Thread: How To Generate Audio Data From A Wav File

Hi,

I've spent the past two evenings installing SDK's, trying out examples and googling the net so now I have decided to directly ask for help:

I am looking for a means of obtaining audio sample data from a given wav file. This will permit me to write filters (such as compress, delay etc...) by manipulating the raw audio data in its waveform...the reason I need explicit access to the waveform data is to perform operations on it via the CPU and GPU.

If you know of any such functions already built into the likes of DirectAudio, e.g GetSampleData
or something then that'd be pretty sweet. Or if you know of a different library that offers such functionality that'd also be sweet. Basically any c++ sound library that offers data manipulation and goes beyond SoundPlay() SoundStop() or hardcoded filters like SoundChorus() etc..

P.S I believe sdl_sound (via Sound_Sample* name) is capable of doing this but the SVN is down so if anybody has access to the latest Win32 build that might be of great help!

Kindest Regards,
Chu

It might be easier to just use the sample grabber and SampleCB callback functionality so that you can directly edit the sample prior to it being pased to the rendering filter, which can be a file writer.

Thanks for the replies.

I'll look into your suggestion abachler, if I can point to the waveform in memory after its been read and decoded then that'd be ideal.

I'm dealing with uncompressed wav from the offset so thats fine. I'm failing to find a function in the Win32 multimedia API that will enable me to point to and process the waveform...I guess I'll have to try and hunt down a sdl_sound win32 build so I can use the sound_sample function.

if its 44100 16 bits per sample steroe, then you can just skipo the header and then alternately read the left adn then teh right channel data in until you hit feof(). A simple loop that fread()'s or ReadFile()'s will do it.

or was it right adn then left I forget

Cheers abachler I'll give that a try when I'm home.

Just in case somebody has anything similar, here's what I'm after:

http://icculus.org/SDL_sound/docs/ht...d__Sample.html

As I say I can't get hold of the build (svn is down on their site) - it would be nice to have a function like that in an up to date library like directx.

I'll give abachlers advice a try anyway.

Regards,
chu