereo coding followed this idea to map two channels to one channel with maximum energy and parameterize the secondary channel. This paper investigates the conventional PCA method performance under general stereo model with multiple sound sources and different directions, and then proposes a Polar Coordinate based PCA (PC-PCA) stereo coding method. It has been proved that when multiple sound sources exist with different directions, proposed method is better than the conventional PCA method in certain conditions. A stereo codec based on PC-PCA has also been proposed to validate the performance improvement of proposed method.

Real-time software video codec with a fast adaptive motion vector search

Abstract: A PC-based real-time software MPEG-4 video codec with a fast adaptive motion vector search is presented. In a fast adaptive motion estimation (ME) technique, the search order is dynamically changed in accordance with the motion of objects. This technique suppresses load fluctuation in the ME and contributes to the stable real-time work of the codec. MMX instructions are used to increase the codec speed. On a portable PC, the software video codec supports satisfactory mobile visual communication at 64 kbps and 128 kbps, for example, at QCIF 15 fps. The codec on a 450 MHz Pentium II processor can encode and decode 30 CIF frames in real-time.

Apparatus including audio codec and methods of operation therefor

Abstract: In an embodiment, an electronic device includes one or more audio codec nodes and one or more audio application nodes, which communicate audio information with each other over a communications bus. The communications bus is a packet-based bus, in an embodiment. Power is selectively controlled to selected ones of the audio codec node and the audio application nodes, based on whether or not a node is of use at a particular time.