InQodec
Build a SIP Codec with a Raspberry Pi
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For most people, buying a ready made SIP Opus Codec from our online store is the best option.

Introduction

If you like a challenge, with the InQodec Firmware from In:Quality, you can build your own broadcast quality IP codec. InQodec is optimized for use with a USB microphone or interface, the sip.audio service, and the Opus codec.

Build an IP codec with a Raspberry Pi and a USB microphone

You will need...
  • Raspberry Pi 3 Model B (minimum)
  • Raspberry Pi Power Supply
  • MicroSD Card (8gb minimum)
  • Raspberry Pi Case
  • Ethernet Cord
  • Card Reader
  • USB Microphone or Interface
  • Headphones
Step by step...
  1. Download the latest InQodec Firmware.
  2. Download and install balenaEtcher.
  3. Insert microSD card in card reader, and attach card reader to your computer.
  4. Run balenaEtcher, and select the downloaded inqodec .zip file as the image.
  5. Select the new microSD card / card reader as the target drive.
  6. Double-check that you have selected the correct target. Click Flash!.
  7. While the image is flashing, you can prepare your Raspberry Pi. Insert it into its case, and consider adding heat sinks to the main board components.
  8. Connect your microphone or audio interface to any USB port. For optimum results, connect your headphones to the microphone, not the Pi.
  9. Connect an ethernet cable from the Pi to your internet router. Most wifi routers also have ethernet sockets on the back.
  10. For the initial setup, it's useful to also connect an HDMI monitor (TV). You may also choose to connect a USB keyboard and mouse, but this should not be necessary.
  11. Insert the newly flashed microSD card into the slot underneath the Pi's main board. The contacts should be facing upwards.
  12. Connect the Micro USB power supply to the Pi, and to the mains. The Pi should power up, and you should see network activity on the ethernet port.
  13. You can configure the device using a USB keyboard and mouse, but it's easier to connect to its web interface from your computer. For this you'll need to find out what IP address your router has assigned to the device.

    The easiest way to determine the IP address is to connect it to any TV or monitor using an HDMI cable. The IP address is then displayed at the bottom of the screen.

    You may also log into your internet router to see the allocated IP address, or on some networks, you can try visiting http://inqodec/ in your web browser.
  14. When you know the IP address, enter it into the address bar of your favorite web browser. You should now see the First Time Setup page.
  15. Submit the default settings, or amend as desired.
  16. You can now configure the device with your SIP account credentials. For full functionality and optimum results, use a sip.audio account.

    Note: You can actually configure more than one SIP account, if for instance you are given specific SIP account credentials for a radio station.
  17. When configuration is complete, the SIP codec will attempt to register to the SIP server (PBX), and will display a phone icon if successful.
  18. You may find that the default audio buffer settings need to be increased to give stable audio to and from your USB device. Try increasing by 5ms at a time until the audio is clean. For instance, the Rode NT-USB Mini can need as much as 60ms to eliminate clicking.
  19. You can now be called from ipDTL or any supported SIP enabled device at your.address@sip.audio

    Using the web interface you can create shortcuts and make calls using a SIP address, or ISDN/phone number.

    You could even add a touchscreen to allow simple dialing of shortcuts.
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