Recommend DV to some people. . . . Introduce the basic knowledge of dv.

The information here is very comprehensive.

DV is the abbreviation of Digital Video, which means "digital video" when translated into Chinese. It is a digital video format jointly developed by many famous home appliance giants such as Sony, Panasonic, Shengli, Sharp, Toshiba and Canon. There are also English abbreviations such as spray valve and digital voltage source.

DV is the abbreviation of English Digital Video, which is a digital camera.

Meaning. DV can also be translated into "digital video", which is a digital video format jointly developed by many famous home appliance giants such as Sony, Panasonic, JVC, Sharp, Toshiba and Canon. However, in most cases, DV stands for digital camera.

Edit this digital video

Digital video refers to video materials recorded with digital information. The English equivalent phrase is a digital vid canon camera with SD card as storage medium.

Eo. But English digital video also tends to refer to devices or systems that collect digital video. Corresponding to digital video is analog video, such as ordinary (analog) TV sets. Digital video is usually recorded on magnetic tape and usually distributed through optical disks, especially DVDs. Of course there are exceptions. Some new cameras can record the collected video content directly on DVD or hard disk. Digital video is recorded on an ordinary analog video tape with a digital camera.

Edit this camera

Camera Atlas (3) Cameras usually have two different video acquisition formats: interlaced scanning mode and progressive scanning mode. When an interlaced camera scans an image, it scans it every other line: odd images are scanned at the same time, then even images are scanned after a certain time interval, then odd images, and then even images ... images containing only odd and even lines are called fields, and adjacent odd and even fields form a frame. Similarly, for interlaced images, all the scanning lines on each image together are also called a frame. If interlaced images are to maintain the same frame rate as progressive images, the number of interlaced scans per second needs to be twice that of progressive scans. If we observe the still images of interlaced video, it is easy to find some wrong line distortions caused by two different acquisition fields. At this time, we need to use the method of de-interlacing (or de-interlacing) to solve this distortion. Usually, if you shoot images at the same frame rate and the same size, progressive cameras are much more expensive than interlaced cameras. The standard film is usually 16 mm film and 35 mm film, and the frame rate is 24 frames per second. The United States uses the NTSC system, and the frame rate of digital cameras is 29.97 frames per second (30/ 1.00 1). PAL system is adopted in Europe, and the frame rate of digital camera is 25 frames per second. Because most cameras use interlaced scanning, the number of frames per second mentioned here is not accurate. A better statement than 29.97 frames per second is 60 (59.94) fields per second, so the time interval between every two fields is about 1/60 seconds. If the digital video keeps the same format (without recompression-this is often done in video editing and distribution, including some cases where lossless compressed video codec is used), the digital video will be lossless format. This is relative to analog video-copying, transmitting and even playing analog video will lead to quality loss; And digital video, even if you copy 10000 times, its quality is exactly the same as the original. So more and more analog videos are converted into digital videos for storage. However, in this conversion process, the speed of some video capture cards or computers is not fast enough, which may lead to frame loss during acquisition. At this time, there is usually no difference in the subjective quality of video, but the accompanying audio sometimes ticks and is noticed by users, especially when dealing with music. Therefore, when making this conversion, you must choose a fast enough device. For nonlinear editing systems, digital video editing is usually performed by NLE. This system is specially designed for video and audio editing. Usually it can be injected into an analog or digital video/audio source, but usually it can do nothing but edit. Almost all TV programs, some movies and advertisements you see are made by nonlinear editing system. Nowadays, digital video editing can also be done on personal computers, which usually requires certain hardware (such as IEEE 1394 interface card, fast enough CPU and large enough hard disk) and certain software (such as Avid, Adobe Premiere, Final Cut Pro, iMovie, MGI Videowave, video toaster, audio-visual drawing, etc.). More and more people use computers to make their own small movies. Compared with 35 mm film, the cost of digital video is much lower, especially when editing. For example, if you want to cut a scene from 35mm film, you need the photographer and director to do it very seriously-because if something goes wrong, the scene may be scrapped. Rechargeability is a great advantage of digital video. The low cost of digital video also makes it possible to shoot personal movies. For example, shooting a film with 35mm film usually costs tens of thousands of dollars. If you use digital video, it may only cost several hundred dollars, even if there is no usable part in the video. Using digital video is also much faster than using film, because digital video can be watched immediately after shooting without the process of developing. For these reasons, more and more movies are shot and processed by digital movies, such as Star Wars. Digital video is not only used for film production. Since 2000, digital TV, including HDTV, has been gradually popularized in most developed countries. In narrow-band applications, mobile video communication, commercial videophone and video conference all have mature products. Streaming video and peer-to-peer video transmission on the Internet are also recent hot spots. There are many different digital video coding methods and file container formats, which support image coding with different sizes, quality, resolution, chroma accuracy and coding functions. Up to 2005, the highest resolution digital video demonstration was 33 million pixels, that is, 7680 x 4320, and the frame rate was 60 frames per second-called UHDV, although it was only conducted in a special laboratory environment, see [1]. At the resolution of 1024 x 1024, the highest frame rate reaches 1 10,000 frames per second (in a very short time, of course), which is what industrial high-speed cameras can achieve.

