MMF to SF — Format Comparison & Online Converter
Fast, instant MMF (SMAF) to SF (IRCAM) conversion. No signup required. Just drop your .mmf file and get .sf in seconds.
Batch Settings
MMFファイルをSF形式へ変換するこのページへようこそ。デジタルコンテンツが溢れる現代において、ファイル形式の互換性は時に頭を悩ませる問題となります。特に、かつての携帯電話で親しまれたMMF形式の音声ファイルを、より汎用性の高いSF形式へとスムーズに移行させたいと考える方は少なくないでしょう。思い出の着信音や、過去のプロジェクトで作成した短いサウンドクリップなど、大切な音源を現代の環境で再び活用できるよう、当社の変換ツールがお手伝いします。複雑な設定は一切不要。数クリックの簡単な操作で、元の音質を損なうことなく、迅速かつ正確に変換を完了させることができます。この変換を通じて、あなたのデジタルライフがさらに豊かになることを願っております。
- ガラケー時代の着信音の再利用
- ビジネス用音声メモのアーカイブ化
- 同人ゲーム・アニメ制作素材の互換性確保
日本では、フィーチャーフォン（ガラケー）で広く利用されたMMF形式のサウンドデータが多数存在します。これらをPCやスマートフォンで編集・再生可能なSF形式に変換することで、過去のデジタル資産を現代の環境で有効活用するニーズが高まっています。
About MMF (SMAF) to SF (IRCAM) Conversion
MMF and SF are both audio formats, but they differ in important ways. MMF is a widely used file format. SF is a widely used file format.
When you convert MMF to SF, the goal is to convert between formats quickly. Converting MMF to SF maintains high quality with CocoConvert's optimised encoder settings. Understanding these technical differences helps you choose the right format for your workflow.
Your MMF file is decoded and re-encoded as SF. The conversion involves 4 steps: (1) your mmf file is uploaded and validated, (2) the file is decoded (parsed into its raw data), (3) the data is re-encoded in sf format, (4) the converted file is ready for download.
CocoConvert's converter handles the entire pipeline server-side using FFmpeg, Sharp, and qpdf — battle-tested libraries used by streaming platforms and enterprise tools. Files are encrypted in transit and deleted within 24 hours.
This conversion is ideal when you When you need a SF file. For the opposite direction, CocoConvert also supports SF to MMF conversion.
How to Convert MMF (SMAF) to SF (IRCAM)
- 1
Upload .mmf file
Select your MMF file by dragging it to the upload zone or using the file picker. Batch upload is available for multiple files.
- 2
Choose .sf
Set SF as the output format. The converter uses optimal settings based on the MMF→SF conversion profile.
- 3
Convert
The server-side engine decodes your MMF file and re-encodes it as SF. Processing time depends on file size and complexity.
- 4
Download result
Grab your converted .sf file. Multiple output files can be downloaded together.
What Happens When You Convert MMF (SMAF) to SF (IRCAM)
Your MMF file is decoded and re-encoded as SF.
Your MMF file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in SF format
The converted file is ready for download
Format Comparison
MMF (SMAF)
.mmf file
| Extension | .mmf |
| MIME Type | audio/x-smaf |
| Category | Audio |
SF (IRCAM)
.sf file
| Extension | .sf |
| MIME Type | audio/x-sf |
| Category | Audio |
Should You Convert MMF (SMAF) to SF (IRCAM)?
When to Convert
- ✓When you need a SF file
Frequently Asked Questions
What is the difference between MMF and SF?
MMF is a widely used file format. SF is a widely used file format.
Does MMF to SF conversion affect quality?
Converting MMF to SF maintains high quality with CocoConvert's optimised encoder settings.
Which format has better compression, MMF or SF?
MMF is a common audio format. SF is widely supported. The better choice depends on whether you prioritize file size or quality.
How long does MMF to SF conversion take?
Most conversions finish in seconds. Larger files or complex audio content may take 10–30 seconds. CocoConvert processes files in parallel for batch jobs.
Is MMF or SF better for long-term storage?
Both formats use lossy compression, so consider keeping your original source file for long-term storage.
Versions are pinned in our worker Dockerfile and re-built via CI on every change.