VR-1HD: How to Synchronize Audio with Video
On the VR-1HD, there are two stages of delay:
Input Delay
Each individual analog and digital audio input has their own delay setting
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MENU > AUDIO INPUT > (Any Input Except Playback) > DELAY
- If using the RCS software, go to the Audio Mixer and click on the SETUP button for any of the inputs on the channel strip, you will see the DELAY setting in the window that pops up.
- If using the RCS software, go to the Audio Mixer and click on the SETUP button for any of the inputs on the channel strip, you will see the DELAY setting in the window that pops up.
- This helps if routing additional microphones through cameras, which the VR-1HD mixes as embedded audio
- Or if you have an external mixer running into the RCA inputs and need to delay them to match the cameras
How to Test
- Connect the "Main" HDMI output to a TV and headphones to the same TV.
- You can also connect headphones to the VR-1HD if the TV does not have a headphone connector.
- Clap your hands in front of a camera to see if it is in sync. If it appears off, adjust the delay for each audio input that is off.
- You may not need to adjust all audio inputs, but it helps to test each one that you use individually, if possible.
- It may also help to record the HDMI output and check how far off it is in video editing software, to help you accurately calculate the delay. More info in the "Verifying the Delay" section of this guide.
Output Delay
The AUX audio bus and USB Streaming output have their own delay settings as well
-
MENU > AUDIO OUTPUT > AUX BUS or USB STREAM > DELAY
- If using the RCS software, go to the Audio Mixer and click on the SETUP button for USB STRM on the channel strip, you will see the DELAY setting in the window that pops up.
- This setting delays the entire mix, this can be useful for synchronizing your audio with video when streaming
- This does not affect the Main mix itself going to the HDMI output
How to Test
- Connect the "USB Stream" output to a computer and headphones to that same computer.
- Do not connect headphones to the VR-1HD, as you are checking for any latency issues on the just the computer, assuming your input delay settings are correct.
- Clap your hands in front of a camera to see if it is in sync on the computer. If it appears off, adjust the delay for the USB audio output.
- It may also help to record the USB Stream output and check how far off it is in video editing software, to help you accurately calculate the delay. More info in the "Verifying the Delay" section of this guide.
If the issue is that two cameras have different delay amounts and you are not using their audio, you will need a converter that can add video delay like our VC-1-DL to get cameras in sync. Before doing that, make sure the cameras are outputting the same resolution and frame rate, like 1080p 59.94. If they are the same camera model, check firmware updates and all settings to make sure the cameras are as identical as possible.
Verifying the Delay Amount
1. With your workflow configured, make a test recording of a hand clap or production slate in front of the cameras and microphones.
2. Open the recording in video editing software, un-link the audio tracks and video track, and adjust the audio track until it is in sync with the video.
3. Measure the sync offset, and apply that setting to the relevant VR-1HD delay channels.
Please Note: If the sync offset is only measured in frames in your video editing software, you will need to convert to milliseconds.
If you recorded the USB Output: With 1080P and 1080i there are 29.97 frames per second in your video file. With 720P and 480P there are either 29.97 or 59.94 frames per second. Check Menu > Video Output > USB Stream to confirm.
If you recorded the HDMI output: With 1080P and 720P, there are 59.94 frames per second. 1080i signals are actually 29.97 frames per second (59.94 interlaced fields).
To calculate the offset, divide 1000 (milliseconds) by the number of frames (either 29.97 or 59.94), and multiple by the frame offset.
This example gives you the offset, in milliseconds, for a 4 frame delay.
Example 1: 1000 / 59.94 = 16.68 x 4 = 66.7 ms
Example 2: 1000 / 29.97 = 33.37 x 4 = 133.5 ms
4. Make another test recording to confirm the changes synchronize the audio and video.