Convert M4R to AMR

The M4R file extension stands for MPEG-4 Ringtone and is primarily used for creating custom ringtones for Apple devices, particularly iPhones. This format, a variant of the standard MPEG-4 Audio (M4A), emerged alongside the introduction of the iPhone in 2007. M4R files utilize Advanced Audio Coding (AAC) for compression, ensuring high-quality sound in a compact file size. Their use is strictly tied to Apple's ecosystem, allowing users to personalize their device's ringtones through the iTunes platform. M4R's history is closely linked to the evolution of mobile technology and the personalization trend in smartphone usage.

Adaptive Multi-Rate Codec (AMR) is a file extension used primarily in voice applications, including VoIP, audio messaging, and mobile phone telephony. Originating from the European Telecommunications Standards Institute (ETSI) in 1999, AMR files enable efficient compression and transmission of speech audio. The codec dynamically adjusts bit rates during transmission to optimize audio quality and network capacity. Its efficient bandwidth utilization and compatibility with various communication standards have made AMR a preferred choice for many modern communication systems.