MASTER VIDEO-TO-VIDEO CHARACTER REPLACEMENT — JUSTIN BIEBER TO REAL CATVIDEO DURATION: Match the complete original reference video (approximately 12.8 seconds).REFERENCE VIDEO: Use the uploaded video as the absolute reference for every movement, action, facial expression, body motion, camera angle, camera movement, scene transition, lighting condition, background element, and timing.1. MAIN OBJECTIVEReplace Justin Bieber with one realistic, adorable domestic cat while preserving everything else in the original video exactly as it appears.The cat must perform the same actions Justin Bieber performs in the reference video, following the original choreography, body movements, head movements, gestures, poses, expressions, and timing as closely as physically possible.Only replace Justin Bieber with the cat. Do not recreate or redesign the entire video.2. CAT CHARACTERUse a photorealistic domestic cat with natural fur, realistic anatomy, expressive eyes, detailed whiskers, and believable body proportions.The cat must look like a real, live-action cat, NOT a 3D animation, cartoon, illustration, or CGI character.Keep the cat's appearance, fur color, markings, facial features, and body proportions consistent throughout the entire video.Position the cat in the exact location occupied by Justin Bieber in each frame.Match the original subject's size, position, orientation, and movement relative to the camera.Preserve realistic feline anatomy. Adapt human gestures into visually convincing cat movements wherever necessary, without changing the intended action.Keep the cat naturally integrated into the original footage, with matching lighting, shadows, perspective, reflections, and motion blur.3. EXACT ACTION AND MOTION MATCHINGAnalyze the entire reference video frame by frame before generating the replacement.Reproduce the original sequence of actions in precisely the same order.Match every movement and pose to the corresponding moment in the reference.Replicate head turns, body movements, gestures, changes in direction, and pauses.Match the original rhythm and movement timing to the music.Preserve the original subject's position and movement trajectory.Ensure the cat does not introduce extra actions, random movements, unnecessary jumps, additional gestures, or unrequested expressions.Do not skip, extend, shorten, or rearrange any action.Maintain temporal consistency between consecutive frames.The result should feel like the original video was filmed with a real cat performing the same scene instead of Justin Bieber.4. PRESERVE THE ORIGINAL AUDIO AND SONGKeep the original audio track completely unchanged.Retain the exact original song and background music.Preserve the original vocals, lyrics, instrumental arrangement, rhythm, beat, and audio timing.Do not replace, remix, regenerate, or modify the music.Do not add meowing, purring, sound effects, dialogue, or additional audio.Keep the audio synchronized with the original video from beginning to end.The original soundtrack must remain intact.5. BACKGROUND AND ENVIRONMENT LOCKPreserve the original environment exactly as shown in the reference footage.Keep the same background, location, scenery, objects, and surrounding details.Preserve the original colors, lighting, shadows, atmosphere, and depth of field.Do not add, remove, or replace background objects.Do not change the environment to a different room, location, or setting.Do not introduce additional animals, people, props, or visual elements.Only the main subject should change from Justin Bieber to the cat.6. CAMERA AND COMPOSITION LOCKFollow the original camera work exactly.Preserve every original camera angle, shot size, framing, and perspective.Match all original camera movements, pans, tilts, zooms, and transitions.Maintain the original distance between the camera and the subject.Do not introduce additional zoom-ins, zoom-outs, camera shakes, pans, tilts, or reframing.Do not move the cat independently of the original subject's movement.Keep the original composition consistent throughout the video.The camera must follow the reference video, not invent new movements.7. VISUAL QUALITY AND REALISMGenerate a seamless, photorealistic video replacement.Natural, detailed cat fur.Realistic feline anatomy and proportions.Consistent character identity across all frames.Smooth, temporally consistent movement.Accurate subject placement and perspective.Natural contact shadows and environmental lighting.No flickering, warping, morphing, ghosting, duplicated body parts, or inconsistent fur patterns.No artificial transitions or changes in visual style.No subtitles, captions, watermarks, logos, or additional text.The cat must look as though it genuinely belongs in the original footage.8. STRICT PRESERVATION RULESThe following elements must remain unchanged:Original song and audio track.Original background and environment.Original sequence of actions.Original action timing and rhythm.Original camera angles and movements.Original scene transitions and editing.Original lighting, color grading, and visual atmosphere.Original video composition and framing.The ONLY intended change is replacing Justin Bieber with a realistic cat that follows the original performance as closely as possible.9. NEGATIVE PROMPTCartoon cat, animated cat, 3D character, CGI appearance, human face on cat, human body on cat, anthropomorphic character, unrealistic anatomy, inconsistent fur, changing cat identity, extra limbs, missing limbs, distorted paws, floating body, incorrect movement, random gestures, altered choreography, incorrect timing, extra actions, missing actions, camera shake, unwanted zoom, unwanted camera movement, changed background, new location, altered lighting, scene redesign, additional characters, additional objects, changed music, remixed audio, added sound effects, subtitles, text overlays, flickering, jitter, ghosting, frame distortion, morphing, unnatural motion, abrupt cuts.FINAL INSTRUCTIONTreat the uploaded reference video as the single source of truth. Preserve its original visual sequence, soundtrack, timing, camera work, environment, and editing. Replace Justin Bieber with one realistic domestic cat and reproduce the original performance as closely as possible.Do not invent anything. Do not change anything unnecessarily. Do not modify the original soundtrack. Keep everything the same except the main character replacement.