HTTP Live Streaming1/ Let you send audio and video over HTTP from an ordinary web server for playback on iOS (based devices: iPhone, iPad, iPod touch, and Apple TV) and on desktop computers (Mac OS X). 2/ iPhone and iPad apps that send large amounts of audio or video data over cellular networks are required to use HTTP Live Streaming. 3/ Where possible, use the <video> tag to embed HTTP Live Streaming, and use the <object> or<embed> tags only to specify fallback content. 4/ Bonus: MPEG-4 is one of the latest (audio and video) compression method standardized by MPEG (Moving Picture Experts Group), designed especially for low-bandwidth /băng thông/ (less than 1.5MBit/sec bitrate) video/audio encoding purposes. The major MPEG standards include the following: MPEG - 1 • The most common implementations of the MPEG-1 standard provide a video resolution of 352-by-240 at 30 frames per second (fps). This produces video quality slightly below the quality of conventional VCR videos (videocassette recorder). MPEG - 2 • Offers resolutions of 720x480 and 1280x720 at 60 fps, with full CD-quality audio. MPEG-2 is used by DVD-ROMs. MPEG-2 can compress a 2 hour video into a few gigabytes. While decompressing an MPEG-2 data stream requires only modest computing power, encoding video in MPEG-2 format requires significantly more processing power. MPEG - 3 • Was designed for HDTV but was abandoned in place of using MPEG-2 for HDTV. MPEG - 4 • A graphics and video compression algorithm standard that is based on MPEG-1 and MPEG-2 and Apple QuickTime technology. Waveletbased MPEG-4 files are smaller than JPEG or QuickTime files, so they are designed to transmit video and images over a narrower bandwidth /băng thông hẹp/and can mix video with text, graphics and 2-D and 3-D animation layers. MPEG - 7 • Formally called the Multimedia Content Description Interface, MPEG-7 provides a tool set for completely describing multimedia content. MPEG-7 is designed to be generic and not targeted to a specific application. MPEG - 21 • Includes a Rights Expression Language (REL) and a Rights Data Dictionary. Unlike other MPEG standards that describe compression coding methods, MPEG-21 describes a standard that defines the description of content and also processes for accessing, searching, storing and protecting the copyrights of content. Overview HTTP Live Streaming Server component Taking input streams of media Distribution component Consists of standard web servers Client software Determining the appropriate media to request Encoding them digitally Accepting client requests Downloading those resources Encapsulating them in a format suitable for delivery Delivering prepared media and associated resources to the client Reassembling them so that the media can be presented to the user in a continuous stream Preparing the encapsulated media for distribution For large-scale distribution: Use edge networks or other content delivery networks . Encodes the media (H. . and the EXT-XDISCONTINUITY tag must be set on the following segment.The transport stream is a packaging format that can be used with a number of different compression formats..Server Components . . Server Compone nts Stream Segmen ter . The file segmenter performs the same tasks as the stream segmenter.The index is used to track the availability and location of the media files. CTAssetsPickerController.Encrypt each media segment and create a key file as part of the process.The video encoder should not change stream settings—such as video dimensions or codec type—in the midst of encoding a stream..Takes a real-time signal from an audio-video device .Media segments are saved as .Break it into segments of equal length. . .) for sending video on demand via HTTP Live Streaming. or MPEG elementary streams for audio-only). .Divides it into a series of small media files of equal duration. .If a stream settings change is unavoidable. the settings must change at a segment boundary.Is a process. .Creates an index file containing references to the individual media files. . .Index files are saved as . Media Encoder .264 video and HE-AAC audio ) .The encoder delivers the encoded media in an MPEG-2 Transport Stream over the local network to the stream segmenter.Encapsulate media file encoded in an MPEG-2 transport stream . .M3U8 playlists.GPUImage. (MPEG-2 Transport Streams for audio-video. File Segmen ter Allows you to use a library of existing audio and video files (Streaming Kit. the index file is updated. but it takes files as input instead of streams. . . . which reads the Transport Stream from the local network .MPEG-2 transport streams should not be confused with MPEG-2 video compression.Encapsulates it for transport.Each time the segmenter completes a new media file.ts files (MPEG-2 transport stream files). # H. Apple has official adopted H. and is destined to be the future standard format for Blu-ray. the consumer format offered by the same people behind Blu-ray and for use in camcorders and Blu-ray recorders. Even AVCHD. H. # Example http://stackoverflow. Developed for use in high definition systems such as HDTV.264 offers better quality at lower file sizes than both MPEG-2 and MPEG-4 ASP (DivX or XviD). uses H.You should always run the validator prior to serving a new stream or alternate stream set.com/questions/13088123/http-live-streaming-ext-x-discontinuity-tag-makes-allsegments-afterwards-only Deploying HTTP Live Streaming Create either an HTML page for browsers or a client app (Receiver) Configuring /thiết lập cấu hình/ a Web Server Validating // Your Streams Serving Key Files Securely Over HTTPS .The media stream validator shows a listing of the streams you provide. followed by the timing results for each of those streams.246 H. H.264 is also known as MPEG-4 AVC (Advanced Video Coding). . .264 as the main video format.264 is a next-generation video compression format. Blu-ray and HD DVD as well as low resolution portable devices such as Sony’s PSP and Apple’s iPod. It is also one of the formats chosen to be supported by both high definition DVD standards.264 as the format for QuickTime. the credentials on the client device—HTTP Live Streaming does not provide user dialogs for authentication. The key every 3-4 HTTP IVs can be periodically. hours and =>send the changed Who you change the keys periodically. certificate . or you must store Streaming. up to you.com/iphone/samples/bipbop/bipbopall.apple. share the IV after securely keys with is every 50 Mb over HTTPS.You must either initiate your server with own dialog for the user to HTTP Live authenticate.Install an SSL certificate obtain an signed by a trusted authority on SSL your HTTPS server.m3u8" height="300" width="400" > </video> </body> </html> EX fallback in html .Serving Key Files Securely Over HTTPS The file Current segmenter recommenda It is possible and stream tions for for an Key files segmenter encrypting eavesdroppe require an both have media while r to obtain initialization encryption minimizing copies of the vector (IV) to options=>ca overhead is key files if decode n change the to change they are encrypted encryption the key sent over media. Creating an HTML Page <html> <head> <title>HTTP Live Streaming Example</title> </head> <body> <video src="http://devimages.The authentication domain for signed by a trusted the key files must be the same authority in as the authentication domain order to use for the first playlist file. an HTTPS . There are three conditions you must meet in order to use HTTPS to serve keys for HTTP Live Streaming: You must . of data. theSimple Mail Transfer Protocol(SMTP).apple.http://code. and other kinds.M3U8 . as well as the ASCII text handled in the original protocol.com/tutorials/quick-tip-html5-video-with-a-fallback-to-flash--net-9982 MIME (Multi-Purpose Internet Mail Extensions) is an extension of the original Internet e-mail protocol that lets people use the protocol to exchange different kinds of data files on the Internet: audio. Mặc định là 86400 giây tức 24 giờ.ts MIME Type application/xmpegURL or vnd. video. application programs. images.tutsplus.mpegURL video/MP2T TTL (Time to live) là thời gian mà nameserver khác được cập nhật lại. . Multipurpose Internet Mail Extensions (MIME) is an Internet standard that extends the format of email to support: Text in character sets other than ASCII Non-text attachments Message bodies with multiple parts Header information in non-ASCII character sets File Extension . tính theo giây.