claude's first attempt

2026-03-11 13:34:14 +02:00
parent 1c2fd5b280
commit c1d92e84ac
16 changed files with 1655 additions and 42 deletions
@@ -0,0 +1,89 @@
+import AVFoundation
+
+struct VideoProber {
+  static func probe(url: URL) async throws -> [String: Any] {
+    let asset = AVURLAsset(url: url)
+
+    let duration = try await asset.load(.duration)
+    let tracks = try await asset.loadTracks(withMediaType: .video)
+
+    guard let videoTrack = tracks.first else {
+      throw NSError(
+        domain: "ExpoVideoCompress",
+        code: 1,
+        userInfo: [NSLocalizedDescriptionKey: "No video track found"]
+      )
+    }
+
+    let naturalSize = try await videoTrack.load(.naturalSize)
+    let preferredTransform = try await videoTrack.load(.preferredTransform)
+    let estimatedDataRate = try await videoTrack.load(.estimatedDataRate)
+    let nominalFrameRate = try await videoTrack.load(.nominalFrameRate)
+    let formatDescriptions = try await videoTrack.load(.formatDescriptions)
+
+    // Determine codec from format descriptions
+    var codec = "unknown"
+    if let formatDescription = formatDescriptions.first {
+      let mediaSubType = CMFormatDescriptionGetMediaSubType(formatDescription)
+      codec = fourCCToString(mediaSubType)
+    }
+
+    // Detect rotation from transform
+    let rotation = rotationFromTransform(preferredTransform)
+
+    // Apply rotation to get display size
+    let isRotated = rotation == 90 || rotation == 270
+    let width = isRotated ? Int(naturalSize.height) : Int(naturalSize.width)
+    let height = isRotated ? Int(naturalSize.width) : Int(naturalSize.height)
+
+    // Check for audio track
+    let audioTracks = try await asset.loadTracks(withMediaType: .audio)
+    let hasAudio = !audioTracks.isEmpty
+
+    // Get file size
+    let fileSize: Int
+    if let attributes = try? FileManager.default.attributesOfItem(atPath: url.path),
+       let size = attributes[.size] as? Int {
+      fileSize = size
+    } else {
+      fileSize = 0
+    }
+
+    // Bitrate: use estimated data rate, or calculate from file size
+    let durationSeconds = CMTimeGetSeconds(duration)
+    var bitrate = Int(estimatedDataRate)
+    if bitrate == 0 && durationSeconds > 0 {
+      bitrate = Int(Double(fileSize * 8) / durationSeconds)
+    }
+
+    return [
+      "width": width,
+      "height": height,
+      "duration": durationSeconds,
+      "bitrate": bitrate,
+      "fileSize": fileSize,
+      "codec": codec,
+      "hasAudio": hasAudio,
+      "frameRate": nominalFrameRate,
+      "rotation": rotation
+    ]
+  }
+
+  private static func rotationFromTransform(_ transform: CGAffineTransform) -> Int {
+    let angle = atan2(transform.b, transform.a)
+    let degrees = Int(round(angle * 180.0 / .pi))
+    // Normalize to 0, 90, 180, 270
+    let normalized = ((degrees % 360) + 360) % 360
+    return normalized
+  }
+
+  private static func fourCCToString(_ code: FourCharCode) -> String {
+    let chars: [Character] = [
+      Character(UnicodeScalar((code >> 24) & 0xFF)!),
+      Character(UnicodeScalar((code >> 16) & 0xFF)!),
+      Character(UnicodeScalar((code >> 8) & 0xFF)!),
+      Character(UnicodeScalar(code & 0xFF)!)
+    ]
+    return String(chars).trimmingCharacters(in: .whitespaces)
+  }
+}