Uncompressed audio formats
Below, we list the various types of uncompressed linear audio formats. The first three are the ones that have become the main ones supported by most of today’s professional audio applications and are: audio swap file format :
-AIF, AIFF The audio exchange file format is of Apple (1985) origin and allows the storage of mono or multichannel samples of 8 or 16 bits and various sampling rates. Being a format designed to be portable, it can also be easily converted (as we will see, Microsoft RIFF is similar) and is therefore often used. Extensions RIFF WAVE :
-WAV Developed by Microsoft and IBM in 1992, the RIFF WAVE (whose full name is Resource Sharing File Format Waveform Audio Format) follows the specifications of the more general rich information file format. It was introduced starting with Windows 3.1 and quickly became the most popular format for PC applications. WAV files support various types of sampling: they are single or multi-channel, 8 or 16 bits at different sampling rates with various encoding systems, even if the most common are PCM and ADPCM. Extensions TRANSMISSION WAVE FORMAT (BWF) :
-WAV It is an extension of the popular WAVE format and was created by the European Broadcasting Union (EBU) in 1997 and updated in 2001 and 2003. The purpose of this format is to add to the normal .WAV metadata format to facilitate the exchange of data between different platforms and different audio applications, allowing the files thus encoded to identify themselves autonomously and allow synchronization with other recordings. Since the only difference from “normal” WAVE files is in the extended information written in the file header area, the two formats are absolutely compatible and a particular player is not required for playback. In order to overcome the limitation on the maximum size of the WAVE file (2 Gb) in 2006, it was specified as an extension of the BWF l! RF-64, SD2 Sound Designer II Format SD2f file extension The Sound Designer 2 format is proprietary to Digidesign and is the evolution of the original Sound Designer 1 format, unlike which it structures the data so that all audio samples are stored in the file’s data fork and all parameters in place . resource holder. This is extremely convenient in files where the data fork can become hundreds of Mb and more, because it is possible to modify, add, cut the parameters of the audio file without having to modify the sample data, a feature that saves a lot of time, especially at a time when computers and hard drives were vastly smaller in capacity and slower in data processing and writing. It can also be monophonic or multichannel (interleaved), Sampling depth of up to 24 bits at different sampling frequencies of up to 192 KHz, as in the case of Pro Tools HD. It should be noted that in multitrack applications such as Pro Tools, the standard professional market software created for a DSP based card system, each track is recorded in a separate mono file, even for stereo or multi-channel tracks. In the case of a stereo track, the “split stereo” file is used, which consists of two monophonic files with the same name but with the two suffixes .L and .R (or in previous versions (L) and (R) ), that remain physically separated but that the application treats as a single stereophonic file, operating all the editing operations on both files simultaneously in perfect phase coherence; In native applications (ie fully dependent on CPU processing power), all those in practice outside of Pro Tools software (not Pro Tools LE or Pro Tools M-Powered who are also “native” even if they depend of specific Digidesign software or M-Audio production hardware), instead, the use of “interleaved” files is generalized, that is, stereo or multichannel files in which all the channels are stored in a single file. The stereo track is represented by a single file containing the two channels, which are “written” in blocks (first a number n of blocks from the left channel followed by an equal number n of blocks from the right channel, and so on). This type of file, created to dominate applications, used in multitrack applications still generates a bit of confusion, because although it is more practical (in theory) to be used within the native application, it needs to become a “split” file when imported into Pro Tools.
