 digital television. These are the learning outcomes of the session. Let me ask you one question. What are the examples of the analog video players and the digital video players? You can pause the video, think on that question and write down your answer in your notebook. And after writing the answer, come back and resume the video. Let me give the answer of the question. Analog video players are the videotapes recorders, videocassette recorders, etc. Whereas digital video players are CD players and the DVD players. So what is the analog television? Basically analog television involves the analog signals and the cathode rate tube sets. The signal is made of the continuously varying radio waves that the TV translates into the picture and the sound. The analog signal can reach to the person's TV over the air through the cable or via the satellite. The picture illustrates the examples of the analog television sets. What are the disadvantage of the analog television? The conventional CRT set displays around only 480 visible lines of the pixel. So the broadcasters will face a difficulty for the huge television sets in order to display the signal. So what happens because of the less availability of the 480 lines? In case of the larger display, the video will be blurred. So another is that analog pictures are interlaced by the CRT electron gun. So the interlaced scanning makes the picture flicker. So in order to overcome this disadvantage, we have a digital television. So digital means what sending the information in terms of 1s and 0s instead of sending the information as a wave. Over the air broadcasting, a DTV generally uses the UHF portion for the radio spectrum with the 6 MHz bandwidth just like that of the analog television do. The Advanced Standard Television Committee that is ATSC made the 18 different resolution formats available for the digital broadcasting. All are built in and the external DTV tuners are required in order to decode that 18 different formats. The practical application of the DTV broadcasting however has come down to the three resolutions that is 480p, 720p and 1080i. The picture listed the example of the DTV, we have the digital setup box that will encode that 18 digital standard format to display on to the TV. As well as DVD is one of the best example of the digital signal. The advantage of the digital television is that the picture when it is displayed on a smaller TV it will provide the better quality. A digital signal can support the higher resolution. So the picture will look good when it is displayed on larger TV also. The picture will not get blurred as in case of the analog TV we have only the 480 pixels. So the resolution will be less in case of the largest TV it will the picture will get blurry and the loss of there is loss of the sharpness color contrast of the image. So the video can be the progressive rather than the interlaced so scanning here it is used as a progressive. So the screen shows the entire picture from for the every frame instead of every line of the picture. The TV stations can broadcast several signals using the same bandwidth so which is called as a multicasting. If the broadcasters choose to they can include the interactive contents or the additional information with the DTV because of the multicasting. So it can support high definition broadcast also. Let us see some important factors regarding to the DTV. Well first factor is that the aspect ratio. The aspect ratio of the monitor is defined as the ratio of the width of the image to the height of the image that it displays. So the aspect ratio along with the screen resolution these are the two important factors of the monitor that defines how the image or the video is to be displayed on to the screen. The 4S to 3 aspect ratio is also called as a full screen aspect ratio whereas a 16S to 9 aspect ratio is called as a wide screen aspect ratio. Resolution a resolution is a very important factor for the image quality. How the image is better is totally depends on the resolution. A resolution is nothing but the number of pixels which are present in that image. So better larger number of the pixels will be the better quality of the image. Each pixel consists of the information related to the image in terms of the spatial domain. So more number of the pixels will be have a more number of the information about the image and so the image image will have a better quality. Here is an one example which is shown a 16x16 image which is also have the less in number of the pixel which is present in that how to calculate the number of pixels just to multiply the 16x16 you will have the number of total number of the pixel which are present in that image. So again 32x32 have the better quality more number of pixels are available again 500x500 it will have a more better number of the pixels than as compared to the 16x16 so it will provide you the better quality. This is one another example with the resolution of 1920 cross 1080 pixels image compared to the 320 cross 180. So the first factor here it represents the number of pixels which are present in the horizontal row and this represent the number of pixels which are present in a vertical. So from this image we can clearly see that number of pixels are more the image will be sharper it will have the better contrast better color color illumination as well as the image will look good in high resolution than that of the low resolution frame rate. So in a motion picture television the motion is nothing but the frames number of frames which are played per second. So the frame rate defines the number of frames per second. Generally the frame rate is about 24, 25, 30 frames per second are common which is defined by the SM PTE that is a society of motion picture and television editors. The professional frame rates for the motion picture is generally 24 per second and for the television it is of 30 per second. The video sources are listed with the letter P are called as a progressive scan. As the 480p the P stands for the progressive scan and 720p P stands for the progressive scan. If there is a I it will be called as an interlaced video. In case of the progressive scan the video contents are displayed both the even and odd scan lines at the same time on the TV. That is the entire video frame is displayed on a TV at the same time. Whereas in case of the interlaced scan the even scan lines are drawn on the screen then the odd scan lines are drawn on the screen. Two of this even and odd scan lines fills make up the video frame. So, this is how the image is displayed by the progressive scan and the interlaced scan. So, what is a SDTV? Which is nothing but the standard definition TV. This is nothing but the part of the digital television. It is totally defined on the basis of the resolution. The quality of the SDTV is similar to that of the digital versatile disc that is DVD. The broadcasters can transmit up to the 5 SDTV programs simultaneously which is called as a multicasting. The resolution of the SDTV is about 480p which is similar to that of the analog broadcasting TV, but it transmitted in a digital term. The image is made up of the 480 lines or pixels or rows of resolutions can be progressively. The aspect ratio is 4s to 3 that is a full screen aspect ratio. Frame rate for the SDTV is around 24p to 60 frames per second. High definition television. Most important aspect of this HDTV is that the better resolution or we can call it as increased resolution. The HDTV constitutes a tremendous leap forward in an image quality by providing up to the 5 times resolution than that of the standard analog television. This means the image will be sharper, the image will have a better color fidelity and wide screen format is available that is 16s to 9. The aspect ratio of the HDTV is 16s to 9, more like the movie screen and the resolution is about 1920 by 1080 pixels. Frame rates ranges from about 24 frames per second to the 60 frames per second. HDTV versus SDTV. So, what is the difference between them? Totally the difference is regarding to the resolution and the aspect ratio. In case of the SDTV we have the 480 pixels for the vertical resolution whereas, the HDTV has maximum about 1080 pixels in a vertical resolution and aspect ratio is about 16 to 9. If we think about the pixel number of pixels regarding to the HDTV for the horizontal and vertical pixels we have we have more number of the pixels because of that the more information about the picture is present. Again the width and to height ratio is about 16s to 9. So, this part will provide us a more information about the image and also the number of pixels together it will provide you the more information about the image. So, because of that the better quality of the image is available. This is the example of the picture which has a 4s to 3. The same picture with the 16s to 9 ratio will have a more information or the extra picture area is available for the display. Next is the resolution terms we can see the area of the resolution for the fish here and resolution for the fish here. The detailing of is not available in case of the SDTV whereas, here we can see the detail about that fish and again this is another example. So, this is the blurry image because of the less number of the pixels and here we have a clear image because of the high resolution. So, these are the references for the session. Thank you.