PARA_ERROR(READ_STDIN, "failed to read from stdin"), \
PARA_ERROR(OPEN_COMP, "OpenAComponent() error"), \
PARA_ERROR(UNIT_INIT, "AudioUnitInitialize() error"), \
+ PARA_ERROR(UNIT_START, "AudioUnitStart() error"), \
PARA_ERROR(DEFAULT_COMP, "can not find default audio output component"), \