Convert MPEG-4 Video (Apple) (.m4v) 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 .m4v 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.
M4V files carry H.264 video and AAC audio in Apple's MPEG-4 container, while AMR (Adaptive Multi-Rate) is a narrowband voice codec designed for GSM cellular networks. AMR operates at just 4.75-12.2 kbps with an 8 kHz sampling rate, making it one of the most bandwidth-efficient audio codecs in existence. Converting M4V to AMR extracts the audio, downsamples it dramatically, and encodes it for voice-oriented applications on cellular networks.
AMR is the standard voice codec for GSM and 3G cellular systems worldwide. Converting M4V audio to AMR is necessary when you need to create voice messages, ringtones for legacy phones, or audio clips for MMS delivery over cellular networks. The extreme compression reduces file sizes to roughly 1 KB per second of audio, making it viable for the most bandwidth-constrained scenarios.
FFmpeg decodes the AAC audio from the M4V, downsamples from the original sample rate (typically 44.1 or 48 kHz) to 8 kHz mono, and encodes using the libopencore_amrnb encoder. The output is a raw AMR file with the standard #!AMR header. AMR-NB operates at fixed or adaptive bitrates between 4.75 and 12.2 kbps. The codec is specifically optimized for human speech frequencies (300-3400 Hz) and will severely degrade music or environmental sounds.
AMR is designed exclusively for speech. Music, sound effects, and background noise will sound heavily distorted. Even speech quality is comparable to a phone call — acceptable for communication but far from high-fidelity. At 12.2 kbps, speech is clear and intelligible. Below 7.4 kbps, noticeable artifacts and robotic tones appear.
| Device | M4V | AMR |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Native | Partial |
| iPhone/iPad | Native | 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
M4V to AMR conversion serves a narrow but important niche: extracting voice content for cellular and telephony applications. The quality trade-off is extreme, but AMR's tiny file sizes make it indispensable for mobile voice applications.
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Herhangi bir tarayıcı, herhangi bir cihaz
| Özellik | M4V | AMR |
|---|---|---|
| Tam Ad | iTunes Video | Adaptive Multi-Rate Audio |
| Uzantı | .m4v | .amr |
| En İyi Kullanım | Apple ecosystem | Speech optimized |