Feature: Improve formatting for dialogues (-) and 3-line subtitles

No project files or tests are named; the issue includes an HTML/JavaScript prototype for subtitle processing. Start by locating the subtitle formatting entry point and its existing tests, then compare the prototype's dialogue and multi-line cases with current behavior. Done means both requested formatting modes work without changing one- or two-line subtitles.

This issue proposes adding two new features to improve subtitle formatting:

1. Dialogue Support (Lines starting with -)
   Currently, two-person dialogues are not handled properly. I have added a feature that detects lines starting with a dash (-) and splits each person's dialogue into a separate line.

before

after

3-Line to 2-Line Conversion**
I also added a feature that intelligently converts subtitles with 3 or more lines down to 2 lines, using punctuation rules and word count balancing.

after

I have already written and tested the code for these features. I would be happy to submit a Pull Request (PR) to add this to the project if you are interested!

<title>Advanced Subtitle Fixer</title> <style> body { font-family: Tahoma, sans-serif; padding: 20px; background: #f4f4f9; } textarea { width: 100%; height: 250px; margin-bottom: 10px; direction: ltr; padding: 10px; font-family: monospace; font-size: 14px; } button { padding: 12px 24px; font-size: 16px; cursor: pointer; background: #28a745; color: white; border: none; border-radius: 5px; } button:hover { background: #218838; } </style>

3-Line to 2-Line Subtitle Converter (Dialogue Support -)

Paste your subtitle file in the box below. This version detects two-person conversations starting with a dash (-) and places each person on a separate line:

<textarea id="inputSrt" placeholder="Paste the original subtitle here..."></textarea>
<button onclick="fixSrt()">Smart Process Subtitle</button>
<textarea id="outputSrt" placeholder="The final subtitle will be displayed here..." readonly></textarea>

<script>
    function fixSrt() {
        const text = document.getElementById('inputSrt').value;
        // Separate subtitle blocks completely independently
        const blocks = text.trim().split(/\r?\n\s*\r?\n/);
        
        const processed = blocks.map(block => {
            const lines = block.split(/\r?\n/);
            
            // If the subtitle has 3 or more lines of text
            if (lines.length > 4) {
                const index = lines[0];
                const time = lines[1];
                const textLines = lines.slice(2);
                
                let line1 = "";
                let line2 = "";
                let isDialogSplit = false;

                // Golden rule: Check for a two-person conversation (find the line starting with -)
                for (let i = 1; i < textLines.length; i++) {
                    // If the line starts with a dash (might have leading spaces)
                    if (textLines[i].trim().match(/^[-–—]/)) {
                        line1 = textLines.slice(0, i).join(" ").trim();
                        line2 = textLines.slice(i).join(" ").trim();
                        isDialogSplit = true;
                        break; // Found it, so we break here
                    }
                }

                // If not a two-person conversation, move to punctuation rules (period, comma)
                if (!isDialogSplit) {
                    let splitIndex = -1;
                    let maxScore = -1;
                    let minDiff = Infinity;
                    
                    const totalWords = textLines.join(" ").split(/\s+/).length;

                    for (let i = 0; i < textLines.length - 1; i++) {
                        const line = textLines[i].trim();
                        const wordsSoFar = textLines.slice(0, i + 1).join(" ").split(/\s+/).length;
                        const diff = Math.abs(wordsSoFar - (totalWords / 2));
                        
                        let score = 0;
                        if (line.match(/[.?!]["']?$/)) score = 2; 
                        else if (line.match(/[,;:]["']?$/)) score = 1; 
                        
                        if (score > maxScore || (score === maxScore && diff < minDiff)) {
                            maxScore = score;
                            minDiff = diff;
                            splitIndex = i;
                        }
                    }

                    if (maxScore > 0) {
                        line1 = textLines.slice(0, splitIndex + 1).join(" ").trim();
                        line2 = textLines.slice(splitIndex + 1).join(" ").trim();
                    } else {
                        const fullText = textLines.join(" ").trim();
                        const words = fullText.split(/\s+/);
                        const mid = Math.ceil(words.length / 2);
                        line1 = words.slice(0, mid).join(" ");
                        line2 = words.slice(mid).join(" ");
                    }
                }
                
                return `${index}\n${time}\n${line1}\n${line2}`;
            }
            // 1 and 2-line subtitles remain completely untouched
            return block;
        });
        
        document.getElementById('outputSrt').value = processed.join("\n\n");
    }
</script>