We are trying to record externally from our Blackmagic Decklink 8K Pro card into our Blackmagic Hyperdecks via SDI. We can easily get the SDI video feed into the Hyperdeck but audio is not following automatically.
We have looked in all the menu's for options to send the audio through the SDI and can't find anything. We've also spent days trying different node configurations... no dice.
Any help would be greatly appreciated. Our production is this coming Monday!
Hi,
In the camera compounds, the audio output is under the video out:
You can mix 3 audio inputs using the Record_3-Audio compound:
Or using an Audio Mixer module:
Note, that the audio is exposed together with a video out by connecting it under it. More on exposing video outputs here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/scripting-in-aximmetry/flow-editor/flow-editor/#exposed-video-output-index
If you are still not hearing any audio, you could check if you are receiving any audio by using an Audio Peeker module:
If you don't see any change in Audio Peeker's video, then there is probably some trouble with the input. If you see changes in it, then the problem is in the output.
Warmest regards,
Hi JD,
How is the audio exposed with the video in Aximmetry? Also, are you sure you selected the same output index for your capture card in the output settings?
"the problem is in the output", I am referring to the devices outputting the audio (e.g., capture card, Sound Blaster).
To answer your other question in the other post about how to choose an audio track > right track or left track:
In the Flow Editor, these tracks are called channels. You can assemble them using the Audio Channel or Audio Merger module. When you peek at (CTRL + mouse) the audio connection, you can see which channels are used:
Warmest regards,
Adding to this topic: Is there a way to receive, send, route and mix audio of the main SDI output independently of the video routing?
I need to get talkback from two cameras, embedded in the SDI audio channels 13-16, mix the signals 1:1 channel by channel and embed those four signals back onto the main SDI output, again on SDI audio channel 13-16.
Hi Stefan,
I'm not exactly sure what you mean by independently of the video routing. However, I don't see why it wouldn't be possible.
Simply use a Video Input module and expose it as described here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/scripting-in-aximmetry/flow-editor/flow-editor/#exposed-video-output-index Alternatively, you can use a Video Device Out module.
For the audio channels, if you are using all 16 channels, you will likely need 16 Audio Channel modules to be able to split and then merge all the channels with the Audio Merger module.
Warmest regards,
Hi JD,
I'm not sure why you needed to change the Windows sound output.
You won't have an Audio Output option for capture cards, as they carry the audio signal within the video. To add the audio to the video, follow the instructions provided here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/scripting-in-aximmetry/flow-editor/flow-editor/#exposed-video-output-index
Or if you are using the Video Device Out module, it also has an Audio pin:
Warmest regards,
I specifically do *not* want to pipe all 16 audio channels from input to output. I want to extract Audio channels 13-16 from two 4K SDI input Signals, Mix them channel by channel (1/13 + 2/13, 1/14 + 2/14 and so on) and embed the 4 resulting channels into the 1080p SDI PGM signal as 13-16 again. That will give me camera talkback to the ATEM HD8 that takes the PGM signal for further processing and also sends the return signal to the cameras, thus also providing comms (and camera control) in the opposite direction.
My current workaround is taking audio and video signals from both cameras on a video input Module and individually sending them to the SDI output matrix, downscaling to 1080p in the process. Connecting these SDI outputs to spare inputs on the ATEM gives me the Talkback I need, but I feel that it ties up a lot of Ressources unnecessarily.
Hi Stefan,
You shouldn't be concerned about the performance load of mixing audio, even if you need 16 Audio Channel modules. These audio editing modules consume very little performance, and all of the processing is handled by the CPU.Note: You could somewhat test the actual load on your system by having only the audio channel-changing logic in your compound, without including anything else related to your virtual studio rendering (such as camera compounds and Unreal module).
Warmest regards,
Does the video input module already consume resources when it has an input connected or does that only apply if the video signal is actually going somewhere, in our case a scaled output? In the latter case it would be great to be able to do Audio only Routing here and then embed the end result into the PGM SDI signal.
Hi,
If you have SDI input, the Video Input module will still need to process the video to extract the embedded audio. However, subsequent modules (such as scaling) in the video stream will not be used if they are not outputted.
In the newly released version of Aximmetry (2024.3.0), there is a feature called Show Active Routes that can visualize which modules are active:
For example, if a module like Cropper is not executed, it will be grayed out while Show Active Routes is turned on:
Conversely, if the Cropper module is connected to an active output, then the Cropper module will be used and not grayed out:
You can read more about module execution here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/scripting-in-aximmetry/flow-editor/module/#module-execution
Warmest regards,
Hi,
Yes, the Audio Output module does not provide access to the SDI's embedded audio channels.
You will need to connect to the video from input to output:
I am not sure there could be a faster implementation for this case. Anyway, I can add a request to our list to explore the possibility of faster audio-only editing for SDI.
Warmest regards,
