SRT merger

Overview

The srt_merge.py script is designed to merge and manipulate subtitle files in the SRT format. It takes two SRT files and a set of commands to produce a merged output file.

This tool can be particularly useful for re-aligning a translation for a slightly different edition of the same movie, where the new edition does not provide that translation. By using the commands, you can adjust the timing and mapping of subtitles to fit the new version.

(Also, this is an attempt to use AI to generate code. Could be better, could be much worse.)

Usage

The script is given four parameters:

• srt1_filename: The filename of the first SRT file.
• srt2_filename: The filename of the second SRT file.
• commands_filename: The filename containing the commands to process.
• output_filename: The filename where the merged output will be saved.

The commands will be processed, generating merged subtitles which will be saved as SRT to the specified output_filename.

Supported Commands

The script supports the following commands:

COPY

Copies subtitles from one file to the output, preserving their original timing.

Syntax:

COPY <source> <index_or_range>

• <source>: The source SRT file, specified as 1 or 2.
• <index_or_range>: A single index or a range of indices (e.g., 5 or 5-10).

MAP

Maps a sequence of subtitles from one stream to the other. The command supports two different syntaxes.

Syntax 1:

MAP <text_source> <text_start> <time_start> <count>

• <text_source>: The source SRT file for text, specified as 1 or 2.
• <text_start>: The starting index in the text source.
• <time_start>: The starting index in the time source.
• <count>: The number of subtitles to map.

Syntax 2:

MAP <text_source> <text_range> <time_start>

• <text_source>: The source SRT file for text, specified as 1 or 2.
• <text_range>: A range of indices in the text source (e.g., 5-10).
• <time_start>: The starting index in the time source.

SYNC

Aligns a subtitle text found only in one SRT file based on the time delta between that text and the previous entry. The entry used as the "time source" in the other stream must correspond to the previous entry in the text stream.

Typically it can be used to re-align subtitles for episode names, which are not present in the original language's subtitles.

Syntax:

SYNC <text_source> <text_index> <time_index>

• <text_source>: The source SRT file for text, specified as 1 or 2.
• <text_index>: The index of the text to align.
• <time_index>: The index of the time entry in the other SRT file that corresponds to the previous entry in the text stream.

PUT

Outputs text at an existing entry's timestamp.

Syntax:

PUT <source> <index> <text>

• <source>: The SRT file used as the time source, specified as 1 or 2.
• <index>: The index of the entry whose text is being provided.
• <text>: The text to insert.