An audio format is a type of computer file that stores music. Music formats are either uncompressed lossless, compressed lossless, or lossy.
A bitrate is the number of bits conveyed or transferred in a unit of time. When talking about music formats, bitrate is used in kilobits per second (kbps)
. When comparing files with different bitrates (of the same song), the file with the higher bitrate has the higher quality. For example, an MP3 320kbps (CBR) file transfers 320 kilobits per second.
Uncompressed lossless formats store all of the original recorded data. Since silence is given the same number of bits per second as sound is, uncompressed lossless files are huge. The main uncompressed lossless format is pulse-code modulation (PCM)
. For example:
- WAV (PCM) (used on Windows)
- AIFF (PCM) (used on macOS)
Compressed lossless formats store all of the original recorded data in less space than uncompressed lossless formats by compressing the data. By giving silence almost no bits per second and compressing sound, a compressed lossless file is usually half as big as the same song stored in an uncompressed lossless file.
Since both uncompressed lossless formats and compressed lossless formats retain all the data from the original recording, they can be transcoded between each other without a loss in quality. For example:
- Free Lossless Audio Codec (FLAC)
- Apple Lossless Audio Codec (ALAC)
- Monkey's Audio (APE)
Lossy formats are always compressed. Lossy formats have smaller file sizes than both uncompressed lossless formats and compressed lossless formats because they remove some of the original data. Usually the removed data is in the higher frequencies that humans can't hear, however, there can be obvious audible differences between lossy formats and lossless formats.
Lossy formats CANNOT
be transcoded into any other lossy format without losing more quality. It CANNOT
be transcoded into lossless either, because it wouldn't be a true lossless file when the source medium is already lossy. Examples of lossy formats include:
- MPEG Layer 3 Audio (MP3)
- Advanced Audio Encoding (AAC)
- Windows Media Audio (WMA)
- Dolby Digital Audio Codec 3 (AC3)
- DTS Coherent Acoustics Codec (DTS)
Here's an example of how the file size of the same song varies depending on whether the song's format is uncompressed lossless, compressed lossless, or lossy. Let's take the classic pop song, Sk8er Boi by Avril Lavigne. For reference, the song is 3 minutes, 24 seconds long.
- Uncompressed Lossless — WAV (PCM): 34.3 MB
- Compressed Lossless — FLAC: 25.75 MB (25% compressed)
- Lossy — MP3 320 (CBR): 7.78 MB (78% compressed)
Transparency is a term used to describe the audible quality of a lossy music file. A lossy file is considered transparent if the average human cannot tell the difference between the lossy file and a lossless file of the same song by just listening to both without knowing which file is which. For most people, MP3 192kbps (CBR) is considered transparent.
CD Ripping and Burning
CD ripping is a way to extract the music files from a CD. CD burning is a way to make a CD from music files.
A log file is a text file with the file extension ".log". Like its name suggests, it acts as a log of the entire ripping process and it records any errors that may have occurred. You may not, for any reason, modify a log file. It is strictly against the rules and will result in warnings/loss of upload privilege/account disabling.
A cue file is a text file with the file extension ".cue". Cue files act as a catalog or a table of contents of a CD and allow you to burn a CD identical to an original CD.
Suggested CD Ripping Programs
sonixgvn.net suggests using Exact Audio Copy (EAC)
on Windows or Linux (with Wine), and X Lossless Decoder (XLD)
on macOS. Both EAC and XLD produce high quality rips with sufficient logs to prove that the files are up to standard.
These programs must be setup according to the guides available on our wiki to ensure quality rips that meet the sites standards.
LAME Ain't An MP3 Encoder (LAME)
is an encoder that converts and compresses any input audio file and outputs an MP3 file. The resulting MP3 file can have a constant, variable, or average bitrate. sonixgvn recommends LAME as an MP3 encoder because it is open source, customizable, and outputs high quality MP3 files.
Constant Bitrate (CBR)
When encoding a constant bitrate (CBR) file, the user (you) chooses a preset bitrate and LAME targets that bitrate throughout the entire file. This means that every second in the file has the same number of bits, no matter how simple or complex the sound is. Every second in a CBR file has the same quality. Because silence is given the same number of bits as more complex sounds, CBR files are larger than VBR and ABR files of the same quality. This also means that CBR files have a predictable file size.
Variable Bitrate (VBR)
When encoding a variable bitrate (VBR) file, the user (you) chooses a preset quality and LAME targets that quality, letting the bitrate vary throughout the entire file. This means that every second of the file has a different number of bits that depends on how complex the sound is at that second. For example, a second of silence would receive much fewer bits than a second of loud, blaring music. Every second can range from 0 to 320kbps (the ceiling for MP3) based on the preset and the audio data being encoded. Since VBR files target a certain quality instead of a certain bitrate, exact VBR file sizes are more unpredictable. The resulting filesize for a VBR encode depends on two factors: the preset selected, and the music itself. The better the preset, the larger the resulting file will be. The more music data necessary to encode, the larger the resulting file will be. When one refers to the 'bitrate' of a VBR file, they are talking about the mean bitrate (in kilobits per second) for the whole song, which is calculated by dividing the filesize by the duration.
LAME has certain VBR presets V0 to V9. V0 is the highest quality VBR preset and V9 is the lowest quality VBR preset. The most popular VBR preset on sonixgvn is V0, which usually ends up with a bitrate between 230 and 270 kbps.