- Extension
- .gsm
- .m4r
- Format
- Binary
- Binary
- Category
- Audio
- Audio
- Developer
- European Telecommunications Standards Institute (ETSI)
- Apple Inc.
- Description
- A lossy file format used to compress speech in Global Standard for Mobile (GSM) telecommunications. It is very effective for reducing audio file size. However, encoding and decoding audio signals severally is discouraged as the final product will have a lot of noise. Popular with some voice mail software but it is CPU intensive.
- M4R is an iTunes ringtone file that stores mono channel audio. They are identical to the M4A format files only that they are correctly used for ringtones.
- MIME Type
- audio/x-gsm
- audio/x-m4r
