Resources for “Introduction to Sound Programming with ALSA”

I typed the simple playing program and I made some tests, it works almost with no problems.

However, this is not the case for the simple capture program. It is typed like the article says, I compiled and no errors, but the file where the result is redirected has in appearence not information. I played the content of this file with the simple playing. I have tried with different inputs, the CD and the MIC on the KMix interface without many success. The same happens with the 6735l4.c file, there is any idea???
The version of the ALSA API is 1.0.8rc2.
thanx,

--marco.

I get this when I try to run listing 1. I am using alsa version 1.0.6
Do I need to link something?

> /tmp/ccY117TW.o(.text+0x47): In function `main':
> : undefined reference to `snd_pcm_stream_name'
> /tmp/ccY117TW.o(.text+0x84): In function `main':
> : undefined reference to `snd_pcm_access_name'
> /tmp/ccY117TW.o(.text+0xc1): In function `main':
> : undefined reference to `snd_pcm_format_name'
> /tmp/ccY117TW.o(.text+0xd0): In function `main':
> : undefined reference to `snd_pcm_format_description'
> /tmp/ccY117TW.o(.text+0xdd): In function `main':
> : undefined reference to `snd_pcm_format_name'
> /tmp/ccY117TW.o(.text+0x11e): In function `main':
> : undefined reference to `snd_pcm_subformat_description'
> /tmp/ccY117TW.o(.text+0x12b): In function `main':
> : undefined reference to `snd_pcm_subformat_name'
> /tmp/ccY117TW.o(.text+0x16c): In function `main':

I am using ALSA version 1.6a and seem to be having problems with listing2,3 and 4. I keep getting the error "unable to set hw parameters: Invalid argument -22" I added the -22 by printing the rc value. The error is caused by the snd_pcm_hw_params( handle, params) call to write the parameters to the driver. I looked at the ALSA documentation and can't seem to find a breakdown of the params struct. It would help if I knew what parameter are bad.