videocutting/src/Cutting.php

<?php

namespace DanielSiepmann\Videcutting;

/*
 * Copyright (C) 2020 Daniel Siepmann <coding@daniel-siepmann.de>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

use Symfony\Component\Process\Process;

class Cutting
{
    /**
     * @var VideoInfo
     */
    private $video;

    /**
     * @var string
     */
    private $tempFolder = '';

    /**
     * @var array
     */
    private $tempFilenames = [];

    public function __construct(
        VideoInfo $video,
        ?string $tempFolder = null
    ) {
        $this->video = $video;
        $this->tempFolder = $tempFolder ?? sys_get_temp_dir();
    }

    public function getCommandsForCutting(): \Generator
    {
        $start = $this->video->getStart();
        $end = $this->video->getEnd();

        if ($this->video->getAds() === []) {
            yield $this->getCuttingCommand($start, $end);
            return;
        }

        // Each video starts with end of last ad, and end at next ad start.
        foreach ($this->video->getAds() as [$adStart, $adEnd]) {
            $end = $adStart;

            yield $this->getCuttingCommand($start, $end);

            $start = $adEnd;
        }

        yield $this->getCuttingCommand($start, $this->video->getEnd());
    }

    public function getCommandForGeneratingMetadata(): Process
    {
        $command = sprintf(
            'ffmpeg -y -i %s -f ffmetadata %s',
            escapeshellarg($this->video->getOriginalFilename()),
            escapeshellarg($this->getMetadataFilename())
        );

        return Process::fromShellCommandline($command);
    }

    public function getCommandForGeneratingConcatInputFile(): Process
    {
        if ($this->tempFilenames === []) {
            throw new \InvalidArgumentException(
                'No temp files for concat available. Did you call "getCommandsForCutting()" before?',
                1601455216
            );
        }

        $lines = [];
        foreach ($this->tempFilenames as $filename) {
            $lines[] = 'file ' . $filename;
        }

        $command = 'printf ' . escapeshellarg(implode('\n', $lines)) . ' > ' . $this->getConcatFilename();
        $process = Process::fromShellCommandline($command);
        $process->setTimeout(2 * 60);

        return $process;
    }

    public function getCommandForGeneratingVideo(): Process
    {
        $command = sprintf(
            'ffmpeg -y -f concat -safe 0 -i %s -c copy'
            . ' -f ffmetadata -i %s -c copy -map_metadata 1'
            . ' -metadata Title=' . escapeshellarg($this->video->getTitleForHumans())
            . ' %s',
            escapeshellarg($this->getConcatFilename()),
            escapeshellarg($this->getMetadataFilename()),
            escapeshellarg($this->video->getTargetFilePath())
        );
        return Process::fromShellCommandline($command);
    }

    public function getCommandForCleanup(): Process
    {
        $tempfiles = implode(' ', array_map(function (string $filename) {
            return escapeshellarg($filename);
        }, $this->tempFilenames));

        $command = sprintf(
            'rm %s %s %s',
            $tempfiles,
            escapeshellarg($this->getConcatFilename()),
            escapeshellarg($this->getMetadataFilename())
        );
        return Process::fromShellCommandline($command);
    }

    private function getCuttingCommand(string $start, string $end): Process
    {
        $command = sprintf(
            'ffmpeg -y -ss %s -to %s -i %s -c copy %s',
            escapeshellarg($start),
            escapeshellarg($end),
            escapeshellarg($this->video->getOriginalFilename()),
            escapeshellarg($this->getNextTempFilename())
        );

        return Process::fromShellCommandline($command);
    }

    private function getNextTempFilename(): string
    {
        $count = count($this->tempFilenames) + 1;
        $nextName = $this->tempFolder
            . DIRECTORY_SEPARATOR
            . $this->video->getOriginalFilenameWithSuffix('cut-' . $count);

        $this->tempFilenames[] = $nextName;
        return $nextName;
    }

    private function getMetadataFilename(): string
    {
        $file = new \SplFileInfo($this->video->getOriginalFilenameWithSuffix('metadata'));

        return $this->tempFolder . DIRECTORY_SEPARATOR . $file->getBasename('.' . $file->getExtension()) . '.txt';
    }

    private function getConcatFilename(): string
    {
        $file = new \SplFileInfo($this->video->getOriginalFilenameWithSuffix('concat'));

        return $this->tempFolder . DIRECTORY_SEPARATOR . $file->getBasename('.' . $file->getExtension()) . '.txt';
    }
}