feat: Added loop filter.

filters.nu

@@ -1,16 +1,31 @@
 #!/usr/bin/env -S nu --stdin
 
 export def "parse filter" [
-] {
-  $in | parse --regex '^(?<name>[^=]+)=(?<params>.*)' | first |
-  update params { parse --regex `(?<param>[^=]+)=(?<value>[^:]+):?` }
+]: string -> table<name: string params: table<param: string, value: string>> {
+  $in | parse --regex '^(?<name>[^=]+)=(?<params>.*)' | first | update params {
+    parse --regex `(?<param>[^=]+)=(?<value>[^:]+):?`
+  }
 }
 
-export def "filter to-string" [] {
-  each { |filter| $'($filter.name)=($filter.params | format '{param}={value}')' } |
-  str join ':'
+export def "filter to-string" [
+]: table<name: string params: table<param: string, value: string>> -> string {
+  each {
+    $'($in.name)=($in.params | format '{param}={value}')'
+  } | str join ':'
 }
 
+# Build a record representaion of a complex filter
+export def complex-filter [
+  name: string
+  params: record = {}
+]: nothing -> record<name: string params: table<param: string, value: string>> {
+  {
+    name: $name
+    params: ($params | transpose param value | compact param value)
+  }
+}
+
+
 export def "complex-filters to-string" [
   --pretty-print (-p)
 ]: table<input: list<string>, filters: table<name: string, params: table<param: string, value: string>>, output: string> -> string {
@@ -20,3 +35,22 @@ export def "complex-filters to-string" [
       str join ']['
     } | format '[{input}]{filters}[{output}]' | str join (";" + (if $pretty_print { "\n"  } else { "" })) | str replace --all '[]' ''
 }
+
+# =============
+# Begin Filters
+# =============
+
+# loop video frames
+export def loop [
+  loop: int # Set the number of loops. Setting this value to -1 will result in infinite loops. Default is 0.
+  size: int # Set maximal size in number of frames. Default is 0.
+  --start (-s): int # Set first frame of loop. Default is 0.
+  --time (-t): float # Set the time of loop start in seconds. Only used if option named start is set to -1.
+] {
+  complex-filter loop {
+    loop: $loop
+    size: $size
+    start: (if ($time | is-empty) { $start } else { -1 })
+    time: $time
+  }
+}