thats-me/backend/app/Services/EventMediaProbe.php

<?php

namespace App\Services;

use Illuminate\Support\Facades\Log;
use Symfony\Component\Process\ExecutableFinder;
use Symfony\Component\Process\Process;

/**
 * Reads the duration of an audio or video file and extracts a poster frame
 * from a video, using ffprobe / ffmpeg when they are installed.
 *
 * Both are optional: without them a video is stored without a poster and a
 * recording without a duration. The upload itself never fails because of a
 * missing tool.
 */
class EventMediaProbe
{
    private const TIMEOUT_SECONDS = 30;

    public function durationMs(string $path): ?int
    {
        $ffprobe = $this->binary('ffprobe');
        if ($ffprobe === null) {
            return null;
        }

        $process = new Process([
            $ffprobe,
            '-v', 'error',
            '-show_entries', 'format=duration',
            '-of', 'default=noprint_wrappers=1:nokey=1',
            $path,
        ]);
        $process->setTimeout(self::TIMEOUT_SECONDS);

        try {
            $process->run();
        } catch (\Throwable $e) {
            Log::info('ffprobe failed', ['path' => $path, 'exception' => $e->getMessage()]);

            return null;
        }

        if (! $process->isSuccessful()) {
            return null;
        }

        $seconds = (float) trim($process->getOutput());

        return $seconds > 0 ? (int) round($seconds * 1000) : null;
    }

    /**
     * Write a JPEG poster frame of the video to $targetPath.
     *
     * @return bool true when the frame was written
     */
    public function posterFrame(string $videoPath, string $targetPath, ?int $durationMs = null): bool
    {
        $ffmpeg = $this->binary('ffmpeg');
        if ($ffmpeg === null) {
            return false;
        }

        // A frame a little into the clip avoids the black first frame many
        // recordings start with; very short clips take the first frame.
        $seek = $durationMs !== null && $durationMs > 2000 ? '0.5' : '0';

        $process = new Process([
            $ffmpeg,
            '-v', 'error',
            '-y',
            '-ss', $seek,
            '-i', $videoPath,
            '-frames:v', '1',
            '-q:v', '3',
            $targetPath,
        ]);
        $process->setTimeout(self::TIMEOUT_SECONDS);

        try {
            $process->run();
        } catch (\Throwable $e) {
            Log::info('ffmpeg poster extraction failed', ['path' => $videoPath, 'exception' => $e->getMessage()]);

            return false;
        }

        return $process->isSuccessful() && is_file($targetPath) && filesize($targetPath) > 0;
    }

    /**
     * Re-encode an audio recording as AAC in an MP4 container.
     *
     * @return bool true when the file was written
     */
    public function transcodeAudioToM4a(string $sourcePath, string $targetPath): bool
    {
        $ffmpeg = $this->binary('ffmpeg');
        if ($ffmpeg === null) {
            return false;
        }

        $process = new Process([
            $ffmpeg,
            '-v', 'error',
            '-y',
            '-i', $sourcePath,
            '-vn',
            '-c:a', 'aac',
            '-b:a', '96k',
            '-movflags', '+faststart',
            '-f', 'mp4',
            $targetPath,
        ]);
        $process->setTimeout(self::TIMEOUT_SECONDS * 4);

        try {
            $process->run();
        } catch (\Throwable $e) {
            Log::info('ffmpeg audio transcode failed', ['path' => $sourcePath, 'exception' => $e->getMessage()]);

            return false;
        }

        return $process->isSuccessful() && is_file($targetPath) && filesize($targetPath) > 0;
    }

    private function binary(string $name): ?string
    {
        return (new ExecutableFinder)->find($name);
    }
}