Helix On The OLPC

1. Helix On The OLPC Python Extensions of Helix Helix Summit 2007

2. Introductions • We support open software, open communities, and an open world • Peter Krenesky • Lead Software Engineer • Tech Lead for OLPC projects @ OSL Helix Summit 2007

3. Foreword • OLPC is a very unique device • Its is not just a “laptop” Helix Summit 2007

4. Summary • Python API Overview • Helix Player On the OLPC: • Watch & Listen • ProducerSDK On the OLPC: • Produce • Teleconference • Future Plans: • Audio Presentations Via Producer Helix Summit 2007

5. Pykit - Overview • Python Modules • HxPlay • HxRecord • Capture • Editing • Encoding Helix Summit 2007

6. Pykit - Design Goals • Simplify the interface • Hide engine initialization • Hide initialization of components • Resizing • Seeking • Reuse as much as possible • Start from pyplayer • Feature implementations borrowed from splay Helix Summit 2007

7. HxPlay - Overview • Ported to atlas • Target: player_kit_python • Code cleanup • Added new features • QuickSeek • Video Site Resizing • Playlist support • Color Controls Helix Summit 2007

8. HxPlay - Player sample Import hxplay hxplay.init() player = hxplay.open(“foo.mp3”) player.start() Helix Summit 2007

9. HxPlay – Incomplete Features • Support other than Linux • Support for Multiple Players • Audio Formatting • Audio Visualization Helix Summit 2007

10. HxRecord - Overview • New Python Bindings Around ProducerSDK • Target: player_kit_python_hxrecord • ProducerSDK modifications • Porting to atlas • Adding features Helix Summit 2007

11. HxRecord - Design Goals • Match ProducerSDK workflow • Full featured • Simplicity • Merger with hxplay Helix Summit 2007

12. HxRecord - Code Sample dictionary = { ‘pluginType’ : ’avFileInput’ , ’filename’ : ’foo.avi’ } input = hxrecord.createInput(dictionary) encodingjob.setInput(input) Helix Summit 2007

13. HxRecord – Roadmap • Bindings Mostly Complete • Debug Ported ProducerSDK • Merge ProducerSDK components with Atlas • Merge HxRecord and HxPlay Helix Summit 2007

14. ProducerSDK - Current Hierarchy Atlas ProducerSDK Media Playback EncodeSVC Class Factory Class Factory Video Output (sites) Video Output (sites) Container Classes Container Classes Helix Summit 2007

15. ProducerSDK – Intermediate Step Atlas Media Playback EncodeSVC Class Factory Class Factory Video Output (sites) Video Output (sites) Container Classes Container Classes Helix Summit 2007

16. ProducerSDK - Planned Hierarchy Atlas Media Playback EncodeSVC Class Factory Video Output (sites) Container Classes Helix Summit 2007

17. PyKit - Current Hierarchy HxPlay HxRecord Engine Initialization Engine Initialization Helix Summit 2007

18. PyKit - Planned Hierarchy PyKit HxPlay HxRecord HxEngine Helix Summit 2007

19. Helix Player on the OLPC • Named “Watch and Listen” after the activity that children are doing. • Lots of possible features but need to keep it simple Helix Summit 2007

20. Watch & Listen - Screenshot Helix Summit 2007

21. Watch & Listen - Features • Standard Playback Buttons • Seeking via slider • Screen size toggles • Metadata display • Playlist Support Helix Summit 2007

22. The OLPC Journal • Stores a history of what a child has done • Activities can be resumed • Files have a mime-type • Only place where Watch & Listen can be launched Helix Summit 2007

23. Journal - Screenshot Helix Summit 2007

24. W & L - Features We’d Like to Add • Visualizations for audio Playback • Keyboard Shortcuts • Sharing - Collaboration among children Helix Summit 2007

25. Sharing - Overview • It’s a collaboration tool not just a laptop! • Shared learning experiences Helix Summit 2007

26. Watch & Listen - Multicasting • Positives • Scales very well for 1:M transmission • Negatives • Server is a large image • Simultaneous multicasts may degrade mesh Helix Summit 2007

27. OLPC - Mesh Networking • 802.11s • Ad-hoc Wireless network • May easily span miles • Peers may connect indirectly through other Peers Helix Summit 2007

28. W & L - Synchronized Viewing • Positives • Doesn’t require a much larger image • Negatives • Limited Scaling • Must all have access to video • Keeping video synchronized is difficult Server Helix Summit 2007

29. Produce - Overview • Capture - video and audio • Encoding • Simple Video Editing • Cropping • Resizing • Cutting & Joining videos • Add Audio Tracks Helix Summit 2007

30. Produce - Record Mockup Helix Summit 2007

31. Produce - Record Screenshot Helix Summit 2007

32. Produce - Editing Mockup Helix Summit 2007

33. Teleconference - Overview • Audio and video Teleconferencing using Helix • Senior Capstone Project • Year long project required for graduation Helix Summit 2007

34. Teleconference - Overview • Will use both HxRecord & HxPlay • 1:1 Video and or Audio at usable rates • CPU power bigger issue than bandwidth • M:N Conferencing may not be possible with CPU limitations Helix Summit 2007

35. Teleconference - 1:1 Workflow Child 1 Child 2 Producer (out) Player (in) Player (in) Producer (out) Helix Summit 2007

36. Teleconference - M:N Challenges • Every Participant adds 2 streams • Videos must be decoded and drawn to screen • Audio must be multiplexed Child 1 Child2 Producer (out) Combined Stream Producer (in) Audio Child3 Player (in) Helix Summit 2007

37. Teleconference – Special Requirements • All communication between laptops must use Python dbus • XO has special libraries for locating and communicating with peers on the mesh • Plugins will be required for both Producer and Player Helix Summit 2007

38. Webcaster – Overview • PowerPoint + Recorded Audio • Proposed project • Will probably be done in pieces as class projects Helix Summit 2007

39. Recap • Python API – A lot of momentum • Helix On the OLPC: • Watch & Listen • Produce • Teleconference • Audio Presentations Via Producer Helix Summit 2007

40. Questions? • Peter Krenesky • Email: Peter@osuosl.org • Web: http://osuosl.org • Ribosome Targets: • Player_kit_python • Player_kit_python_hxrecord • http://laptop.org Helix Summit 2007