Tutorial · Alerts

Creating a jumpscare video for Stream To Earn

Create a short video with a transparent background, upload it in Stream To Earn, set it as an alert trigger, and make it interrupt the screen. Works on any Pro or Expert tier.

CapCut timeline showing a green-screen zombie clip ready for chroma key removal
Overview

The full workflow

Eight steps from “I have an idea for a scare” to “the alert is live on stream”.

01Generate a short video on a green screen
02Open it in CapCut
03Remove the green background with Chroma Key
04Export from CapCut as MOV with RLE codec
05Convert the MOV to WebM using CloudConvert
06Upload the WebM in Stream To Earn
07Set it as an alert trigger with Screen: Interrupt
08Delete the large MOV after the final WebM works
Part 01

Generate the video

Use any AI video generator that can produce a short clip from text or an image — Gemini/Veo, Runway, Kling or whatever you already pay for. The only thing that really matters is that the generated video has a clean green-screen background.

Recommended source video
  • Duration: 2–5 seconds
  • Format: MP4 is fine
  • Background: flat bright green
  • Subject: one clear character or object
  • Motion: simple and readable
  • Camera: simple movement or locked
  • No text, logos, scenery, floor, shadows or detailed background
Example prompt 1 A scary creature stands in front of a perfectly flat bright green screen. The background is evenly lit with no shadows, no floor, no objects, and no scenery. The creature suddenly moves toward the camera in one short dramatic motion. Short 4 second video, 16:9, clear subject, simple camera, no text, no logo. Example prompt 2 A creepy mask-like face is centered in front of a clean bright green screen. The face stays still for a moment, then quickly rushes close to the camera. The green screen background stays flat and uniform. Short 3 second clip, 16:9, no environment, no props, no text.
Prompt tips
  • Say “flat bright green screen”
  • Say “evenly lit”
  • Say “no shadows on the background”
  • Keep the action simple
  • Avoid complex scenes — they make background removal harder
  • If the subject has green clothing, green skin or green glow, change it — Chroma key may remove those parts too
Part 02

Remove the green background in CapCut

Three CapCut timeline states: enable Chroma Key, pick green color, adjust intensity until the green disappears
Enable Chroma Key → pick green color → adjust intensity
Steps
  1. Open CapCut and create a new project
  2. Import the generated video
  3. Drag the video to the timeline
  4. Select the clip
  5. In the right-side panel, go to Video
  6. Open Remove BG
  7. Enable Chroma key
  8. Use the color picker and click the green background
  9. Increase Intensity until the green background disappears
  10. Keep Shadow at 0 unless you specifically need to adjust it
Intensity
~60
Shadow
0
What you should see
  • The green background disappears
  • CapCut may show the removed background as black in preview — that's normal
  • The subject should remain visible and have no holes
  • There should be little or no green outline around the subject
If green is still visible
  • Increase Intensity
  • Pick a different green area with the color picker
  • Regenerate the source video with a cleaner flat green background
If parts of the subject disappear
  • Lower Intensity
  • Avoid subjects that contain green colors
  • Regenerate with a more separated subject and background
Part 03

Export from CapCut with transparency

This step is important. A normal MP4 export usually does not preserve transparency, which is why we route through MOV + RLE first.

CapCut export dialog showing MOV format with the RLE codec selected and the alpha channel hint visible
CapCut export dialog with MOV format and RLE codec selected
Export settings
  1. Click Export
  2. Set a clear file name, e.g. zombie-face-burst
  3. Set resolution to 1080P or the source resolution
  4. Open the codec dropdown
  5. Choose RLE
  6. Make sure the export format is MOV
  7. Export the video
Why MOV + RLE?
  • It preserves the alpha channel (transparency)
  • The file will be large — that's normal
  • This file is only a temporary conversion file
Heads up

Do NOT upload the MOV to Stream To Earn

Convert it to WebM first using CloudConvert (next step).

Part 04

Convert MOV to WebM with CloudConvert

Open cloudconvert.com/mov-to-webm — that's the converter we use.

Three CloudConvert screens: homepage, file uploaded showing MOV to WebM, and conversion in progress
CloudConvert homepage → file uploaded → converting
Conversion steps
  1. Open cloudconvert.com/mov-to-webm
  2. Click Select File
  3. Choose the exported CapCut .mov file
  4. Confirm the page says MOV to WEBM
  5. Click Convert
  6. Wait for upload and processing
  7. Download the final .webm
File size

The final WebM file should be much smaller than the MOV. That's normal — WebM uses efficient compression.

Preview check

After conversion, preview the WebM if possible. Check that the background is transparent and not a black or green rectangle.

After conversion

Once the WebM is confirmed working, delete the large MOV. Keep only the final WebM unless you need to edit or reconvert later.

Part 05

Upload to Stream To Earn

Upload steps
  1. Open Stream To Earn
  2. Go to the Alerts tab
  3. Upload the final .webm video
  4. Set it as a trigger
  5. Set the Screen parameter to Interrupt
  6. Save the alert
  7. Run a test trigger
Expected result
  • The alert appears over the stream / game
  • The video interrupts the screen
  • The background is transparent
  • Audio from the WebM works (Stream To Earn supports audio inside uploaded overlay videos)

Recommended final asset

Format
WebM
Background
Transparent
Audio
Allowed
Duration
2–5 s
Resolution
1080p / 720p
Screen param
Interrupt
Troubleshooting

Common problems

Six things that go wrong most often, and how to fix each one. Click to expand.

Black rectangle behind the video+
The alpha channel was lost. Re-export from CapCut as MOV + RLE, then convert again to WebM.
Green background still visible+
The chroma key was too weak. Return to CapCut, increase Intensity, or pick the green color again.
Green outline around the subject+
The key is almost correct but not strong enough. Slightly increase intensity or regenerate with cleaner lighting.
Subject has missing parts+
The key is too strong, or the subject contains green. Lower intensity or regenerate with different subject colors.
MOV file is huge+
That's normal. MOV with RLE is only an intermediate file — delete it after the WebM is ready.
WebM has no audio+
Make sure audio was included during CapCut export and CloudConvert conversion. Silent output usually means audio was lost earlier.
Short checklist

Before you go live

Tick these off and you're done.

  • Source video has a clean green background
  • CapCut Chroma Key removed the green
  • Export is MOV
  • Codec is RLE
  • Converted final file is WebM
  • Final WebM has a transparent background
  • Final WebM includes audio if needed
  • Uploaded in Alerts
  • Set as a trigger
  • Screen is set to Interrupt
  • Large MOV deleted after conversion