Abstract
This chapter presents a novel approach to search in shared audio file storages, such as P2P-based systems. The proposed method is based on the recognition of specific patterns in the audio contents in such a way to extend the searching possibility from the description based model to a content-based one.
Key Terms in this Chapter
Audio Signal Processing: The coding, decoding, playing, and content handling of audio data files and streams.
Bark-Scale: A non-linear frequency scale modeling the resolution of the human hearing system. One Bark distance on the Bark-scale equals to the so called critical bandwidth that is linearly proportional to the frequency under 500Hz and logarithmically above that. The critical bandwidth can be measured by the simultaneous frequency masking effect of the ear.
Client/Server Model: A communicating model, where one host has more functionality than the other. It differs from the P2P model (see below).
Peer-to-Peer (P2P) Model: A communication model where each node has the same authority and communication capability. They create a virtual network, overlaid on the Internet. Its members organize themselves into a topology for data transmission.
Pattern Recognition: The procedure of finding a certain series of signals in a longer data file or signal stream.
Synchronization: The name of that procedure which is carried out for finding the appropriate points in two or more streams for the correct parallel playing out.
Application Level Network (ALN): The applications, which are running in the hosts, can create a virtual network from their logical connections. This virtual network is also called overlay (see below). The operations of such software entities cannot be understood by one another without knowing their logical relations. In most cases, these ALN software entities use the P2P model (see below), not the client/server one (see below) for the communication.
Manhattan-Distance: The L1 metric for the points of the Euclidean space defined by summing the absolute coordinate differences of two points (|x2-x1|+|y2-y1|+…). Also known as “city block” or “taxi-cab” distance; a car drives this far in a lattice-like street pattern.
Content-Based Recognition: When media data is identified based on its content and not on the attributes of its file. Its other name is content-sensitive searching.
Overlay: The applications which create an ALN (see above) working together; they usually follow the P2P communication model (see below).