refactor: replace transcript parser by mantas-done/subtitles library

composer.json

@@ -20,6 +20,7 @@
     "james-heinrich/getid3": "^2.0.0-beta5",
     "league/commonmark": "^2.4.2",
     "league/html-to-markdown": "5.1.1",
+    "mantas-done/subtitles": "^1.0.21",
     "melbahja/seo": "^v2.1.1",
     "michalsn/codeigniter4-uuid": "v1.0.2",
     "mpratt/embera": "^2.0.36",

modules/Media/CastopodSubtitles/CastopodSubtitles.php

@@ -0,0 +1,73 @@
+<?php
+
+/**
+ * @copyright  2024 Ad Aures
+ * @license    https://www.gnu.org/licenses/agpl-3.0.en.html AGPL3
+ * @link       https://castopod.org/
+ */
+
+namespace Modules\Media\CastopodSubtitles;
+
+use Done\Subtitles\Code\Converters\ConverterContract;
+use Done\Subtitles\Code\Converters\SrtConverter;
+use Done\Subtitles\Code\Converters\VttConverter;
+use Done\Subtitles\Subtitles;
+use Exception;
+
+class CastopodSubtitles extends Subtitles
+{
+    /**
+     * @var array<array{extension:string,format:string,name:string,class:class-string<ConverterContract>}>
+     */
+    public static $formats = [
+        [
+            'extension' => 'vtt',
+            'format'    => 'vtt',
+            'name'      => 'WebVTT',
+            'class'     => VttConverter::class,
+        ],
+        [
+            'extension' => 'srt',
+            'format'    => 'srt',
+            'name'      => 'SubRip',
+            'class'     => SrtConverter::class,
+        ],
+        [
+            'extension' => 'json',
+            'format'    => 'json',
+            'name'      => 'JSON',
+            'class'     => JSONConverter::class,
+        ],
+    ];
+
+    /**
+     * @param string $format
+     * @param array<mixed> $options
+     * @return string
+     */
+    public function content($format, $options = [])
+    {
+        /** @var ConverterContract $converter */
+        $converter = $this->getConverterByFormat($format);
+
+        return $converter->internalFormatToFileContent($this->internal_format, $options);
+    }
+
+    /**
+     * @param string $format
+     * @return ConverterContract
+     */
+    private function getConverterByFormat($format)
+    {
+        foreach (self::$formats as $row) {
+            if ($row['format'] === $format) {
+                $full_class_name = $row['class'];
+                /** @var ConverterContract $converter */
+                $converter = new $full_class_name();
+                return $converter;
+            }
+        }
+
+        throw new Exception("Can't find suitable converter, for format: {$format}");
+    }
+}

modules/Media/CastopodSubtitles/JSONConverter.php

@@ -0,0 +1,67 @@
+<?php
+
+/**
+ * @copyright  2024 Ad Aures
+ * @license    https://www.gnu.org/licenses/agpl-3.0.en.html AGPL3
+ * @link       https://castopod.org/
+ */
+
+namespace Modules\Media\CastopodSubtitles;
+
+use Done\Subtitles\Code\Converters\ConverterContract;
+
+class JSONConverter implements ConverterContract
+{
+    /**
+     * @param string $file_content
+     * @return bool
+     */
+    public function canParseFileContent($file_content)
+    {
+        json_decode($file_content);
+        return json_last_error() === JSON_ERROR_NONE;
+    }
+
+    /**
+     * @param string $file_content
+     * @param string $original_file_content
+     * @return array<array{start:int,end:int,lines:array<string>}>
+     */
+    public function fileContentToInternalFormat($file_content, $original_file_content)
+    {
+        /** @var array<array{startTime:int,endTime:int,text:string}> $jsonTranscriptArray */
+        $jsonTranscriptArray = json_decode($file_content, true);
+
+        $internalFormat = [];
+        foreach ($jsonTranscriptArray as $segment) {
+            $internalFormat[] = [
+                'start' => $segment['startTime'],
+                'end'   => $segment['endTime'],
+                'lines' => explode(PHP_EOL, $segment['text']),
+            ];
+        }
+
+        return $internalFormat;
+    }
+
+    /**
+     * @param array<array{start:int,end:int,lines:array<string>}> $internal_format
+     * @param array<mixed> $output_settings
+     */
+    public function internalFormatToFileContent(array $internal_format, array $output_settings): string
+    {
+        /** @var array<array{number:int,startTime:int,endTime:int,text:string}> $jsonTranscriptArray */
+        $jsonTranscriptArray = [];
+
+        foreach ($internal_format as $key => $value) {
+            $jsonTranscriptArray[] = [
+                'number'    => $key,
+                'startTime' => $value['start'],
+                'endTime'   => $value['end'],
+                'text'      => implode(PHP_EOL, $value['lines']),
+            ];
+        }
+
+        return (string) json_encode($jsonTranscriptArray);
+    }
+}

modules/Media/Entities/Transcript.php

@@ -10,98 +10,7 @@ declare(strict_types=1);
 
 namespace Modules\Media\Entities;
 
