SDI Signal Recording and Frame Grabs

LiveGrade Pro 3 supports the display and capturing of live HD-SDI signals. With this feature and the proper video capturing hardware you can watch the live video signal on your computer monitor. How to use the image viewer to compare different image sources is explained in the article Image viewer.

Once the setup is complete, it is possible to record clips on the HDD or grab frames for grading reference. How to properly setup your HD-SDI viewing environment with LiveGrade is described in the article HD-SDI setup for LiveGrade.

Supported Capture Hardware in LiveGrade Pro 4

The following SDI capture devices are supported:

  • AJA Io Series (e.g. AJA Io XT or IO 4K)
  • AJA KONA Cards (e.g. KONA 3G)
  • Blackmagic Design UltraStudio Series (e.g. Ultrastudio HD Mini, Ultrastudio 4K or Ultrastudio Mini Recorder)
  • Blackmagic Design DeckLink Cards (e.g. DeckLink Duo 2)

All listed capture devices similarly support ANC metadata coming from the SDI stream in LiveGrade Pro 4.

For a list of compatible devices for HD-SDI output in LiveGrade Pro 3 and 4 please see the article Image View Output to HD-SDI in LiveGrade Pro.

Supported Capture Hardware in LiveGrade Pro 3

The following SDI capture devices are supported:

  • Blackmagic Design UltraStudio Series (e.g. Ultrastudio HD Mini, Ultrastudio 4K or Ultrastudio Mini Recorder)
  • Blackmagic Design DeckLink Cards (e.g. DeckLink Duo 2)

Available Capture and Output/Playback Channels

  • AJA IO 4K: 4 bi-directional capture and playback channels offer e.g. up to 3 SDI channels capture and 1 SDI channel for output simultaneously
  • Ultrastudio HD Mini and Ultrastudio 4K: Simultaneous capture and playback of 1 SDI signal. Does not support capture of multiple image streams at the same time.
  • DeckLink Duo 2: Offers 4 bi-directional capture and playback channels each of which can be used either for capture or playback
  • Ultrastudio Express: Only one channel for capture OR playback. When used as capture device the SDI out only loops the input signal.

Adding a Video Capture Device

In order to add a video capture device, you have to select Main Menu -> Devices -> Add Video Stream. A wizard will appear, where you can select the connected device and the input video format:

figure 1: adding a video stream

The type of capture source you have to choose depends on your setup and the incoming signal. Choose between :

  • Direct camera output: This setting is needed if you capture the original camera signal without prior look-up in LiveGrade (often a logarithmic signal).
  • LUT box output (graded): This setting is needed if you capture an already graded (pre-graded) signal in LiveGrade.

In case that a black image is displayed, please check that the video input format is correctly set on the Blackmagic Desktop Video Manager. Additionally, you can check that the «Use PsF» check box is unmarked.

Once you click on «Open Stream», the stream will be associated to a grading slot. The grade applied to that particular slot will be the one applied to the live video stream. Any modification of the grade will be immediately shown on the live video stream.


Recording Clips

Now that the video signal is being fed into the computer, you can use LiveGrade to record clips or create frame grabs for future reference. Both recordings and frame grabs are saved as the original image source. However, they are saved in the library with their look associated. This way the look will be applied during playback of the clips and frame grabs.

figure 2: record and grab frames

To start a recording click on the «Record» button on the top left of the UI (figure 2). This action will start to record the video feed on the computer HDD, under the folder /User/Movies/LiveGrade Recordings. The clip recordings folder can be modified on the Preferences>General menu.

Additionally, the video recording HUD will appear during the clip capture. Here you can customize the metadata of the clip currently being recorded, for further reference in the Clip Library:

figure 3: video HUD

figure 3: video recording HUD


You can grab frames from the video signal by clicking on the framegrab button. This takes a frame from the video stream and saves it on the Clip Library with the associated grade for further reference. When creating frame grabs you can also enter custom metadata:

figure 3: framegrabs

figure 4: framegrabs

Framegrabs from Pre-Graded Image Sources

Pre-graded image sources have special characteristics. A grey “Type” icon in the look library will appear to mark a frame grab from a pre-graded image source. The look of pre-graded frame grabs in the look library can not be updated as there is no original signal available.

To update the framegrab and the grade of a Look/Still in the library use the Main Menu entry under “Project > Update selected Look and Replace Image” or alternatively use the shortcut Cmd + Shift + U. This will update still image and grade of the Still in the Library. Please see the article Create Clips, Stills and Looks for more information about updating Looks and Replacing Still Images.

Please be aware of other special characteristics throughout LiveGrade Pro (e.g. in Clips mode) based on frame grabs from pre-graded image source that due to there origin cannot change the look of their associated still image.

Recording options

There are several recording settings that can be modified on the Preferences menu:

figure 6: Recording options

figure 6: Recording options



  • Record format: lets you choose the quality level of the ProRes compression
  • Record action:
    • Current image source: only records the live video signal from the selected slot.
    • All image sources: records all the available live signals.
    • Auto Record: when enabled, LiveGrade listens for a record flag on the SDI that is sent by the camera and starts a recording in LiveGrade automatically.
figure 7: auto record options

figure 7: auto record options

  • Record folder: you can choose the destination folder where the clips and frame grabs are saved.







Please note: The documentation is currently in transition from LiveGrade Pro version 3 to version 4 and may not be up to date yet.