1. Confirm whether it is a single video or multiple videos:
(1) If this phenomenon occurs in a single video, it may be a resource problem. It is recommended to try to change the player.
(2) If multiple video images are dark/unclear, please continue to the next step.
2, compared with other mobile phones to confirm whether there is the same phenomenon:
(1) The same phenomenon is the problem of application resources.
(2) Other mobile phones do not have this phenomenon for the next operation.
3. Restart the phone and try whether to restore or clear the application cache.
4. Unload and reload the backup data.
5. Restore the backup data to the factory settings.
If the above investigation still cannot be solved, please bring the purchase invoice, warranty card and mobile phone to the nearest official OPPO service center for testing and handling by professional engineers.