<video height="370" width="660" autoplay="" loop="" muted=""><source type="video/mp4" src="http://i.imgur.com/zvATqgs.mp4"></video>
If you open up zvATqgs.mp4 you are redirected to a .gifv file, which is an HTML document. It has a video tag that mutes the audio.edit: This is interesting, though:
~/temp curl -I http://i.imgur.com/zvATqgs.mp4
HTTP/1.1 200 OK
Last-Modified: Fri, 26 Sep 2014 20:44:27 GMT
ETag: "2342c1e692a327e61be8395bf4d9109c"
Content-Type: video/mp4
Browsers, however, are redirected to the .gifv link, while curl gets the raw mp4 file. Interesting. I was expecting a 30x response code.Further edit: Passing a user agent to curl also causes the raw mp4 file to be returned, with no redirection. Anyone know how they are doing this redirection for browsers but not for curl?
Neither the accept header alone nor the user-agent alone are sufficient. It seems they are testing for both.
curl -H "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8" -A "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:32.0) Gecko/20100101 Firefox/32.0" -I http://i.imgur.com/zvATqgs.mp4Or is that wget that uses 1.0... Fire up wireshark ;)
Edit:
So it was the useragent and accept header that did it. Nevermind my stupid idea.
An important feature of gifs is that you know they will not make noise. Videos however like to blare obnoxious music and yell at you to grab your attention.
If it somehow became a browser convention that .gifv videos will not play sound by default, then users would be much less anxious about clicking and sharing .gifv links compared to .mp4 links.