Network streaming applications has gain its importance with the development of Internet and multimedia technologies. Streaming media means the user neednt to download the data to the local machine. In recent times, most portable computers and smart phones have some type of inbuilt Wi-Fi network interface cards. Such development of Wi-Fi networks allows the user to convert the video distribution system to wireless networks. In this paper, we describe a real -time multimedia system based on embedded processor. The objective is to provide mobile users with Wi-Fi enabled devices, with an ability to watch live programs.
The multimedia can be streamed in real-time to wireless handheld devices, for e.g., it is used to distribute the digitally captured OnCampus live events such as lectures, rules and regulations of university to new attendees and other events of general interest in real-time. In addition to the primary objective of distributing live videos, the server also provides the Video-on-demand feature, where the user can start video when he wants, make pauses, go forward and back in the video at his desire. Since the ability to access information at ones convenience is a desired feature of any multimedia distribution system, video-ondemand is of course the best in video streaming and is a dream of every user. In this paper, a new player based on ARM11 processor is developed, that uses RTSP protocol to stream video. This player is designed to solve some shortcomings of other media player, such as poor performance, delay, cost, inefficiency, complexity etc. Test plans has been carried out to check the performance of system and results states that it fully meets the needs of users and it proves that, it is an effective application for embedded system.
II. Definition Of Related Concepts
ARM 11 processor(Raspberry pi) The initial ARM11 core (ARM1136) was released to licensees in October 2002. In terms of instruction set, the ARM11 builds on the preceding ARM9 generation. It incorporates all ARM926EJ-S features and adds the ARMv6 instructions for media support (SIMD) and accelerating IRQ response. Microarchitecture improvements in ARM11 cores include: SIMD instructions which can double MPEG-4 and audio digital signal processing algorithm speed. Cache is physically addressed, solving many cache aliasing problems and reducing context switch overhead. Unaligned and mixed-endian data access is supported. Reduced heat production and lower overheating risk. Redesigned pipeline, supporting faster clock speeds (target up to 1 GHz) The arm chips have the general characteristics of the RISC systems; moreover some special advanced technologies are adopted in the processor by engineers to ensure the high performance with the minimized chip size and reduced power consumption. Raspberry pi board is used as the development platform in this paper. The Raspberry Pi is based on the Broadcom BCM2835 system on a chip (SoC), which includes anARM1176JZFS 700 MHz processor, Video Core IV GPU, and was originally shipped with 256 megabytes of RAM, later upgraded (Model B & Model B+) to 512 MB. The system has Secure Digital (SD) or Micro SD (Model B+) sockets for boot media and persistent storage. The Raspberry Pi chip, operating at 700 MHz by default, will not become hot enough to need a heat sink or special cooling. The SoC is stacked underneath the RAM chip, so only its edge is visible. Though the Model A does not have an 8P8C ("RJ45") Ethernet port, it can connect to a network by using an external user-supplied USB Ethernet or Wi-Fi adapter. On the model B the Ethernet port is provided by a built-in USB Ethernet adapter. Dec 2014 (Volume 1 Issue 7) JETIR (ISSN-2349-5162) JETIR1407066 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 931 Generic USB keyboards and mice are compatible with the Raspberry Pi. The video controller is capable of the following video resolutions: 640 × 350 EGA; 640 × 480 VGA; 800 × 600 SVGA; 1024 × 768 XGA; 1280×720 720p HDTV; 1280 × 768 WXGA [B] Streaming protocol The Real-Time Streaming Protocol (RTSP) establishes and controls either a single or several time-synchronized streams of continuous media such as audio and video. It does not typically deliver the continuous streams itself, although interleaving of the continuous media stream with the control stream is possible. The protocol supports the following operations: Retrieval of media from media server, Invitation of a media server to a conference, Addition of media to an existing presentation. RTSP has the following properties: Extendable, easy to parse, secure , transport-independent, multi-server capable, control of recording devices, Separation of stream control and conference initiation, Suitable for professional applications, Proxy and firewall friendly, HTTP-friendly etc. Each presentation and media stream may be identified by an RTSP URL. RTSP is identified by an RTSP URL, which points to the media server handling that particular media stream and names the stream stored on that server. Several media streams can be located on different servers; for example, audio and video streams can be split across servers for load sharing. The description also enumerates which transport methods the server is capable of. RTSP has some overlap in functionality with HTTP. It also may interact with HTTP in that the initial contact with streaming content is often to be made through a web page. The current protocol specification aims to allow different hand-off points between a web server and the media server implementing RTSP. It also enables On-demand delivery of real -time data. Some of the RTSP commands commonly used are as follows:
OPTIONS DESCRIBE SETUP PLAY PAUSE RECORD TEARDOWN
An example of such a client request using OPTIONS is as follows(assuming port number of 554): OPTIONSrtsp://220.127.116.11/sample.1RTSP/1.0 In response to the clients request, the server will response with ASCII based status code similar to HTTP. Examples of the status codes with their meanings are as follows: 200: OK 301: Redirection 405: Method not allowed 451: Parameter not understood 462: Destination unreachableIII. Hardware Design
Hardware system design Video streaming system consists of four blocks: Web Camera, Video streaming server, application server, and client side devices. Web Camera: It is used to record videos to be stored in server. There is a plug with in ARM used as extension to connect the camera. This web camera continuously monitor the room and send the video. Video streaming server: It is used for compression and processing of videos. Streaming Media server allows you to send media to clients across the internet through the streaming media protocol .Raspberry pi used as a development platform for streaming media server. It enables live streaming of video content from a single server to a large number of clients. Video streaming server is implemented and installed on a raspberry pi with ARM11 processor and linux as the operating system. Application Server: It is used to send and receive multimedia. Through web server ,it forwards the data packets between computer network making connection through Ethernet cable on ARM11 Board(Raspberry pi). Using Wi-Fi we can stream the video through mobile or PC.