.htaccess - If the mp4 video was not found, throw the flv video -

i own video sharing website users upload videos it.

usually videos converted mp4 file , streamed. however, many times due server failures, video gets converted flv files. flv , mp4 files stored within same location under same name.

the player calls 1 video file source:

http://server.mysite.com/location/user/id/file.mp4 

i want server throw same link flv file instead of mp4 (if mp4 file not found), in case if mp4 video not found server throw:

http://server.mysite.com/location/user/id/file.flv 

how achieve using htaccess?

custom 404 page

how dropping custom 404 error page looks whether alternative file exists , redirects there.

mod_rewrite

second option involves mod_rewrite (untested pseudo-code):

in /etc/httpd/conf/httpd.conf (or wherever httpd.conf lives in distro) enable rewriteengine (you can per vhost if wish so):

rewriteengine on 

also don't forget set allowoverrides directory:

<directory /foo/bar>    allowoverrides  fileinfo </directory> 

then in .htaccess do:

rewritebase /foo/bar rewritecond %{script_filename} !-f rewriterule   ^(.*).mp4 $1.flv [r=301] 

note if apply rewriterules in .htaccess have to setup rewritebase otherwise you'll seeing weird redirects. if set httpd.conf - can still not required.

as option [r=301] replaced [p], means software think it's getting .mp4 file whereas in fact payload .flv file

see mod_rewrite docs more info