Convert MPEG to AMR: Free Online Converter
Convert MPEG Video to Adaptive Multi-Rate Audio online for free. Fast, secure video conversion with no watermarks or registration.
MPEGに対応
アップロードすることで、これらのファイルの権利を有していること、および利用規約に同意することを確認したものとみなされます。
変換設定: ファイルを追加すると調整できます
安全な転送
HTTPS暗号化アップロード
プライバシー優先
ゲストのファイルは約2時間で自動削除
登録不要
すぐに変換を開始
どこでも動作
あらゆるブラウザ、あらゆるデバイス
MPEG から AMR への設定
- エンジン
- メディア
- 設定
- 調整できる設定: 9
- Trim Start
- Trim End
- Volume
- Fade In
- Fade Out
- Bitrate
- Audio Channels
- Reverse Audio
- Strip Metadata
変換方法
アップロードエリアにドラッグするか、クリックして選択し、.mpegファイルをアップロードしてください。
必要に応じて出力設定を調整してください。デフォルト設定ではオリジナルの品質を維持します。
「変換」をクリックし、準備ができたら.amrファイルをダウンロードしてください。
MPEGからAMRへの変換について
MPEG video files contain audio tracks that far exceed what low-bandwidth voice applications require. AMR (Adaptive Multi-Rate), standardized by 3GPP in 1999, is a speech-optimized codec that operates at bitrates from 4.75 to 12.2 kbps using eight narrowband modes. Converting MPEG to AMR extracts just the voice content in the smallest possible audio format.
MPEGをAMRに変換する理由
AMR was designed specifically for GSM cellular voice transmission and remains the codec of choice for MMS audio messages, voice memos on older phones, and voice-over-IP applications in bandwidth-constrained environments. When you need to extract speech from MPEG recordings — such as news broadcasts, interview footage, or recorded phone calls — AMR delivers intelligible voice at file sizes 10-20x smaller than MP3.
Telecom and voicemail systems often require AMR input. If you are building an IVR system, archiving call recordings, or distributing voice content to regions with limited connectivity, converting MPEG audio to AMR ensures compatibility with the widest range of voice-centric devices and platforms.
主な活用例
- Extracting voice memos from MPEG video recordings for mobile distribution
- Creating compact audio clips for MMS messaging from broadcast footage
- Building voice prompt libraries for IVR and telephony systems
- Archiving interview audio from MPEG-encoded video at minimal storage cost
- Distributing spoken-word content to users on 2G cellular networks
仕組み
FFmpeg decodes the MPEG audio track and re-encodes it using libopencore_amrnb at a fixed narrowband rate (8000 Hz, mono). The typical command is `-vn -acodec libopencore_amrnb -ar 8000 -ac 1 -b:a 12.2k`. AMR-NB supports eight bitrate modes; 12.2 kbps provides the best quality, while 4.75 kbps is the most compact. The codec automatically adapts frame-by-frame in real-time voice applications, but for file encoding, a fixed rate is used.
品質とパフォーマンス
AMR-NB is a narrowband codec limited to 300-3400 Hz, the range of human speech fundamentals. Music, ambient noise, and high-frequency detail are almost entirely lost. Speech intelligibility is good at 12.2 kbps but degrades noticeably below 7.4 kbps. This conversion is appropriate only for voice content.
デバイス互換性
| Device | MPEG | AMR |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No | No |
プラットフォーム別の推奨設定
YouTube
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
TikTok
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Twitter/X
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Discord
Resolution: 1280x720
Bitrate: 4 Mbps
8MB free, 50MB Nitro
最良の結果を得るためのヒント
- 1Use the highest AMR bitrate (12.2 kbps) for best speech quality — the file size difference compared to lower rates is trivial
- 2Pre-process the MPEG audio with a high-pass filter at 300 Hz to remove low-frequency noise that AMR cannot encode
- 3If you need better speech quality than AMR-NB provides, consider AMR-WB (wideband) — it doubles the frequency range
- 4Ensure your MPEG source contains actual speech before converting — AMR will make non-speech content unintelligible
- 5Test playback on the target device or system, as AMR decoder implementations vary in quality across platforms
関連する変換
MPEG to AMR is a purpose-built conversion for voice extraction, producing the smallest possible audio files while maintaining speech clarity for telephony and mobile messaging applications.
MPEGとAMRの比較
| 特徴 | MPEG | AMR |
|---|---|---|
| 正式名称 | Moving Picture Experts Group | Adaptive Multi-Rate Audio |
| 拡張子 | .mpeg | .amr |