Exo-Player - Video Streaming Spearhead @Hotstar

Transcript

1. Video Streaming Spearhead
2. Hello ! I am Ayushi Gupta Android Engineer at Hotstar You can reach me out at: Twitter : @droidyayu Email : ayushig@hotstar.com
3. About Hotstar • #1 OTT platform in India • Over 350M+ downloads • 1 Day,100M users, 2.5X increase in concurrency • Available in >15 languages • Variety of content ◦ Live/On-Demand ◦ Sports/News/TV/Movies ◦ Regional Catalogue
4. What is the highest concurrency ?
5. Let’s talk about scale 2012 8M Felix Baumgartner’s Supersonic Jump YouTube 2018 3.1M NBC’s Super Bowl NBC Sports App 2018 10.3M IPL 2018 - Finals hotstar May 2019 18.6M IPL 2019 - Finals hotstar July 2019 25.3M World Cup - India vs New Zealand hotstar
6. Let’s start the journey to streaming
7. 3rd Party Player • No control • Non customisable on fly • Long mail chains to execute simple change • Non agile • Reduced development speed • SDK size of ~8mb
8. Quest for control
9. Redefining Player Old Content Support New Content Support Extensible, Customisable?
10. Engineering Requirements • Product based player -customizable • Tune to streaming stack • Optimizable • Extensible
11. Old Content Support New Content Support Exo Player
12. Exo Player • Open source library • Hardware accelerated decoding • Software decoding fallbacks • Play both audio and video - locally and over internet • DASH and Smooth Streaming adaptive playbacks • Customizable • Extendable • Can be updated through play store application updates
13. Hotstar Player - Journey
14. Just replace it ? • No compromise to user experience. • Update huge user base. • One shot update or progressive update • It’s not a backend ◦ Rollback needs time ◦ There is always residual users • Certain product features - A must to have!
15. Ads @Hotstar • Ads = Revenue • AVOD Business demand • Seamless transitions • Pre - rolls, mid rolls support • Support for both LIVE and VOD
16. Exo Ads Playback New extension for playing ads, wrapping the Interactive Media Ads SDK (IMA) using Ads Media Source • Complete control of execution flow • In - house ads playback experience • IMA SDK handles standard VAST response • Display ads on it’s “internal” logic • IMA SDK - not complete open source. • Non customisable
17. Hotstar Ads Playback • Fetch Ads marker along with playback url • Insert markers in existing url - Tags • Custom HLS Parser - Tag Based • On the basis of tags call Ads API Player Switching Approach 1. 2 Players at same time. 2. One for ads 3. One for content Ad Stitching Approach 1. Get Ads marker before video start 2. Combine it in current media source 3. Redirect when ads
18. Ad Stitching • For both live and VOD contents • Updating content manifest by inserting tags • Take care of timeline and subtitles • Multi audio packaged content
19. Content Security • Exo Player supports Widevine DRM for DASH content • Support only from API 19 and above • minApiVersion = 15 • Can’t neglect customer base
20. Instrumentation • Playback performance - Key metric • Movement of instrumentation layer • Re - testing on new player • Test against our instrumentation layer • Right metrics - Decision maker
21. Implementation Strategy
22. Building from scratch - HSPlayer • “Don’t mess with something which is already Working” • New separate module • An interface - HSPlayer exposed to App Module • Agnostic about app
23. HSPlayer - Functionality • Smart layer • Handles player’s lifecycle callbacks • Even event callbacks, error callbacks,retry callbacks etc. • Handling user inputs • Video settings like subtitle, audio language, video resolution etc
24. App Role • Fetch playback url and give it to player module • Required additional metadata to make certain decisions • Display custom player controls • Handling of error messages. • Handle analytics events based on player’s lifecycle • Event and error callback analytics • Handle player orientation changes
25. Key Metrics and Performance
26. Watch Time • Most important metric • Indicator of player health • Uninterrupted watch session • Constant observation, if sudden drop it raises an alert. • Immediate attention needed
27. PFR - Playback Failure Rate • Highest metric • Failed Video vs Started Video • Work on retry policies • Eye on status codes - Recoverable or Non Recoverable
28. Start Lag • Time taken by player to render it’s first frame. • Difference between playback url given to player and first buffering end callback received • Start lag can be high if : 1. Slow network 2. High network latency 3. High initial bitrate •
29. Buffering time and Buffering Count • Buffering / unit watch time • Buffering indicator /unit watch time • Playback @higher bitrate
30. Current scenario • High fluctuating data networks • Very less users on stable WIFI “A balanced equation of available bandwidth, estimated bandwidth, forward buffer and content availability in different resolutions” •
31. Player Rollout Strategy
32. Rolling Upgrade • A/B testing is the key to rollout any feature • A/B controlled player • Measure player key metrics • Measure user experience via funnels • Make decisions
33. Initial Targeted Users • Delivering seamless content with ads is always challenging. • Time needed to develop ads + streaming • For premium users it’s an ads free experience • Premium subscribed users were first use case of performance
34. Handling different contents differently ! • Downloads and offline content • DownloadManager of Exo player • Rolling out VOD and Live separately • Optimizing parameters for manifest specifications, content encoding ,live latency based on content • Different player parameters for different specification
35. Player Resilience
36. Uninterruptible Experience • Robust retry mechanism • Resilient player • Exo player - DefaultLoadErrorHandlingPolicy • More retries -> Reduced Failure Rate -> Increase Watch Time • During retry -> Increased buffering
37. Preemptive Watching • Optimised player for cw contents • Playback position is determined pre-handedly • Prefetching of chunks • Smooth playback • Reduced buffer time
38. Recycler View + Exo Player • Autoplaying feed • Single instance player • Listen to scroll movements • Attach and detach player smartly • Caching at player level • Resume at same point when clicked • Resolution capping • Bitrate capping
39. Video performance tool • Tool to know the stream specifications during playback • Can know the widevine security levels whether L1 or L2 • Run time buffer analysis • Network analysis • Rescue to customer care support
40. Ever going Journey
41. We have some ideas!
42. Thank You !