Analyzing the main audio formats Part 2

Compressed and uncompressed audio files

Let’s start by examining three categories into which all audio file formats can be grouped. They are determined by the degree of data compression and the associated loss of sound quality.
If a special algorithm (or codec) was not used to compress the audio in your file, this will lead to a double result: first, there will be no loss of sound quality, and second, you will soon run out of audio space. your hard drive.
In essence, the uncompressed recording is fully consistent with the original audio file, in which real sound signals are recorded in digital representation.
WAV, AIFF or FLAC: uncompressed formats
WAV and AIFF are the most popular uncompressed audio file formats. Both are based on PCM (Pulse Code Modulation), a well-known mechanism for directly converting audio to digital format. WAV and AIFF use similar technologies, but the storage methods are slightly different. CD-quality files and higher resolution files can be burned in these formats.
The WAV format was developed by Microsoft and IBM and is therefore used on Windows-based platforms; it is the standard CD recording format.
The AIFF format was created by Apple as an alternative to WAV; And while AIFF files are less common, they provide more comprehensive metadata support, allowing you to store album art, song titles, and the like.
The downside to these formats is that they require a large amount of memory. CD-quality files (16-bit, 44.1 kHz) occupy approximately 10 MB of disk space per minute of sound.
ALAC, FLAC, WMA Lossless: lossless audio formats
We all love FLAC. Lossless format, files in FLAC (Free Lossless Audio Codec, Free Lossless Audio Codec) are almost half the size of uncompressed WAV or AIFF files with equivalent sample rate, but in terms of sound, no loss of quality is noted. FLAC also supports higher resolution than CD quality, up to 32-bit and 192 kHz.
Besides FLAC, there are other lossless formats: ALAC (Apple Lossless) and WMA Lossless (Windows Media Audio). The former is a great alternative for iOS and iTunes, although the file size is slightly larger than FLAC. Not all smartphones and tablets support it.
AAC and MP3: lossy audio formats
Who has not heard of MP3? Everyone has heard of him. This most common audio format is convenient for storing music on iPods or tablets and is compatible with almost any device. However, this requires the sacrifice of a significant amount of information. To reduce file sizes by an order of magnitude compared to CD-quality recordings, a significant percentage of the original data needs to be discarded, leading to a loss in sound quality.
The bit rate at which the MP3 file is recorded also affects the sound quality. 128 kbps MP3s lose more information than 320 kbps files (this means “kilobits per second”, where each “bit” is essentially a small part of a song). Given the steep decline in memory costs, there is no reason these days to listen to files at 128 kbps; 320kbps MP3s make sense with limited storage space and are also still the standard format for downloading files from online stores.
Another lossy format, AAC (Advanced Audio Coding), also offers compression like MP3, but thanks to slightly more efficient algorithms, it provides better sound quality. AAC is used for iTunes downloads and Apple Music (256 kbps) streams and YouTube streams.
The Vorbis format, often referred to as Ogg Vorbis to emphasize the use of the Ogg container, is an open source, patent-free alternative to MP3 and AAC. This 320 kbps bit rate format is used in Spotify streams.
If you plan to use lossy formats, consider the following fact: increasing the number of “bits” generally leads to an increase in sound quality, but it is highly dependent on the efficiency of the codec with which the file is converted. If most of the music in your collection is encoded at 128 Kbps, you may have noticed that despite the fundamental similarity in sound, due to the low efficiency of the codec, MP3 files are likely to be somewhat audible. worse than AAC or Ogg. Vorbis.