
Audio formats

The audio format is a type of computer file that contains music. There are lossless uncompressed, lossless compressed and lossy music audio formats.

Bit rates
Bit rate is a unit of measurement for data that indicates the number of bits transmitted in a given time. When it comes to music formats, the bit rate is expressed in kilobits per second (kbps) transmitted. If you compare the same song encoded at different bit rates, the file with the highest bit rate will be of higher quality. For example, a 320 kbps (CBR) MP3 file transmits 320 kilobits for every second of the audio stream.
Audio formats containing uncompressed lossless data (Uncompressed Lossless)
Lossless uncompressed data formats retain all original recorded information. Since silence is encoded at the same number of bits per second as sound, files containing uncompressed lossless data are often large. Formats containing lossless and uncompressed data are encoded using pulse code modulation (PCM). Examples:
WAV (PCM) (used in Windows)
AIFF (PCM) (used in Mac OS).
Audio formats containing lossless compressed data (Compressed Lossless)
Lossless compressed formats store all original recorded information in a smaller volume than uncompressed lossless data when compressing data. Silence is encoded at the lowest bit rate and audio is compressed, so files that contain lossless compressed data are usually half the size (file size) of the same song in a format that contains non-data. uncompressed loss.
Since formats that contain compressed data without loss of quality and formats that contain uncompressed data without loss of quality both retain all the information from the original recording, they can be transcoded to each other without loss of quality. Examples:
Free Lossless Audio Codec (FLAC)
Apple Lossless Audio Codec (ALAC)
Mono Audio (APE).
Lossy audio formats
Lossy formats always compress data. Lossy audio formats are smaller than those that contain lossless compressed data and formats that contain uncompressed lossless data by removing some of the original information. These are usually high frequencies that most people cannot hear, however in some cases the difference in lossy and lossless audio formats can be very large.
Since lossy formats lose data during compression (and therefore sound quality), they CANNOT be transcoded to lossless or other lossy audio formats without further loss of sound quality. Examples:
MPEG Layer 3 Audio (MP3)
Advanced Audio Coding (AAC)
Windows Media Audio (WMA)
Dolby Digital 3 (AC3) audio codec
DTS Coherent Acoustics Codec (DTS).
File sizes
Here we can see how the file size of the same song depends on the format in which it is presented: uncompressed data without loss of quality, compressed data without loss of quality or loss of quality. Take Avril Lavigne’s classic pop song Sk8er Boi for example. The song is 3 minutes and 24 seconds long.
Lossless uncompressed format – WAV (PCM): 34.3 MB
Lossless compressed format – FLAC: 25.75 MB (25% compression)
Lossy format – MP3 320 (CBR): 7.78 MB (78% compression)
Sound transparency
Sound transparency is a term used to describe the sound characteristic of a lossy file. The sound of a lossy file is considered transparent if the average person cannot hear the difference between it and a lossless file with the same song, having listened to both files and not knowing in what sequence they were heard. For most people, MP3 192kbps (CBR) is considered transparent.
Allowed audio formats
While there are many types of lossy and lossless audio formats, only a few are allowed on RED.
Since some lossless audio formats can be transcoded to other lossless audio formats without loss of audio quality, the only lossless audio format allowed on RED is FLAC. You can always download FLAC and transcode it to ALAC (for iTunes) or any other lossless or lossy audio format you want.
Allowed lossy audio formats:
MP3 (the minimum bit rate for MP3 is 192 kbps (CBR))
AAC (can be replaced by any MP3 torrent except downloads purchased from the iTunes store and containing exclusive tracks from iTunes)
AC3 (usually found on DVD)
DTS (usually found on DVD)
MP3 is the most popular audio format on RED. We allow you to upload albums to AAC purchased from iTunes because they often contain bonus tracks from iTunes, and since AAC is a lossy format, it cannot be transcoded to other audio formats without losing sound quality. Also, AC3 and DTS are often found on DVD and are lossy audio formats, so they cannot be transcoded to other audio formats without losing sound quality.











