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 iPhone 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?
Answer
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.