audio – Creating a WAV file from raw PCM data using the Android SDK-ThrowExceptions

Exception or error:

I’m trying to use the AudioRecord class to record a WAV file. The problem is that it only supplies the raw PCM data, and if I write it to a file, there is no header information, so it will not play in any media player. How can I create a WAV file from this raw data?

Or alternatively, is there any other way to record sound in Android to a WAV file (or, alternatively MP3)?

Oh, and I know that MediaRecorder can’y be used because it doesn’t support either WAV or MP3 formats.

How to solve:

OK, I’ve got this figured out. This post was crucial in helping me:
http://computermusicblog.com/blog/2008/08/29/reading-and-writing-wav-files-in-java

Basically, I used ByteArrayOutputStream to write the raw PCM data from AudioRecord, which then lets me get the byte array and its size when the process is done. I can then use that data in conjunction with the SampleRate, BitRate, and Stereo/Mono settings to create the WAV header as per the link above. The resulting file works perfectly!

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Check the MediaRecorder.setOutputFormat(), you can set different container formats for your recording; there is MediaRecorder.OutputFormat.MPEG_4 and MediaRecorder.OutputFormat.THREE_GPP; the only allowed format along RAW is setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);

Sorry but MP3 is not avail. You really need mp3 for recording?
WAV on the opposite of MP3 is a container, not a format; WAV can be any kind of encoding format.

You are always free to prepend some WAV RIFF header in front of your raw pcm data (as long as you exactly know the format). Check here for how it has to look like:
http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/WAVE.html

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You may want to use mediarecord class

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