ALA Compander audio object is the core of complex ALA object. This object is basically a combination of a compressor and expander module. Its aim is to calculate target gain that has to be applied to the input entertainment signals, according to user’s tuning and according to the updated parameters received from ALA Control audio object.
In BYPASS mode the dynamic effect of the ALA is completely bypassed. Here Compander acts as if it is a compressor of ratio 1 and both after gain and extra gain are set to zero. In the case of NO_EXTRA_GAIN mode, the Compressor Ratio and the After Gain are dynamically adjusted based on the parameterization given to the module.
ALA Compander audio object is added with resetObjectHistory API which clears the history data. This API can be called from application to clear the history.
Control Inputs
| Control Input | Min | Max | Default | Unit | Description |
| Compressor Threshold | -140 | 0 | -30 | dB | The threshold level for gain reduction or expansion |
| Compressor Ratio | 1.0 | 20.0 | 1.0 | controls the amount of compression that occurs once the signal rises above the threshold | |
| Compander After Gain | -20.0 | 20.0 | 0.0 | dB | Gain which can be applied to makeup the amount of level (to be recovered) lost during compression |
| Compander Extra Gain | -20.0 | 20.0 | 0.0 | dB | parameter to compensate the level of weak sources |
Tuning Parameters
| Parameter | Min | Max | Default value | Description |
| Threshold | -140 | 0 | -30.0(dB) | Compander threshold: the compressor starts compressing the signal above this level ((This value is just used for Init reasons and will be overwritten by the next controlSet call and will be controlled by AlaControl or any other object connected to the first pin) |
| Ratio | 1 | 20 | 1 | Compression ratio |
| Attack | 1 | 10000 | 20.0(ms) | The time for compander to reach to full compression factor from zero compression |
| Release | 1 | 10000 | 50.0(ms) | Time to stop compression |
| Bypass | 0 | 1 | 0 | Bypass the dynamic effect of ALA object |
| rms_smoothing | 0 | 10000 | 0.0(ms) | Average rms computed from last and previous rms values calculated |
| soft_knee | -20 | 20 | 0.0(dB) | Compressor knee depth (defines the drastic or smooth transition between no compression and compression in given ratio) |
| after_gain | -20 | 20 | 0.0(dB) | The gain after compression |
| peak_hold | 0 | 10000 | 0(ms) | Compressor peak hold time |
| Ngate_treshold | -140 | 0 | -140.0(dB) | Noise gate threshold – Signal below this threshold will be attenuated, no boost will be applied |
| Ngate_attack | 1 | 10000 | 20.0(ms) | Noise gate attack time – time for gate to open |
| Ngate_release | 1 | 10000 | 50.0(ms) | Noise gate release time – time to get the gate closed |
| Ngate_gain_reduction | -50 | 50 | 0.0(dB) | Noise gate gain reduction |
| Ngate_hyst | -50 | 50 | 0.0(dB) | Noise gain hysteresis |