Difference between revisions of "Audio Subsystem"
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| + | This page describes the audio playback subsystem for the Portsdown 5. It is not applicable to the Portsdown 2020 or Portsdown 4. | ||
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===Audio Volume Control=== | ===Audio Volume Control=== | ||
There are 2 ways of controlling the audio output volume on a Portsdown 5. The first is the "Master" volume, and the second is the application volume. | There are 2 ways of controlling the audio output volume on a Portsdown 5. The first is the "Master" volume, and the second is the application volume. | ||
| − | The master volume control (effectively alsamixer) only works for USB Dongle and some custom audio devices. It does not work for HDMI. It can be set from the System Config Menu as a percentage. The default setting is 50%. | + | The master volume control (effectively alsamixer) only works for the USB Dongle and some custom audio devices. It does not work for HDMI. It can be set from the System Config Menu as a percentage. The default setting is 50%. |
| − | The application volume control is only implemented for VLC (not ffplay) and can be set from the System Config Menu and the Receive Config Menu. It is a numeric value in the range 0 to 512. It can also be adjusted from the Receive or Stream viewing screens (in VLC mode only) by touching the lower right corner (reduce), upper right corner (increase) and middle right area ( | + | The application volume control is only implemented for VLC (not ffplay) and can be set from the System Config Menu and the Receive Config Menu. It is a numeric value in the range 0 to 512; the default setting is 255. It can also be adjusted from the Receive or Stream Player viewing screens (in VLC mode only) by touching the lower right corner (reduce), upper right corner (increase) and middle right area (toggle mute). If the displayed video is MPEG-2 or H264, a text caption is briefly displayed in the top left corner of the screen with the new setting (as a percentage). This volume control works with all audio output devices, although it cannot be adjusted from the viewing screen if using an HDMI display. |
| − | If the volume control does not seem to work, the first thing to check is that you are using VLC (not ffplay) as the Player. This is selected from the Receiver Config Menu. | + | If the volume control does not seem to work, the first thing to check is that you are using VLC (not ffplay) as the Player. This is selected from the Receiver Config Menu, or by selecting the correct player on the Stream Player Menu. |
===Audio Devices=== | ===Audio Devices=== | ||
Latest revision as of 20:01, 19 November 2025
This page describes the audio playback subsystem for the Portsdown 5. It is not applicable to the Portsdown 2020 or Portsdown 4.
Audio Volume Control
There are 2 ways of controlling the audio output volume on a Portsdown 5. The first is the "Master" volume, and the second is the application volume.
The master volume control (effectively alsamixer) only works for the USB Dongle and some custom audio devices. It does not work for HDMI. It can be set from the System Config Menu as a percentage. The default setting is 50%.
The application volume control is only implemented for VLC (not ffplay) and can be set from the System Config Menu and the Receive Config Menu. It is a numeric value in the range 0 to 512; the default setting is 255. It can also be adjusted from the Receive or Stream Player viewing screens (in VLC mode only) by touching the lower right corner (reduce), upper right corner (increase) and middle right area (toggle mute). If the displayed video is MPEG-2 or H264, a text caption is briefly displayed in the top left corner of the screen with the new setting (as a percentage). This volume control works with all audio output devices, although it cannot be adjusted from the viewing screen if using an HDMI display.
If the volume control does not seem to work, the first thing to check is that you are using VLC (not ffplay) as the Player. This is selected from the Receiver Config Menu, or by selecting the correct player on the Stream Player Menu.
Audio Devices
The following audio devices are supported by default
- The standard Portsdown white audio dongle
- HDMI audio
Custom audio devices can be added, but the audio device name must be entered on the System Config menu first. To find the name of an audio device, log in to the command line, and with the device connected, enter "aplay -L". Look for the lines referring to your device that are similar to this:
hw:CARD=UACDemoV10,DEV=0
UACDemoV1.0, USB Audio
Direct hardware device without any conversions
The text required in this example is UACDemoV10 from the first line: hw:CARD=UACDemoV10,DEV=0. Go to Config Menu, System Config, Custom Audio Out Device and replace not_set with the exact text for your device (case sensitive). After entering it, you should see that the "Audio Out" button has changed to show your device name.