This module contains a few methods for easy manipulation of subtitle text files.

Clone this repository and import the module.

PS> git clone 'https://git.beverli.net/bvli/pwsh-srt'
PS> Import-Module './pwsh-srt'

This is probaly the most needed capability of the toolset. We all know the situation where we're going to watch a movie, and then the subtitles appears 10 seconds before the dialog. This is exactly why this toolset was created. So find the offset by timing the difference between when the dialog appear and the subtitle appear by watching the movie and let's fix it. If you want the titles to appear ealier use a negative number, if you want them to appear later, use a positive number.

PS> Get-Content -Path 'Pretty Woman (1990).en.srt' | 
    ConvertFrom-Srt | 
    Add-SrtTimeDifference -MilliSeconds -500 | 
    ConvertTo-Srt | 
    Out-File '.\Pretty Woman (1990).en.fixed.srt'

Sometimes the first few entries in a subtitle file contains ads or other information, you don't want to have in the file. It's quite easy to delete these, while still keeping the sequence in sync.

PS> Get-Content -Path 'Pretty Woman (1990).en.srt' | 
    ConvertFrom-Srt | 
    Select-Object -Skip 1 | 
    ConvertTo-Srt |
    Out-File -Path 'Pretty Woman (1990).en.no-ads.srt'

If you want to be one of the annoying persons, adding entries to a subtitle file (you don't!) then it's quite easy as well:

PS> @('0', '00:00:00,000 --> 00:00:02,000', 'Manipulated by pwsh-srt', '© bvli, 2021', '') + (cat '.\Pretty Woman (1990).en.srt') | 
    ConvertFrom-Srt | 
    ConvertTo-Srt | 
    Out-File -Path '.\Pretty Woman (1990).en.ads.srt'

The sequence number of the inserted entry is not important here, as the ConvertTo-Srt cmdlet will handle the sequencing when converting back to the srt file format.

Of course you can mix and match as you'd like - and probably do it all in a one-liner of you prefer. Just remember to take file encodings into consideration when working with subtitles with special characters. (So please backup your original file before trying to manipulate it in a single go)

    $FileName = 'Pretty Woman (1990).en.srt'
    (Get-Content -Path $FileName | 
        ConvertFrom-Srt | 
        Select-Object -Skip 1 |
        Add-SrtTimeDifference -Seconds 15
        ConvertTo-Srt) | 
    Out-File -Path $FileName