Main Principles of Video Production
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Interactive Media

With the rapid development of technology, it is presently possible to watch a video online and on the move. Internet and mobile devices offer a great number of interactive products, such as games, web sites and other interactive applications, which incorporate digital video. DVD has replaced VHS, which is an analog video recording media. The most popular format for watching video has become digital format. There are particular requirements for video incorporation in interactive media products such as World Wide Web, mobile devices and DVD. Factors such as file format and compression are very important for video functionality on a particular platform.

A video transferred from a video recording device to a computer is called a raw video. The raw video has a large file size which is impractical for storage and transfer especially over the Internet. Considering that, video compression is needed in order to reduce the amount of data in a digital video. Compression creates a new file with a smaller size. There are two kind of compression lossy and lossless. It is considered lossless when the file can be decompressed to the original format without any loss of data. It is considered lossy when it causes loss of data. Video files can be compressed in wide variety of ways. This way, there are many different file formats or containers, which store, in a particular way, compressed data such as video and audio streams. Codec is a device which achieves compression of a video file in different formats. There are a great number of codecs that encode or decode the video. Media Player is computer software which can read different file formats. The most common file formats are AVI, FLV, WMV, MP4, MOV, MPG, SWF, 3GP and ASF. AVI file format is developed by Microsoft. Its file has a huge size which is neither suitable for transferring data over the Internet nor for storing it on a digital media such as DVD. The smaller the size of the data the easier it will stream and require less space. AVI container can contain both video and audio data. FLV is a Flash video format which has become extremely popular over the Internet. FLV file extension is encoded by the Adobe Flash software to play within the Adobe Flash Player. FLV gives one of the smallest file sizes and retains good quality. MP4 is also a web based file format and it can be played within Flash Player. MP4 H.264 has become the preferred file format as its content is compatible with both the web and mobile devices. H.26 codec allows efficiently encoding high definition video. WMV is a windows media video file and can be played within Windows Media Player. Its file size is tiny which results a low video quality. WMV can be used for both streaming and downloading from the Internet. MOV file format is developed by Apple and can be played within QuickTime Player which also exists on almost all PCs. It is one of the most common sharing formats. It stores good looking video but its size is big. MPG format is standardized by the Moving Picture Experts Group. It is typically incorporates MPEG-1 and MPEG-2 compressions. MPEG-1 codec encodes data for video CD format. MPEG-2 codec encodes data for DVD format and has better video quality than MPEG-1 standard. MPG format is usually used for creating downloadable movies. It can be played within Windows Media Player and QuickTime Player. SWF is an Adobe Flash format. It is the most popular format for animated vector graphics on the web. It can contain different media, animation and ActionScript. 3GP file format is a multimedia container format. It can transfer data between the 3G mobile phones and the web. The video captured from the 3G mobile phone has .3gp file extension and can be shared over the Internet. ASF is the preferred file format for Windows Media as it stores multimedia data which can be encoded with a wide variety of codecs. Aspect ratio represents relationship between the width and the height of the image. 4:3 aspect ratio is a television standard format. 16:9 is a new standard format for a widescreen TV, DVD and high definition video. There are two ways to view media such as video, animation and audio: streaming and downloading methods. The downloading method is considered to be when the end user starts watching the video after it has been downloaded on the computer. The streaming method is when the end user starts watching the video as soon as it begins downloading. As a result of this, broadcasting live events is possible. Progressive downloading is a hybrid method. The end user is able to watch a video when a portion of it is received. There are also other factors such as resolution, frame rate, color depth, compressor and audio settings which can reduce the size of the video. Like frame rate, small resolution of an image significantly reduces the video file. Video that contains 16 bit color has a smaller size than video with 24 bit color. Frame rate defines how many frames will be displayed on a monitor per second. The higher the frame rate the smoother the video will be. There are three main frame rates: 24 fps, 25 fps and 30 fps. The best frame rate for encoding one video is the frame rate from the raw video. If the frame rate exceeds 30fps, the video should be encoded at half of that frame rate. For example, if it is 50fps, the video will be encoded at 25fps. 29.97fps is NTSC television standard used in the US and Japan. 25fps is PAL television standard used in Europe and some parts of Asia. Video games can require 60fps for smoother scene. The quality of the video depends on date rate. The data rate is the size of the video per second of data. The lower the data rate, the lower the quality of the compressed video. If the audio settings of the video were limited to mono, the user should not encode it in stereo, especially if the audio is only a speech. The most common sample rates are 44.1 kHz, 48 kHz, 96 kHz and 192 kHz. The higher sample rate, the higher bandwidth is required. The bit range of audio is between 96 and 320 Kbps. 128 Kbps reproduces the sound quality equals to the radio sound quality. The bit rate of 160 Kbps has the same sound quality as CD while 320 Kbps is the highest sound quality. Here are some files formats supported by YouTube and typically used codecs:

•          MPEG4, 3GPP and MOV file formats - h264, mpeg4 video codecs and AAC audio codec

•           AVI – MJPEG video codec and audio is PCM

•          FLV - Adobe-FLV1 video codec and MP3 audio

Digital rights management (DRM) is any system that tries to prevent infringement online. DRM systems are especially important for digital content such as music and videos shared over the Internet as everyone can copy them. DRM schemes control not only coping but also viewing, printing, altering and everything else you can possibly do with digital content. The systems works on three levels: establishing a copyright for a particular content, managing the distribution of this content and controlling what a user can do with the copyrighted content.

There is a wide variety of uses of video. It is especially used in advertising, trailers, e-learning, games, virtual reality tour and viral marketing in order to promote, educate and entertain the end user. It is used not only over the Internet but also uses platforms such as DVD, CD, mobile devices, presentations and kiosks.