Determine video codecs

CHDataManagement/Model/FileResource.swift

@@ -343,6 +343,62 @@ final class FileResource: Item, LocalizedItem {
         }
     }
 
+    private var _videoType: String?
+
+    func videoType() -> String? {
+        if let _videoType {
+            return _videoType
+        }
+        _videoType = determineVideoType()
+        return _videoType
+    }
+
+    private func determineVideoType() -> String? {
+        #warning("TODO: Move ffmpeg path to settings")
+        switch type {
+        case .webm:
+            return "video/webm"
+        case .mp4, .m4v:
+            if isExternallyStored {
+                return "video/mp4"
+            }
+            break
+        default:
+            return nil
+        }
+
+        return content.storage.with(file: identifier) { path in
+            let process = Process()
+            let arguments = "-v error -select_streams v:0 -show_entries stream=codec_tag_string -of default=noprint_wrappers=1:nokey=1 \(path.path())"
+                .components(separatedBy: " ")
+            process.launchPath = "/opt/homebrew/bin/ffprobe"
+            process.arguments = Array(arguments)
+
+            let pipe = Pipe()
+            process.standardOutput = pipe
+            process.standardError = pipe
+
+            process.launch()
+            process.waitUntilExit()
+
+            let outputData = pipe.fileHandleForReading.readDataToEndOfFile()
+            let outputString = String(data: outputData, encoding: .utf8) ?? ""
+
+            if process.terminationStatus != 0 {
+                print("Failed to determine video type for \(identifier)")
+                print(outputString)
+                return nil
+            }
+            let firstLine = outputString.components(separatedBy: .newlines).first!.trimmed
+            guard let type = VideoBlock.SourceType.h265(codec: firstLine) else {
+                print("Unknown codec type for \(identifier): \(firstLine)")
+                print(outputString)
+                return "video/mp4"
+            }
+            return type.mimeType
+        }
+    }
+
     // MARK: Paths
 
     func removeFileFromOutputFolder() {