Ffmpeg does not work from php

I installed the version from http://ffmpeg.org/releases/ffmpeg-2.5.3.tar.bz2 and also tried the yum version but it is not new enough for youtube-dl.

I tried export PATH=$PATH:/usr/local/bin/ffmpeg and PHP/Apache still cant find FFmpeg.

Apache user runs PHP script on CentOS 6.5.
Calling my youtube-dl.php from php command line as root works (with FFmpeg)
Calling my youtube-dl.php from php apache user works (not with FFmpeg)

What I am trying to do: shell exec youtube-dl (youtube dl calls FFmpeg in its binary code which there is now to modifiy it to add the full path). This works but the FFmpeg part my youtube-dl.php file

$output = shell_exec('youtube-dl -o "/home/test/%(title)s.%(ext)s" '.$url.'      -f bestvideo+bestaudio 2>&1');
echo "<pre>$output</pre>";

# which ffmpeg
/usr/local/bin/ffmpeg

Someone on other pages on this site says local/bin is for customized versions but I downloaded it directly from FFmpeg and did the standard ./configure make install.

Done:

 chmod 755 to /usr/local/bin/ffmpeg

Running FFmpeg as a test command directly (sometimes works and doesn't as I upgraded/rebooted/updatedb/etc)

$output = shell_exec('ffmpeg 2>&1');
echo "<pre>$output</pre>";

Result:

<pre>sh: ffmpeg: command not found</pre>

I read all of these similar questions but they didn't help:

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Solution what worked for me. I followed the tutorial here to install ffmpeg: http://www.wikihow.com/Install-FFmpeg-on-Windows

Set up the PATH then I checked ffmpeg –version from command prompt it was working.

Then I tried to download a 1080p video with youtube-dl (youtube link) -f bestvideo+bestaudio but I got the same message: "WARNING: You have requested multiple formats but ffmpeg or avconv are not installed. The formats won't be merged." Of course it was installed.

Then I opened the command prompt with Run as Administrator, tried the same and it worked finally.