Convert RealMedia Variable Bitrate (.rmvb) to Adaptive Multi-Rate Audio (.amr) online for free. Fast, secure video conversion with no watermarks or registration.
Conversion settings — add a file to adjust
Upload your .rmvb file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .amr file when it's ready.
AMR (Adaptive Multi-Rate) is a speech-focused audio codec designed for GSM cellular networks, encoding narrowband voice at 4.75 to 12.2 kbps. RMVB files contain full multimedia audio tracks (music, effects, dialogue) that far exceed AMR's intended scope. This conversion extracts audio from RMVB and aggressively compresses it for voice-only applications — producing some of the smallest audio files possible at the expense of music fidelity.
AMR is required by MMS messaging systems, legacy voice recording applications, and certain telephony infrastructure. When RMVB dialogue or spoken content needs to reach users on basic phones via MMS, or needs to be stored in voice-oriented databases, AMR is the appropriate target format.
FFmpeg decodes the RealAudio stream, downsamples to 8 kHz mono (required by AMR-NB), and encodes using libopencore-amrnb. The codec's CELP (Code-Excited Linear Prediction) algorithm is optimized for human speech, applying strong spectral shaping in the 300-3400 Hz voice band. Each 20ms frame is independently encoded at the selected bitrate mode.
AMR severely degrades audio quality for anything other than human speech. Music, ambient sound, and sound effects will be heavily distorted. At 12.2 kbps, spoken dialogue is clear and intelligible but sounds telephonic. RMVB's original audio quality (typically 64-128 kbps) is reduced by roughly 90%.
| Device | RMVB | AMR |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No |
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Resolution: 1280x720
Bitrate: 4 Mbps
8MB free, 50MB Nitro
RMVB to AMR conversion is strictly for speech-extraction scenarios where extreme compression and cellular compatibility are priorities. It's not suitable for preserving any aspect of RMVB's multimedia audio quality.
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隐私优先
文件处理后自动删除
无需注册
即刻开始转换
随处可用
任何浏览器，任何设备
| No |
| 特性 | RMVB | AMR |
|---|---|---|
| 全称 | RealMedia Variable Bitrate | Adaptive Multi-Rate Audio |
| 扩展名 | .rmvb | .amr |
| 最适合 | Variable bitrate | Speech optimized |