Hi Francois, Are you sure your sound card driver isn't just pre-processing the signal to simulate some conditions (concert hall, rock, etc)? Or do you think there might be some crosstalk interference between the wires? Have you tried changing the output settings in Windows between headphone, speakers, etc?
On Sat, Jun 13, 2009 at 9:53 AM, Francois PIETTE <francois.pie...@skynet.be>wrote: > Hi ! > > I'm writing a small application which has to generate audio waveform using > the sound card (PCM, 11025KHz, stereo, 8 bits). I'm using waveOutWrite and > related API function. > > For now, I have a single buffer. As I understand, audio samples are one > byte for left, one byte for right up to the end of buffer. > I compute the waveform (a simple sinusoide for my test, different frequency > on each channel), store the bytes in the buffer and play the sound. I use an > oscilloscope to see the generated waveform. > > When I set a single channel, that is having one byte with the computed > value and one byte with value 128, I get the correct waveform shown on the > oscilloscope whatever channel I compute. But when I compute both channels, I > get strange results: left channel is the > some of computed left channel and a fraction of right channel; right > channel is the sum of right channel and a fraction of left channel. See > attached screen dump. > > I don't understand why this happend ! > Any help appreciated. > Best regards, Laurent _______________________________________________ Delphi mailing list -> Delphi@elists.org http://lists.elists.org/cgi-bin/mailman/listinfo/delphi
