How do I split an OGX (video) file?

Question

I'm trying to make a PHP script that will deliver a given .ogx file based on a seek position (transmited as a parameter to the script). The purpose is to make a HTML5 video player with server-side seeking functions.

I have studied the container format a bit and made the .php script to start delivering data from the first instance of the "OggS" string that occurs before the seek position (given in bytes).

The problem is, even though my new .ogx file starts with the "OggS" string, it is completely unplayable in HTML5, VLC or any other player as long as the seeking position is other than 0.

If I set the seeking position to 0, the script will give me the whole file and that's playable.

So how do I trim the start of an .ogx file while still producing a valid bitstream?

Answer 1

You should take a look at FFMpeg, which is a library that let's you manipulate in different kind of ways video and audio files. http://www.ffmpeg.org/

From their site

FFmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It includes libavcodec - the leading audio/video codec library.