Running UIbuntu 12.04, and I have need to record what I hear over the speakers onto a sound file.
I can generate Morse code by using the command line program called morse. It outputs in either ALSA or OSS, and I selected ALSA since the other does not work. Using command line utilities that ship with ALSA, I can set the sound card with amixer to stereo mix, and use arecord to record to a wave file. Morse will play and arecord will record, and I can play it back in a music player.
My problem is, arecord's output is RIFFL format wave instead of RIFF format, as seen in a hex editor. The DC bias is above the center line in my RIFF editor, and it is below the center line if I am recording off the microphone in my RIFF-compatible editor. I can invert the RIFFL waveform to make the DC bias be the same on both, but that is about all I can do with it. If I zero out the DC bias, if I try to reduce noise, then the file gets noisy. if I use the Sound Converter, the resulting file will be noisy. So I can DO Stereo Mix, but I can't convert the file for use on my web site.
I used Ardour, which recorded a nice RIFF file from my microphone, but if I use amixer to set to Stereo Mix, the Morse won't produce a sound until the Ardour is closed. Sweep won't record it either, because if Morse is playing, Sweep finds the resource busy. If I record then play Morse, Sweep records a blank file.
Of course Windows software in Wine won't touch it. My Syntrillium Software Cool Edit just records a blank file if I have Stereo Mix turned on. I run "Windowa XP." Wine uses ALSA driver.
Maybe there's some hope with PulseAudio? That leaves my Cool Edit out and I will have to use one of the Linux sound editors, but the morse program only supports ALSA or OSS.
There may be another way around this, by playing Morse on one computer and recording to another or to my voice recorder -- the latter would eat a lot of batteries! But it would give me an MP3 file I can load back into the computer, rip and edit.
Anybody have ideas of how I might get this done?
Hmm. Maybe I could burn an audio CD from the arecord file, then play the CD back. Each track of an audio CD is seen as a wave file, maybe of the RIFF variety.....