-use CodeIgniter\Files\File;
-use Exception;
-use Modules\Media\TranscriptParser;
-
 class Transcript extends BaseMedia
 {
-    public ?string $json_key = null;
-
-    public ?string $json_url = null;
-
     protected string $type = 'transcript';
-
-    public function initFileProperties(): void
-    {
-        parent::initFileProperties();
-
-        if ($this->file_metadata !== null && array_key_exists('json_key', $this->file_metadata)) {
-            helper('media');
-
-            $this->json_key = $this->file_metadata['json_key'];
-            $this->json_url = service('file_manager')
-                ->getUrl($this->json_key);
-        }
-    }
-
-    public function setFile(File $file): self
-    {
-        parent::setFile($file);
-
-        $metadata = lstat((string) $file) ?? [];
-
-        helper('filesystem');
-
-        // set metadata (generated json file path)
-        $this->json_key = change_file_path($this->file_key, '', 'json');
-        $metadata['json_key'] = $this->json_key;
-
-        $this->attributes['file_metadata'] = json_encode($metadata, JSON_INVALID_UTF8_IGNORE);
-
-        $this->file = $file;
-
-        return $this;
-    }
-
-    public function saveFile(): void
-    {
-        $this->saveJsonTranscript();
-
-        parent::saveFile();
-    }
-
-    public function deleteFile(): bool
-    {
-        if (! parent::deleteFile()) {
-            return false;
-        }
-
-        if ($this->json_key) {
-            return service('file_manager')->delete($this->json_key);
-        }
-
-        return true;
-    }
-
-    private function saveJsonTranscript(): void
-    {
-        $transcriptContent = file_get_contents($this->file->getRealPath());
-
-        $transcriptParser = new TranscriptParser();
-
-        if ($transcriptContent === false) {
-            throw new Exception('Could not read transcript file at ' . $this->file->getRealPath());
-        }
-
-        $transcript_format = $this->file->getExtension();
-        switch ($transcript_format) {
-            case 'vtt':
-                $transcriptJson = $transcriptParser->loadString($transcriptContent)
-                    ->parseVtt();
-                break;
-            case 'srt':
-            default:
-                $transcriptJson = $transcriptParser->loadString($transcriptContent)
-                    ->parseSrt();
-        }
-
-        $tempFilePath = WRITEPATH . 'uploads/' . $this->file->getRandomName();
-        file_put_contents($tempFilePath, $transcriptJson);
-
-        $newTranscriptJson = new File($tempFilePath, true);
-
-        service('file_manager')
-            ->save($newTranscriptJson, $this->json_key);
-    }
 }

