Avisynth+ 3.7.5 / 3.7.6 Beta
AviSynth+ is the modernized fork of the legendary AviSynth frameserver, built to meet the demands of today's video encoding workflows.
Rather than working through a traditional graphical interface, AviSynth+ processes video through plain-text scripts that you write in any text editor and save as .avs files.
This script-driven approach unlocks a level of precision, repeatability, and batch processing power that no conventional video editor can match.
If you have ever needed to apply the same filtering chain across hundreds of video files, automate complex deinterlacing and denoising routines, or feed precisely processed frames into an encoder like x264 or x265, AviSynth+ is the tool that makes it possible.
How AviSynth+ Frameserving Works
The "frameserver" concept is central to how AviSynth+ works. Your script describes a sequence of operations - loading a source, applying filters, resizing, color correction - and AviSynth+ serves the resulting frames on demand to whatever application requests them.
That application might be VirtualDub2 for visual preview and quick edits, StaxRip for batch encoding to H.264, HEVC, or AV1, or FFmpeg for command-line processing pipelines.
The beauty is that no temporary files are created during processing - AviSynth+ generates frames in real time, saving disk space and dramatically speeding up complex workflows.
64-Bit Support, Multithreading, and Deep Color
AviSynth+ brings major improvements over the original AviSynth. Full 64-bit support means you can work with large files and allocate more memory for demanding filter chains. Native multithreading distributes processing across all available CPU cores, turning what used to be single-threaded bottlenecks into parallel operations.
Deep color space support handles 10-bit, 12-bit, 14-bit, and 16-bit video natively - essential for HDR content and professional color grading workflows.
The scripting language itself has been extended with loops, multiline conditionals, and array support, making complex automation scripts much easier to write and maintain.
What's New in Version 3.7.5 and 3.7.6 Beta
Version 3.7.5 delivers stability fixes for non-Intel platforms including ARM64 (aarch64), resolves a YtoUV crash regression, and updates the interface to v11.1 with proper 64-bit data member declarations.
The 3.7.6 beta pushes further with new filters like MultiOverlay for bulk compositing, enhanced Animate functions with custom function support and 64-bit input, improved resizer behavior that respects ChromaLocation frame properties, and expanded AVX-512 and ARM NEON CPU flag support. Cross-platform compatibility now extends to Linux, macOS, Haiku, and even Raspberry Pi builds.
GUI Front-Ends and Companion Tools
The real power of AviSynth+ emerges through its ecosystem of companion tools. MeGUI was designed from the ground up around AviSynth, providing a comprehensive GUI for DVD ripping and transcoding workflows that lean on .avs scripts for all video processing.
StaxRip similarly integrates AviSynth+ as its filtering backbone, letting you build encoding profiles that chain together source loading, noise reduction, resizing, and output encoding in a single portable package. AVSGenie provides a dedicated script editor with real-time preview, making it easier to experiment with filter parameters before committing to a full encode.
Previewing Scripts and Playback
For users who prefer visual feedback while building scripts, loading your .avs file into VirtualDub or VirtualDub2 gives you frame-by-frame preview with the ability to scrub through the timeline.
You can check deinterlacing results, verify crop coordinates, and confirm color adjustments before sending the script to your encoder of choice. Any DirectShow-compatible media player can also open .avs files directly - MPC-HC and VLC Media Player both work, though dedicated preview in VirtualDub2 remains the preferred approach.
Codec Requirements and Source Filters
AviSynth+ depends on having the appropriate codecs installed on your system for source file decoding.
Installing the K-Lite Codec Pack or LAV Filters ensures broad format compatibility when loading source files through DirectShowSource. For MPEG-2 DVD sources, the VirtualDub-MPEG2 plugin expands format support.
Modern workflows increasingly use LSMASHSource or FFmpegSource2 plugins instead, which handle virtually every container and codec format without relying on DirectShow at all.
From Script to Encoded Video
Once your script produces the filtered output you want, the encoding stage connects AviSynth+ to the broader video compression ecosystem.
Pipe frames directly to x264 for universally compatible H.264 output, x265 for efficient HEVC compression at half the file size, or leverage GPU-accelerated encoding through NVEnc on NVIDIA hardware. For cutting-edge AV1 output, front-ends like StaxRip connect AviSynth+ scripts to SVT-AV1 seamlessly.
After encoding, MKVToolNix handles muxing your encoded video with audio tracks and subtitles into a clean MKV container.
Learning Curve and Community
AviSynth+ is not the easiest tool to learn - there is no getting around the fact that you are writing code rather than dragging sliders. But for anyone processing video at scale, building reproducible encoding pipelines, or needing filter combinations that no GUI editor offers, the scripting approach is unmatched.
The active community at the Doom9 forums maintains hundreds of third-party plugins covering everything from AI-powered upscaling to advanced temporal noise reduction, ensuring AviSynth+ continues to evolve alongside modern video technology.
System Requirements
AviSynth+ runs on Windows XP through Windows 11 (32-bit and 64-bit), with additional builds available for Windows ARM64, Linux, and macOS (Intel and Apple Silicon).
The installer is 8.2 MB and requires the Microsoft Visual C++ Redistributable. A portable version is also available for users who prefer not to modify their system registry.
