I have some videos and I need to be able to seek to various points in them without having downloaded the entire video prior to that point. So far I have it working great in Firefox and Chrome using the html5 video tag with NodeJS and the vid-streamer module. However, IE 11 insists on downloading the entire video, I can't get it to skip ahead until it has downloaded up to the point I want to play. Does IE support partial content, and is there some trick to triggering it? Or is it already asking for it with one of the other headers (GetContentFeatures.DLNA.ORG??) and my server doesn't understand?
Sample firefox request header--it sends a new request whenever you seek, key piece being the range header, which it sends even for the initial request (bytes=0-):
Accept video/webm,video/ogg,video/*;q=0.9,application/ogg;q=0.7,audio/*;q=0.6,*/*;q=0.5
Accept-Language en-us,en;q=0.5
Connection keep-alive
Cookie connect.sid=...
Host ...
Range bytes=75661312-
Referer ...
User-Agent Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0
And server response:
Accept-Ranges bytes
Cache-Control public
Connection keep-alive
Content-Disposition inline; filename=video.webm;
Content-Length 12509
Content-Range bytes 75661312-75673820/75673821
Content-Transfer-Encoding binary
Content-Type video/webm
Date Wed, 03 Sep 2014 21:42:08 GMT
Last-Modified Thu, 28 Aug 2014 15:05:24 GMT
Pragma public
Server VidStreamer.js/0.1.4
Vary Accept-Encoding
X-Powered-By Express
status 206 Partial Content
IE11 does not send a range:
Request GET /videos/video.mp4 HTTP/1.1
Accept */*
If-Modified-Since Mon, 16 Nov 2009 14:05:45 GMT
User-Agent Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko
Referer ...
GetContentFeatures.DLNA.ORG 1
Pragma getIfoFileURI.dlna.org
Accept-Language en-US
Accept-Encoding gzip, deflate
Host ...
Connection Keep-Alive
Cookie ...
And the server (reasonably, I think) responds with the whole video and a 200 OK instead of 206 partial content:
Response HTTP/1.1 200 OK
X-Powered-By Express
Vary Accept-Encoding
Cache-Control public
Connection keep-alive
Content-Type video/mp4
Content-Disposition inline; filename=video.mp4;
Pragma public
Last-Modified Mon, 16 Nov 2009 14:05:45 GMT
Content-Transfer-Encoding binary
Content-Length 36373917
Server VidStreamer.js/0.1.4
Date Wed, 03 Sep 2014 21:38:42 GMT
Figured it out. IE11 does support pseudo streaming but it wants the "Accept-Ranges: bytes" header before it will bother requesting a range, so the server needs to respond with that regardless of whether it is actually sending a byte range. I had to modify my vid-streamer module to do that.
Caveat: I have no idea which browsers support the video tag but not byte ranges, so I can't say for sure that this won't break something somewhere, but it seems like it should be ok...
I had the same problem until after some test I figured out that the initial request from IE/Edge does not include a range header. If you correspondingly respond with an initial Content-Range of the file size equal to your Content-Length header IE will assume you just want to send the whole file in one go. If you don't get an range header you are better off choosing some content length that is less than the size of the file. I chose 1Mb, but it doesn't really matter I think.
来源：https://stackoverflow.com/questions/25654422/http-pseudo-streaming-in-ie11