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Total 7 Tagged in ’#AdventCalendar’
  • V8 Hidden class
    Masami Yonehara 2018.06.27

    I am a frontend engineer at LINE. I've moved from Fukuoka to Tokyo in 2016.

    As a frontend engineer, I feel I still need to know more about the structure of JavaScript and web browsers, in order to provide quality UX to our users. Thankfully, we are given an access to peak through JavaScript's thoughts, thanks to Google and Mozilla for making their engine code available to public, along with nicely prepared documentation. The availability of various means for tracing and profiling code surely helps too.

    AdventCalendar JavaScript

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  • LINE Animation Sticker Checker on Web browser
    ha1f 2018.06.04

    I develop iOS apps at LINE Fukuoka.

    Great to meet you all. This is ha1f from LINE Fukuoka, I develop iOS apps at LINE. Back when I was as a part timer at LINE, I was involved in making in-house tools for LINE. To share a little bit of my background, I was hired as a part timer with a confirmed offer to a full time position. Anyway, today, I'd like to show you a tool I developed during my time as a part timer, the Animation Sticker Checker.

    What is APNG?

    Before we get into the details of the tool, let's discover what APNG is. APNG (Animated Portable Network Graphics) is a specification for animated image, consisting of images each numbered with a sequence number. LINE animation stickers use APNG. Unlike GIF, APNG supports full color, alpha channel and has a high compression rate. APNG is compatible with PNG, and is displayed as a still image for image viewers that do not support APNG. If you have the right tool, you can convert a sequence of PNG files into an APNG file.

    apng

    AdventCalendar APNG

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  • Floor map management system on web, with Leaflet
    Yasunori Iwatsuki 2018.04.03

    LINE Japan's office relocated in April, 2017 to JR Shinjuku Miraina Tower to accommodate its growing number of staff. At the time of relocation, the IT support department introduced a number of new systems into the company. One of those is the LINE Floor Map system which I am going to share with you in this post.

    Background story

    Before we moved to Shinjuku, we used to manage our floor map with Microsoft Excel. Here is a part of the excel file. (We've erased names off from the screenshot.)

    AdventCalendar Leaflet Floor map Map API JavaScript Map

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  • The structure of the LINE LIVE's encoder layer
    Suhyuk Kim 2018.03.06

    On December 10th of 2017, we celebrated our second anniversary for LINE LIVE, our live streaming service. The service has been up and running ever since the launch with no trouble, thanks to the efforts put in by countless engineers at LINE. On this blog post, as a member of ITSC, a team at LINE running a global infrastructure system, I'd like to share with you some of decisions we had to make in the initial phase of designing and implementing the system. Back then, I had absolutely no experience in building or running a live media service.

    AdventCalendar LINE LIVE Live Broadcasting PC Broadcasting Live Video

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  • Buffer overflow in PJSIP, a VoIP open source library
    Kim Youngsung 2018.02.27

    He's a security engineer at LINE. He enjoys looking for bugs and is highly interested in secure coding.

    Hi all, I am Youngsung Kim (Facebook, Twitter) of the Application Security team at LINE and am in charge of evaluating security of LINE services. On this post, I'd like to share a vulnerability (CVE-2017-16872, AST-2017-009) of PJSIP, a VoIP open source library. PJSIP is a multimedia communication library based on the following standard protocols; SIP, SDP, RTP, STUN, TURN, and ICE. The Asterisk framework, widely used on IP-PBX and VoPI gateway has an SIP stack implemented based on PJSIP.

    The cause of the vulnerability was due to incautiousness about sign extension for Integers in the process of converting signed int to unsigned long when handling client's SIP requests on 64-bit environment. There was no window to report the security issue to the PJSIP development teams, so I made my report to the Asterisk's security page. Afterwards, I've consulted with George Joseph, an engineer at Asterisk, and the patch (PJSIP patch, Asterisk patch) has been applied on the pjproject v2.7.1. I'd like to express my gratitude to George for processing the patch.

    VoIP Security Vulnerability OpenSource CVE PJSIP PJPROJECT ASTERISK AdventCalendar

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