Revert "Upgrade to go 1.19 and update dependencies (#3069)" (#3085)

This reverts commit bba7c23957.

vendor/github.com/asticode/go-astisub/.travis.yml

@@ -6,7 +6,6 @@ install:
 - go get -t ./...
 - go get golang.org/x/tools/cmd/cover
 - go get github.com/mattn/goveralls
-- go install github.com/mattn/goveralls
 matrix:
   allow_failures:
   - go: tip

vendor/github.com/asticode/go-astisub/README.md

@@ -7,7 +7,7 @@ This is a Golang library to manipulate subtitles.
 
 It allows you to manipulate `srt`, `stl`, `ttml`, `ssa/ass`, `webvtt` and `teletext` files for now.
 
-Available operations are `parsing`, `writing`, `applying linear correction`, `syncing`, `fragmenting`, `unfragmenting`, `merging` and `optimizing`.
+Available operations are `parsing`, `writing`, `syncing`, `fragmenting`, `unfragmenting`, `merging` and `optimizing`.
 
 # Installation
 
@@ -43,9 +43,6 @@ s1.Optimize()
 // Unfragment the subtitles
 s1.Unfragment()
 
-// Apply linear correction
-s1.ApplyLinearCorrection(1*time.Second, 2*time.Second, 5*time.Second, 7*time.Second)
-
 // Write subtitles
 s1.Write("/path/to/example.srt")
 var buf = &bytes.Buffer{}
@@ -60,10 +57,6 @@ If **astisub** has been installed properly you can:
 
         astisub convert -i example.srt -o example.ttml
 
-- apply linear correction to any type of subtitle:
-
-        astisub apply-linear-correction -i example.srt -a1 1s -d1 2s -a2 5s -d2 7s -o example.out.srt
-
 - fragment any type of subtitle:
 
         astisub fragment -i example.srt -f 2s -o example.out.srt
@@ -93,7 +86,6 @@ If **astisub** has been installed properly you can:
 - [x] merging
 - [x] ordering
 - [x] optimizing
-- [x] linear correction
 - [x] .srt
 - [x] .ttml
 - [x] .vtt

vendor/github.com/asticode/go-astisub/subtitles.go

@@ -640,19 +640,6 @@ func (s *Subtitles) Unfragment() {
 	}
 }
 
-// ApplyLinearCorrection applies linear correction
-func (s *Subtitles) ApplyLinearCorrection(actual1, desired1, actual2, desired2 time.Duration) {
-	// Get parameters
-	a := float64(desired2-desired1) / float64(actual2-actual1)
-	b := time.Duration(float64(desired1) - a*float64(actual1))
-
-	// Loop through items
-	for idx := range s.Items {
-		s.Items[idx].EndAt = time.Duration(a*float64(s.Items[idx].EndAt)) + b
-		s.Items[idx].StartAt = time.Duration(a*float64(s.Items[idx].StartAt)) + b
-	}
-}
-
 // Write writes subtitles to a file
 func (s Subtitles) Write(dst string) (err error) {
 	// Create the file