在android中用于存储录制的音频格式

Question

I am developing application which records voice from mic, currently I am storing recorded audio in wave file but size of wave is becoming an issue.

I came to know that android do not have mp3 decoder is it true? What would I do to store recorded audio in compressed form?

I am using AudioRecord class for recording and don't want to use MediaRecorder.

Answer 1

Using AudioRecord does not give you many options. It stores audio in PCM format only. You can lower size only by setting channel config to CHANNEL_IN_MONO and audio format to ENCODING_PCM_8BIT. Additionally, you can try to extend AudioRecord class and override read() method. Then you must convert audio yourself but that's not recommended.

I know you don't want this but the best option would be refactoring your code to use MediaRecorder. Here is example from reference documentation:

MediaRecorder recorder = new MediaRecorder();
 recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
 recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
 recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
 recorder.setOutputFile(PATH_NAME);
 recorder.prepare();
 recorder.start();   // Recording is now started
 ...
 recorder.stop();
 recorder.reset();   // You can reuse the object by going back to setAudioSource() step
 recorder.release(); // Now the object cannot be reused

On this site http://developer.android.com/guide/appendix/media-formats.html#core you have nice table presenting all supported formats taking into considerations Android versions. Try these AAC LC, AMR-NB, AMR-WB. Except sizes check the quality.

Answer 2

There is no Mp3 decoder but the default format which all android version will support is .mgp and .amr format which will be played using MediaPlayer and AudioPlayer classes by default

Note : This is not guarantee that all the players will support this extension , if it is not an android device