You have an .AVI DivX, a VOB file, or a movie in some other format, and you want to encode it for playback on a website or blog. Currently, the best format for such use is FLV (Flash Video), as almost all browsers will display it natively without need of installing extra plugins. It is for example the format used in Google Video. FLV is played from within a SWF file, which supports pseudo-streaming, meaning that the playback will start immediately without need for the whole file to be downloaded first.
Open ffmpegX and drop your movie file to ffmpegX icon or "Open" field or "From" area to open it, or click the Open.. button to locate the file from your hard disk.
The "Save as..." name will be set by ffmpegX. You may modify it if needed.
Choosing the preset:
Click the Target Format pulldown menu in the Summary tab and choose "FLV".
You may change the preset values if you wish. Just remember that bigger image sizes, bitrate, framerate, etc will lead to bigger file sizes, and that you will probably burn out your bandwidth quota in a snap if you allow too large file sizes on a website.
You may go in the Filters tab to add cropping and/or padding if needed.
Subtitles are not supported (unless you create a file beforehand with subtitles burned in the image, and then encode such file).
Click the "Encode" button.
Encoding takes places in ffmpegX Progress window.
You can continue working with other applications while encoding. OSX Unix core reallocates processor ressources in realtime as needed.
Enable online viewing of the FLV file:
Locate the encoded file by clicking the icon.
You may preview the file with the ffmpegX "Preview" button.
To make a webpage containing your movie, you need first a controller in SWF format. It is the SWF file which will be embedded in your webpage as a normal Flash element. The SWF file will load any FLV video files and display them on the page, as well as control any function like start/stop. There are many ways to make the SWF player, and there are many SWF open source players ready to use. I would suggest to download this one by Jeroen Wijering (but you may do your research and find better ones).
To make it work, just copy the files on your webserver, and replace the file "video.flv" with your own flv file as encoded above. Point your browser to the flvplayer.html file and you should see and hear the movie playing in the browser.
To customize the code used to embed the movie in the page, put this in your html page: