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Add image or video B-roll in Tella by choosing a Media layout under Layout for part of a clip, or by setting the Screen or Camera slot’s Source to Media in Customize layout. Use it to cut to a product screenshot, a stock video, a diagram, or an AI-generated visual while your voice keeps playing.

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What you can use as media

Anything you put in the Media slot of a layout becomes your B-roll for that section. You have three sources:
  • Upload: drop in an image (PNG, JPEG, WebP, GIF) or a video file (MP4, MOV, WebM, etc.) from your computer.
  • Media library: pick from media added to the current Video, saved to Personal (only you), shared with your Team, or choose a clip from another video under Clips.
  • Generate with AI: describe what you want and Tella generates an image for you. You can attach a reference image to steer the look.

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Add media to a layout

Every layout section has two slots, Screen (the main panel) and Camera (the bubble), and each slot has its own source. You can put media in either slot, so B-roll works on any clip: two-track recordings, screen-only clips, camera-only clips, and uploaded videos.
  1. Open your video and click Layout.
  2. Drag across the time range where you want the media. You can also select one or more existing layout cards.
  3. Under Presets, find the Media family and choose a full-frame or two-slot arrangement.
  4. Pick an item from the Media Library, upload a new image or video, or generate an image with AI.
Tella creates sections for selected ranges, updates selected cards in place, and attaches the media in one action.

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Change a layout source manually

You can also add media from Customize layout:
  1. Select a layout card and open Customize layout.
  2. Open the Screen or Camera section and change its Source to Media:
    • Screen → Media: media fills the main panel (classic B-roll). Your camera recording, if present, stays in the bubble alongside it.
    • Camera → Media: media takes over the bubble while your recording in the main panel keeps playing. Use this for inset visuals like a reaction GIF, a logo, or an illustration over your demo.
  3. The Media Library opens automatically. Choose, upload, or generate an item.
That section of your video now shows the media in the slot you picked, while the rest of the layout (your camera, background, borders, and so on) stays the same.
Each slot’s Source is independent: Recording, Media, or None. You can set one slot to None to hide that part of the layout, but at least one slot has to be active.

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On camera-only or screen-only clips

The same two-slot controls apply when your clip has only one recording:
  • Camera-only clip: set Screen → Media to cut to a full-frame visual with your camera tucked into a bubble, or set Camera → Media to keep yourself on camera with media floating beside you.
  • Screen-only or uploaded clip: set Screen → Media to fully replace the screen, or Camera → Media to add an inset bubble of media over your screen recording.
For the most predictable result on a single-recording clip, start with a Media preset that already has the full-frame or two-slot arrangement you want. You can pick another compatible style under Customize layout.

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Adjust media (trim, crop, audio)

Once a clip is in a B-roll section, you can fine-tune which part of it plays, how it’s framed, and how loud it is from a single Adjust media modal. Open it from the timeline:
  1. Right-click a layout card that uses media.
  2. Pick Trim media to edit the source range, or Adjust volume to open the Audio panel at that media’s volume control.
To silence video media immediately, choose Mute audio from the same menu. Choose Unmute audio to restore its sound. If both the Screen and Camera slots use media, the menu labels each action by slot. The modal shows a live preview followed by a timeline with the full source clip.

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Trim the inpoint and outpoint

  • Drag the start and end handles on the timeline to pick the range of the source clip you want to use. The red playhead above the track tracks playback. Drag it to scrub.
  • Press space to play just the trimmed range in the preview.
  • Need exact timing? Double-click the duration below the track to type a duration. You can also nudge a selected handle by 10 ms with the arrow keys, or 100 ms with Shift + arrow.
A video B-roll section can’t be resized longer than its media has left to play. On the timeline, the section’s edges (and the seam between two sections) stop where the media (from its trim start to the end of the clip) runs out, instead of looping to fill a longer section. Images don’t have this limit since they don’t loop.

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Crop the framing

Click the crop icon in the modal footer to crop the media to a tighter framing. The preview shows the cropped result, and narrow crops are letterboxed to match your video’s aspect ratio. Crop and any explicitly set media volume are preserved when you split a B-roll section, so both halves keep the same framing and audio level.

