{"servers":[{"url":"https://api.modellix.ai/api/v1/bytedance/seedance-2.5-v2v"}],"post":{"description":"[Core Function] Seedance 2.5 V2V is ByteDance Dreamina Seedance 2.5 video-to-video generation covering multimodal reference, video editing, and video extension. [Strengths] It accepts up to 10 reference videos, 30 reference images, and 10 audio clips, with 4-30 second output and mp4 or mov containers. [Best For] Highly recommended for: editing existing clips, extending motion from a base video, multi-reference restyling, and prompt-driven composition that cites Video n or Image n. [Limitations] Do NOT use this model for text-only or first-frame-only workflows. video_urls is required. Do NOT send first_frame_image or last_frame_image. Do NOT use this model when the user requires 1080p or 4k output. Do NOT use this model for audio-only input. [Routing] Prefer this model for Seedance 2.5 edit, extension, and video-reference jobs. Use Seedance 2.5 T2V for text-only and Seedance 2.5 I2V for image-first generation.","operationId":"seedance25V2vAsync","requestBody":{"content":{"application/json":{"examples":{"edit":{"summary":"Video editing (source-master object replacement)","value":{"duration":8,"generate_audio":true,"output_format":"mov","prompt":"[Video 1] is the sole source and timeline master. It shows one table lamp beside an actor. [Image 1] defines the replacement lamp only: aged brass stem, green glass shade, short pull chain, and the exact proportions shown in the image. Replace only the single lamp in [Video 1] with the single lamp from [Image 1]. The replacement must follow the original lamp's position, scale, perspective, occlusion, reflections, light interaction, and visibility over time. Preserve the actor, table, room, camera, edit, motion, dialogue, and ambience. Exactly one lamp; no duplicate shade, no extra furniture, no change to the actor's hands.","reference_images":["https://example.com/replacement_lamp.jpg"],"video_urls":["https://example.com/edit_input.mov"]}},"extension":{"summary":"Video extension with reference images","value":{"duration":12,"generate_audio":true,"prompt":"[Image 1] defines the curator's face and charcoal suit. [Image 2] defines the display case. [Video 1] is the source: it begins with the curator's right hand already touching the case. Extend 6 seconds before [Video 1]. The curator walks from the left aisle toward the same case, slows, turns her shoulders toward it, and raises her empty right hand. End the extension with her fingertips about to make contact in the same pose, direction, framing, and light as the first source frame. The artifact visible inside the source case must not appear outside it, and no second curator or second case may appear. Use quiet gallery room tone and measured footsteps in the new segment, then match the source audio naturally at the boundary. Do not alter the source segment or its original audio.","reference_images":["https://example.com/curator_identity.jpg","https://example.com/display_case.jpg"],"resolution":"720p","video_urls":["https://example.com/source_curator_case.mp4"]}},"multimodal":{"summary":"Video with reference images","value":{"duration":10,"output_format":"mp4","prompt":"Restyle [Video 1] using the look of [Image 1]","reference_images":["https://example.com/style.jpg"],"video_urls":["https://example.com/clip.mp4"]}}},"schema":{"description":"video_urls is required (1-10). Optional prompt, reference_images (up to 30), and audio_urls (up to 10). First/last frame parameters are not supported.","properties":{"audio_urls":{"description":"Optional reference audio URLs (1-10). Must accompany video_urls","example":["https://example.com/bgm.mp3"],"items":{"format":"uri","type":"string"},"maxItems":10,"minItems":1,"type":"array"},"camera_fixed":{"default":false,"description":"Whether to keep the camera fixed during generation","example":false,"type":"boolean"},"duration":{"default":5,"description":"Video duration in seconds. Allowed values are integers from 4 to 30","enum":[4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30],"example":5,"type":"integer"},"execution_expires_after":{"default":172800,"description":"Task expiration time in seconds","example":172800,"maximum":259200,"minimum":3600,"type":"integer"},"generate_audio":{"default":true,"description":"Whether to generate an audio track with the video","example":true,"type":"boolean"},"output_format":{"default":"mp4","description":"Output video container. mp4 for general playback; mov for higher color precision in editing workflows","enum":["mp4","mov"],"example":"mp4","type":"string"},"prompt":{"description":"Optional editing, extension, or generation instruction. You may cite media with placeholders such as [Image 1], [Video 1], or [Audio 1]. For editing, declare [Video 1] as the sole timeline master, name the edit scope, and list what must be preserved. For extension, define how the new segment connects at the source boundary. Maximum 10000 characters","example":"[Video 1] is the sole source and timeline master. Replace only the single lamp in [Video 1] with the lamp from [Image 1]. Preserve the actor, room, camera, motion, and original audio.","maxLength":10000,"minLength":1,"type":"string"},"ratio":{"default":"16:9","description":"Specifies the aspect ratio for the generated video","enum":["21:9","16:9","4:3","1:1","3:4","9:16"],"example":"16:9","type":"string"},"reference_images":{"description":"Optional reference image URLs (1-30)","example":["https://example.com/style.jpg"],"items":{"format":"uri","type":"string"},"maxItems":30,"minItems":1,"type":"array"},"resolution":{"default":"720p","description":"Specifies the resolution tier for the generated video. Seedance 2.5 supports 480p and 720p only","enum":["480p","720p"],"example":"720p","type":"string"},"return_last_frame":{"default":false,"description":"Whether to return the last frame of the generated video","example":false,"type":"boolean"},"seed":{"default":-1,"description":"Random number seed for reproducibility. Use -1 for random. Identical seeds cannot guarantee completely identical results","example":-1,"maximum":4294967295,"minimum":-1,"type":"integer"},"video_urls":{"description":"Required reference video URLs (1-10) used as edit source, extension base, or multimodal references","example":["https://example.com/edit_input.mov"],"items":{"format":"uri","type":"string"},"maxItems":10,"minItems":1,"type":"array"}},"required":["video_urls"],"type":"object"}}},"required":true},"responses":{"200":{"content":{"application/json":{"schema":{"properties":{"code":{"description":"Response code, 0 indicates success","example":0,"type":"integer"},"data":{"description":"Detailed data about the submitted asynchronous task.","properties":{"get_result":{"description":"API information to query the task result","properties":{"method":{"description":"HTTP method","example":"GET","type":"string"},"url":{"description":"Full URL to query the task result","example":"https://api.modellix.ai/api/v1/tasks/task-abc123","type":"string"}},"type":"object"},"model_id":{"description":"Model ID","example":"model-123","type":"string"},"status":{"description":"Task status","enum":["pending","processing"],"example":"pending","type":"string"},"task_id":{"description":"Unique task identifier","example":"task-abc123","type":"string"}},"required":["status","task_id","model_id"],"type":"object"},"message":{"description":"Response message","example":"success","type":"string"}},"required":["code","message","data"],"type":"object"}}},"description":"Task submitted successfully"}},"summary":"Seedance 2.5 V2V","x-mint":{"href":"bytedance/seedance-2-5-v2v"}}}