<p>As a summary of the differences:</p>
<h2>AviSynth</h2>
<ul>
<li><strong>Outdated and no longer recommended for use</strong></li>
<li>Only available in 32bit – not able to use 64bit plugins/filters</li>
<li>No multi-threading (unless you install AviSynth-MT, another fork, which is prone to errors and issues and no updates over last 4+ years)</li>
<li>Older and only supports 8bit video</li>
<li>Lacks support for some color spaces (YV16, YV24 etc.)</li>
<li>Latest release over 4 years ago (May 2016)</li>
</ul>
<h2>AviSynth+</h2>
<ul>
<li>Has both a 32bit and 64bit version, although the 32bit version apparently <a href="http://www.digitalfaq.com/forum/video-restore/9619-advantages-avisynth-vs.html#post60894" rel="nofollow noreferrer">has some issues</a></li>
<li>Supports multi-threading which can significantly improve rendering performance for some functions (similar to AviSynth-MT, another fork, but AviSynth+’s appears more stable)</li>
<li>Be aware that using the 64bit version will require all plugins and filters to also be 64bit – and not all of them have 64bit versions. There are some filters that are 64bit only, however, which means you’re able to use those.</li>
<li>QTGMC runs faster in multi-threaded mode, and also <a href="http://www.digitalfaq.com/forum/video-restore/9619-advantages-avisynth-vs.html#post60894" rel="nofollow noreferrer">apparently</a> in 64bit mode</li>
<li>AviSynth+ specific documentation is limited, but most of the great AviSynth wiki also applies to AviSynth+ and many pages now have notes mentioning any specific instructions for working with AviSynth+.</li>
<li>Also runs on Linux, which is useful when you need to run it on a server</li>
<li>Regularly updated, with latest release Jun 2020</li>
</ul>
<p>Note: be sure to get a recent version of AviSynth+ from <a href="https://github.com/AviSynth/AviSynthPlus/releases" rel="nofollow noreferrer">https://github.com/AviSynth/AviSynthPlus/releases</a>. There was a pinterf fork and it has been merged back to upstream.</p>
<p>Or you can use the <a href="https://www.videohelp.com/software/Universal-Avisynth-Installer" rel="nofollow noreferrer">Universal AviSynth Installer</a> which allows you to easily switch between the different versions of AviSynth, AviSynth-MT, and AviSynth+ (32bit and 64bit).</p>
<h2>VapourSynth</h2>
<ul>
<li>Rewritten to use Python, a much more powerful and flexible scripting language</li>
<li>Multi-threaded</li>
<li>Supports generalized colorspaces whereby new or custom colorspaces can be specified at runtime</li>
<li>Also runs on Linux, which is useful when you need to run it on a server</li>
<li>Documentation isn't as detailed as AviSynth (it's not a community wiki)</li>
<li>Regularly updated, with latest release Aug 2020</li>
</ul>

CC BY-SA 4.0
2019-09-21T15:48:16.287Z
Maybe add VapourSynth info as well.
Gyan
CC BY-SA 4.0
2020-01-11T16:48:24.290Z
Any reason we need a full programming language to configure video filter pipelines?  Was the prior method just missing some unnecessary complexity and bloat, from the perspective of the user?
J. M. Becker
CC BY-SA 4.0
2019-09-21T14:57:06.577Z
2020-08-10T18:40:18.897Z
2020-08-10T18:40:18.897Z
Simon East
<p>There is no reason to use old, obsolete AviSynth — <em>“old-but-still-useful”</em> are almost all programs, but why to complicate your life with old, unsupported versions of them?</p>

<p>Every script for AviSynth works well in the AviSynth+, so even if you know AviSynth, there is nothing to relearn. The opposite is not true, however.</p>

<p><strong>Use AviSynth+</strong> (pros: all, cons: none), particularly <a href="https://github.com/pinterf/AviSynthPlus/releases" rel="nofollow noreferrer">pinterf/AviSynthPlus</a> (forked from already dead AviSynth/AviSynthPlus).</p>

<hr>

<p><em>Note:</em></p>

<p>The other situation is with <em>GUI programs</em> — if the old version satisfied you and the new one is too complicated, with changed menus, new icons, colors etc. </p>

<p>But it is not the case of AviSynth+ — you don't “see” the new commands, functions or parameters, so they don't disturb you.</p>

CC BY-SA 4.0
2019-09-25T06:41:40.983Z
Thanks for the answer. The net is full of old posts referring to AviSynth, and I initially wasn't sure if AviSynth+ was compatible or maintained, but as you've pointed out the pinterf version is both and the best modern version to use. 
Simon East
CC BY-SA 4.0
2019-09-25T10:30:49.427Z
You're welcome.
MarianD
CC BY-SA 4.0
2021-03-22T13:08:18.940Z
AviSynth+ was never dead. There was a coordinated and hickup-free maintainer change to pinterf without development hiatus, and for some reason pinterf decided to use his own repo in the beginning. Now he even changed back to the original repo and so active development is again at its original place at AviSynth/AviSynthPlus on GitHub.
ultimA
CC BY-SA 4.0
2019-09-21T22:38:05.077Z
2019-09-22T04:05:20.557Z
2019-09-22T04:05:20.557Z
MarianD
<p><a href="http://avisynth.nl/index.php/Main_Page" rel="noreferrer">AviSynth</a> is an old-but-still-useful tool for processing video via script, but I’ve noticed that there is a fork called <a href="http://avs-plus.net" rel="noreferrer">AviSynth+</a> that appears to have some improvements. And then there’s VapourSynth rewritten to use Python. </p>

