What is .QTCH file extension?
(Cache|cache file created by QuickTime, a media player for Mac and Windows; saves the cache of an audio or video file downloaded or streamed from the Internet; can be opened in QuickTime Player by changing the file extension to match the original file (e.g., .MP3, .MPEG, .MOV), but only if the file was created by QuickTime 6.5 or earlier.
Beginning with QuickTime 7, the software scrambles the header data of QTCH files so they can't be played by simply changing the file extension.
You can see a list of software programs here on easyfileopener.org that can open this file type so that you don’t need to search for it on the web. You can then open your file with this extension using a software listed below.