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brief introduction

The biggest difference between digital video camera and traditional video camera is that it has a high-definition home entry dv, which can browse pictures in time.

This screen is called the display screen of a digital camera, and it is usually a liquid crystal structure (LCD). At present, the LCD screen size of digital cameras is 2.5 inches or 3.0 inches. The commonly used LCD of digital camera is TFT. What is a TFT? Firstly, it includes polarizer, glass substrate, thin film transistor, orientation film, liquid crystal material, light guide plate, color filter, cathode fluorescent lamp, etc. For LCD, backlight is the light emitted by fluorescent tubes. These light sources will pass through a polarizer first, then through the liquid crystal, and then the arrangement of liquid crystal molecules will change the angle of light passing through the liquid crystal. When using LCD, we find that we can see different colors and contrasts at different angles. This is because most of the light from the screen is vertical. If we look at an all-white picture from a very oblique angle, we may see black or color distortion. The LCD of digital camera is very expensive and fragile, so users must be careful when using it, and usually need to do maintenance work. Compared with analog cameras, DV has the following outstanding features: high definition. As we know, analog cameras record analog signals, so the image clarity (also called resolution, resolution or resolution) is not high. For example, the horizontal resolution of VHS camera is mainly 240 lines. It is better to mention that the Hi8 model has only 400 lines. DV records digital signals, and the horizontal resolution has reached 500~540 lines, which is comparable to professional cameras. The color is purer. The bandwidth of chroma and brightness signal of DV is almost 6 times that of analog camera, while chroma DV

Brightness bandwidth is one of the most important factors to determine the image quality, so the color of DV images is more pure and gorgeous, reaching the level of professional cameras. Lossless replication. The signal recorded on DV tape can be transcribed countless times, and the picture quality will not be degraded at all, which is beyond the reach of analog cameras. Small size and light weight. Compared with analog cameras, the size of DV cameras is greatly reduced, generally only about 123mm× 87m× 66mm, and the weight is also greatly reduced, generally only about 500g, which greatly facilitates users, and the size is only 74.7mm×6 1.9mm×26.9mm, and the weight is only 90g, which is lighter than most mobile phones. When shooting, users can watch the moving image to be shot through the LCD screen of DV, and they can see the shot moving image immediately after shooting. Through DV, the captured moving images can be converted into digital signals and stored in DV band together with the sound signals recorded by the microphone. DV can be connected to a computer, read the contents of the DV tape, and then post-process these contents, such as editing, or carve them into VCD or DVD for storage. DV can also be connected to a TV, which can not only read the contents of DV tapes, but also record TV programs. Pixel is the most important technical index of DV. The higher the pixel, the higher the image resolution. The lens of DV can be divided into CCD and COMS.

