如何通过PHP编写一个简单的在线视频编辑器

<form action="upload.php" method="post" enctype="multipart/form-data">
    <input type="file" name="video">
    <input type="submit" value="上传">
</form>

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $targetDir = "uploads/";
    $targetFile = $targetDir . basename($_FILES["video"]["name"]);
    $uploadOk = 1;
    $videoFileType = strtolower(pathinfo($targetFile,PATHINFO_EXTENSION));

    // 检查文件格式
    if($videoFileType != "mp4" && $videoFileType != "avi" && $videoFileType != "mov") {
        echo "仅支持MP4、AVI和MOV格式的视频";
        $uploadOk = 0;
    }

    // 检查文件大小限制
    if ($_FILES["video"]["size"] > 50000000) {
        echo "视频大小不能超过50MB";
        $uploadOk = 0;
    }

    // 保存文件
    if ($uploadOk == 0) {
        echo "上传失败";
    } else {
        if (move_uploaded_file($_FILES["video"]["tmp_name"], $targetFile)) {
            echo "上传成功";
        } else {
            echo "上传失败";
        }
    }
}
?>

<?php
$videoFile = "uploads/video.mp4";
$outputFile = "uploads/edited.mp4";
$startTime = "00:00:10";
$duration = "00:00:20";

$cmd = "ffmpeg -i $videoFile -ss $startTime -t $duration -c:v copy -c:a copy $outputFile";
exec($cmd);
?>

<?php
$videoFile = "uploads/video.mp4";
$outputFile = "uploads/edited.mp4";

$cmd = "ffmpeg -i $videoFile -vf 'drawtext=fontfile=/path/to/font.ttf:text='Hello World':fontsize=40:x=10:y=10:enable=between(t,2,5)' -c:a copy $outputFile";
exec($cmd);
?>