Modify DVD Firmware

I have a USB DVD player that I use to play video files from my usb drive. When I press a number on the remote, the corresponding video number plays automatically. Example, when I press 23, video number 23 starts playing automatically. The interval between when I press a number and when the video starts playing is very short, about 2 seconds. Example, If I want to play video number 1203, and I enter 12, if I don't press 0 within 2 seconds then video number 12 starts playing automatically. I am not fast in pressing the buttons on the remote, and so in many occasions, a video starts to play as I am navigating to the next digit. Example, I want to play video number 193. I enter 1 then as am about to press the next digit 9, the video number 1 starts to play automatically because I did not enter the next digit within the 2 seconds interval. I would like the Auto Play functionality to be modified. The modification entails extending the duration to 9 seconds, so that when I input a number, I have 9 seconds interval before I input the next digit. I do not have the source code, I only have the firmware in bin format. It uses Sunplus chipset 8202RQ and Eeprom EN25T80 Since I do not have the source code, the developer might have to reverse engineer the firmware or work with a hex editor, or any other method that works. TASK: To extend the Auto-Play interval to 9 seconds