OPUS CODEC DECODER CHIP UPDATE

Opusenc bandwidth=1102 bitrate=12000 audio=true complexity=5 ! Unfortunately, the only way I could get the pipelines to work in gstreamer 1.x was to pack the opus encoded audio into RTP: $ gst-launch-1.0 -v alsasrc device=hw:3 ! In order to encode the audio using opus codec, we simply add an opus encoder with suitable parameters to the server and a decoder to the client. To run them on different machines simply replace localhost at both ends with the IP address of the server. The above client and server runs on the same machine using locashost as client and server. The following gstreamer pipeline reads audio samples from a sound card and sends the raw samples to a TCP socket, if a client is connected: $ gst-launch-1.0 -v alsasrc device='hw:1' !ДЄudio/x-raw, format=(string)S16LE, channels=1, rate=48000 !ДЄ corresponding client that reads the samples from the TCP socket and sends them to a different sound card is like follows: $ gst-launch-1.0 -v tcpclientsrc host=localhost port=12345 ! The default frame length is 20 millisecond and can be adjusted down to 2.5 milliseconds.ДЄlthough I chose the opus codec, gstreamer allows experimenting with a large variety of audio codecs, including raw uncompressed samples.

For AM, FM and SSB voice it can provide excellent audio quality with no more than 12 kbps. The opus codec is a quite amazing audio codec useful for both music and speech. On the downside, gstreamer is a rather large framework with many dependencies, so implementing a dedicated client and server applications will still make sense later.

So I decided to start with gstreamer because it allows building a client and server in a matter of minutes. After some time I thought, ok, this is going to take time to learn and get it right.

Uses TCP network connection between client and server.ДЇew weeks ago I started implementing my own client and server code, including interfacing to the ALSA audio system.

Uses the Gstreamer multimedia processing framework.

To that end, I have decided that the first iteration of the audio client and server is going to be as follows: I have been working on and off on the audio client and server part, which is pretty much the last piece I need before I can do some realistic field tests.

OPUS CODEC DECODER CHIP UPDATE

It has been a few weeks since my last update about the IC-706 remote rig project so here is a new one.

2022.03

Opus codec decoder chip