Appion

h1. MRC PHP Extension Installation and Testing

MRC Tools is installed as a php extension and is required for displaying mrc files live on the web browser.

h2. Make sure you have installed the prerequisite packages

You may find installation information for the following packages under [[Web_Server_Installation#Web-Server-Prerequisites|Web Server Prerequisites]].

h3. php-devel

You can check whether php-devel is installed by typing

<pre>

 >phpize

</pre>

h3. php-GD/FFTW3-devel

Make sure that php-GD and FFTW 3 devel libraries are installed.

*TODO:* provide a screenshot of info.php when correctly installed.

h2. MRC Tools Installation

mrctools is installed from the php devel directory. This is usually located in /usr/include/php/ext where you will find other php extension source such as gd. After the installation, mrc.so should be placed in php's extension directory. The location of the extension directory can be found by looking for "extension_dir" in http://your_host/info.php.

h3. 1 Download "php_mrc_src_1_5_1.tgz":http://emg.nysbc.org/attachments/107/php_mrc_src_1_5_1.tgz.

h3. 2 cd to your php devel directory

<pre>

> cd /usr/include/php/ext/

> mv [downloads]/php_mrc_src_[x].tgz .

</pre>

h3. 3 Untar the archive

<pre>

> tar zxvf php_mrc_src_[x].tgz

> cd mrc/

</pre>

h3. 4 Install mrc tools

<pre>

> phpize

> ./configure 

> make

> make install

</pre>

More information on the gd library can be found "here":http://www.php.net/manual/en/image.requirements.php.

If you find that you can only view images as png instead of jpg, it may be that you do not have gd jpeg support installed.

h3. 5 mrc.so should be in your php extension directory

<pre>

> ls /usr/lib/php/extensions

mrc.so

</pre>

h3. 6 Edit your php configuration file.

<pre>

> vi /etc/php.ini

</pre>

* Increase memory

You should increase the memory_limit field. It is set to 8M by default. The more the merrier!

4kx4k float MRC image is about 64MB

<pre>

memory_limit = 256M; Maximum amount of memory

</pre>

* Check extension_dir value

<pre>

extension_dir = /usr/lib/php/extensions

</pre>

* Add the "mrc.so" extension to the end of the *extension section*

 <pre>

 extension=mrc.so

 </pre>

*Note:* If you do not see a number of extensions already activated in this section, you should probably follow the alternative path below to enable the extension in a separate file

*OR*

 * if your linux distro has a /etc/php.d/ or /etc/php.d/conf.d/ directory where other .ini files reside, create and edit mrc.ini:

 <pre>

 > cd /etc/php.d

 > vi mrc.ini

 </pre>

 * add the following lines

 <pre>

 ; Enable mrc extension module

 extension=mrc.so

 </pre>

h3. 7 restart your webserver

<pre>

> /etc/init.d/apache2 restart

</pre>

*OR*

<pre>

> /etc/init.d/httpd restart

</pre>

h3. 8 Verify the mrc tools installation

h4. Check php information

Visit or refresh http://yourhost/info.php which you created earlier. It should have a section looking like this (The version should correspond to what you've just installed):

!http://emg.nysbc.org/software/leginon/images/images/phpmrc.png!

If mrc is not listed, the extension did not get added in the right order.

h4. Alternative approach if mrc module does not show up in info.php output

1. find in the info.php web page the location of "additional .ini files parsed" in the first table (such as /etc/php.d/conf.d/*).

2. Go to the directory and make a copy of any ini file to use as a template for mrc.ini

<pre>

      >cd [additional_ini_directory]

      >cp gd.ini mrc.ini

</pre>

3. Edit mrc.ini to the following

<pre>

      ; comment out next line to disable mrc extension in php

      extension=mrc.so

</pre>

4. Comment out mrc extension from php.ini (found in /etc/php.ini/ on a typical PHP installation)

<pre>

      ;extension=mrc.so

</pre>

5. restart your webserver

<pre>

      > /etc/init.d/httpd restart

</pre>

h4. Test the MRC module installation

Download this MRC file "mymrc.mrc":http://emg.nysbc.org/attachments/55/mymrc.mrc and the following 2 scripts into the same directory to test the PHP mrc extension. 

* gd module testing script "ex1.php":http://emg.nysbc.org/attachments/53/ex1.php

* fftw module testing script "ex2.php":http://emg.nysbc.org/attachments/54/ex2.php

Run the scripts with the following commands:

The expected results are shown below. If you get the same images, you've installed the extension properly.

<pre>

> php -q ex1.php | display

</pre>

* gd module test result:

!http://emg.nysbc.org/attachments/57/ex1.php.png!

<pre>

> php -q ex2.php | display

</pre>

* fftw module test result:

!http://emg.nysbc.org/attachments/58/ex2.php.png!

Test files work but images not showing up in the ImageViewers?

[[Troubleshooting Notes|Here's one way this was fixed.]]