LLM reel caption and video description + Refactor in services

app/Services/FileTools/VideoDescriptor/AbstractLLMVideoDescriptor.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace App\Services\FileTools\VideoDescriptor;
+
+use App\Services\FileTools\VideoDescriptor\IVideoDescriptor;
+use Log;
+
+abstract class AbstractLLMVideoDescriptor implements IVideoDescriptor
+{
+    public const MAX_FRAMES = 5;
+
+    abstract public function getDescription(string $filePath): ?string;
+
+    /**
+     * Cut the video into screenshots.
+     * Using ffmpeg to cut the video into screenshots at regular intervals.
+     * The screenshots will be saved in a temporary directory.
+     * @param string $filePath
+     * @return array array with timestamps as key and screenshot file paths as values.
+     */
+    protected function cutVideoIntoScreenshots(string $filePath): array
+    {
+        $tempDir = sys_get_temp_dir() . '/video_screenshots';
+        if (!is_dir($tempDir)) {
+            mkdir($tempDir, 0777, true);
+        }
+        else {
+            // Clear the directory if it already exists
+            array_map('unlink', glob($tempDir . '/*'));
+        }
+
+        Log::info("Cutting video into screenshots: $filePath");
+
+        $videoDuration = shell_exec("ffprobe -v error -show_entries format=duration -of csv=p=0 " . escapeshellarg($filePath));
+        if ($videoDuration === null) {
+            Log::error("Failed to get video duration for file: $filePath");
+            return [];
+        }
+        $videoDuration = floatval($videoDuration);
+
+        $framesInterval = ceil($videoDuration / self::MAX_FRAMES);
+        $fps = 1/$framesInterval; // Frames per second for the screenshots
+
+        $outputPattern = $tempDir . '/screenshot_%d.png';
+        $command = "ffmpeg -i " . escapeshellarg($filePath) . " -vf fps={$fps} " . escapeshellarg($outputPattern);
+        exec($command);
+
+        // Collect all screenshots
+        $screenshots = glob($tempDir . '/screenshot_*.png');
+        $array = [];
+        foreach ($screenshots as $screenshot) {
+            $array[] = [
+                "screenshot" => $screenshot,
+                "timestamp" => floor(sizeof($array) * $framesInterval),
+            ];
+        }
+        return $array;
+    }
+}