Vidu Q3 API

Introduction

Vidu Q3 image-to-video turns one opening frame and a written brief into a clip of 1 to 16 whole seconds at 540p, 720p or 1080p. Both inputs are required: image_url fixes the subject, wardrobe, set and the shape of the output, and prompt carries what happens after that frame – the action, the camera move and the sound. There is no aspect ratio field, so the clip comes back in the proportions of the image you send, which must stay between 1:4 and 4:1. Audio is generated in the same pass and is on by default.

Key features

The frame is followed literally

The model starts from exactly what the still shows: the face, the outfit, the set and the composition. The flip side is that anything the frame does not show has to be invented, so a turn that reveals the back of an outfit, or a camera move into a part of the room outside the still, is where drift appears.

Movement scale is its own control

movement_amplitude takes auto, small, medium or large. On auto the model reads the opening frame and decides; raise it when a still scene needs to move more, and keep it low when the brief rules motion out. In the published blinds example nothing moves but the light, and a high setting would invent exactly the movement that brief excludes. The prompt is then free to name the specific beat – a shift of weight, a half turn, a walk out of frame.

Sound in the same pass

generate_audio defaults to true, so room tone, foley and ambience are rendered with the picture and land in sync. Describe the sound in the prompt the way you describe the light – sea roar and wind, a curtain breathing – and set the field to false when the clip is going under your own mix.

Request parameters

Pricing

Prices are in credits, the same credits you use on the website (1 credit = $0.01). The hold is taken when the task is accepted and settled to the actual charge when it finishes; failed tasks are refunded.

Each task is rounded up to whole credits, so one run at the lowest tier costs 53 credits for a 5-second clip ($0.53).

For an exact number before you run, send the same body to POST /jobs/quote.

Use cases

Approved stills that must not drift

A campaign photo, a character sheet or a storyboard frame that has been signed off stays the anchor. Because the clip starts from it, the face, wardrobe and set carry through, and the review narrows to one question: does the movement work? Put big reveals into the still rather than asking the prompt to invent them.

One scene, vertical and widescreen

The output takes the frame's shape, so a 9:16 crop and a 16:9 crop of the same scene give you a story cut and a feed cut without changing any other field. Do the cropping in the image pass, before you upload.

Light-only and atmosphere shots

Some shots need the subjects to hold still while something else changes. The 8-second 1080p example keeps two figures under a white sheet in place while hard blind stripes travel across their shoulders as the sun drops. A prompt that says nothing moves but the light, a restrained movement_amplitude and generate_audio switched off do the work.

Stings and full beats from one endpoint

duration_seconds runs from 1 to 16, so a one-second reaction cut and a sixteen-second scene with a beginning and an end use the same fields.

Prompt guide & pro tips

Prepare the opening frame

Crop the still to the delivery shape first, because the clip inherits it, and keep the ratio between 1:4 and 4:1. Put everything that must appear – subject, wardrobe, set – into the image. The model starts from what the frame shows and has to invent the rest.

Write the movement in order

Describe what happens after the frame in the order it happens – action, camera, light, sound – without re-describing the still. It closes on light and camera: a sheer curtain in the sun, dust in the beam, a slow handheld drift. None of those actions is in the frame; all of them are in the prompt.

Adapt the included example

The published clifftop example runs 5 seconds at 720p, with generate_audio left at its default, from a still of a woman in a white dress above the sea. Keep its structure – one force, several materials, one camera move – and swap in your own subject and setting.

The wind gusts and the long grass runs in waves across the clifftop; her white dress and hair stream sideways and snap. She turns from the sea into the wind toward the camera, catching the hair off her face with one hand and laughing, then spreads both arms and leans into the gust. Gulls cross far below. Slow steadicam arc around her, bright overcast daylight, cool green and pale blue, sea roar and wind.

Wind as the subject: the long grass runs in waves, the dress and hair stream sideways and snap, and a steadicam arcs around her while she leans into the gust. Everything is one continuous force acting on three different materials, which is a harder test of an animated still than a person simply turning round.

Draft at 540p, deliver at 1080p

Iterate at 540p until the motion reads right, then re-run at 1080p with the same frame, prompt and seed, so resolution is the one value that changed. A fixed seed keeps two runs comparable; it does not promise a frame-identical result. When a take drifts, look first at the areas the still never showed – the back of a garment, the edge of the room – and move that reveal into a new opening frame instead of adding more prompt text.

API quick start

Call the Vidu Q3 API in three steps

1. Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow- and use the same credits as the website.
2. Send the request. POST /jobs/createTask with model vidu/q3/image-to-video and an input object that follows the parameter table. The response returns a task ID straight away.
3. Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.

# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "vidu/q3/image-to-video",
  "input": {
    "prompt": "A slow aerial shot drifting over a misty pine forest at sunrise",
    "image_url": "https://media.popnow.ai/influencer/examples/marco.webp",
    "duration_seconds": 5,
    "resolution": "720p",
    "movement_amplitude": "auto"
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.

Vidu Q3 API questions

All Vidu models

Vidu Q4 Preview adds reference scenes, clip extension and output up to 4K, at a lower starting price per second.

• Vidu Q4 Preview APIUp to 4K clips with sound and spoken dialogueFrom 34 credits for a 5-second clip
• Vidu Q3 Turbo APIFast image animation with sound, up to 16 secondsFrom 32 credits for a 5-second clip
• Vidu Q3 APIAnimate a frame for up to 16 seconds at 1080pFrom 53 credits for a 5-second clip
• Vidu Q3 Pro APIAnimate a frame with sound on by default, up to 16 secondsFrom 41 credits for a 5-second clip

Other video APIs

• MiniMax H3 APIExpressive clips with audio, up to 2KFrom 28 credits for a 5-second clip
• Seedance 2.5 APIByteDance's newest: 30-second clips with native audioFrom 56 credits for a 5-second clip
• Kling 3.0 API4K clips, multi-shot cuts and motion controlFrom 51 credits for a 5-second clip
• Wan 3.0 APIUp to 30-second clips with synced audioFrom 34 credits for a 5-second clip
• Kling O3 APIKling’s unified model: create, animate, reference and edit up to 4KFrom 51 credits for a 5-second clip
• MiniMax H3 Max APIFast clips with ambience, effects and musicFrom 38 credits for a 5-second clip

More about Vidu Q3

Try it

Vidu Q3 Image to Video AI onlineCreate videos with Vidu Q3 in PopNow

Docs

Vidu Q3 model ID and input schema in the API docsPopNow API quickstart: your first request in five minutesImage to video guide for the PopNow APIWebhooks: get Vidu Q3 results without polling