php - Laravel FFMPEG 中的条件格式

Question

我目前在 Laravel 项目中使用 Laravel FFMPEG 并运行以下运行良好 https://github.com/protonemedia/laravel-ffmpeg
这是一个有效的代码示例:

 $lowBitrate = (new X264)->setKiloBitrate(250);
            $midBitrate = (new X264)->setKiloBitrate(500);
            $highBitrate = (new X264)->setKiloBitrate(1000);
            $superBitrate = (new X264)->setKiloBitrate(1500);

            FFMpeg::open('steve_howe.mp4')
                ->exportForHLS()
                ->addFormat($lowBitrate, function($media) {
                    $media->addFilter('scale=640:480');
                })

                 ->addFormat($midBitrate, function($media) {
                    $media->scale(960, 720);
                })
                ->addFormat($highBitrate, function ($media) {
                    $media->addFilter(function ($filters, $in, $out) {
                        $filters->custom($in, 'scale=1920:1200', $out); // $in, $parameters, $out
                    });
                })
                ->addFormat($superBitrate, function($media) {
                    $media->addLegacyFilter(function ($filters) {
                        $filters->resize(new \FFMpeg\Coordinate\Dimension(2560, 1920));
                    });
                })
                ->save('adaptive_steve.m3u8');

现在，我的挑战是，在客户端，我的用户需要选择他们希望在转码作业中包含哪些格式，并且一项作业可能包含 2 个或更多比特率变化，因此在调用之前需要有一个条件语句 -> addFromat()
理想情况下，我需要解决这个问题:

 $lowBitrate = (new X264)->setKiloBitrate(250);
        $midBitrate = (new X264)->setKiloBitrate(500);
        $highBitrate = (new X264)->setKiloBitrate(1000);
        $superBitrate = (new X264)->setKiloBitrate(1500);

        FFMpeg::open('steve_howe.mp4')
            ->exportForHLS()
            ->addFormat($lowBitrate, function($media) {
                $media->addFilter('scale=640:480');
            })
             /// adding if statement here
             ->addFormat($midBitrate, function($media) {
                $media->scale(960, 720);
            })
            ->addFormat($highBitrate, function ($media) {
                $media->addFilter(function ($filters, $in, $out) {
                    $filters->custom($in, 'scale=1920:1200', $out); // $in, $parameters, $out
                });
            })
            ->addFormat($superBitrate, function($media) {
                $media->addLegacyFilter(function ($filters) {
                    $filters->resize(new \FFMpeg\Coordinate\Dimension(2560, 1920));
                });
            })
            ->save('adaptive_steve.m3u8');

不知道如何在此处添加 if/else 语句。你认为我应该如何处理这个问题？
谢谢

Answer 1

我们可以使用条件尾随如下:

$ffmpeg = FFMpeg
   ::open('steve_howe.mp4')
   ->exportForHLS()
   ->addFormat($lowBitrate, function($media) {
       $media->addFilter('scale=640:480');
   });

//condition here:
if (true) { 
   $ffmpeg = $ffmpeg->addFormat($midBitrate, function($media) {
       $media->scale(960, 720);
   });
}
// 2nd condition here:
if (true) { 
   $ffmpeg = $ffmpeg->addFormat($highBitrate, function ($media) {
       $media->addFilter(function ($filters, $in, $out) {
           $filters->custom($in, 'scale=1920:1200', $out); // $in, $parameters, $out
       });
   });
}

$ffmpeg->save('adaptive_steve.m3u8');