Getting avconv working with x265 on Linux Mint 17.1 - linux-mint

Question

I compiled and installed the x265 codec from multicoreware as suggested here: https://bitbucket.org/multicoreware/x265/wiki/Home and then manually installed libav with libx265 enabled as suggested here: https://wiki.libav.org/Encoding/hevc
Now, when I am trying to convert a x265 file to some other format using avconv (a tool that comes with libav) it is showing this error:
avconv: error while loading shared libraries: libx265.so.50: cannot open shared object file: No such file or directory
When I try to do whereis libx265.so.50, it gives me this:
libx265.so: /usr/local/lib/libx265.so /usr/local/lib/libx265.so.50
So, libx265 is indeed there but why isn't avconv/libav detecting it?
UPDATES:
Alternatively, you can simply answer how to get x265 working with avconv.
My system specs are: Linux Mint 17.1, based on Ubuntu 14.04

Answer 1

Okay. This works fine now. I was trying to convert an x265 video to an x264 video but there were a few things I was doing wrongly.
First, when I compiled my avconv manually, I only enabled the x265 codec and not the x264. Then, I was following wrong syntax for conversion in avconv. I will explain both here.
Let me tell it in plain steps:
First, of all. Install x265 as explained here: https://bitbucket.org/multicoreware/x265/wiki/Home.
Install missing x264 packages if they aren't installed:
sudo apt-get install libx264-dev x264
Then, manually compile avconv by downloading it from their website: https://www.libav.org/download.html. While compiling it, do it this way (this is the key):
./configure --enable-libx264 --enable-libx265 --enable-gpl
make; sudo make install;
Now the conversions can be done without fail:
avconv -i Some.Movie.x265.mkv -c:v libx264 -c:a copy out.mkv
PS: That error error while loading shared libraries was perhaps due to some mistake I did previously while compiling avconv or maybe due to wrong avconv syntax. I don't exactly know what fixed it. But the point is, it should now work just fine if one follows the above steps carefully.