partsProcessed property
The number of parts of the video that YouTube has already processed.
You can estimate the percentage of the video that YouTube has already processed by calculating: 100 * parts_processed / parts_total Note that since the estimated number of parts could increase without a corresponding increase in the number of parts that have already been processed, it is possible that the calculated progress could periodically decrease while YouTube processes a video.
Implementation
core.String? partsProcessed;