Thanks @kornrunner for these changes:
* Test against PHP 8
* U-Tests: FFProbe: OptionsTester: handle phpunit deprecation of at
* FiltersCollection: tweak for call_user_func_array and PHP 8 named arguments
* Support multiple -vf commands
Marge Filters into one command
* Ordering Scale
Using -vf to scale instead of -s to have ordering
* Correct the ResizeFilterTest
* Remove useless comments
* Fixed filter bug
Add checking on filters if only one process.
* Fixed typo error
When the metadata filter is applied on an `Audio` media, the `artwork`
parameter was being unset from the metadata array.
Saving the same `Audio` instance into multiple formats generated the
correct commands for the first export, but the subsequent commands were
missing the `artwork` parameter.
This commit fixes this issue by copying (by value) the `metaArr`
property to a local variable each time the filter is applied.
* Creation of a feature to concatenate files into a new one.
* Update of the README
* Creation of the tests for the concatenation
* We use an array of videos instead of a path to a text files
* We use the bundle Temporary File System instead of getcwd
* Adding a missing use statement in src/FFMpeg/Filters/Video/ExtractMultipleFramesFilter.php
* We remove a user specific folder from the gitignore
* We remove an unused use statement from src/FFMpeg/Filters/Video/ExtractMultipleFramesFilter.php
* We remove an unused use statement from src/FFMpeg/Filters/Video/PadFilter.php
* We remove an unused use statement from src/FFMpeg/Media/Waveform.php
* We remove an unused variable from src/FFMpeg/Filters/Waveform/WaveformDownmixFilter.php
* We fix the name of a variable in src/FFMpeg/Filters/Audio/AddMetadataFilter.php
* Creation of a media to extract video sequences into gif files
* We add a gif method to the class Video to be able to use the Gif Media.
* Parameters where missing in the declaration of the gif function
* One parameter was badly defined in the gif method
* We use the proper media in the method gif
* We add a missing declaration in the Video class
* Update of the README file
* Modification of the README file
* We remove an empty class