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Adjust the media’s audio

Click the volume icon in the modal footer to open the media volume slider. This is the same control as Media volume (this layout) in the Audio panel. Set it to zero to mute the media’s own sound while keeping your voiceover. When you’re done, click Apply to save your changes to that section.
B-roll playback continues across a layout split. If you split a section that uses media, the second half picks up where the first half left off in the source clip instead of restarting from the beginning.

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Replace the media in a section

You can pick a different clip for a section at any time (from the Media Library, a new upload, or AI generation) without deleting the section first. Open Customize layout, then click the existing media row, or right-click the layout card on the timeline and choose Replace media.
  • If the replacement is shorter than the current section, the section shortens to match the new clip’s length.
  • If it’s longer, the section keeps its current length. Open Adjust media afterward if you want to use more of the new clip.

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Does my voice keep playing during B-roll?

Yes. Your microphone audio keeps playing during a media section. Swapping in media doesn’t remove your voiceover. Audio from a recording can also keep playing when its video is hidden. Use the Audio controls when you want to mute microphone or system audio too; changing a visual source to None does not mute its recording audio. If the media file has its own sound (e.g. a video clip with audio), it’s mixed in on top of your voice. To balance or mute it:
  1. Right-click the media section in the timeline.
  2. Select Adjust volume to open the Audio panel at the volume control for that media.
  3. Adjust Media volume (this layout), or drag it to zero to fully mute the media’s sound.
For a quick toggle, select Mute audio or Unmute audio directly from the media section’s menu.
If your voiceover sounds quiet during a media section, it’s usually the media’s own audio competing with it. Turn down Media volume (this layout) rather than re-recording.
You can also click directly on the empty B-roll area in the canvas to open the Media Library. If the section already has an AI prompt saved, the placeholder shows the prompt. Click it to jump back to the generator and edit it.

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The Media Library

Selecting Media for an empty slot or clicking Browse media for a slot that already contains media opens the Media Library panel. Use the Video / Personal / Team / Clips control to choose a source:
  • Video: media added while editing the current video. This is the default tab, and every editor of the video sees the same items.
  • Personal: media only you can access across your videos.
  • Team: media everyone in your workspace can access across videos.
  • Clips: clips from other videos you can access. You need edit access to the source video to add one.

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Add a clip from another video as B-roll

  1. Open the Media Library for the layout slot where you want the clip, then choose Clips.
  2. Search for a video or browse the list. Only my videos is on by default; turn it off to see other videos you can access.
  3. Open the video and choose a clip. You can search the clips by name and hover over a clip to preview it. Selecting a video with one available clip picks that clip directly.
  4. Wait for the clip to render under Video. Tella adds it to the selected layout slot when it’s ready, even if you close the library while it renders.
To add an editable timeline clip instead of B-roll, use Add clip → Select from existing. See Remix and reuse videos and clips. You can manage the active library in these ways:
  • Search: type to filter it by name.
  • Upload: drop files into the panel or use the upload button to add them to the active tab. You can also paste a copied file (⌘V / Ctrl+V) while the library is open; pasted files go to Video.
  • Generate: click the sparkles control in the header to expand or collapse the AI image composer. Media generated while editing is added to Video.
  • Save for reuse: open the menu for an item under Video, then choose Save to personal or Save to team. The original stays under Video, and you can save it to both libraries. If it is already saved in that destination, Tella shows Already saved to Personal or Already saved to Team.
  • Move between libraries: for an item under Personal or Team, open its menu and choose Move to team or Move to personal.
  • Rename, download, or delete: open a tile’s menu to manage it.

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Generate media with AI

At the top of the Media Library panel, the Generate section lets you create an image with a prompt:
  1. Describe what you want in the prompt box, e.g. “a soft pastel gradient with abstract shapes” or “a person typing on a laptop, warm lighting.”
  2. (Optional) Click the photo icon at the bottom-left of the prompt box to add a reference image. Tella uses it as visual inspiration. You can upload a PNG, JPEG, or WebP up to 10 MB. The selected reference image appears as a thumbnail inside the prompt composer. Click the × to remove it. Use the ⋯ menu next to the photo icon to pick Current image as reference and iterate on whatever’s already in the slot.
  3. (Optional) Open the ⋯ menu next to the photo icon and choose an option under Image model:
    • Sunburst · Best quality: the default and most capable model, with the most precise reference-image matching.
    • Flare · Faster: choose this for faster image generation.
  4. Click Generate. The new item appears as a placeholder while it’s processing and turns into a real tile when it’s done.
Media generated while editing is added to the current video’s Video tab. To reuse it in other videos, open its menu and choose Save to personal or Save to team.