modules/Media/TranscriptParser.php

@@ -1,220 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-/**
- * Converts a SRT or VTT file to JSON
- *
- * @copyright  2022 Ad Aures
- * @license    https://www.gnu.org/licenses/agpl-3.0.en.html AGPL3
- * @link       https://castopod.org/
- */
-
-namespace Modules\Media;
-
-use Exception;
-use stdClass;
-
-class TranscriptParser
-{
-    protected string $transcriptContent;
-
-    public function loadString(string $content): self
-    {
-        $this->transcriptContent = $content;
-
-        return $this;
-    }
-
-    /**
-     * Adapted from: https://stackoverflow.com/a/11659306
-     *
-     * @return string Returns the json encoded string
-     */
-    public function parseSrt(): string
-    {
-        if (! defined('SRT_STATE_SUBNUMBER')) {
-            define('SRT_STATE_SUBNUMBER', 0);
-        }
-
-        if (! defined('SRT_STATE_TIME')) {
-            define('SRT_STATE_TIME', 1);
-        }
-
-        if (! defined('SRT_STATE_TEXT')) {
-            define('SRT_STATE_TEXT', 2);
-        }
-
-        if (! defined('SRT_STATE_BLANK')) {
-            define('SRT_STATE_BLANK', 3);
-        }
-
-        $subs = [];
-        $state = SRT_STATE_SUBNUMBER;
-        $subNum = 0;
-        $subText = '';
-        $subTime = '';
-
-        $lines = explode(PHP_EOL, $this->transcriptContent);
-        foreach ($lines as $line) {
-            switch ($state) {
-                case SRT_STATE_SUBNUMBER:
-                    $subNum = trim($line);
-                    $state = SRT_STATE_TIME;
-                    break;
-
-                case SRT_STATE_TIME:
-                    $subTime = trim($line);
-                    $state = SRT_STATE_TEXT;
-                    break;
-
-                case SRT_STATE_TEXT:
-                    if (trim($line) === '') {
-                        $sub = new stdClass();
-                        $sub->number = (int) $subNum;
-                        [$startTime, $endTime] = explode(' --> ', $subTime);
-                        $sub->startTime = $this->getSecondsFromTimeString($startTime);
-                        $sub->endTime = $this->getSecondsFromTimeString($endTime);
-                        $sub->text = trim($subText);
-                        $subText = '';
-                        $state = SRT_STATE_SUBNUMBER;
-                        $subs[] = $sub;
-                    } elseif ($subText !== '') {
-                        $subText .= PHP_EOL . $line;
-                    } else {
-                        $subText .= $line;
-                    }
-
-                    break;
-            }
-        }
-
-        if ($state === SRT_STATE_TEXT) {
-            // if file was missing the trailing newlines, we'll be in this
-            // state here.  Append the last read text and add the last sub.
-            // @phpstan-ignore-next-line
-            $sub->text = $subText;
-            // @phpstan-ignore-next-line
-            $subs[] = $sub;
-        }
-
-        $jsonString = json_encode($subs, JSON_PRETTY_PRINT);
-
-        if (! $jsonString) {
-            throw new Exception('Failed to parse SRT to JSON.');
-        }
-
-        return $jsonString;
-    }
-
-    public function parseVtt(): string
-    {
-        if (! defined('VTT_STATE_HEADER')) {
-            define('VTT_STATE_HEADER', 0);
-        }
-
-        if (! defined('VTT_STATE_BLANK')) {
-            define('VTT_STATE_BLANK', 1);
-        }
-
-        if (! defined('VTT_STATE_TIME')) {
-            define('VTT_STATE_TIME', 2);
-        }
-
-        if (! defined('VTT_STATE_TEXT')) {
-            define('VTT_STATE_TEXT', 3);
-        }
-
-        $subs = [];
-        $state = VTT_STATE_HEADER;
-        $subNum = 0;
-        $subText = '';
-        $subTime = '';
-
-        $lines = explode(PHP_EOL, $this->transcriptContent);
-        // add a newline as last item, if it isn't already a newline
-        if ($lines[array_key_last($lines)] !== '') {
-            $lines[] = PHP_EOL;
-        }
-
-        foreach ($lines as $line) {
-            switch ($state) {
-                case VTT_STATE_HEADER:
-                    $state = VTT_STATE_BLANK;
-                    break;
-
-                case VTT_STATE_BLANK:
-                    $state = VTT_STATE_TIME;
-                    break;
-
-                case VTT_STATE_TIME:
-                    $subTime = trim($line);
-                    $state = VTT_STATE_TEXT;
-                    break;
-
-                case VTT_STATE_TEXT:
-                    if (trim($line) === '') {
-                        $sub = new stdClass();
-                        $sub->number = $subNum;
-                        [$startTime, $endTime] = explode(' --> ', $subTime);
-                        $sub->startTime = $this->getSecondsFromVTTTimeString($startTime);
-                        $sub->endTime = $this->getSecondsFromVTTTimeString($endTime);
-                        $sub->text = trim($subText);
-                        if ($subSpeaker !== '') {
-                            $sub->speaker = trim((string) $subSpeaker);
-                        }
-
-                        $subText = '';
-                        $state = VTT_STATE_TIME;
-                        $subs[] = $sub;
-                        ++$subNum;
-                    } elseif ($subText !== '') {
-                        $subText .= PHP_EOL . $line;
-                    } else {
-                        /** VTT includes a lot of information on the spoken line
-                         * An example may look like this:
-                         * <v.loud.top John>So this is it
-                         * We need to break this down into it's components, namely:
-                         * 1. The actual words for the caption
-                         * 2. Who is speaking
-                         * 3. Any styling cues encoded in the VTT (which we dump)
-                         * More information: https://www.w3.org/TR/webvtt1/
-                         */
-                        $vtt_speaker_pattern = '/^<.*>/';
-                        $removethese = ['<', '>'];
-                        preg_match($vtt_speaker_pattern, $line, $matches);
-                        if (isset($matches[0])) {
-                            $subVoiceCue = explode(' ', str_replace($removethese, '', $matches[0]));
-                            $subSpeaker = $subVoiceCue[1];
-                        } else {
-                            $subSpeaker = '';
-                        }
-
-                        $subText .= preg_replace($vtt_speaker_pattern, '', $line);
-                    }
-
-                    break;
-            }
-        }
-
-        $jsonString = json_encode($subs, JSON_PRETTY_PRINT);
-
-        if (! $jsonString) {
-            throw new Exception('Failed to parse VTT to JSON.');
-        }
-
-        return $jsonString;
-    }
-
-    private function getSecondsFromTimeString(string $timeString): float
-    {
-        $timeString = explode(',', $timeString);
-        return (strtotime($timeString[0]) - strtotime('TODAY')) + (float) "0.{$timeString[1]}";
-    }
-
-    private function getSecondsFromVTTTimeString(string $timeString): float
-    {
-        $timeString = explode('.', $timeString);
-        return (strtotime($timeString[0]) - strtotime('TODAY')) + (float) "0.{$timeString[1]}";
-    }
-}

