timestamp property
- @JsonKey(name: 'timestamp')
getter/setter pair
      - Field description: Video frame timestamp in milliseconds.
Recommended value: this parameter can be set to 0 for custom video capturing.
In this case, the SDK will automatically set the timestampfield. However, please "evenly" set the calling interval ofsendCustomVideoData.
Implementation
@JsonKey(name: 'timestamp')
int timestamp;