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Combine media with layout styles

Media works with all of Tella’s layout styles, so you can stage it however you like:
  • Camera Bubble: your media (or screen) fills the frame with the other slot as a small bubble in a corner.
  • Side-by-side: the two slots split the frame.
  • TV Presenter: one slot takes the spotlight with the other floating alongside.
  • Screen only / Camera only: show just one slot, full-frame.
Change the style under Customize layout to keep the attached media where the new style supports it. Picking an ordinary preset or preset favorite from the main Layout picker clears the section’s media and source overrides. On camera-only, screen-only, and uploaded clips, Media favorites keep media in the slots their layouts support. Saved custom layouts also keep media in supported slots.

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Save and reuse a Media layout

You can favorite a Media preset from the Layout picker or use Add to favorites in Customize layout. The saved layout appears under Favorites for compatible clips. To save your own arrangement instead, use Save as favorite in Customize layout. On camera-only, screen-only, and uploaded clips, select a Media favorite to reuse its arrangement. If the section has no media yet, Tella opens the Media Library so you can choose an item; canceling leaves the section unchanged. If the section already has media, the favorite changes its arrangement without replacing the item. On screen-and-camera clips, a favorited Media preset behaves like the matching ordinary preset favorite: applying it clears the section’s media instead of opening the Media Library or preserving existing media. After you change a two-slot Media layout in Customize layout—for example, by turning off Fullscreen—the Media tile remains selected and previews the current arrangement.

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Add effects to media

When media is in a layout’s Screen slot, you can apply zooms, blurs, and highlights to it from Effect. This also works on camera-only clips during sections where media fills the Screen slot.
  • Zooms on media use Manual mode because image and video B-roll does not include recorded cursor data.
  • Blurs and highlights stay attached to the media and end when it leaves the Screen slot.
  • Media in the Camera slot is not affected.
See add zooms and screen effects and blur or highlight part of your video for step-by-step instructions.

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Use media across multiple sections

Because each layout section has its own sources, you can cut between camera and different B-roll throughout a clip. A common pattern:
  1. Start the clip on your base layout (just you and your screen recording).
  2. Add a section, set Screen → Media, and pick a product screenshot.
  3. Add another section later in the clip. This time try Camera → Media for a quick inset cutaway over your screen.
  4. The base layout continues between sections, so you cut back to yourself in between.
Transitions between sections work the same as for any multi-layout video. See Multi-layouts for how to adjust them.

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Add the same media in multiple places

You can add one Media layout and media item to several timeline ranges or layout sections at once when the currently active layout section doesn’t already contain media.
  1. Open the Layout panel.
  2. Select your targets:
    • Drag across one time range, then hold Shift while dragging each additional range.
    • Or hold Cmd on Mac or Ctrl on Windows while clicking the layout sections you want to change.
  3. Choose a Media layout.
  4. Pick an item from the Media Library or upload a new image or video.
Tella applies the layout and media to every eligible selected target in one action. Selected ranges shorter than 0.2 seconds are skipped. If every selected range is too short and no layout sections are selected, Tella doesn’t create a Media section. If you choose a video that is shorter than a selected section, that section shortens to match the available media.
Canceling the Media Library or an upload that fails leaves your selected ranges and sections unchanged.
If the active section already contains media, choosing a Media layout changes the selected sections’ arrangement instead of opening the Media Library for bulk replacement. Use Browse media to replace existing media one section at a time.

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Auto Layouts and media

Auto Layouts can add image B-roll automatically based on what you’re saying. When you generate auto layouts, Tella may insert media sections with AI-generated images that match the content of your clip. You can swap, regenerate, or remove any of these the same way you’d edit any other media section.

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Tips

  • Match your aspect ratio. Tella will fit your media to the layout’s frame, but media shot or generated in the same orientation as your canvas (landscape, portrait, square) looks best.
  • Keep B-roll short. Cutting to media for 2–5 seconds at a time keeps the pace lively.
  • Reuse media across videos. Save an item from Video to Personal or Team so it is available in other videos without re-uploading or re-generating it.
Last modified on October 2, 2026