Earlier we observed that URLs returning "Content-Length" also respond to request's "Content-Range" header. This is why, for simplification, we told that "Content-Length" is required.
But, now we are noticing that a URL may not respond to request's "Content-Range" header even if it returns "Content-Length". This is what happening with cdn.creatomate.com domain. There is no workaround to make this kind of URLs compatible with part-by-part download.
This is a sample video URL that will work for part by part download because it includes both the headers. Content-Length and Content-Range.
This will not work for part by part download because it does not have Content-Range header apart from Content-Length.
For large video uploads, Content-Range headers are also required in the headers of the file.
If Content-Range header is available when we make a GET request with "Range" header, our API will be able to upload large files.