text: // Copyright 2019 The MediaPipe Authors.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //      http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #import <CoreMedia/CoreMedia.h>
  #import <Foundation/Foundation.h>
  
  #include "mediapipe/framework/calculator_framework.h"
  #include "mediapipe/objc/util.h"
  
  /// Helps convert a CMTime to a MediaPipe timestamp.
  @interface MPPTimestampConverter : NSObject
  
  /// The last timestamp returned by timestampForMediaTime:.
  @property(nonatomic, readonly) mediapipe::Timestamp lastTimestamp;
  
  /// Initializer.
  - (instancetype)init NS_DESIGNATED_INITIALIZER;
  
  /// Resets the object. After this method is called, we can return timestamps
  /// that are lower than previously returned timestamps.
  - (void)reset;
  
  /// Converts a CMTime to a MediaPipe timestamp. This ensures that MediaPipe
  /// timestamps
  /// are always increasing: if the provided CMTime has gone backwards (e.g. if
  /// it's from a
  /// looping video), we shift all timestamps from that point on to keep the
  /// output increasing.
  /// This state is erased when reset is called.
  - (mediapipe::Timestamp)timestampForMediaTime:(CMTime)mediaTime;
  
  @end
  