Video player with filters?

[ziptip]

Hello everyone,

I would like to know if there is any video player software (for Windows preferably) that can apply basic filters to videos.
By filter I don't mean video encoding or decoding software (like divx, h264, vp8, webm and such).

For example showing subtitles is a a basic filter applied to the original video.
What I need is a bit more filters, like for example drawing a blue, opaque square on the bottom-left part of the video. Or turning the sound off for the first two minutes of the video, or reducing the sound volume by 50% for the last three minutes of the video.
I do not need to be able to save the resulted video. I just want to watch it, with my chosen filter.

Is there any such player that allows the user to apply basic filters to videos they are watching?

Thanks

[butterw]

For video, it can be done efficiently in realtime with user gpu shaders (a MaskBox is what you are looking for, ex: bShaders barMask.hlsl Mode 2). Hlsl is supported by many directshow players (I would recommend mpc-hc for this), Mpv uses glsl based .hook.
VLC has some buit-in cpu filters (including a logo filter) and mpv has built-in ffmpeg video filters.

For audio, I think it should be possible with mpv / ffmpeg audio filters.

If Avisynth+ is installed, Avisynth scripts can also be opened by some videoplayers (no indexing is required with mp4/mov video with LSMASHSource plugin).

[ziptip]

Thank you very much!

I am trying to make AviSynth work with VLC, I found an AviSynth plugin for VLC here.
It worked for an .asf video very well.

But I can't open mp4 videos (encoded with h264). It says that the format is unknown. Is there a solution for having AviSynth open mp4 files?

[jagabo]

Consider PotPlayer. It has an AviSynth filter built in.

You probably need to install a source filter like LSMASH or ffms2. Then you need to know how to write scripts.

[butterw]

Avisynth+: with LSMASHSource plugin, no indexing is required for mp4/mov video.

If you use an avs script you have to provide the filepath to the video.

[ziptip]

I downloaded L-SMASH-Works (L-SMASH-Works_20210423.7z) from this link - https://github.com/HolyWu/L-SMASH-Works/releases/

I copied the file plugins\LSMASHSource.dll into the folder C:\Program Files (x86)\AviSynth+\plugins+

But it still doesn't work.

My AVS script looks like this:

DirectShowSource("D:\MyVideo.mp4", fps=25, convertfps=true)

It works with ASF but it doesn't work with MP4

What do I have to do to make it work?

[butterw]

LSmashVideoSource("D:\MyVideo.mp4")