Refractor and cleanup code

Signed-off-by: Ethan Dye <mrtops03@gmail.com>

Sources/macSubtitleOCR/Extensions/DataExtensions.swift

@@ -27,8 +27,9 @@ extension Data {
             return bytes.reduce(0) { T($0) << 8 + T($1) }
         }
     }
-
-    func hexEncodedString() -> String {
-        map { String(format: "%02hhx", $0) }.joined()
-    }
+    /* Useful for debugging purposes
+     func hexEncodedString() -> String {
+         map { String(format: "%02hhx", $0) }.joined()
+     }
+     */
 }

Sources/macSubtitleOCR/VobSub/MPEG2PacketType.swift

@@ -0,0 +1,12 @@
+//
+// MPEG2PacketType.swift
+// macSubtitleOCR
+//
+// Created by Ethan Dye on 9/26/24.
+// Copyright © 2024 Ethan Dye. All rights reserved.
+//
+
+enum MPEG2PacketType {
+    static let psPacket: UInt32 = 0x0000_01BA
+    static let pesPacket: UInt32 = 0x0000_01BD
+}

Sources/macSubtitleOCR/VobSub/RLEFragment.swift

@@ -0,0 +1,12 @@
+//
+// RLEFragment.swift
+// macSubtitleOCR
+//
+// Created by Ethan Dye on 9/26/24.
+// Copyright © 2024 Ethan Dye. All rights reserved.
+//
+
+struct RLEFragment {
+    let offset: Int
+    let size: Int
+}

Sources/macSubtitleOCR/SUB/SUBFileHandler.swift → Sources/macSubtitleOCR/VobSub/VobSub.swift

@@ -1,5 +1,5 @@
 //
-// SUBFileHandler.swift
+// VobSub.swift
 // macSubtitleOCR
 //
 // Created by Ethan Dye on 9/21/24.
@@ -9,44 +9,43 @@
 import CoreGraphics
 import Foundation
 import ImageIO
+import os
 
-class VobSubDecoder {
-    struct Subtitle {
+class VobSub {
+    struct IdxSubtitleReference {
         let timestamp: String
         let offset: Int
     }
 
     var idxPalette = [UInt8]()
     var decodedSubtitles = [CGImage]()
+    var logger = Logger(subsystem: "github.ecdye.macSubtitleOCR", category: "VobSub")
+    private var stderr = StandardErrorOutputStream()
 
     func readVobSubFiles(subFileURL: URL, idxFilePath: String) -> (FileHandle, String)? {
         do {
             let fileHandle = try FileHandle(forReadingFrom: subFileURL)
             let idxData = try String(contentsOf: URL(fileURLWithPath: idxFilePath), encoding: .utf8)
             return (fileHandle, idxData)
         } catch {
-            print("Error reading files: \(error)")
             return nil
         }
     }
 
-    func parseIdxFile(idxData: String) -> [Subtitle] {
-        print("Parsing idx file")
-        var subtitles = [Subtitle]()
+    func parseIdxFile(idxData: String) -> [IdxSubtitleReference] {
+        var subtitles = [IdxSubtitleReference]()
         let lines = idxData.split(separator: "\n")
-        print("Lines: \(lines)")
         let timestampRegex: NSRegularExpression
         let offsetRegex: NSRegularExpression
         do {
             timestampRegex = try NSRegularExpression(pattern: "timestamp: (\\d{2}:\\d{2}:\\d{2}:\\d{3})")
             offsetRegex = try NSRegularExpression(pattern: "filepos: (\\w+)")
         } catch {
-            print("Error creating regular expressions: \(error)")
+            print("Error: Failed to create regular expressions: \(error)", to: &stderr)
             return []
         }
 
         for line in lines {
-            print("Parsing line: \(line)")
             if line.starts(with: "palette:") {
                 let entries = line.split(separator: ", ").map { String($0) }
                 for entry in entries {
@@ -62,18 +61,17 @@ class VobSubDecoder {
                     let timestamp = (line as NSString).substring(with: timestampMatch.range(at: 1))
                     let offsetString = (line as NSString).substring(with: offsetMatch.range(at: 1))
                     if let offset = Int(offsetString, radix: 16) {
-                        subtitles.append(Subtitle(timestamp: timestamp, offset: offset))
+                        subtitles.append(IdxSubtitleReference(timestamp: timestamp, offset: offset))
                     }
                 }
             }
         }
         return subtitles
     }
 
-    func extractSubtitleImages(subFile: FileHandle, subtitles: [Subtitle]) throws {
+    func extractSubtitleImages(subFile: FileHandle, subtitles: [IdxSubtitleReference]) throws {
         var idx = 0
         for subtitle in subtitles {
-            print("Parsing subtitle at offset \(subtitle.offset) with timestamp \(subtitle.timestamp)")
             let offset = UInt64(subtitle.offset)
             var nextOffset: UInt64
             if idx + 1 < subtitles.count {
@@ -86,8 +84,8 @@ class VobSubDecoder {
             var pic = VobSubSubtitle()
             try readSubFrame(pic: &pic, subFile: subFile, offset: offset, nextOffset: nextOffset)
             subFile.seek(toFileOffset: UInt64(pic.rleFragments[0].offset))
-            print("Found image at offset \(subtitle.offset) with timestamp \(subtitle.timestamp)")
-            print("Image size: \(pic.imageWidth) x \(pic.imageHeight)")
+            logger.debug("Found image at offset \(subtitle.offset) with timestamp \(subtitle.timestamp)")
+            logger.debug("Image size: \(pic.imageWidth) x \(pic.imageHeight)")
             let cgImage = try decodeRLEToCGImage(subPicture: pic, fileData: subFile, palette: idxPalette)
             decodedSubtitles.append(cgImage!)
             idx += 1
@@ -96,10 +94,9 @@ class VobSubDecoder {
 
     func decodeVobSub(subFilePath: String, idxFilePath: String) throws {
         guard let (subFile, idxData) = readVobSubFiles(subFileURL: URL(filePath: subFilePath), idxFilePath: idxFilePath) else {
-            print("f")
+            print("Error: Failed to read files", to: &stderr)
             return
         }
-        print("Here")
         let subtitles = parseIdxFile(idxData: idxData)
         try extractSubtitleImages(subFile: subFile, subtitles: subtitles)
     }

Sources/macSubtitleOCR/VobSub/VobSubError.swift

@@ -0,0 +1,11 @@
+//
+// VobSubError.swift
+// macSubtitleOCR
+//
+// Created by Ethan Dye on 9/26/24.
+// Copyright © 2024 Ethan Dye. All rights reserved.
+//
+
+enum VobSubError: Error {
+    case invalidRLEBufferOffset
+}