Photo Ayaka Maeda of the Faculty of Medicine reading the alumni representative's answer at the graduation ceremony of Kumamoto University = XNUMXth morning, Prefectural Theater in Chuo-ku, Kumamoto City (Satoshi Ishimoto)
Graduation ceremony at Kumamoto University Impact of new corona, first time in XNUMX years
If you write the contents roughly
The ceremony was broadcast live on the Internet.
The graduation ceremony of Kumamoto University was held at the prefectural theater in Chuo-ku, Kumamoto City on the XNUMXth, and XNUMX people including graduate students took a step toward society ... → Continue reading
Kumamoto Daily Newspaper
The Kumamoto Nichinichi Shimbun is a local newspaper in Kumamoto. Full of information about Kumamoto such as news and sports.
Wikipedia related words
If there is no explanation, there is no corresponding item on Wikipedia.
Normally, the file is opened after the download is completed, but when playing a large file such as a movie, it takes a very long time to download, which causes a big problem especially in live distribution.Therefore, by downloading the file and playing it at the same time, the waiting time of the user is greatly reduced.This method is often loosely referred to as "streaming".
Similar transfer methodProgressive downloadThere is. It is the same as streaming in that it plays while downloading the file,HTTPSince it can be transferred byVendor Lock InnStreamingserverNo need to buy,Reverse proxy,Content delivery networkThere is a big advantage that it can be delivered on a large scale at low cost, such as good compatibility with.On the other hand, unlike streaming, after playback,hard diskHowever, there was a time when the service provider avoided it from the viewpoint of copyright protection because the multimedia file remained accessible.Flash video is a typical file format that can be downloaded progressively.YouTube,Nico Nico DougaPost type such asVideo distribution siteIt is also commonly used for free content distribution. Recently, streaming technology that adds bandwidth control to progressive download has also appeared (Microsoft Smooth Streaming, Adobe Dynamic Streaming, HTTP Live Streaming, MPEG-DASH, etc.),GYAO!,Yahoo! JAPANWas adopted by.
Browser standard compatible protocol
- ア ッ プ ルHTTP-based streaming protocol by.IETFSpecifications have been published for standardization, and many servers andclientIs supported.Also someWeb browser(Safari,ChromeEtc.) can also be played directly. Flash Player also supports playback.Also, by using a script such as hls.js,HTML5 Of It can also be played on a browser that supports the API.
- (Dynamic Adaptive Streaming over HTTP)
- HTTP-based streaming technology developed by MPEG. In addition to VLC and GPAC playback support, you can also use dash.js to play on a browser that supports the HTML5 Media Source Extensions API, and use dash.as to play on Flash Player. be able to.
- MP4Box and FFmpeg support the generation of MPEG-DASH compatible MP4 fragments.
Protocols that require plugins for browser playback
- It is standardized by IETF,RealMedia / QuickTime / Windows Media / GStreamer It can be played on many players, including.Also, from Flash Player, it can be played through players such as Locomote Video Player.However, many browsers do not support it directly,PluginAnd need to use an external player.
- Most streaming software can send this.
- Windows MediaUsed for streaming delivery of. Due to EU antitrust issues, protocol specifications including DRM using elliptic curve cryptography have been published. Many players can play MMS, but some have compatibility issues. Also, many browsers don't support it directly, requiring the use of plugins and external players.
- Some streaming software can do this.
- Microsoft Smooth Streaming
- By MicrosoftSilverlightStreaming protocol for. Using HTTP progressive download technology.VLC media player 2.1 or later supports this playback. It can be played from Flash Player by using Smooth Streaming Plugin for OSMF. Many browsers don't support it directly, so you'll need to use a plugin or external player.
- FFmpeg supports the generation of ISMV fragments used for smooth streaming.
- AdobeStreaming protocol for Flash Video by.reverse engineeringMany because the spec has been parsed byOpen source softwareCorresponds to this reproduction and transmission.However, many browsers cannot play directly and require the use of plugins.This is especially problematic for mobile devices that don't support plugins.
- Adobe HTTP Dynamic Streaming (HDS)
- Adobe's HTTP-based streaming protocol for Flash Video.The method of dividing the file and downloading it for each fragment is used.Many browsers do not support it directly and you need to use a plugin.
