Raw ALSA PCM

[Ryan McClue]

Hello,
I'm trying to play a simple PCM buffer with ALSA without asoundlib.
This has proven very difficult as there are very few resources that show usage without asoundlib.
Through my investigations I was fortunate enough to obtain a gist that attempts to do this: https://gist.github.com/takaswie/d8a9553c230971d974a3dfc759b2ff67
Unfortunately this application does not work. I tested the application using the virtual snd-dummy driver and the application produced the same error. So, it is most likely an application error, rather than an Intel HDA error.
I'm emailing to ask for help in getting the program to work. I'm really lost as to what should be changed in the code. I'm sure that a working example of this will be useful for many programmers.
Thank you