Avanti GUI is a free front-end for FFmpeg with the option to insert Avisynth as pre-processor.
It can be used with almost all Windows OS builds of FFmpeg. It offers user friendly control over all basic and advanced FFmpeg options.
A number of template examples are included. There's no need to be familiar with Avisynth to use the predefined Avanti/Avisynth pre-processor options.
Avanti GUI бесплатный портативный инструмент аудио-видео перекодировки с графическим интерфейсом. Avanti GUI это графический интерфейс для FFmpeg кодека и может перекодировать MPEG, AVI, Xvid форматы. Avanti GUI предоставляет удобное управление всеми основными и дополнительными параметрами FFmpeg кодека. Сочетание с FFmpeg дает возможность запускать AviSynth как предпроцессор. FFmpeg включает libavcodec, ведущая библиотека-кодек с открытым исходным кодом для кодирования и декодирования аудио / видео.

Key Features:
Easy access to all FFmpeg codecs and basic encode settings.
All advanced FFmpeg options are available through user command addition.
All settings are saved and restored at the next session.
All encoder settings, user additions and scripts can be saved in template files.
Display of estimated encode time, remaining time and encode speed.
Option to set encode time limit (in minutes) to encode test clips.
Option to auto-shutdown your system after encoding and job processing.
Re-direction of FFmpeg screen output to Avanti GUI (hides FFmpeg).
Option to process system controlled 2-pass encoding.
Advanced batch job processing (with dynamic template support).
ES option to encode to mpeg2 elementary audio/video streams for DVD authoring.
Option to modify mpeg2 header flags (incl. 2:3 pulldown on 23.976 p).
Option to modify AVI header fields (FourCC and frame rate).
Selectable Avisynth AUTO and USER modes with build-in Avisynth Editor. ... (supports virtual source paths which allows scripts to run from templates).
Internal Video Preview with Avisynth script preview (debug) option.
Option to use advanced Avisynth color correction (with preview).
Selectable FFmpeg/Avisynth crop/scale/pad option (with preview and calculator).
Option to burn-in subtitles (with style editor and preview).
Support for the VirtualDub (*.vdr) frameserver format.
Option to convert PAL video source to NTSC destination and vice-versa.
Option to convert audio from PAL to NTSC and vice-versa (with pitch correction).
Option to expand luminance level from 16-235 to 0-255.
Avisynth SuperEQ (18 bands) preset editor with preview option.

FFmpeg codec has built-in GUI Avanti GUI
кодек FFmpeg уже встроен в графическую оболочку Avanti GUI