aacĪpple Lossless Audio Codec (ALAC), or Apple Lossless Encoder (ALE) If a file is saved and re-saved in a lossy format, the audio fidelity/quality will be lost each time the file is re-saved.Ĭommon audio file formats: Lossless versus lossy Lossy data compression approximates information, and although this allows for much smaller files, it does mean a loss of quality.Lossless data compression is a way of compressing data that allows the original uncompressed data to be perfectly reconstructed from the compressed data - that is, files with lossless compression will be smaller than uncompressed files, but the sound quality will be unaffected (or not very affected) so audio is still of the highest quality.Data compression encodes file data so a file is a smaller size than if uncompressed.The audio of an uncompressed file is the highest quality, but the file size may be very large. Uncompressed data means there is no data compression.Other file formats compress data highly, but at the expense of audio quality these file formats are called "lossy". Some file formats are effective at compressing the data of an audio file, and reducing file size, while maintaining audio quality file formats that can do this are called "lossless". However, much quality has been lost in the highly compressed image.ĭata compression of audio files is similar in this way a lossy format of audio compression can make audio files a much smaller file size, but at the cost of audio quality. jpg, which is a lossy file format.Īs you can see, the higher quality image is a larger file size, and the lower quality image is a smaller file size. (How much quality is lost also depends on the file format.)Īs an example of how data compression affects quality, we will look at image data compression, which functions in a similar way as audio data compression (sound waves are squared off, and information is lost when audio files are compressed too much).īoth of these images are the same file format. It depends on the file format (some file formats are more efficient at compressing data), but often a highly compressed file will have low audio quality. The more compressed a file is, the smaller its file size is.
This means how data is compressed, or coded, in a file format. Data Compression - Uncompressed, Lossless, and LossyĬompression in this section means “data compression”.
For example, renaming "vacation.avi" to "vacation.mov" would not convert the video file to the other file format. If you want to change a file to another file format, you cannot simply rename the file's extension. avi part of the file because it may prevent a program that would otherwise be able to open the file from doing so. You could rename the "vacation" part of "vacation.avi" and it would not affect the audio or visual content of the file. avi file and that this file is a particular kind of video file. For example, a file named "vacation.avi" would let you know that the file is an.
This extension will usually be three characters, and come after a full stop or period. This helps you know what kind of a file format the file is. Usually files will have a suffix, known as a file extension, at the end of the file's name. One video file may have a different file format from another video file, depending on how each file was recorded or rendered. A file format is a way information is stored in a file.