Which audio format can be recorded and played back by iPhone and Android?

I am designing an app that can record short audio files on iP开发者_开发问答hone and Android that can be played back on both platforms, as well as hopefully any other smartphone.

Right now I'm using *.caf with the iLBC codec, as I know the iPhone does not encode mp3.

Is there a file format/codec that I should use in this case?

It used to be that there were no common audio encoding formats for Android and iPhone.

iPhone: iPhone audio encoding supported formats

Android: Android supported media formats

But Android 2.3.3 adds support for AMR-WB and AAC: Android Audio Encoder AAC

See Media Framework at Android 2.3.3 API changes

So I believe AAC is your format choice if you want interop between Android and iPhone devices and can handle the Android 2.3.3 limitation.

Otherwise, just pick from the list for widest coverage (AMR-NB on Android) or plan on converting the recorded audio to a suitable format.

A quick check shows that AMR is patented and I assume AAC would have some patent coverage as well. PCM is decodable on iPhone and Android and most cellphones at the expense of larger filesize.

All smartphones can play WAV files (even Android as of 2.2). These are known as "Linear PCM" in iOS and "PCM/WAVE" in Android.

Try modifying the file type in your ios version file to be .wav and you should be able to listen to this audio file on an Android phone, as well as a Windows operating system.

You'll find that mp3 has hardware decoding in all recent iOS devices and most Android mobile phones as well (but not cheap tablets, budget phones, etc).

As explained above by typo.pl, the generally compatible format is AMR or WAVE(PCM), but in practice, we prefer a progressive solution:

produce AAC on iOS and Android 2.3.3+, but fallback to produce AMR (WB) on Android pre-2.3.3. Both formats are playable on all platforms.

I guess it's a fairly easy solution for better compatibility and audio quality.