Issue regarding the Chuck Upload API

Hi,
We are facing an issue regarding the File Upload API. As per the API below are the mandatory details to start the file upload session.
i) File ID
ii) File Size
iii) File Name

We are getting a live stream of file data from the other service, from that we can provide the two details except for the 'File Size'.

We need to implement the box file upload/upload part API for stream data. We do not provide actual file length and the File Size is compulsory on the above API. How can we implement the file upload/upload part API without the File Size?

If we don't provide the 'File Size', we get the below error.
{ code: 'bad_request',
help_url: 'http://developers.box.com/docs/#errors',
status: 400,
message: 'Stream ended unexpectedly',
type: 'error' }

Did anybody faced a similar issue or had a solution to the above problem?

Thanks,
Manish.