- FFmpeg supports HDS fragment generation.
P2P multicast delivery protocol
- It is a P2P protocol for Flash developed by Adobe, and the protocol specification is published as RFC 7016. Supports P2P multicast distribution.
- PeerCast protocol
- The protocol used by PeerCast.
- It is a Web standard P2P API that enables P2P multicast distribution, and is directly supported by browsers. The P2P delivery protocol itself is not standardized. Chrome, Firefox, and Opera are browsers that support WebRTC.
In addition, P2P multicast distribution using Java applets is also used.
Communication path encryption
The HTTP-based protocol can encrypt the communication path by passing HTTPS instead of HTTP.
- An encrypted streaming protocol for Flash based on RTMP and SSL developed by Adobe.Many open source software supports this playback and transmission because the specifications have been analyzed by reverse engineering.
- RTMP and developed by AdobeDiffie-Hellman key agreementAn encrypted streaming protocol for Flash based on.Many open source software supports this playback and transmission because the specifications have been analyzed by reverse engineering.There is a flaw in the design that allows a man-in-the-middle attack..
- Clear Key
- W3C standardEncrypted Media ExtensionsThe encryption method specified in. Google Chrome etc. support decryption.
- HLS encryption
- Encryption using AES-128.
DRM for streaming
For streaming purposes in streaming formatCopy guardIs often provided, making it difficult to save video and music to a file. However, copyguards have been criticized for deliberately creating design flaws that narrow the viewer's viewing environment, hinder the viewer's legitimate use, and even eliminate competitor products.Defective by Design), new media aiming to be viewed on demand on any device anytime, anywhere (New media) Is often not used.
- Google Widevine DRM
- DRM using AES-128 CTR. Based on Common Encryption (CENC, ISO/IEC 23001-7). It can be used with MPEG-DASH. Chrome and Android support decryption. Open source Bento 4 Supports encryption. FFmpeg And edash-packager and MP4BOX Supports both encryption and decryption.
- As of 2016, a problem has been found in Google's implementation of Widevine DRM.
- Microsoft PlayReady
- DRM using AES-128 CTR. Based on Common Encryption (CENC, ISO/IEC 23001-7). It can be used with Microsoft Smooth Streaming and MPEG-DASH. Decryption is supported by Internet Explorer, Windows Phone and Silverlight. Microsoft Expression Encoder, Azure Media Services samples, open source Bento4 Supports encryption. FFmpeg And MP4BOX Supports both encryption and decryption.
- Adobe Primetime DRM
- Old Adobe Access DRM. It can be used with pRTMP and PHDS. 38-bit binary for Windows after Adobe Flash Player or Firefox 32 Corresponds to decryption. Adobe Media Server supports encryption.
- Marlin DRM
- OMA DRM v2.0
These are legacy, and Hollywood Studios (excluding Disney) is promoting DRM for Ultra Violet.
- DRM using elliptic curve cryptography. It can be used with MS-RTSP and MMS. Windows Media Player and Windows Phone support decryption. Windows Media Rights Manager (WMRM) supported encryption.
- With the Windows 10 Anniversary Update, WMDRM decryption has been removed, making it impossible to watch media encrypted with WMDRM.
- Helix DRM
- Can be used with RealRT SP. Real Player supports decryption. Helix Universal Server (Discon) Supported encryption.
- QuickTime Player supports decryption. 2016, Microsoft Azure supports FairPlay encryption.
Main streaming server
Currently, with the spread of HTTP-based streaming protocols, it is becoming mainstream to fragment videos and send them on HTTP servers.
- Adobe Media Server (Formerly Adobe Flash Media Server (FMS))
- A streaming server for Windows and Linux provided by Adobe.Today, it was the only way to deliver copy-protected videos to the most popular multi-platform Flash Player on PCs.De facto standardIt has become. It also supports distribution to iOS, which cannot use Flash Player, and can be played from a browser by using the Protected HLS protocol.Similarly, for distribution to Android 4.1 or later, which cannot use Flash Player, it is necessary to install the Adobe Air application on the playback side.To use copy guard, you need to use the professional version or higher.Since there are license restrictions on the maximum number of simultaneous connections and the number of processes depending on the version, it is necessary to purchase multiple licenses for one server and stack the licenses for large-scale distribution.
