To convert audio, follow these steps:
- Use the "Local file" or "Online file" buttons to specify how to upload the audio to the server. Use the "local file" if you need to convert a file from your computer, in order to specify a file on the Internet, select "Online file" and in the appeared field paste the link to the file. We do not set any limits on the size of the audio file, but the larger the file, the more time it will take to convert. Just be patient and everything will turn out. You can convert files from audio or video formats. For formats that support tags, the data will also be transferred.
- To start the conversion, click the "Convert" button to start the transformation. If the conversion is successful, the file will be available in the "Conversion Results" section. If you just need to download a file, click on the file name. If you want to get other ways to save, then click on the icon to generate a QR code to upload the result to your mobile phone or tablet, and also if you want to save the file in one of the online storage services such as Google Drive or Dropbox.
Please be patient in the conversion process.
Compare MP4 with AMR
|Format introduction|| MPEG-4 Part 14 or MP4 is a digital multimedia format most commonly used to store video and audio, but can also be used to store other data such as subtitles and still images. Like most modern container formats, it allows streaming over the Internet.MPEG-4 Part 14 or MP4 is a digital multimedia format most commonly used to store video and audio, but can also be used to store other data such as subtitles and still images. Like most modern container formats, it allows streaming over the Internet.|| The Adaptive Multi-Rate (AMR or AMR-NB or GSM-AMR) audio codec is an audio compression format optimized for speech coding. AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM and UMTS.|
|Technical details|| Most kinds of data can be embedded in MPEG-4 Part 14 files through private streams. A separate hint track is used to include streaming information in the file. The registered codecs for MPEG-4 Part 12-based files are published on the website of MP4 Registration authority (mp4ra.org).|| AMR speech codec consists of a multi-rate narrowband speech codec that encodes narrowband (200-3400 Hz) signals at variable bit rates ranging from 4.75 to 12.2 kbit/s with toll quality speech starting at 7.4 kbit/s. Sampling frequency 8 kHz/13-bit (160 samples for 20 ms frames), filtered to 200-3400 Hz.|
|File extension|| .mp4, .m4a, .m4p, .m4b, .m4r, .m4v|| .amr, .3ga|
|MIME|| video/mp4|| audio/amr|
|Developed by|| International Organization for Standardization|| 3GPP|
|Type of format|| Media container|| Audio compression format|
|Associated programs|| Windows Media Player, RealPlayer, MPlayer, Media Player Classic, VLC Media Player, K-Multimedia Player|| Audacity, FFmpeg, MPlayer, QuickTime, VLC media player|
|Wiki|| https://en.wikipedia.org/wiki/MPEG-4_Part_14|| https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_codec|