Development history

It has been 13 years since the first digital camera was born in 2008. In this 13 year, great changes have taken place in digital cameras, with storage media ranging from DV to DVD to hard disk, with total pixels ranging from 800,000 to 4 million, and image quality ranging from standard definition DV(720×576) to high definition HDV( 1440). 1995 the first DV camera was born 1995. In July, Sony released the first DV camera DCR-VX 1000. Once launched, it has been widely adopted by TV reporters and producers all over the world. This product uses mini DV format tapes. 3CCD sensor (3 pieces 1/3 inch, 4 1 10000 pixel CCD), 10 times optical zoom and optical anti-shake system are adopted. The price was as high as $4,000 when it was released. DCR-VX 1000 is a great change in the history of images. Since then, civil digital cameras have entered the digital age. The first DVD camera was born in 2000. In August 2000, Hitachi introduced the first DVD camera DZ-MV 100. At that time, this product could only be burned on DVD-RAM. Hitachi brought DVD as the storage medium into digital cameras for the first time, and used 8cm DVD-RAM to burn optical discs as the storage medium, which got rid of the inconvenience of DV tapes and was a great innovation after DV cameras. However, not many people paid attention to this product at that time. DZ-MV 100 is only sold in Japan, and it is hard to find traces in the domestic market. DVD cameras are widely recognized. In 2004, the first miniature hard disk camera was born. In September 2004, JVC launched the first batch of 1 inch micro hard disk cameras MC200 and MC 100. Hard disk began to enter the field of consumer digital cameras. The shooting capacity of the two hard disks is 4GB, and the captured video images are compressed by MPEG-2. Users can flexibly change the compression rate to extend the shooting time. The use of hard disk media makes the communication between digital camera and computer very convenient. MC200 and MC 100 and several later 1 inch micro hard disk cameras can flexibly replace micro hard disks. In June 2005, JVC released the Everio G series of 1.8 inch large-capacity hard disk camera. The maximum capacity is 30GB, and the volume is well controlled, and the price is kept at the level of similar DV cameras. In 2004, the first HDV 1080i HD camera was born. In September, 2003, Sony, Canon, Sharp and JVC jointly formulated the HD camera standard. In September 2004, Sony released the first HDV 1080i HD camera HDR-FX1E. The recording resolution of HDV has reached 1440× 1080, and the horizontal scanning line has doubled that of DVD, which has revolutionized the definition. HDR-FX 1E, including the later HDV camera, all follow the original DV tape and still support DV format shooting. Backward compatibility played a good transitional role in the initial promotion of HDV cameras.

principle of operation

The basic principle of digital camera is simply the conversion and transmission of photoelectric digital signals. That is to say, the optical signal is converted into current through the photosensitive element, and then the analog electrical signal is converted into digital signal, and the information obtained after special chip processing and filtering is restored to the dynamic picture we see. The photosensitive element of digital camera can convert light into charge, and the charge is converted into digital signal through analog-to-digital conversion chip. There are two main types: one is the widely used CCD (Charge Coupled Device); The other is CMOS (complementary metal oxide conductor) device.

Storage of DV

Nowadays, with the continuous emergence of high-definition video DVs, the storage medium capacity of DVs has become the most concerned topic. So a lot of dv suddenly appeared in the market overnight. The biggest difference between these DVs may be the different storage media used. Although the capacity is different, there are advantages and disadvantages. So I'll give you a brief analysis. JVC camera with hard disk as storage medium

Now DV on the market can be divided into four categories according to storage media: hard disk, optical disk, DV tape and memory card. First of all, talk about hard disk DV. The hard disk DV on the market is mainly the DV of JVC brand, and the mainstream capacity is 20-60GB. The advantage of hard disk DV is that it has a large storage space, so it is convenient to store the recorded programs in the computer or directly take out the discs with the supporting DVD burning equipment to watch them for a while. However, this kind of machine also has its weakness, that is, if you can't replace the hard disk to continue shooting after shooting, and because the hard disk DV uses a hard disk, the machine can't fall, otherwise the machine is likely to be reimbursed directly and all the data in the hard disk will be reimbursed. Therefore, Panasonic cameras using DVD as storage media are used to purchase this machine.

Be careful when you do it. CD-ROM media products are the most expensive products, but also the most convenient machines. It is convenient because DVD is used as the storage medium of optical disc medium DV. After shooting, just take out the DVD directly and play it on any DVD player. However, although this is very convenient, the image quality is somewhat compressed, and the life of the optical storage medium is relatively short. Everyone should weigh it when buying. I don't need the media to introduce DV products. The advantage is that it is cheap and can be bought everywhere, but the disadvantage is that the tape is kept for a short time, and the shooting speed is slow and uncomfortable when the video is exported to the computer. However, it is suitable for beginners. The development of this machine has matured, and the price of the main machine also adopts Panasonic camera and DV tape as storage medium.

It's the cheapest of all product lines. The products of memory card media generally focus on the use of cheap and good SD cards. With the continuous upgrading of SD capacity and the appearance of SDHC standard memory card, the capacity of SD card has developed to N GB level, and this development will continue to spread. Compared with other storage media cards, this machine is the smallest and the most convenient to carry. Disadvantages are high power consumption, short standby time and poor lens performance.

