kopia lustrzana https://github.com/f4exb/sdrangel
2.2 KiB
2.2 KiB
Audio input plugin
Introduction
This input sample source plugin gets its samples from an audio device.
Interface
The top and bottom bars of the device window are described here
1: Start/Stop
Device start / stop button.
- Blue triangle icon: device is ready and can be started
- Green square icon: device is running and can be stopped
- Magenta (or pink) square icon: an error occurred. In the case the device was accidentally disconnected you may click on the icon, plug back in and start again.
2: Device
The audio device to use.
3: Refresh devices
Refresh the list of audio devices.
4: Audio sample rate
Audio sample rate in Hz (Sa/s).
5: Decimation
A decimation factor to apply to the audio data. The baseband sample rate will be the audio sample, divided by this decimation factor.
6: Volume
A control to set the input volume. This is not supported by all input audio devices.
7: Channel Map
This controls how the left and right audio channels map on to the IQ channels.
- Mono L - Real samples are taken from the left audio channel and are heterodyned by the fourth of the sample rate (fs/4) to obtain complex samples. Therefore the spectrum of the complex baseband is centered at the fourth of the sample rate (fs/4). As per Nyquist rule only a bandwidth of half of the sample rate (fs/2) is available for real signals. Frequencies outside the [0, fs/2] interval are artefacts and can be eliminated by decimating by a factor of 2.
- Mono R - Same as above but takes the right audio channel for the real signal.
- I=L, Q=R - The left audio channel is driven to the I channel. The right audio channel is driven to the Q channel for a complex (analytic signal)input.
- I=R, Q=L - The right audio channel is driven to the I channel. The left audio channel is driven to the Q channel for a complex (analytic signal)input.
8: Auto remove DC component
Software DSP auto remove DC correction.
9: Auto make I/Q balance
Software DSP auto I/Q imbalance correction. The DC correction (8) must be enabled for this to be effective.