The QNX CAR platform acoustic echo cancellation component includes a configuration file with keys for configuring io-acoustic.
The io-acoustic resource manager gets its configuration keys from a configuration file. This file sets up the mapping between the hardware devices on your system and the acoustic processing inputs and outputs, as well as other operational parameters. It is a plain-text file with a series of key-value pairs, separated by module markers.
The QNX CAR platform is shipped with a default configuration file for the current reference board. The keys in this file are preset for optimal performance and sound quality, given the assumptions QNX was able to make about the environment in which the platform will be used. The default configuration file is /etc/acoustic/acoustic.conf.
You can specifiy another configuration file by using the -c at startup. You can also change some other keys at startup. For more information, see the io-acoustic startup options.
The prefix, number of threads, and verbosity can be set in the configuration file or with the command line at startup. However, if these options are set in the configuration file, io-acoustic ignores the values entered at startup.
When io-acoustic starts up it uses the routing specified in its configuration file. If the routing specified in this file fails, then the routing will fall back to the following configuration, using the system-preferred input and output devices:
| Direction | ||
|---|---|---|
| Input | Microphone in | Phone in |
| Channel 1 mapped to IOAP_MIC_IN_1. | Channel 2 mapped to IOAP_PHONE_IN_1. | |
| Output | Speaker out | Phone out |
| Channel 2 mapped to IOAP_SPK_OUT_1. | Channel 1 mapped to IOAP_PHONE_OUT_1. |
Since the name of the Bluetooth audio interface varies from system to system, this default routing doesn't configure audio to flow through Bluetooth. However, the routing specified in acoustic.conf should be correct for the reference board on which the QNX CAR platform has been implemented, given the assumptions QNX was able to make about the board and the environment in which it will be used.
For information about configuring other acoustic processing parameters, see "Configuration keys" below.