MPEG-4 Audio (M4A) stores AAC-encoded audio in an MPEG-4 container, the standard audio format produced by iTunes and Apple devices. RMVB file (RMVB) stores data in the RMVB format. This conversion changes the file's encoding, compression method, and supported feature set. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. The result is a standard RMVB file readable by any compatible application. 1converter handles M4A-to-RMVB 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.