Skip to content

H.264 Audio

HDMI Audio Support

Audio feature overview

The latest One-KVM supports real-time HDMI audio transmission via H.264/WebRTC, with audio quality sufficient for smooth music playback. The system uses the Linux ALSA sound driver, while ustreamer and janus capture HDMI audio and transcode it to Opus.

Configuration

Docker users

Use the environment variable -e AUDIONUM=0 to specify the audio device. See the Docker environment variables.

Integrated image users

Edit the audio configuration file /etc/kvmd/janus/janus.plugin.ustreamer.jcfg:

1
2
3
4
5
6
7
video: {
    sink = "kvmd::ustreamer::h264"
}
audio: {
     device = "hw:0"
     tc358743 = "/dev/video0"
}

Configuration notes:

  • device: audio device address
  • tc358743: capture card video device path

Find audio devices

On Linux, use the following commands to list available audio devices: 

1
2
arecord -L   # Detailed device list
arecord -l   # Brief device list

The following three methods are supported to specify the audio device:

  1. By card index: hw:0
  2. By card name: hw:CARD=MS2109
  3. By device file: hw:/dev/snd/controlC0

Choose one method to enable HDMI audio.

Demonstration

HDMI audio