ตัวแปลงไฟล์ออนไลน์ฟรี F4V เป็น AMR

F4V is a Flash Video format supported by Adobe Flash Player software and all browsers with flash video playback. The container uses boxes for data storage and it is compatible with h.264 video and AAC audio compression standards. F4V files provide better quality than FLV but need a newer version of Flash (9.0.115 or higher) and a faster processor.

This format was originally intended for voice compression and is able to change the bit rates of encoded audio data. AMR is actively used for encoding and decoding voice while its being transmitted over network channels. The format allows one to consider network capacity and adapt it to channel loads. Due to this, the voice quality is practically undiminished.