PHP Function to Convert SBV to SRT

convert_sbv_to_srt.php

		
function convert_sbv_to_srt( $lines )
{
    if( !$lines ) return "";

	// BREAK LINES ON RETURN
	$lines = explode("\n", $lines);

	// ADD A BLANK SPACE AT THE BEGINNING,	
	// I USE BLANK SPACES TO DETERMINE BETWEEN THE DIFFERENT TEXT BLOCKS
	array_unshift($lines,"");

	// RETURN VARIABLE
	$srt = "";

	$num = 1;
	foreach( $lines as $c => $line )
	{
		// IF LINE IS EMPTY, SHOULD BE A NEW BLOCK
		if( !$line )
		{
			// DOING THE WHOLE BLOCK FROM INSIDE THE EMPTY LINE

			// SET NUMBER OF BLOCK
			$srt .= $num . "\n";

			// GRAB THE TIME 
			$time = $lines[$c + 1];

			// SANITIZE THE TIME
			$time = str_replace(","," --> ", $time);
			$time = str_replace(".",",", $time);
			$srt .= $time . "\n";
				
			// GRAB TEXT
			$text = $lines[$c + 2];
	
			// IF TWO LINES OF TEXT, APPEND IT
			if( isset($lines[$c + 3]) AND $lines[$c + 3] != "") $text .= "\n" . $lines[$c + 3];
				
			// MUST ADD RETURNS TO END
			$srt .= $text . "\n\n";

			// INCREMENT BLOCK NUMBER
			$num++;
		}
	}

    // RETURN THE GOODIES
    return $srt;
}
		

// UPLOAD A SBV THROUGH A FORM
move_uploaded_file($_FILES['caption']['tmp_name'], "captions/{$id}.sbv");

// GET THE CONTENTS OF THIS FILE
$sbv  = file_get_contents("captions/{$id}.sbv");

// CONVERT
$srt = convert_sbv_to_srt( $sbv );

// WRITE BACK AS A .SRT
file_put_contents("captions/{$id}.srt", "\xEF\xBB\xBF" . htmlspecialchars_decode($srt, ENT_QUOTES));

Thanks it works but leave PHP notice Undefined Offset on line 28 and 36;

I have fixed this here:

if (!empty($lines[$c + 1])){
    			// GRAB THE TIME 
	    		$time = $lines[$c + 1];

                // SANITIZE THE TIME
			    $time = str_replace(","," --> ", $time);
    			$time = str_replace(".",",", $time);
	    		$srt .= $time . "\n";
            }	
            
            if (!empty($lines[$c + 2])){
    			// GRAB TEXT
                $text = $lines[$c + 2];
                        
                // IF TWO LINES OF TEXT, APPEND IT
    			if( isset($lines[$c + 3]) AND $lines[$c + 3] != "") $text .= "\n" . $lines[$c + 3];
                
    			// MUST ADD RETURNS TO END
	    		$srt .= $text . "\n\n";
            }

Fixed for warning file_get_contents:

// GET THE CONTENTS OF THIS FILE
$sbv  = @file_get_contents("captions/{$id}.sbv");