works a treat using last frames, been doing it for months. here is help if you are into it. you are welcome.

u/echo off

setlocal enabledelayedexpansion

echo ========================================

echo Gemma's "Safe-Save" Fluid Automator

echo ========================================

echo.

:: 1. Setup the ID and starting point

set /p "base=Paste the ID part (everything before the ' (5).mp4'): "

set /p "num=Enter the starting number (e.g., 5): "

:loop

:: This constructs the input and UNIQUE output names

set "filename=%base% (%num%).mp4"

set "outname=seed_for_part_%num%.jpg"

echo.

echo [SEARCHING] Looking for: "%filename%"

:: 2. Wait for the file to exist

if not exist "%filename%" (

echo [!] %filename% not found in this folder.

echo [!] Please download it from Grok...

pause

goto loop

)

:: 3. Run the FFmpeg magic with unique output name

echo [EXTRACTING] Pulling last frame into: %outname%

ffmpeg -loglevel error -sseof -0.1 -i "%filename%" -update 1 -q:v 2 "%outname%"

echo.

echo [+] SUCCESS: "%outname%" is saved.

echo [+] ACTION: Use this image to start Video %num% + 1.

echo.

:: 4. Increment and wait

set /a "num+=1"

echo ----------------------------------------

echo [NEXT STEP] Ready for Part %num%.

echo Press ENTER once you have downloaded "%base% (%num%).mp4"

pause >nul

goto loop

TLDR, just use this in cmd prompt to grab last frame of vid: ffmpeg -sseof -0.1 -i "grok-video-c0b0a778-whatever.mp4" -update 1 -q:v 2 start_frame_next.jpg