I'm testing the Amazon S3 plugin. Small videos upload fine. However, when I try to upload a large file (about 300MB), I get a "413 Request Entity Too Large" error. My current hosting plan doesn't allow me to set the max file size above 128MB, and I don't understand max file size should be a problem because the video is being upload to Amazon anyway.
Well actually im sorry there is not any solution available for this .The issue is in both video vibe and wplms s3 plugins .
In both first the video file is uploaded to your server and then we read the whole file contents of the uploaded file in one go and upload it to the amazon s3 and vimeo servers .
now when we read the content makes request to vimeo and amazon servers the request contents contains the video file binary data which is large .
To upload the videos you need to increase your upload limit(upload_max_filesize) , and post max file size(post_max_size) in your php configuration on your server.
Please contact your webhost to increase those and check again .