- Wowza Streaming Engine(Formerly Wowza Media Server)
- A video streaming server developed by Wowza Media Systems. Although it can communicate with Adobe Flash Player using RTMP, it also supports remote procedure calls between client and server, in which case the server side is written in Java. From version 4.0, it is equipped with a GUI that can be managed on a web browser basis.
- A multi-platform streaming server for open source Flash Player written in Java.The license is Apache License 2.0 (changed from LGPLv3). It supports not only video distribution by RTMP and encrypted video distribution by RTMPE, but also Flash shared objects and Remoting.However, the programming language is Java, and server-side scripts written in ActionScript for FMS cannot be run directly.
- An open source streaming server based on NGINX. It supports not only RTMP but also live streaming by HLS and MPEG-DASH.
- WinampIs known as the development and distribution destination ofNullsoftWas provided free of charge, but was acquired by Internet radio station Radionomy.
- Platforms from Windows 95/98/Me/NT/2000/XP/2003 to FreeBSD, Linux,MacOS A wide range of servers, Solaris 2.x servers (Sparc version) and supported OSbinaryIt is distributed in.
- MP3Format data can be transmitted by streaming. In addition, you can perform live transmission by combining the plugin installed Winamp and SHOUTcast server.
- MP3An open source streaming server capable of streaming formats.
- VLC media player (VideoLAN Client)
Major development-stopped streaming server
- Helix Universal Server
- RealServer's successor product,Real networksWas on sale. Discon.. The media types that can be distributed are Real Media, Windows Media,Quick TimeThere are abundant and OS types as platforms are Windows NT, Windows 2000,Linux,FreeBSD,Solaris,HP-UXAnd so on.
- It does not support copy protection of other companies' products. Although it has its own copy guard, Helix DRM, it is rarely used because it can only be viewed with Real Player. In addition,Real networksAlthough the player has developed Harmony technology to support copy protection of other companies' products in order to ensure DRM interoperability, it has stopped development due to possible lawsuits from Apple.
- Helix DNA Server
- An open source version of Helix Universal Server developed by Real Networks. It applied its own license. The final version is 2006 released in 11.1.
- VLS (VideoLAN Server)
- An open source streaming server developed by the VideoLAN project. Currently, most of the VLS functions are also implemented in VLC, and development of VLS has been completed.
- Darwin Streaming Server
- An open source streaming server.
- QuickTime Streaming Server
- OS X ServerStreaming server installed in.
- An open source streaming server for Flash Player written in Python. The license is GPLv3.
- C ++ RTMP Server
- An open source streaming server for Flash Player written in C++. The license is GPLv3.
- An open source streaming system using P2P technology. It has no transmission function and has only a relay function. It supports RTSP and MMS relay.
- IIS Media Services
- MicrosoftIt is a streaming server for Windows provided bySuccessor product of. Encoders for content development are distributed free of charge. It is difficult to deliver videos with copy guard enabled to PCs and mobile devices other than Windows because they cannot be viewed on other than Microsoft products.
- Not updated and requires workaround for installation on Windows Server 2016 or later.
Main fragmentation software
- It supports the generation of MPEG-DASH compatible MP4 fragments and MPEG-DASH compatible MPEG-2 TS fragments. Open Source.
- It supports the generation of MPEG-DASH compatible MP4 fragments, MPEG-DASH compatible WebM chunks, HDS fragments, and ISMV fragments used for Microsoft Smooth Streaming. Open Source.
- It supports the generation of MPEG-DASH compatible MP4 fragments. ISO Common Encryption andWidevine DRM encryption/decryption, which is one of the above. Open Source.
- TITAN File
- ATEME video conversion software. It supports MPEG-DASH, Smooth Streaming, and HLS compatible fragment generation.
- Amazon Elastic Transcoder
- Supports MPEG-DASH, Smooth Streaming, HLS.
- Azure Media Services
- Supports MPEG-DASH, Smooth Streaming, HLS.
- Akamai Media Services Live / On Demand
- Arkena Cloud4TV
Major web-based streaming media players
- HTML5 and Flash based web player. Open Source.
