How to disable Apache gzip compression for some media files in .htaccess file?

Question

I would like to disable gzip compression for some media files which are already compressed on an Apache server via the .htaccess file.
Reason: as it's written on e.g. jPlayer's site, gzip encoding should be disabled for media files: "Media files are already compressed and the GZIP will just waste CPU on your server. The Adobe Flash Plugin will experience issues if you GZIP the media."

I'm currently having the problem that Content-Length header is not properly set when gzip is enabled - so when playing some mp3-files with a SoundManager2 player, the track's length progress bar doesn't work appropriately (so maybe that's the problem they told about on jPlayer's site).

I can test if a content is served gzipped here.
I do have mod_deflate, mod_mime and mod_rewrite modules enabled on the server.
According to a phpinfo(), here is a list of all the loaded modules:

core mod_log_config mod_logio itk http_core mod_so mod_alias mod_auth_basic mod_authn_file mod_authz_default mod_authz_groupfile mod_authz_host mod_authz_user mod_autoindex mod_cgi mod_dav mod_dav_svn mod_authz_svn mod_deflate mod_dir mod_env mod_mime mod_negotiation mod_php5 mod_reqtimeout mod_rewrite mod_setenvif mod_ssl mod_status

I'm using Drupal 6, so I already have a RewriteRule, which is the following:

# Rewrite URLs of the form 'x' to the form 'index.php?q=x'.
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !=/favicon.ico
RewriteRule ^(.*)$ index.php?q=$1 [L,QSA]

---

I've already tried these to disable gzip, but they didn't work (there are 6 different tries! - maybe some of them would have to be set globally in Apache's httpd.conf?!):

• # http://www.cyberciti.biz/tips/speed-up-apache-20-web-access-or-downloads-with-mod_deflate.html
  SetOutputFilter DEFLATE
  SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI \.(?:exe|t?gz|zip|bz2|sit|rar)$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI \.pdf$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI \.avi$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI \.mov$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI \.mp3$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI \.mp4$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI \.rm$ no-gzip dont-vary    
  

• ## Step 2. here: http://www.mydigitallife.info/how-to-enable-mod_deflate-gzip-compression-on-cpanel-web-hosts/
  <IfModule mod_deflate.c>
  SetOutputFilter DEFLATE
  
  RemoveOutputFilter mp3
  # Don’t compress already-compressed files
  SetEnvIfNoCase Request_URI .(?:gif|jpe?g|png)$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI .(?:exe|t?gz|zip|bz2|sit|rar)$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI .(?:avi|mov|mp3|mp4|rm|flv|swf|mp?g)$ no-gzip dont-vary
  SetEnvIfNoCase Request_URI .pdf$ no-gzip dont-vary
  </IfModule>
  

• RemoveOutputFilter mp3
  

• # for files that end with ".mp3"
  <FilesMatch \.mp3$>
  SetEnv no-gzip 1
  </FilesMatch>
  

• RewriteRule \.mp3$ - [NS,E=no-gzip:1,E=dont-vary:1]
  

• RewriteRule ^((.*)\.mp3)$ $1.mp3 [NS,E=no-gzip:1,E=dont-vary:1]   
  

The only one which works correctly, and disables gzip compression, BUT it is global:

• RewriteRule ^(.*)$ $1 [NS,E=no-gzip:1,E=dont-vary:1]
  

Response headers for an mp3-file when NOT using this RewriteRule: http://pastebin.com/AkUZ6m5Y
Response headers for an mp3-file when using this RewriteRule: http://pastebin.com/b8j3NF6D

Answer 1

I had to disable compression for odp files for use by external plugin Just added the following rule in .htaccess file

SetOutputFilter DEFLATE
SetEnvIfNoCase Request_URI \.odp$ no-gzip dont-vary

And the server disabled compression for odp files Make sure to clear the browser cache before testing

Answer 2

Are you not going about this the wrong way round by using the directive SetOutputFilter DEFLATE and then trying to disable this for stream which already include some form of compresstion? Isn't it a lot easier not to use this directive and then compress the stream that are compressible. E.g.

<IfModule mod_deflate.c>
    AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css application/x-javascript application/javascript application/ecmascript application/rss+xml
</IfModule>

And possibly adding a Vary header:

<IfModule mod_headers.c>
    <FilesMatch "\.(js|css|xml|html)$">
        Header append Vary Accept-Encoding
    </FilesMatch>
</IfModule>

OK this may miss the odd type that you've not thought of, but it will achieve 99+% of your compression potential.