Audio Switching

The capability to transmit or stream sound from either the video capture device (EasyCap) or a microphone connected through a cheap USB dongle was overhauled and further developed in software 201707221.

In the Console, System Setup, Audio Input menu there are 5 options: auto, mic, video, bleeps and no_audio. The switching behaviour is as follows:

1 If "no_audio" is selected, no audio stream is generated.

2 If "bleeps" is selected, mono bleeps are transmitted.

3 If neither an EasyCap or USB Sound Dongle is detected (see below), no audio channel is generated, unless the option for "bleeps" has been requested. In which case "bleeps" are generated.

4 In "auto" mode:

If both an EasyCap and a USB Sound Dongle are detected, the video source is checked. If video from the Pi Cam is selected, mono audio from the USB Sound Dongle is transmitted. If the EasyCap is selected for video, stereo audio from the EasyCap is transmitted.

If only a USB Sound Dongle is detected, mono audio from the USB Sound Dongle is transmitted.

If only an EasyCap is detected, stereo audio from the EasyCap is transmitted.

5 In "mic" mode, if a USB Sound Dongle is detected, mono audio from the USB Sound Dongle is transmitted. If no USB Sound Dongle is detected, but an EasyCap is, stereo audio from the EasyCap is transmitted.

6. In "video" mode, if an EasyCap is detected, stereo audio from the EasyCap is transmitted. If no EasyCap is detected, but a USB Sound Dongle is, mono audio from the USB Sound Dongle is transmitted.

The "auto", "mic" and "EC" (video) modes can also be selected from Menu 2 of the Touchscreen.