Audio data is saved in the same way as here:
// 1. create AudioRecord instance
// 2. audioTrack.play();
// 3. in separate thread reading into buffer
// int bytesRead = audioRecord.read(buffer, 0, bufferSize);
// 4. save buffer to file
// fio.write(buffer, 0 , bytesRead);
// 4. audioTrack.stop();
What codec/format is used as saved file can't be opened as WAV file, but can be read and played using AudioTrack class?