modules/MediaClipper/VideoClipper.php

@@ -13,6 +13,7 @@ namespace Modules\MediaClipper;
 use App\Entities\Episode;
 use Exception;
 use GdImage;
+use Modules\Media\CastopodSubtitles\CastopodSubtitles;
 use Modules\Media\Entities\Transcript;
 use Modules\Media\FileManagers\FileManagerInterface;
 use Modules\MediaClipper\Config\MediaClipper;
@@ -122,66 +123,17 @@ class VideoClipper
             throw new Exception('Episode does not have a transcript!');
         }
 
-        if ($this->episode->transcript->json_url) {
+        $subtitleString = file_get_contents($this->episode->transcript->file_url);
-            $this->generateSubtitlesClipFromJson($this->episode->transcript->json_key);
-        } else {
-            $subtitlesInput = $this->episode->transcript->file_url;
-            $subtitleClipCmd = "ffmpeg -y -i {$subtitlesInput} -ss {$this->start} -t {$this->duration} {$this->subtitlesClipOutput}";
-            exec($subtitleClipCmd);
-        }
-    }
 
-    public function generateSubtitlesClipFromJson(string $jsonFileKey): void
+        if (! $subtitleString) {
-    {
+            throw new Exception('Could not load transcript: ' . $this->episode->transcript->file_url);
-        /** @var FileManagerInterface $fileManager */
-        $fileManager = service('file_manager');
-
-        $jsonTranscriptString = (string) $fileManager->getFileContents($jsonFileKey);
-        if ($jsonTranscriptString === '') {
-            throw new Exception('Cannot get transcript json contents.');
         }
 
-        $jsonTranscript = json_decode($jsonTranscriptString, true);
+        $subtitles = CastopodSubtitles::loadFromString($subtitleString);
-        if ($jsonTranscript === null) {
-            throw new Exception('Transcript json is invalid.');
-        }
 
-        $srtClip = '';
+        $subtitles->trim($this->start, $this->end);
-        $segmentIndex = 1;
-        foreach ($jsonTranscript as $segment) {
-            $startTime = null;
-            $endTime = null;
 
-            if ($segment['startTime'] < $this->end && $segment['endTime'] > $this->start) {
+        $subtitles->save($this->subtitlesClipOutput);
-                $startTime = $segment['startTime'] - $this->start;
-                $endTime = $segment['endTime'] - $this->start;
-            }
-
-            if ($segment['startTime'] < $this->start && $this->start < $segment['endTime']) {
-                $startTime = 0;
-            }
-
-            if ($segment['startTime'] < $this->end && $segment['endTime'] >= $this->end) {
-                $endTime = $this->duration;
-            }
-
-            if ($startTime !== null && $endTime !== null) {
-                $formattedStartTime = $this->formatSeconds($startTime);
-                $formattedEndTime = $this->formatSeconds($endTime);
-                $srtClip .= <<<CODE_SAMPLE
-                {$segmentIndex}
-                {$formattedStartTime} --> {$formattedEndTime}
-                {$segment['text']}
-
-
-                CODE_SAMPLE;
-
-                ++$segmentIndex;
-            }
-        }
-
-        // create srt clip file
-        file_put_contents($this->subtitlesClipOutput, $srtClip);
     }
 
     public function formatSeconds(float $seconds): string