- HTML5 and Flash based web player. Open Source.
- HTML5 and Flash based web player. Open Source.
- Shaka Player
- HTML5-based web player from Google. Open Source.
- Strobe Media Playback
- Flash-based web player from Adobe. It is based on OSMF (Open Source Media Framework). Open Source. Updating is stopped.
- For OSMF, Microsoft has released Smooth Streaming Plugin for OSMF that supports Smooth Streaming.
- Locomote Video Player
- Flash-based web player. Open Source. It also supports RTSP.
Live streaming (en: Live streaming) Is to stream live media. More specifically, computerized (live) media recorded on the fly.networkReal-time streaming delivery via (Live distribution). The following are examples of live-delivered media.
- Live cameraVideo (Weather, scenic spots, disaster areas, astronomical observation (comet))
- Live music video
- Existing media (radio, TV)
Live streamingLive broadcast (en: Live broadcast) Is considered.Live streaming, which is a live broadcast using the Internet, does not require complicated broadcasting approval procedures, examinations, and acquisitions unlike TV media that uses public radio waves.Therefore, it is possible to open pseudo radio broadcasting and TV broadcasting on the Internet, and it will be broadcast on TV by individuals, small corporate groups, and existing radio broadcasting stations (live camera images in the broadcasting station studio). ) Is also actively participating in live broadcasting.As mentioned above, there are almost no regulations (as long as the copyright of the broadcast content is cleared).Media formTherefore, if you prepare the equipment刑 務 所It is also possible to relay to the inside of the network.
The disadvantages include the following.
- In the case of live streaming, it is possible that the viewer forgets the broadcast time and misses the target program, as with existing broadcast media.
- As a common drawback of live streaming and non-live streaming (streaming transmission of on-demand contents without restrictions on broadcast time), when setting the image quality specifications on the Internet TV broadcast side, priority is given to the acquisition of many viewers (low specification). I am worried about whether or not to reduce the image quality, image size, and number of video frames so that I can withstand viewing even on a PC or a PC connected to a low-speed narrowband communication line.
There are various live streaming platforms. See the link below for details.
Live streaming transmission
- Adobe Flash Media Live Encoder
- Open Broadcaster Software (OBS)
- Open Source.
- ^ 9 Special Interview-Ask Yahoo, Why Silverlight
- ^ About MSDN IIS Smooth Streaming
- ^ Media Multicast (RTMFP) Adobe
- ^ Ripping Media Off of the Wire A Step-by-Step Guide P.40 DEF CON 2010
- ^ What is RTMPE Wowza Media Systems
- ^ a b Using PlayReady and / or Widevine Dynamic Common Encryption Microsoft products
- ^ a b c Software DASH Industry Forum
- ^ a b c MPEG DASH Axiomatic Systems
- ^ a b FFmpeg Changelog
- ^ a b Common Encryption GPAC project
- ^ A Bug in Chrome Makes It Easy to Pirate Movies Wired June 2016, 6
- ^ How to watch DRM content in Firefox#Supported environment Mozilla Support
- ^ Marlin Tutorial Intertrust
- ^ a b OMA DRM standardization trends NTT DoCoMo
- ^ OMA DRM GPAC project
- ^ Windows 10 Anniversary Update: Music and Video Loss Microsoft products
- ^ a b Helix Media Delivery Platform RealNetworks
- ^ Microsoft announces general availability of Apple FairPlay Streaming for Azure Media Services MSPoweruser August 2016, 8
- ^ ffserver program being dropped FFmpeg project July 2016, 7
- ^ Workaround: error installing IIS Media Services on Windows Server 2016 Microsoft May 2017, 5
- ^ Amazon Elastic Transcoder now supports MPEG-DASH Amazon May 2016, 5
- ^ Azure Media Services overview and common scenarios Microsoft products
- ^ Media Services Live Akamai
- ^ Media Services On Demand Akamai
- Application streaming
- Internet radio
- Internet tv
- Video on demand (VOD)-Limited to video or video with audioLive streamingMedia with the antonym position of. Since it can be viewed in the same state and content at any time, it is suitable for providing video content that is not very current.
- P2P TV
- Container format - Audio file format
- One-time URL
- Set top box