Introduction
mobile streaming media is implemented on a mobile device video playback, mobile streaming media in general play format is 3GP format, smartphones (Symbian, windows phone, android , iOS, etc.) more and more on these phones can download streaming media player streaming media player
in addition, some non-smart phones can also be streaming media, most of Nokia non-intelligent machines have flow media Player.
Mobile video streaming is generally rtsp //: beginning, this site is not a lot, because the domestic network is not perfect, there are only a few sites, users can log Monternet, or wap.cctv . com watch this video, but the network monthly flow relatively movies, it is not enough, but I believe the near future, people can realize mobile TV.
transmission
twostreaming media transmission: sequential streaming (Progressive Streaming) and real-time streaming (Real-time Streaming).
(1) sequential flow mode. Sequence flow transmission is sequential download, download section side while playing previously downloaded, the order does not have to download interactive. Early sequential flow mode to provide streaming service is IP network mode, generally employed is HTTP (hypertext transfer protocol) via TCP transmission, standard HTTP server can provide the service, no special protocol. The impact of network performance on the situation of basically waiting time. Streaming disadvantage sequential approach is not suitable for long media transport segment, we do not provide random access.
(2) real-time streaming mode. In real-time streaming mode, streaming real-time playback, and provide a VCR function, with interactivity, and the like may be responsive to a user in the fast-forward or rewinding operation during playback. Generally, real-time streaming mode requires special protocols such as RTSP, also requires a dedicated streaming server. Because it is played in real time, the impact on the status of the network playback quality of the performance was more direct. When network congestion and problems, packet loss resulting in poor video quality, playback will be choppy or even halt the phenomenon. The advantages of real-time streaming mode is a more interactive, the disadvantage is the need for special protocols and dedicated servers, configure and manage more complex.
Control Protocol
and application-specific control protocols used are streaming RTP / RTCP, RSVP and RTSP.
(1) Real-time Transport Protocol (RTP) and Real Time Control Protocol (RTCP). RTP / RTCP IP-based application layer protocol to support real-time data (audio, streaming video) transmission, the idea is to send some feedback on the quality of transmission and reception of simultaneous transmission of real-time data, respectively, by these two tasks RTP and RTCP complete. RTP provides mechanisms for reconstruction time, timing, packet loss detection and reordering. RTP supports unicast and multicast can be used for one-way transmission can also be used for two-way traffic, but RTP itself does not provide a mechanism for how the real-time transmission, does not provide a reliable flow congestion control, but through cooperation with RTCP and UDP, the transmission efficiency is optimized. RTP / RTCP provide functionality to transmit real-time data and control mechanisms needed, but do not themselves responsible for high-level tasks such as reordering and synchronization, this is done by the application.
(2) Resource Reservation Protocol (RSVP). RSVP allows the data receiver requests a particular data flow end QoS. Real-time applications using RSVP reserved the necessary resources in the routers, so that when the transmission bandwidth required can be obtained. RSVP is a single process, without distinction between the sender and receiver. RSVP supports multicast and unicast, and to adapt the number of members and route changes. Using RSVP required nodes on the transmission path supports RSVP, which is difficult to be guaranteed, it is generally not streaming applications using RSVP.
(3) Real Time Streaming Protocol (RTSP). RTSP is an application-layer protocol, can be established using RTSP between the server and the client, and the continuous control of audio media and video media stream, a "network remote control" between the server and the client, providing VCR-like audio and video the remote control function. However, in RTSP to be independent of the data transmission channel. RTSP supports unicast and multicast provide transport channel selection method can select UDP, multicast UDP and the TCP, but relies on lower-level transport mechanism RTP or TCP. RTSP coordinated operation with the low-level protocols (e.g., RTP, RSVP), to provide a complete service stream. RTSP is stateful, symmetric protocol, RTSP and RTSP server maintains session state in the media server and the client can request. RTSP and HTTP syntax and operation similar to dedicated audio and video are similar to the HTTP URL.
Applications
in the form of streaming applications can be simply divided into three categories: on-demand applications, and the live applications conference applications.
(1) on-demand applications. On-demand applications, the general demand content stored on the server, to publish as needed. It may be the same or different on-demand multi-point program that multiple terminals can be in different locations, different time, in real time, interactively on-demand, users can view and select content on demand at the same time the same stream files through the portal. According to the needs of users, on-demand process may also be implemented as play, stop, pause, fast forward, rewind and other functions.
(2) broadcast applications. Under Live service mode, users can only view the content playback, you can not be controlled.
(3) meeting applications. Conference applications like live applications, but both have different requirements, such as two-way communications. This includes the media should have a collection of hardware and software, as well as streaming technology in general both sides. Conference type of application and sometimes does not require high audio / video quality.
Latest News
Zhu Neptune Research Inc. said it expects 2013 revenue growth of mobile streaming music will exceed 40%, to $ 1.7 billion.
cooperationoperators and service providers to carry out will further promote the development of streaming music services, media streaming music service to create revenue is expected to exceed full-song downloads.
2013, the United States will surpass South Korea to lead the flow of the mobile streaming music service market.
Swedish telecommunications Sang Neila music player (Spotify) and television, mobile and cable service integration; at the same time, O2 Germany launched simfy music service, offers streaming music service; and Deutsche Telekom AG are released Spotify.
Zhu Neptune Research Inc. report author Windsor Holden said in the past, Apple, Google and Amazon are focused cloud music from a storage point of view, it is regarded as download service remote data centers.
Holden added:. "Apple's upcoming iRadio service, could bring huge impact and challenges to contemporary music player, and stimulate other major OTT operators to participate in the competition"
according to the report, digital music service streaming media privacy monetization profound impact. In the face of obstruction and restriction, Torrent traffic continued to maintain a growth trend. The report also found that mobile music services by content-driven, and it played a role in the evolution of society, such as the habit of sharing, real-time motion and follow the option.
The report notes, ring tones and ring tones and other traditional revenues will continue to decline. Currently, ringtone service revenue in Western Europe accounted for only 2% of its peak period.
emergence and development
means that the so-called streaming media format using streaming transmission manner over a network. Streaming media player does not download the entire file before, only the beginning of the content stored in the memory, the data packet buffers and media data in the computer output correctly. Streaming media data streams transmitted at any time ready to play. In recent years, technology-based broadband cable networks gained rapid development of streaming media, streaming media technology based mobile communication network has become increasingly mature.
Currently, some mobile streaming services can be achieved already on 2.5G networks, 3G networks for mobile streaming media services developed to provide more efficient support. Because 3G networks with higher data transfer rates and data service support, 3G operators can not only provide high-quality voice services to users, but also to provide a high rate of streaming media services. From a global perspective, with the acceleration of 3G commercial process, some mobile operators in Japan and Korea as well as Europe and North America has launched a streaming media technology based mobile video services, mobile streaming media business has become the core business focus and 3G networks business. From practical point of view, to provide mobile streaming media on demand, live broadcast, download, play three service form. Among them, on-demand applications including movie trailers, highlights, MTV and so on; including live television programs, video surveillance, major events, such as music on the spot; download the player is more suitable for those off-line, high quality audio and video multimedia programs . Facing the future, people's mobile streaming media business is full of good expectations. Mobile streaming media business is still in its infancy, but its development is very promising. With the continuous development of mobile communication networks and technologies, mobile streaming media business will become the mainstream mobile value-added business development.
Source: mobile streaming media technology and its application in 3G mobile communication - a communication world.