Using PocketSphinx with Blue Microphone on RPi

Question

I'm trying to compile PocketSphinx and use it to do voice recognition from a Blue Snowflake microphone. The code compiles fine, but when I try to run it, I get the following error:

pi@raspberrypi ~/pocketsphinx-0.8 $ src/programs/pocketsphinx_continuous
[Lots of sphinx text output...]
Error opening audio device default for capture: no such file or directory
FATAL_ERROR: "continuous.c", line 264: Failed to open Audio Device

When I try to change the mic volume in AlsaMixer, it says "This sound device does not have any capture controls."

Does anybody know how to get it to recognize the mic? I've been able to record audio from Audacity, so clearly the mic is being recognized. I also see it listed in "arecord -l", but I can't seem to get arecord to actually pick up the microphone's audio.

I have Audacious and Audacity installed, which brought PulseAudio along with them. I also have alsa-tools, alsa-utils and alsa-mixer installed. Might this be causing a conflict?

Answer 1

layla writes on http://robot.laylamah.com/?p=35

Note, if you receive an error such as the following:

Error opening audio device plughw:1,0 for capture: Connection refused
Mixer load failed: Invalid argument FATAL_ERROR: "continuous.c", line
246: Failed to open audio device

You likely have pulseaudio installed, which is causing sphinxbase to attempt to use pulse instead of alsa.

The workaround (if you indeed wish to use ALSA) is to remove pulse, and then follow the steps above to re-install sphinxbase.

sudo apt-get remove pulseaudio -y
sudo aptitude purge pulseaudio -y
sudo mv /usr/include/pulse/pulseaudio.h /usr/include/pulse/pulseaudio.h.old

If you’ve done everything correctly, running ./configure on sphinxbase should give you ... See http://robot.laylamah.com/?p=35