How to record audio in RAW format?

[rjeevan]

Hello,

I'm trying to Implement pocketsphinx in my iphone project... Currently working towards using pre-recorded audio file to Recognise speech..

pocketsphinx has very specific requirement for pre-recorded audio, It has to be "single-channel (monaural), little-endian, unheadered 16-bit signed PCM audio file sampled at 16000 Hz".

I manage to records and save file into WAV format but I cannot find a way to create their RAW format with no headers and little-endian... (I used this example to Record audio: trailsinthesand.com/exploring-iphone-audio-part-7/)

I'm new to iPhone development also, if any one can help how to record audio in RAW format would be much appreciated...

Thanks..

[hoshizaru]

Hi,

Did you find a solution to your problem? I am also looking for a way to save RAW audio data recorded from the microphone.
If you have a solution, could you please let me know how did you do to get it to work?

Thanks in advance.

[MattW]

Originally Posted by rjeevan

Hello,

I'm trying to Implement pocketsphinx in my iphone project... Currently working towards using pre-recorded audio file to Recognise speech..

pocketsphinx has very specific requirement for pre-recorded audio, It has to be "single-channel (monaural), little-endian, unheadered 16-bit signed PCM audio file sampled at 16000 Hz".

I manage to records and save file into WAV format but I cannot find a way to create their RAW format with no headers and little-endian... (I used this example to Record audio: trailsinthesand.com/exploring-iphone-audio-part-7/)

I'm new to iPhone development also, if any one can help how to record audio in RAW format would be much appreciated...

Thanks..

If you have a WAV file, then it is in raw format. You'll find the audio data right after the WAV file header (which contains important information, such as number of channels, sample rate, etc.). Just search the web for the WAV file format and skip however many bytes the header data is... if memory serves, the header is something like 44 bytes, but you should double check.