Using Open Source Video Tags / Ogg Theora

Codecs by Sanjay

SANJAY:

Introduction

• Tech in camera stores information e.g. colour, keyframe compression
• 7 different kinds of algorithms
• Using open source codecs doesn't lock you into vendors
• Common video format is Flash FLV and H.264
• An open source codec is Ogg Theora

HTML and Flash

• W3C sets HTML standards
• Now there's no standard way to put video on your site
• Everyone uses different Flash player embedded using HTML in a web page

JavaScript (JS)

• helps you change things on the page
• JS and HTML work well together
• can be used to control videos e.g. volume, mute, pause

W3C standard for video tag

• it shouldn't be proprietary
• Ogg Theora was recommended
• Corporations realised this didn't benefit them
• Nokia lobbied W3C and said it's a proprietary codec even though it's not
• Nokia recommended their own codec

Video tag

• Firefox and Opera will support Ogg Theora in the video tag
• IE will maybe not support the video tag

Pad.ma

• will provide embed tags emulated using JS

Other codecs

• Dirac, by the BBC, released early 2008
• Developed to be open source, widely-adopted and non-proprietary

Serious danger in using proprietary formats

• e.g. Flash, Quicktime, Windows Media
• can't open old Word documents in new MS Word
• danger of proprietary tech being discontinued

Misc

• Flash is still widely-adopted
• Ogg has cool features e.g. timeline

Ways to playbank Ogg

• VLC

Ways to playback Ogg in browser

• Mplayer plugin in Linux
• VLC plugin
• Cortao Java Applet

Ways to encode Ogg

• Media coder for Windows
• Simple Theora Encoder for Mac
• mpeg2theora - command-line interface for linux

Example: padma.transmission.cc

• quick preview for videos
• to extract timeline, use a python script - extract_timeline.py

Importing into padma

• Start with raw DV
• and upload using SCP
• Padma can be used to store TX and EngageMedia videos

Extract frame

• When viewing videos in sections, the engine creates a Ogg file with that segment
• No performance issues because engine is efficient

Embed tag

• No embed tag yet because of different standards

LibDirac with ffmpeg

• for encoding Dirac videos on Linux

Quality

• Ogg is excellent for web video while Dirac is great for local

Importing videos into Padma

• Move file into server
• Run the script using the TurboGears shell