Setting up the Local Audio Bridge

Overview

The Local Audio Bridge feature in Spalk is designed to facilitate low-latency audio workflows, particularly useful for integrating remote commentators into on-site live workflows. This guide will explain the purpose of this feature, typical use cases, and detailed setup instructions.

Purpose of the Local Audio Bridge

The Local Audio Bridge allows for the integration of Spalk remote audio into live, on-site workflows with low latency, allowing for the minimum possible delay and commentators to be integrated within familiar production workflows. This could be bridging with the on-site truck so the director can hear the commentary, a remote gallery where the show is being produced, or for low latency feedback to audio operators who are remote themselves.

When to Use the Local Audio Bridge

• On-site distribution integrating remote commentary: Ideal for situations where commentators are not on-site but the world feed is produced for distribution on site.
• Low Latency Requirements: Suitable for remote operators who want to monitor the commentary audio with minimum delay.
• Flexible Audio Requirements: Useful for setups where audio needs to be processed and modified separately from video, to preserve existing GFX, ad signaling or other workflows or to prevent quality loss from video compression.

Setup Instructions

Step 1: Access the Local Bridge

1. Navigate to the Bridge Page: On the Spalk platform, select Bridge in the header where all live events are listed. If you cannot find it, please contact your Spalk representative to ensure it is enabled for your organisation.
2. Select Your Event: Find your event, and commentary team you want to bridge locally and click "Connect" to the Local Bridge.

Step 2: Configure Audio Output

1. Select Audio Output: Choose the appropriate audio output device for your setup. This could be a virtual sound card or a physical output device.
2. Connect to the Local Bridge: Ensure the connection is established and statistics are being gathered.

Step 3: Integrate with Dante Network (Optional)

1. Dante Virtual Sound Card: If using a Dante network, install the Dante Virtual Sound Card software on your computer.
2. Configure Audio Devices: Use Ethernet cables to connect your audio devices within the Dante network.
3. Emit Audio via Dante: Your computer can act as a microphone, playing out audio from Spork into the Dante network for further mixing.

Step 4: Monitoring and Adjustments

1. Monitor Latency and Sync: Use the provided metrics to monitor sync delays and round trip times.
   
   1. Synch Delay is the measured amount that Spalk is delaying the Video (hence negative), to ensure that the audio is in synch with the video. It is recommended you add this delay to your video in order to ensure that the audio and video are well synched.

Typical Workflow

1. On-Site Setup: Cameras and microphones capture the event, with live operators switching, replaying, mixing to produce the live feed.
2. Remote Commentary: Commentators watch the live feed and provide real-time audio commentary.
3. Audio Bridging: The commentary audio is sent to Spalk, and sent to the local bridge with minimum possible latency.
4. Final Mix: The audio is integrated into the final feed, ensuring synchronization with the video before distribution.

Future Enhancements

• Intercom Integration: Coming soon, this feature will also bridge intercom functionality to allow the commentator to integrate seamlessly into the existing workflow.
• Channel Mapping: Map the commentator audio to specific output channels if required. This ensures the correct audio feeds are sent to the appropriate outputs.
• Jitter Buffer Adjustment: Manually set the Jitter Buffer length to account for fluctuations in the commentator, or local connection.
• Scheduling: Automate and schedule audio bridging for upcoming events to minimize errors and reduce pressure of operating systems live.
• External Metrics Integration: Push synch delay and other metrics to external systems for automation and data collection purposes.

Conclusion

The Local Audio Bridge feature in Spork is a powerful tool for integrating remote audio commentary into live broadcasts with minimal latency. By following the setup instructions and understanding typical workflows, users can effectively leverage this feature for enhanced audio production.

For any questions or further assistance, please contact our support team.