7 Live Audio Streaming via RTP

This test is intended to stream live audio captured by the SAMA7G54-EK's PDMC to VLC on a Windows PC via RTP.

Figure 7-1. Audio Over Ethernet on SAMA7G54-EK using Linux
  1. To check the PDMC audio device card number and device number, use the command below.

    $ arecord -l | grep pdmc

    In the following example, the PDMC card number is 0 and the device number is 4:

    This command verifies that the pdmc0 device tree overlay has been applied successfully

  2. To stream live audio captured by the SAMA7G54-EK's, use the following command:

    $ arecord -Dplughw:0,4 -r 8000 -c 1 -f S16_LE | ffmpeg -f s16le -ar 8000 -ac 1 -i - -f mulaw -f rtp rtp://<IP_address>:<Port>

    Example: $ arecord -Dplughw:0,4 -r 8000 -c 1 -f S16_LE | ffmpeg -f s16le -ar 8000 -ac 1 -i - -f mulaw -f rtp rtp://192.168.24.10:1234

  3. Play audio or speak close to microphones MIC3 (C232) and MIC1 (C235) on the SAMA7G54-EK. That audio can be listened to through VLC on a Windows PC.