Get free AI-based frame interpolation tool Flowframes
Before and after: animation processed with video interpolation software Flowframes. The free tool promises to speed up 3D workflows by generating missing frames for animations rendered as alternate frames.
Tools developer NMKD Software has released Flowframes, an interesting free AI-based tool for interpolating between frames of a video to increase its frame rate.
The software, which runs on AMD, Intel and Nvidia GPUs, has been available for a couple of years, and was initially mainly used to retime footage during video editing, or simply to improve old, low-quality videos.
However, recently we’ve begun to see posts on community forums from artists using it to speed up 3D workflows by rendering alternate frames of an animation, then using it to interpolate the missing frames.
GPU-accelerated on Nvidia, AMD or Intel hardware
Flowframes takes advantage of a recent wave of mathematical models for video frame interpolation: mainly RIFE (Real-Time Intermediate Flow Estimation), but also the older DAIN and experimental FLAVR and XVFI.
Although the underlying tech is open-source, Flowframes provides a streamlined GUI to control interpolation, and unlike some similar tools, is free to use, although you can support development on Patreon.
RIFE uses Nvidia’s CUDA API for GPU compute, but the others use the open Vulkan API, and run on AMD, Intel and Nvidia GPUs – although, according to the Flowframes FAQs, RIFE is around 2x faster.
Supports standard movie formats and image sequences
The software can import and export video in a range of standard formats, including MP4, MKV, WEBM and MOV, and export in AVI format or using the VP9 and H.265/HEVC codecs for export.
You also import or export image sequences in JPEG or PNG format.
Flowframes includes scene detection features to avoid artefacts at cuts, and preserves audio and subtitles.
Works for both video editing and 3D rendering workflows
That makes Flowframes a possible alternative to commercial video retiming tools like RE:Vision Effects’ Twixtor for editing and post-production work.
However, we’ve also recently seen posts on community forums that suggests it also works pretty well to speed up 3D workflows in a way analogous to using a render denoiser.
Rather than rendering with lower sampling settings, then using a denoiser to remove the remaining noise, users can render alternate frames of an animation, then use Flowframes to generate the missing frames.
For further time savings – although, obviously, also greater risk of artefacts – you can even render at lower resolution, then upscale the frames with a tool like Topaz Labs’ Gigapixel AI before interpolation.
And even if the result isn’t final-quality output, it looks a handy way of generating quick animation tests.
Pricing and system requirements
Flowframes is available for Windows 10+. It requires either a Nvidia GeForce GTX 750 Ti GPU or newer for CUDA acceleration, or a Vulkan-capable GPU: “anything younger than 6 years should work”.
The software is free to download from itch.io, but to get the latest version (or just to support the project), you will need to back the developer on Patreon.