generateVideo.php

<?php

require 'vendor/autoload.php';
use Symfony\Component\Process\Process;

ini_set("max_execution_time", 30 * 60); //increase the max_execution_time to max of dyno inactivity time interval
if (isset($_POST['videoUrl'])) {
    $videoUrl = $_POST['videoUrl'];
    $streamUrl = $_POST['streamUrl'];
    $videoMetadata = $_POST['videoMetadata'];
    $videoId = $_POST['videoId'];
    $selectedFormat = $_POST['videoFormat'];
    $ipAddr_userAgent = $_POST['uniqueId'];

    $videoMetadataJson = json_decode($videoMetadata, true);

    //Send the response to client and proceed with video generation
    respondOK();

    $videoGenerationCommand = array();
    array_push($videoGenerationCommand, getcwd() . "/ffmpeg");
    array_push($videoGenerationCommand, "-i");
    array_push($videoGenerationCommand, $streamUrl);

    $outputFileName = $videoId . ".mp4";

    foreach ($videoMetadataJson as $metaDataName => $metaDataValue) {
        if ($metaDataName == "title") {
            $outputFileName = removeSpecialChars($metaDataValue) . ".mp4";
        }
        array_push($videoGenerationCommand, "-metadata");
        array_push($videoGenerationCommand, $metaDataName . "=\"" . $metaDataValue . "\"");
    }

    $videoZipCommand = array();
    array_push($videoZipCommand, "zip");
    array_push($videoZipCommand, "-D");
    array_push($videoZipCommand, "-m");
    array_push($videoZipCommand, "-9");
    array_push($videoZipCommand, "-v");
    array_push($videoZipCommand, $videoId . ".zip");
    array_push($videoZipCommand, $outputFileName);

    array_push($videoGenerationCommand, "-c");
    array_push($videoGenerationCommand, "copy");
    array_push($videoGenerationCommand, $outputFileName);

    $process = new Process($videoGenerationCommand);
    $process->setTimeout(30 * 60); //wait for atleast dyno inactivity time for the process to complete
    $process->start();

    foreach ($process as $type => $data) {
        $progress = array();
        $progress['videoId'] = $videoId;
        $progress['data'] = nl2br($data);
        sendProgressToClient($progress, $ipAddr_userAgent);
    }

    $process = new Process($videoZipCommand);
    $process->setTimeout(30 * 60); //wait for atleast dyno inactivity time for the process to complete
    $process->start();

    foreach ($process as $type => $data) {
        $progress = array();
        $progress['videoId'] = $videoId;
        $progress['data'] = nl2br($data);
        sendProgressToClient($progress, $ipAddr_userAgent);
    }

    $progress = array();
    $progress['videoId'] = $videoId;
    $progress['data'] = nl2br("\nVideo generation complete...");

    sendProgressToClient($progress, $ipAddr_userAgent);

}
else {
    echo "Invalid script invocation";
    $ipAddr_userAgent = $_POST['uniqueId'];
    $progress = array();
    $progress['hasProgress'] = 'false';
    $progress['data'] = nl2br("Error occurred in receiving the post form data from the client");

    sendProgressToClient($progress, $ipAddr_userAgent);
}

function removeSpecialChars($string) {
    $string = str_replace(' ', '_', $string); // Replaces all spaces with underscore.
    return preg_replace('/[^A-Za-z0-9_]/', '', $string); // Removes special chars.
    
}

/**
 * Respond 200 OK with an optional
 * This is used to return an acknowledgement response indicating that the request has been accepted and then the script can continue processing
 *
 * @param null $text
 */
function respondOK($text = null) {
    // check if fastcgi_finish_request is callable
    if (is_callable('fastcgi_finish_request')) {
        if ($text !== null) {
            echo $text;
        }
        /*
         * http://stackoverflow.com/a/38918192
         * This works in Nginx but the next approach not
        */
        session_write_close();
        fastcgi_finish_request();

        return;
    }

    ignore_user_abort(true);

    ob_start();

    if ($text !== null) {
        echo $text;
    }

    $serverProtocol = filter_input(INPUT_SERVER, 'SERVER_PROTOCOL', FILTER_SANITIZE_STRING);
    header($serverProtocol . ' 200 OK');
    // Disable compression (in case content length is compressed).
    header('Content-Encoding: none');
    header('Content-Length: ' . ob_get_length());

    // Close the connection.
    header('Connection: close');

    ob_end_flush();
    ob_flush();
    flush();
}

function sendProgressToClient($progress, $ipAddr_userAgent) {

    $options = array(
        'cluster' => 'ap2',
        'encrypted' => true
    );

    $pusher = new Pusher\Pusher('a44d3a9ebac525080cf1', '37da1edfa06cf988f19f', '505386', $options);

    $message['message'] = $progress;

    $pusher->trigger('hotstar-video-download-v1', $ipAddr_userAgent, $message);

}

?>