Free Movies Online 3
Streaming technology has made listening to music or watching movies online as easy as turning on the radio or TV. Here is how the technology works.
The first music and movie files you might find online were just short clips because you had to download the entire file before you decide to could play it. At the present time, on the contrary, you can start playing the file as soon as the first bytes begin to arrive... due to streaming.
This immediacy is possible because streaming does not send files on the net the same as many other files are sent. It uses another protocol.
A protocol is a set of rules defining how two computers connect with each other and just how they send each other data.
Most data that is sent through the internet is first broken up into packets (small blocks of data). The packets are sent separately and are the rejoined at their destination so that the receiver gets the whole file.
The sending of most data on the web is governed by a set of rules called the Transmission Control Protocol (TCP). Streaming however uses the User Database Protocol (UDP).
These two protocols are quite different. The crucial difference is in how they check for errors.
If one packet gets damaged when downloading has been controlled by TCP, downloading will be suspended while that packet is resent. That way, in the event the download has been completed, you may make sure that you have the whole data file.
When you are streaming files, alternatively, UDP allows packets to get lost now and then without interrupting the downloading. This is fine because, when an occasional packet is lost, you are unlikely to notice any interruption to the music or movie. But if everything froze very briefly while a lost packet was being resent, you probably would notice the interruption.
With streaming technology, you do not have to wait for files to be downloaded entirely before you decide to can begin listening to audio or watching a video. You can listen to a concert on the additional side of the world in real time, make a video call or watch full movie a movie much like on television.
Streaming video works in a similar way to streaming audio, except that the video has to be separated into its separate audio and video components when it really is within the buffer in the RAM.
The server that holds the video for streaming will have a video capture expansion card which may capture either a live feed from a video camera or possibly a pre-recorded video. The capture board turns the analogue signals it receives into digital data and compresses it.
At the same time, it employs a trick in order to avoid having to capture more data than it needs in order to make transmission easier.
In the event the camera used to record the video is stationary, ie, it is not panning, the total amount of data created may be reduced. This may be done because all moving images are made up of a series of frames (still images) that change in rapid succession to give the illusion of continuous movement. The rate is usually 30 frames a second which gives the video a smooth look.
The compression system lessens the number of frames needed by comparing adjacent frames and only taking account of pixels that change from one frame to another. It does this by establishing precisely what the background looks like.
As long as the camera remains but, only the changes in the frame, for example the movement of the actors, have to be transmitted. The background only must be transmitted again after the camera starts to pan and also the background changes.
Video streaming may also skip frames when your Internet link is slow, which may make the video jerky. Thus the faster your connection, the smoother the video will be.
When your computer receives the video signals, it's going to decompress them and load them into a small buffer in RAM as it does for audio.
At this point the signals are split into separate video and audio components that are sent to the video card and sound card respectively, whence they may be output to your monitor and speakers so you can watch the film and hear the sound-track.
