What is the best audio format for what purpose?
Comparison of audio formats
All radio and podcast producers are faced with the question: What audio format is best for my shows and contributions? There is usually no simple answer. Each file format and each codec has advantages and disadvantages.
Before converting / converting, you need to be clear about what you plan to do with your audio file: Should it be published to the NRWision media library? Is the program designed to broadcast on the Internet or for the home audio system? Should the file be edited again if necessary? Only then can you weigh which audio format and which properties make the most sense.
Compress without loss?
You must decide whether you want the best possible sound quality or the smallest possible file size. With some audio codecs, sound is retained at its full bandwidth and without loss. Other codecs compress the file so that it takes up less space or is faster to transfer online. At best, it can still be played on many different devices and players. Depending on the strength of the compression, the sound of music or voice recording may also be audibly affected.
In the case of audio files, information such as sample rate and bit rate always play a role.
The sample rate indicates how often the level is saved per second. CDs, for example, have a sample rate of 44,100 Hz. 44,100 values are stored for one second of music.
Bit transfer rate
Bit rate defines the amount of data that is processed per second. It can be constant or variable and therefore also influences the sound quality.
Important: When converting audio files to other formats, the quality cannot be improved, it only deteriorates or is preserved. With each compression, some of the audio data is lost, although it is not necessarily audible.
Next we present the audio formats and their properties.
MP3
File extension: .mp3
MP3 is probably the most popular and widely used audio format in the world. It became the standard for music files on the Internet more than 20 years ago and has been freely available since 2017. By the way, MP3 was developed by the Fraunhofer Institute in Germany, among others. Raw audio is highly compressed when converted to MP3 files to save storage space. Only what humans can hear should be preserved. You can set the degree of compression, the so-called bit rate. 192 kBit / s (kilobits per second) roughly corresponds to CD quality. At higher bit rates, MP3 files sound lossless to most people. Lower bit rates are used, for example, in Internet radios.
Advantage:
widely used, compatible with many playback devices, high compression
Disadvantage:
possibly loss of audible quality, especially at low bit rates
Wav
File extension: .wav
WAV files are not compressed and therefore take up a lot of storage space. But they can be used well for audio editing and can be easily edited in almost any software.
WAV files were developed for Windows computers in 1991. However, they can also be reproduced and used on other operating systems.
Advantage:
no need to encode / decode when editing
Disadvantage:
very large files
WMA
File extension: .wma
Originally, the WMA (Windows Media Audio) format was supposed to compete with MP3, but it could not be established equally. Audio data is also compressed here, if possible without audible loss.
Some versions of WMA files may contain a certificate key to prevent piracy.
Advantage:
good compression with high sound quality
Disadvantages:
not very widespread, only supported by a few players
AAC (advanced audio coding)
File extension: .aac
This audio format is considered the successor to the MP3 format. With the AAC format, developers have managed to further reduce memory size while maintaining the best possible sound quality.
The AAC process is being used with increasing frequency on music websites, Internet radio stations, and as a soundtrack format for video files.
Advantage:
very good compression, small files with high audio quality
Disadvantage:
not yet compatible with all programs and devices
Ogg
File extension: .ogg
In Ogg files, there is actually a container format. In addition to compressed audio, it can also contain video and text data. Also, Ogg files can be used well as an online stream. Even so, the format never prevailed against MP3 among home users.
Advantage:
small file size with good sound quality, no license
Disadvantage:
not compatible with many programs, must be converted for audio processing
FLAC (Free Lossless Audio Codec)
File extension: .flac
The name already gives it away: the FLAC codec is freely available and compresses audio files without loss of quality. The format is mainly used for music that can be faithfully reproduced thanks to FLAC. More and more players support FLAC files, sometimes just with the help of a plugin.
The FLAC codec makes audio files 30 to 60 percent smaller. This makes them much larger than MP3 files. To do this, you can decode it and thus restore the original data without loss.
Advantage:
no loss, no license
Disadvantage:
relatively large files, not natively supported by all players
Opus
File extension: .opus
The latest file format from our overview should become the Internet audio standard. Opus is developed openly and has several advantages. The audio codec significantly reduces the bit rate again. The quality of music and language is preserved as best as possible. Additionally, Opus files can be streamed and contain metadata.
Opus plays practically no role (yet) in audio processing. We are curious to see if and how the format will prevail for years to come.
