Tokyo Video Tech #4 Report (en)
Reported by Takesato Hayashi
Photograph by Akihisa Katsumi
Our 4th meetup event Tokyo Video Tech #4 Villa (Thinking about technology/organization/challenge that supports online video services in a different environment than usual space.) supported by Yahoo! Japan/GYAO! was held on 19 June 2019. This time we had 31 attendees to be gathered. There were three speakers. They provide a lot of slide, photo, demo and shared what they learned. Very special night for online video engineers.
Event page：https://www.meetup.com/Tokyo-Video-Tech/events/261694895/
# Opening remark
Organizer Takesato Hayashi(Takesato) taking Opening remark part.
Well known as one of Japan’s largest open collaboration spaces “LODGE” by Yahoo! Japan is used by many visitors on a daily basis, and various activities and events are held at LODGE. How Tokyo Video Tech is connected to LODGE? Takesato got an offer from Mr. Shimanuki from GYAO Corporation to support Tokyo Video Tech last December. He attended the 1st meetup and very sympathized our style that seeks to improve the end-user experience by sharing knowledge with engineers over company and service boundaries. Had started meeting and discussion with organizer team, with 6 month preparations, finally we were here!
Then Takesato announced upcoming Tokyo Video Tech #5 will be held at Viibar inc. on Wednesday, 28 August, 2019. Details will be posted at Meetup.com and the Slack workspace <https://bit.ly/video-dev-jp>, keep in touch!
# GYAO!’s challenge for development team forming and efforts for improvement
First speaker Kazuya Shimanuki(Shimanuki), GYAO Corporation.
The session titled “GYAO!’s Approach to Technical Challenges -To continue providing valuable services in the course of change-”, he explained the way they repaid their technology debt and the efforts for growth from an engineering manager point of view.
First, Shimanuki looked back on Tokyo Video Tech #2 session titled “How we’ve solved the OVP codebase bloat” by Kentaro Nishimuta. It was said that “The system grows along with the growth of services.” So, people who operate the service were deeply empathic with his words. This is the essence of the issues that everyone is facing. Following his steps, Shimanuki wanted to support the person who encounting same problems. “I think there are many companies that are struggling with old-fashioned system, so our challenge history may become a little piece of reference of organization management”.
Shimanuki considered our industry as “The Streaming Media business we are involved is a business whose challenges are always changing”. And he listed items which arose within 10 years.
Broadband / High Efficiency Codec / Instream AD / SSAI / UGC / commentary / contents recommendation / cognitive service / Smartphone / iOS / Android / Smart TV devices / Set Top Box / Monthly Subscription (SVOD) / Vertical Video / etc….
Service providers has to provide valuable services to end-users in response to changes in user preferences, emerging devices and economics.
For the people encounters problems like “I have a major technical issues, but I do not know where to start…”, Shimanuki started talking about his experience of managing ad-supported OTT service GYAO!.
Originally the target device of GYAO! was PC. Then eventually it’s become multi device service to support PC/Smartphone/TV. In addition to the video catalog prepared by the editor team, videos that suits the user’s preferences are arranged to form a screen. As a result of various functions being added to the system in order to keep up with changes in the business, “the old system has remained…”. The core members of GYAO! reviewed the architecture of the system last year, and identified the following issues.
- I do not know where to fix.
- I do not know what this code is used for.
- Problem recognition itself does not match.
To solve these issues, he explained the approach and showed the materials actually used in his team.
- Identify technical issues
Discuss what issues we have and how we would like to solve them, and identify common technical issues. - Draw and share “Team Vision”
Define the requirements to be solved, disassemble the technical issues into an appropriate form, and make guidelines. Make it a common recognition among development members. Input the guidelines and the form you want to achieve to the Management Team (do not make the issue only for engineers). - Revamp of the team
Use “Organization follows architecture” way.
＊Inspired by Conway’s law. - Change according to the value of the business
We will go through and keep doing the value judgment cycle of technology core competencies. Continue to find out what areas are important and what we have to make with our own hands.
What impressed me strongly was that we put emphasis on working as a whole organization that “share a task among engineers, then put a manager in a team, and every company”. Though his challenge is still in the middle of the road, his slides was concluded with the words, “If you can control the technical issues and continue to pursue the value that users will be pleased with in the process of change!”. His comments were unique to the team that continues to face users seriously. It is wonderful.
# Apple’s Approach to Low-Latency HLS
Next speaker Hiromine Kanazawa(Hiromine), Forecast Communications & co-organizer of Tokyo Video Tech.
The session titled “Apple’s Approach to Low-Latency HLS”, he explained about Apple Worldwide Developer Conference 2019(WWDC) and focusing on media delivery technology related topic newly announced “Low-Latency HLS”.
*The original session of this video (42 minutes) and slides are available on the following site.
