Digital video

Digital video is made of many tiny pictures.

These pictures flash by very fast. This makes them look like they move.

It is easy to copy these videos. You can also share them with friends. You can watch them on a phone. You can watch them on a TV.

Digital video often has sound too. This sound goes with the moving pictures. It makes movies feel real. Most big movies use digital video now. It is a great way to see stories.

Digital video is a way to show moving pictures.

It works by showing many tiny images very fast. These images are called frames. The speed is called the frame rate. It is measured in frames per second.

Each frame is made of tiny dots called pixels.

Digital video is different from analog video. Analog video uses signals to show pictures. Digital video uses data. This makes it easy to copy and share. You can copy digital video without losing any quality. This is not true for analog video. When you copy analog video, the quality gets worse.

People store digital video on many things. You can use a Blu-ray disc.

You can also save it on a computer. Some people stream video over the internet. You can watch it on a phone or a smart TV. Most big movies use digital video now. In 2018, only 24 major films used 35mm film. Most other films used digital tools instead.

Digital video is a special way to show moving pictures using computer data.

Instead of using electrical signals like old analog video, it uses encoded digital information. This video is made of many still images shown very quickly. These images are called frames. The speed at which they play is the frame rate. It is usually measured in frames per second.

Each frame is made of tiny dots called pixels. This digital way of working makes it easy to copy and share video. You can copy digital files without losing any quality. This is much better than analog video, which loses quality when you make copies.

To make digital video, cameras use special sensors to catch light.

These are often called MOS sensors. A very important type of sensor is the charge-coupled device, or CCD. Willard S. Boyle invented the CCD in 1969. He even won a Nobel Prize for his work in physics. Later, in the 1990s, scientists developed a different kind called the CMOS sensor. These sensors turn light into the digital data that makes up a video. This data can then be saved on things like Blu-ray discs.

You can also stream it over the internet to a smart TV.

Making digital video has a long history of new inventions. In 1986, Sony introduced the first commercial digital video format called D1. This format recorded uncompressed video, which means it did not shrink the data. Because it needed many cables to work, only large TV networks used it. In 1988, Sony and Ampex worked together to make the D2 format. D2 was very helpful because it only needed one cable to connect. This made it a great choice for many television studios. These early tools helped the world move away from old analog machines.

Scientists also had to find ways to make video files smaller. This is called compression, and it helps save storage space.

In the 1980s, a method called the discrete cosine transform, or DCT, became the standard. This helped create many popular video formats used today. For example, MPEG-2 became the standard for DVDs and digital TV. In 2003, a format called H.264 was released. This is now the most widely used way to record and share video. Today, many developers use H.264, while others use the newer HEVC format.

Digital video is part of almost everything we see today. Most big movies are now shot using digital cameras instead of film. In 2018, only 24 major films were shot on 35mm film. Since 2016, over 90% of major films have used digital video. This technology is also used in schools for learning. Doctors even use digital video to track things like a baby's heart rate. It is even used in security cameras to keep places safe. From your phone to the big movie theater, digital video is everywhere.

Digital video is an electronic representation of moving images. It uses encoded digital data to represent visual information. This is different from analog video, which uses analog signals. Digital video works by displaying a series of digital images in rapid succession. These individual images are called frames. The speed at which these frames appear is the frame rate. It is usually measured in frames per second. Common frame rates include 24, 25, 30, or 60 frames per second.

Each frame in a digital video is made of tiny dots called pixels. The color of every pixel is represented by a fixed number of bits. For example, 8-bit color captures 256 different levels of a color. Digital video offers many advantages over analog systems. It is easy to copy, multicast, share, and store. One major benefit is that digital video can be reproduced with no degradation in quality. When analog sources are copied, they experience something called generation loss. This means the quality drops each time a copy is made.

To create digital video, cameras use specialized image sensors. The basis for these cameras is the metal–oxide–semiconductor, or MOS, image sensor. The first practical semiconductor image sensor was the charge-coupled device, or CCD. Willard S. Boyle invented the CCD in 1969. His work in physics was so important that he won a Nobel Prize. In the 1990s, the CCD was followed by the CMOS active-pixel sensor. These sensors allow cameras to turn light into the digital data needed for video.

Developing digital video required new ways to handle large amounts of data. In the 1970s, pulse-code modulation, or PCM, helped start digital video coding. However, standard-definition content required very high bit rates of 45 to 140 Mbit/s. By the 1980s, the discrete cosine transform, or DCT, became the standard for compression. Compression is a way to make video files smaller. The first coding standard was H.120, created by the CCITT in 1984. This was not very practical because it used an inefficient algorithm called differential pulse-code modulation, or DPCM.

The H.261 standard was the first practical video coding standard because it used DCT compression. Since then, DCT has been used in all major video coding standards. In 1991, the Motion Picture Experts Group developed MPEG-1 to compress VHS-quality video. This was followed in 1994 by MPEG-2, which became the standard for DVDs and standard-definition digital television. In 2003, H.264/MPEG-4 AVC was released. This is currently the most widely used video coding standard. It is used by 91% of video developers. The current generation is HEVC, also known as H.265, introduced in 2013. HEVC is used by 43% of developers.

Digital video history includes important commercial milestones. Sony introduced the D1 format in 1986. This format recorded uncompressed standard-definition component video. Because it required three cables, it was mostly used by large television networks. In 1988, Sony and Ampex co-developed the D2 format. D2 recorded video in ITU-601 format without compression. The main difference was that D2 used composite encoding. This meant it only needed a single cable. This made D2 a perfect fit for many television facilities. D2 was also used to master laserdiscs.

The shift to digital has changed the entire film industry. In 2013, major films shot on digital overtook those shot on film. Since 2016, over 90% of major films have been shot on digital video. In 2018, only 24 major films were released using 35mm film. Today, companies like Sony, Panasonic, Canon, and Arri offer many choices. Some cameras are designed specifically for the digital cinema market. These high-end cameras offer more resolution and dynamic range than standard broadcast cameras.

Digital video is now part of many different systems. It is used in digital television (DTV) to transmit video from networks to consumers. DTV is faster and offers more options than the analog methods used before the 1950s. Digital video is also used in healthcare to track infant heart rates and oxygen levels. In schools, students and teachers use it for many different purposes. Even security systems have changed. Closed circuit television (CCTV) now uses digital video recorders, or DVRs, to store evidence.