How to make a media player

I was looking for a little project to keep me busy over Christmas and decided to have a look at organising the contents of /home/media. The media directory on my Red Hat Linux box holds:

3523 audio files
595 video files

It got called jplayer because its for private use (by the johnsons) and j follows i and the flash player I used is called jwplayer.

Some top-level ideas

  • Things should be bookmark-able
  • Editing and managing meta-data had to be possible during playback.
  • And some of the RESTful ideas that are running around from my day job should find their way into the design.

In the end it was made using: Perl, MySQL, Apache (XSSI), Javascript including SWFobject, Flash (JWplayer) and CSS. My background is in Perl and database so the challenges were going to be in the javascript and CSS. Here is a step-through the process of creating and playing a media file.

On the command line use


to make an input file. Looks like this:


And then use curl to upload those entries to the database using an HTTP PUT

$ curl -T .avlib http://localhost/cgi-bin/
added 3 rows ok

To start playing the files I have to use a browser and enter a search phrase. An onClick() event creates an Ajax call to the web service. It looks like jplayer/?q=morcheeba

The output from the web service produces a list.

<a href="/jplayer/?playlist=/audio/morcheeba">morcheeba</a>
<div class="summary"></div>
<div class="small">audio/mpeg</div>

Results are piped through a pager so you scroll through 5 items at a time. Selecting an item from the search results loads a new page (to get the bookmark) and displays the playlist. In this context a playlist is just all the files in a folder. Each file has a link that will load the movie into the player and displayer the meta-data in a webform. For example:

<a href=""
onclick="loadSWF( '/audio/morcheeba','shoulder_holster.mp3' , 'jwplayer');
updateForm( '/audio/morcheeba','shoulder_holster.mp3');
return false;">shoulder_holster>/a>

Playback is controlled through the Flash object. Once the meta-data is updated an Ajax calls generates a POST to send the new data to the server.

The web service

PUT /path/to/avfile
200 returns text summary of new rows added
400 returned zero rows

POST a set of REQUEST VARIABLES representing an item
200 returns string saying 'thanks'

GET ?q=Search+String
200 returns a paginated list of playlists matching string

200 returns data items as a web form

no parameters displays name and version

The Perl uses the HTML::Template module to create the presentation layer and the DBI modules to access the MySQL. Otherwise it’s hand-written, even the CGI functions (I was surprised that didn’t help do the PUTs).

Data schema

CREATE TABLE playlist (
pk_pldir varchar(255) NOT NULL,
playlist varchar(127) NOT NULL,
mimetype char(23) NOT NULL,
summary varchar(1023),
PRIMARY KEY (pk_pldir)

pk_pldiravfile varchar(255) NOT NULL,
fk_pldir varchar(255) NOT NULL,
avfile varchar(255) NOT NULL,
title varchar(255) NOT NULL,
duration int(4),
thumbnail varchar(127),
PRIMARY KEY (pk_pldiravfile)

CREATE TABLE pldir__tag (
pk_pldirtag varchar(255) NOT NULL,
fk_pldir varchar(255) NOT NULL,
tag varchar(63) NOT NULL,
PRIMARY KEY (pk_pldirtag)

Web client

There are 3 main areas of the page.

  1. banner and search box
  2. SWF player window and playlist panel
  3. search results OR html form to update playlist metadata

I don’t have a server to host jplayer on tinternet, but here’s a screen grab:


To do

  • Currently I’m using AVS to convert movies FLV. Have upgraded ffmpeg 0.5 and would prefer to use ffmpeg for scripting
    • a series of thumbnails (or if audio use album art or an icon)
    • calculate the duration
  • Improve search by filtering through audio or video


JW Player
HTML playlist
SWF Object

Gypsies entertain the brethren

I’ve never been inside a masonic lodge before. That’s one of the best (and worst) things about being a live performer — you travel a lot. Despite a somewhat faded grandeur The Guild Hall has an impressive architecture that was teeming with life at the brethren’s annual let-the-wives-in event. We Gypsies (also known as 5 Go Swing) swung hard and were rewarded with some yi-haw clapping and blushingly nice compliments from our host. As I scanned the audience I looked for familiar faces (Dan Brown?) but it wasn’t my kind of crowd.

Amusing Our Leader

My friend and I were discussing cats, dogs and how they adapt themselves to human families as if we humans were animal packs. While much has been said about dogs and the alpha male, my friend was telling me about a new theory concerning cats. Apparently our behavior towards cats engenders them to consider themselves as pack leader. With this freshly in mind I came across Ruben (my youngest) grimacing at our largest cat Kovu. Ruben wasn’t just grimacing, he had his little fingers rammed into both corners of his mouth which was pulled taut with a waggling tongue in the middle. His eyes were rolling around like dishes and his head was waving from side-to-side. I asked him why he was pulling faces at the cats. Ruben jumped up and down, and round and around for a bit and then squeaked “to make them laugh of course” and resumed his facial postures. I looked at Our Leader. He was not amused.

Web logs and fallen trees

A tree near my house has fallen and blocked one of our favorite footpaths. Time to get the chainsaw out :-). Things were going well until the saw suddenly stopped dead with the chain pinched tight by the stricken branch. Hmm. After getting angry and swearing had failed I realised that the saw was going to have to be freed by a smaller, hand saw. I felt the humiliation of the bigger saw. Like a mighty and powerful minister trapped in a doorway, he could do nothing but roar and wait while civil servants lowered floorboards and trimmed joists. Everyone needs friends, even the big and powerful.

Sales Sharks and Cardiff Blues

Today I took my eldest son to see Cardiff beat Sale (34-19) in what was apparently a must-win game at Ninian Park. I’m not a rugby fan although I did feel a brief confusion of loyalties. Sale is next to my birth town (Stockport) and Cardiff is where I have made my home. When Cardiff scored first I decided that where you are is better than where you’ve been.

The biggest cheer came from a pitch invasion by a man dressed as a badger.

The beginning!

Last night I saw John Ashley Long play some amazing double-bass with the Miles Davis Tribute band. His technique made me think of Scott La Faro. His classical background was evident mainly in the solo on Footprints (and because he had a C extension). Nice to see so many people at Cafe Jazz, particularly on a snowy night in Cardiff.