Setting upload_max_filesize (etc) for large file uploads

I'm trying to upload files via this jQuery plugin: http://aquantum-demo.appspot.com/file-upload

I am able to upload files up to 1.2GB 开发者_开发知识库without a problem. The next largest file I've tried is 1.8GB and this upload fails. I have set:

max_execution_time = 0
max_input_time = 0

memory_limit = 4000M
post_max_size = 3500M
upload_max_filesize = 3000M

What should these values be if this isn't working? I need to upload video files that are up to 2GB via this method.

Thanks in advance!

possibly you're on shared hosting so the memory is limited. and 1.8GB sounds to me like something nearly 2GB, this is the limit on 32-bit system for integer, applies to PHP also.