Chapter 4: Metadata Magic 107 audio within Wav fi les (the de facto audio fi le format for Microsoft Windows). This information segments the audio data within the sample into smaller chunks, so that each chunk can be looped semi-indepen- dently of the other chunks within the fi le. As a result, the tempo and the pitch of the audio sample can be varied freely, allowing for greater possibilities for sample manipulation. Before ACID, tempo and pitch could be manipulated indepen- dently only with very expensive studio equipment. The development of this format, together with the audio stretching software for it, made real-time audio stretching available to the masses. This functionality has later been incorporated into numerous music software packages, such as Apple’s Garageband. This, in turn, has contributed greatly to the art of real-time mixing and to the currently popular surge of “mashups”, where two or more songs are combined in unorthodox ways. While the ACID format is not exactly a consumer format – in fact just an extension of a consumer format – we can say it provoked a fundamental change in the way musicians dealt with sound samples, and consequently brought the technology within the reach of con- sumers. A lesson to learn here is that sometimes minor additions of metadata into existing formats can have major effects. 4.6.6 DCF and EXIF As discussed in Chapter 1, the increase of digital camera sales during the past few years is nothing short of astonishing. As a result, our mass media devices are fi lled with digital photos. Since most current digital cameras include metadata in Exchangeable Image File Format (EXIF) formats, it is not surprising that EXIF is the dominant image metadata format at the moment. The current version (2006) is EXIF2.2. The EXIF format is part of the DCF (Design Rule for Camera File Systems) standard created by the Japan Electronics and Information 38 Technology Industries Association (JEITA) to encourage interoperabil- ity between imaging devices. DCF is a fi le system standard designed to ensure compatibility for images using recording media (for instance, Flash memory cards) between devices such as digital cameras and printers. The standard defi nes fi le naming conventions and folder structures. DCF-compatible devices allow image fi les to be easily exchanged, even between different series of products or the products of different manufacturers. 38 http://www.jeita.or.jp/english/index.htm