MTS file (MTS) stores data in the MTS format. MPEG-4 Audio (M4A) stores AAC-encoded audio in an MPEG-4 container, the standard audio format produced by iTunes and Apple devices. This extracts the audio stream from the video container, discarding the video track. The audio track is decoded and re-encoded (or stream-copied if the codec matches) while the video frames are discarded. The result is a standard M4A file readable by any compatible application. 1converter handles MTS-to-M4A conversion server-side: files are uploaded over HTTPS, processed on isolated cloud infrastructure, and the converted output is available for download for 24 hours before automatic deletion. No account is required for standard conversions.