<p>What are the pros and cons of these versions?</p>

<p>For use-cases such as QTGMC deinterlacing and high-quality resizing, is one clearly better than the other?</p>

CC BY-SA 4.0
2019-09-24T19:15:45.037Z
Another thing is that VapourSynth also runs on Linux, which is useful when running on a server is a requirement
mcont
CC BY-SA 4.0
2022-01-09T00:08:50.467Z
AviSynth+ is native too starting from version 3.5: https://forum.doom9.org/showthread.php?t=180436
mirh
<video><avi>
AviSynth vs AviSynth+ vs VapourSynth: which one should I choose?
Simon East
# AviSynth vs AviSynth+ vs VapourSynth: which one should I choose?

(Asked by: username_0 on 2019-09-21)

[AviSynth](http://avisynth.nl/index.php/Main_Page) is an old-but-still-useful tool for processing video via script, but I’ve noticed that there is a fork called [AviSynth+](http://avs-plus.net) that appears to have some improvements. And then there’s VapourSynth rewritten to use Python.

What are the pros and cons of these versions?

For use-cases such as QTGMC deinterlacing and high-quality resizing, is one clearly better than the other?

**Tags:** video, avi

> **Comments:**
> **username_1**: Another thing is that VapourSynth also runs on Linux, which is useful when running on a server is a requirement  
> **username_2**: AviSynth+ is native too starting from version 3.5: https://forum.doom9.org/showthread.php?t=180436  

---

## 2 answers

### Answer by username_0 on 2019-09-21. Score: 4

As a summary of the differences:

## AviSynth

* **Outdated and no longer recommended for use**
* Only available in 32bit – not able to use 64bit plugins/filters
* No multi-threading (unless you install AviSynth-MT, another fork, which is prone to errors and issues and no updates over last 4+ years)
* Older and only supports 8bit video
* Lacks support for some color spaces (YV16, YV24 etc.)
* Latest release over 4 years ago (May 2016)

## AviSynth+

* Has both a 32bit and 64bit version, although the 32bit version apparently [has some issues](http://www.digitalfaq.com/forum/video-restore/9619-advantages-avisynth-vs.html#post60894)
* Supports multi-threading which can significantly improve rendering performance for some functions (similar to AviSynth-MT, another fork, but AviSynth+’s appears more stable)
* Be aware that using the 64bit version will require all plugins and filters to also be 64bit – and not all of them have 64bit versions. There are some filters that are 64bit only, however, which means you’re able to use those.
* QTGMC runs faster in multi-threaded mode, and also [apparently](http://www.digitalfaq.com/forum/video-restore/9619-advantages-avisynth-vs.html#post60894) in 64bit mode
* AviSynth+ specific documentation is limited, but most of the great AviSynth wiki also applies to AviSynth+ and many pages now have notes mentioning any specific instructions for working with AviSynth+.
* Also runs on Linux, which is useful when you need to run it on a server
* Regularly updated, with latest release Jun 2020

Note: be sure to get a recent version of AviSynth+ from <https://github.com/AviSynth/AviSynthPlus/releases>. There was a pinterf fork and it has been merged back to upstream.

Or you can use the [Universal AviSynth Installer](https://www.videohelp.com/software/Universal-Avisynth-Installer) which allows you to easily switch between the different versions of AviSynth, AviSynth-MT, and AviSynth+ (32bit and 64bit).

## VapourSynth

* Rewritten to use Python, a much more powerful and flexible scripting language
* Multi-threaded
* Supports generalized colorspaces whereby new or custom colorspaces can be specified at runtime
* Also runs on Linux, which is useful when you need to run it on a server
* Documentation isn't as detailed as AviSynth (it's not a community wiki)
* Regularly updated, with latest release Aug 2020

> **Comments:**
> **username_3**: Maybe add VapourSynth info as well.  
> **username_4**: Any reason we need a full programming language to configure video filter pipelines?  Was the prior method just missing some unnecessary complexity and bloat, from the perspective of the user?  

---

### Answer by username_5 on 2019-09-21. Score: 2

There is no reason to use old, obsolete AviSynth — *“old-but-still-useful”* are almost all programs, but why to complicate your life with old, unsupported versions of them?

Every script for AviSynth works well in the AviSynth+, so even if you know AviSynth, there is nothing to relearn. The opposite is not true, however.

**Use AviSynth+** (pros: all, cons: none), particularly [pinterf/AviSynthPlus](https://github.com/pinterf/AviSynthPlus/releases) (forked from already dead AviSynth/AviSynthPlus).

---

*Note:*

The other situation is with *GUI programs* — if the old version satisfied you and the new one is too complicated, with changed menus, new icons, colors etc.

But it is not the case of AviSynth+ — you don't “see” the new commands, functions or parameters, so they don't disturb you.

> **Comments:**
> **username_0**: Thanks for the answer. The net is full of old posts referring to AviSynth, and I initially wasn't sure if AviSynth+ was compatible or maintained, but as you've pointed out the pinterf version is both and the best modern version to use.   
> **username_5**: You're welcome.  
> **username_6**: AviSynth+ was never dead. There was a coordinated and hickup-free maintainer change to pinterf without development hiatus, and for some reason pinterf decided to use his own repo in the beginning. Now he even changed back to the original repo and so active development is again at its original place at AviSynth/AviSynthPlus on GitHub.  

---

