What an AI video generator actually does
A video model takes a description and any pictures or clips you attach, and predicts a sequence of frames. It has no memory between runs, so nothing carries over from your last take unless you attach it again. That one fact explains most of the craft: reference pictures, character sheets and shared frames are all ways of giving the model what it cannot remember.
Most products you will come across fall into three groups, and it helps to know which one you are buying:
- Models such as Kling 4.0, Seedance 2.5, Wan 3.0 and Veo 3.1. These do the generating. We compare the four here.
- Platforms and resellers such as fal, Higgsfield and Atlas Cloud. They sell access to many models, and the same model can cost twice as much on one as on another.
- Editors and avatar tools such as CapCut, Canva, InVideo, HeyGen and Synthesia. They wrap generation in templates, timelines or presenters. Our roundup lists what each offers.
Five ways to generate, and when to use each
The input you start from matters more than the brand name. This is how we choose:
| Method | You give it | Use it when | Weak spot |
|---|---|---|---|
| Text to video | A written prompt | You are exploring an idea and no exact look is required | Faces, places and brand details change from run to run |
| Image to video | A picture, sometimes a last frame too | You have approved the look and want it to move | A weak picture produces a weak shot |
| Reference to video | Several pictures, each with one job | The same person, product or place has to return in other shots | More references can mean less control |
| Video to video | A clip plus pictures or instructions | The motion is right and what is in the frame is wrong | Some tools re-generate the performance instead of keeping it |
| Avatar and lip sync | A photo or clip, plus a voice | A person has to speak on camera | Gestures are invented, or the mouth softens |
Text to video: when words are enough
Text-only generation is the quickest way to try an idea and the least reliable way to finish one. We rarely use it for delivered work, because each run invents a new person and a new place. It is still useful for mood tests, B-roll with no recurring subject, and finding out what a model does with a sentence.
A prompt that works names things in this order: format and length, subject, setting, one camera move, light, then sound. Keep to one action per few seconds. When we asked for a whole comedy scene in 8 seconds, the models dropped some beats and reordered others. When we asked for a big camera move in a short shot, the camera swung overhead in under two seconds, because that was the only way to fit the path into the time.
The route from an idea to a finished film
- Split the idea into shots. Write one line per shot: what happens, how long it runs, and what the viewer must notice. Most AI shots work better at 3 to 6 seconds.
- Approve pictures before any video. Pictures cost cents and video costs dollars. Edit the last approved picture and change one thing per request. In our test, that took 8 requests where an ordinary chat had taken 26 messages and 33 pictures.
- Make sheets for whatever repeats. Characters, products and locations each get a reference. Here is how we keep them consistent.
- Test on a short, cheap run. Draft at 720p or lower while the prompt is still changing. Our talking-head test used a five-second piece of a 48-second clip before paying for the whole length.
- Generate takes and judge them. Crop faces at full size. Play edits beside the source. Keep the good seconds even from takes you reject.
- Assemble, then add sound and captions. Connecting scenes has its own traps, mostly at the joins.
- Upscale last, and only if it helps. 4K and 60 fps can expose generated footage.
For a sense of what this looks like when finished, One Prompt Studio came from a single 30-second generation, and the Lisbon AI week promo was cut from five shots made on three different models.
What it costs and how long it takes
On a pay-as-you-go API, 5 seconds at 1080p runs from $0.40 to $5.69 at list price. Thirty seconds on Wan 3.0 is $6.00 for one take, which is why we built a cost estimator that counts retakes and your own time. Generation itself ranges from about 20 to about 66 seconds of waiting per second of video on the setup we logged. The timing data is here.
Should you make it yourself or hire someone?
Make it yourself when you can spend the time, the look can vary, and a few bad seconds will not hurt anyone. Our workshops teach exactly that. Hire when a brand, a product or a real person has to look right in every shot and the deadline is fixed. That is what our production service is for, and this guide to AI ads shows how the work runs.
A note on AI music videos
We have not produced an AI music video, so we will not rank tools for it. The techniques that transfer are the ones above: sheets for the performer, short shots cut to the beat, and picture before video. A full music video also has longer continuity demands than the short films in our portfolio, so test one verse before committing to a whole song.
From idea to export in one place
I am building easyai.video so that references, takes and the edit stay together while the models change underneath. It is in final development. Join the waitlist and I will tell you when it opens.
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