Introducing Low-Latency HLS
https://developer.apple.com/videos/play/wwdc2019/502
This year’s WWDC was held in San Jose, California. This event is not for an announcement of new products, but for an annual conference that introduces the next major version of the operating system provided by Apple to developers.
Date: 2019.6.3–2019.6.7
Ticket: US$1,599 (Paid event and random selection)
Sessions: 100+
Attendees: 5,000+
Venue: San Jose McEnery Convention Center
First, Hiromine started talking about today’s main theme “Latency”. Traditional TV broadcasting world,
- Cable TV and Satellite : 2–8 seconds
- Terrestrial digital broadcasting in Japan : 1–3 seconds
- These seconds above varies depending on the receiver devices
Meanwhile, the usual HLS Latency is,
- Live delivery : 20–30 seconds
HLS has more delay than traditional TV broadcasts. Next, Hiromine showed sequence diagram used in WWDC to explain in detail the point where delay is occuring in HLS.
This time, Apple made following 5 changes in HLS specification.
1. Reduce Publishing Latency
2. Optimize Discovery
3. Eliminate Round Trips
4. Reduce Transfer Overhead
5. Switch Tiers Quickly
Hiromine explained about newly added 1–3 with sequence diagram to show us how Apple changed HLS flow for Low-Latency HLS and trying to reduce “Latency”.
Low-Latency HLS is under development now and still in Beta period in 2019. You may test it with TestFlight distribution. (No way to use production environment.)
You can check detailed information and specs below, enjoy!
Protocol Extension for Low-Latency HLS (Preliminary Specification)
https://developer.apple.com/documentation/http_live_streaming/protocol_extension_for_low-latency_hls_preliminary_specification
Finally, Hiromine played “Low-Latency HLS” demo part of WWDC session recordings, the live broadcast from Sydney to San Jose were not performed well. The presenter started to playback, then buffering began… (Live from Cupertino, where Apple’s HQ is located, was playing smoothly.)
With Low-Latency HLS under development in mind, it’s good test it as appropriate while waiting for the official release.
# Yahoo! JAPAN’s original video service initiatives: waiq
Last speaker of the day was Naoya Ishii (Ishii), Yahoo Japan Corporation.
The session titled “Yahoo! JAPAN’s original video service initiatives: waiq”, explained systems and technology used in waiq<https://waiq.yahoo.co.jp/>. He is a member of waiq Team and developing mainly for front end of the application. The slides for this session are only open to the venue.
waiq : A split-prize live entertainment program, distributed daily from 9:00 PM.
3 key features of waiq
- Live Video
Live Streaming via HLS
- Yahoo original live encoder
- Video.js for Player - Real Time Communication
Communication between performers and participants via comments.
- Minimize delivery latency, prevent commenting time lag from participants to performers.
- The duration of HLS segment is 2 seconds (Balancing between low latency and stable delivery) - Questions & Answers
Cast quiz when performers announce it
- Delivery timing is differ by each device, no way to use timer to send cue.
- Embedding quiz casting timing metadata into video file itself (ID3) and deliver it. Application extracts ID3 metadata from video, and cast a quiz.
Ishii would like to cast quiz sametime when performers announce “Here is the first question!!”. So, it is not appropriate sending quiz Cue via socket connection. He choose ID3 metadata to control Cue(Cast quiz! / Cast answer!).
Broadcasting application which controls embedding ID3 metadata is developed by waiq Team. It also technically possible to broadcast from smartphone. As you aware, smartphone has built-in video camera and it’s useful when you are developing a new feature. So, as a real test case example, Ishii start doing live broadcasting from LODGE with his Smartphone (Android) using an in-house development environment.
Finally, Ishii made his conclusion. Utilizing embedded pre-defined metadata, you can provide a richer experience in “Video x Communication”. No need to worry about heavy burden editing video data itself and video file is still clean. What can be done? He mentioned following example.
- Overlay telops and images on video at specified times
- Controlling sound effects (This is adopted by waiq)
I look forward to the further evolution and spread of live entertainment.
Finally,
As usual, we had the Networking with Food & Beverage time. Today we’ve got a lot of questions during the session, so many people kept asking questions to three speakers.
I wish to take this opportunity to thank three speakers. And everyone of GYAO Corporation and Yahoo Japan Corporation who supported this event, offered the popular venue “LODGE” which can not be easily reserve.
Started discussion from scratch on “how to hold an event like Tokyo Video Tech while taking advantage of the characteristics of this space?”, had a half-year preparation period, and also provide venue, Food & Beverage Thank you very much.
Slides
● “GYAO!’s Approach to Technical Challenges” by Kazuya Shimanuki
https://speakerdeck.com/pen2/gyao-ji-shu-ke-ti-hefalsequ-rizu-mi
