Bad sound quality when recording/playing sounds - Android SDK

Question

Hey, I have a problem with andriod programing when I try to record and then play the file that was just recored. I can both record and play the sound but the quality stinks. Its not just bad is really hard to listen to and sound abit like its a computer generated voice... I use the andriod SDK-emulator. The code that sets up the recording looks like this;

MediaRecorder recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(MediaRecorder.OutputFormat.RAW_AMR);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile(path);
recorder.prepare();
recorder.start();

And the code playing the file later looks like this;

MediaPlayer mp = new MediaPlayer();
mp.reset();
mp.setDataSource(path);
mp.prepare();
mp.start();

I dont know what part that makes the audiofile sound really bad... or if its just the emulator that makes it bad and that it would work on a real phone. I would love some help with this.

/Nick

Answer 1

AudioRecord takes a variety of arguments that would influence the recording quality.

Try setting these in the constructor:

• Audio Source: MIC
• Sample rate: 16000
• Number of channels: CHANNEL_CONFIGURATION_MONO
• Format: ENCODING_PCM_16BIT
• Buffer size: 16000 * 30 (30 second buffer)

Code example:

recorder = new AudioRecord(
                          MediaRecorder.AudioSource.MIC,
                          16000,
                          AudioFormat.CHANNEL_CONFIGURATION_MONO,
                          AudioFormat.ENCODING_PCM_16BIT,
                          16000*30);