It’s critical to ensure that you export your track in the correct format and audio quality. That can vary depending on whether you want to export for music distribution or to share with your friends, for instance. Which audio encoding formats are the best? This really depends on what your needs are. In the next tutorial, we will guide you through some of the most used ones.
When working with digital audio and exporting tracks we must consider three factors: sample rate, bit depth, and bit rate. In simple terms, the sample rate specifies the number of audio samples recorded per unit of time. The bit depth specifies the accuracy of these samples. The bit rate represents the number of bits encoded per second. In this context, compression is a process that reduces the size of a file in order to save space and time while streaming, downloading, or saving it. The bit rate is the most relevant aspect when we speak of exporting files and compression. Besides an uncompressed, original version of an audio file, there are two main types of compression which we will cover below.
- Lossless file formats do not exclude any data. That means encoding preserves the original recording’s sound quality.
- Compressed files are those that are lossy. Encoding removes some of the original data. The file and main information are there, but some details have been lost.
Lossless file formats
A common example of lossless file formats is WAV or AIFF. They capture and reproduce an original audio waveform at the best possible quality without changing or modifying its sonic characteristics. WAV encodes data using PCM (Pulse Code Modulation) by splitting it into tiny bits for the best possible quality. The encoded result stands as a mathematical/digital representation of the original audio waveform, with no significant audio quality loss. AIFF is in essence identical to WAV.
Bit rate, expressed in kilobytes per second (kbps), essentially determines the quality of the audio at the time of encoding or compression. For example, file formats like WAV normally operate at 11411 kbps. On the other hand, you might have noticed that MP3 files operate at 192 or 320 kbps. Higher bitrates translate to better sound.
Lossy encoding
Uncompressed audio formats such as WAV and AIFF provide excellent sound quality but result in large file sizes. People soon discovered that transferring uncompressed files over dial-up connections was impractical with the rise of internet file-sharing in the mid-1990s. MP3s (MPEG-2 Audio Layer III) came as the solution. While a three-minute song in WAV or AIFF format would average 30 megabytes (MB) in size, MP3 resulted in a tenth of the size. Because of this, MP3 has been key to internet distribution and has retained that status until now, with compression algorithms that are able to achieve impressively small file sizes.
Different formats of compression use different methods for encoding data to save space. However, as mentioned, saving space means data must be sacrificed. Very high frequencies are often the first to go, as the majority of people cannot hear information at this range anyway.
Another file format that falls into the compressed, or lossy encoding, is M4A or MP4. This type of format is often regarded as the successor of MP3. Since the birth of the iTunes Store, it stood as the predominant standard for music sales made via their online music store. It remains the preferred format for all audio in Mac and iOS App Stores applications. M4A files are encoded with a lossy Advanced Audio Coding (AAC) codec, which provides similar bitrates as MP3, yet achieves tighter compression.