Storage format

CCIR 60 1 is widely used in TV broadcasting. MPEG-4 is a video material for online distribution; MPEG-2 is used for DVD and SVCD；; Use mpeg-1in VCD; H.26 1 for videophone and video conference; H.263 is used for videophone and video conference; H.264 is the tenth part of MPEG-4(AVC). The application range is very wide. Tape DV tape

SX, IMX, digital camera; D 1, D2, D3, D5, D9 (also known as the number-s); DV, minidv-most consumer cameras are now in use; DVCAM, dvcpro-used for professional broadcasting equipment; Numbers 8-5.

Classification by purpose of use

1, broadcast-grade model: This model is mainly used in the field of radio and television, with high image quality and good comprehensive performance, but it is expensive and bulky. They have the highest definition, the highest signal-to-noise ratio and the best image quality. Of course, the price of several hundred thousand yuan is not acceptable to ordinary people. For example, Panasonic's DVCPRO model above 50m and so on. 2. Professional-grade models: These models are generally used in professional TV fields other than radio and television, such as audio-visual education, and the picture quality is lower than that of broadcast cameras. However, in recent years, some high-end professional cameras have surpassed the old models in many aspects, such as performance indicators, and the prices are generally between tens of thousands and hundreds of thousands of yuan. Compared with consumer models, professional DV is not only cooler and more eye-catching, but also much higher in configuration, such as using lenses with better quality and performance and larger CCD, which is more prominent in imaging quality and adaptability to the environment. For friends who pursue image quality, the surprise brought by the improvement of image quality cannot be measured by money at all. Representative models such as Sony's DVCAM series models. 3. Consumer-grade models: These models are mainly cameras suitable for home use, which are used in non-commercial occasions with low requirements on image quality, such as home entertainment. These cameras are small in size, light in weight, easy to carry, simple to operate and cheap. It can be used to make VCD and DVD for personal families in low-demand occasions, and the price is generally in the order of several thousand yuan to ten thousand yuan. If we subdivide home digital cameras, they can be roughly divided into the following categories: entry-level DV, mid-range consumer-grade DV and high-end quasi-professional DV products.

Classification by storage media

1, tape type: refers to a digital camera with mini DV as the recording medium. It was first developed by more than 10 manufacturers 1994.

And become. High quality digital video signal is recorded by 1/4 inch metal vapor deposition tape. 2. CD: refers to a DVD digital camera. The storage medium is DVD-R, DVR+R or DVD-RW and DVD+RW for storing dynamic video images. Simple operation and easy to carry. Don't worry about overlapping shooting when shooting, let alone wasting time rewinding or playing back. Especially, it can be played immediately by DVD player, which saves the trouble of later editing. DVD media is the most secure and stable of all media digital cameras at present. It is not as easy to wear as tape DV, and it is not as demanding on shock prevention as hard disk DV. The disadvantage is that the price of DVD is slightly higher than that of tape DV, and the recording time is shorter. 3. Hard disk: refers to the digital camera with hard disk as storage medium. It was first introduced by JVC in 2005, using micro hard disk as storage medium. Hard disk cameras have many advantages. Large-capacity hard disk cameras can ensure long-term shooting, so that you won't have any worries when traveling. When you get home, you can transfer the shooting materials to the computer, and you don't need complicated and professional video acquisition equipment like the MiniDV tape camera era. Simply connect to the computer through USB cable, you can easily export the material, so that ordinary family users can easily experience the fun of shooting and editing video clips. Like CF card, micro hard disk is smaller than DVD, and its service time is the most considerable among many storage media. However, due to the short time, the hard disk DV still has many shortcomings, such as poor earthquake resistance and so on. With the further decline of prices, the number of people who need help will inevitably increase in the future. 4. Memory card type: refers to a digital camera that uses a memory card as a storage medium, such as the popular "X Easy Shooting" product. As a transitional simple product, it is rare in the market now.

Classification by sensor type and quantity

1, sensor type: CMOS and CCD CCD: Charge-coupled device image sensor (CCD), made of high-sensitivity semiconductor material, can convert light into charge, and then convert it into digital signal through analog-to-digital conversion chip. CMOS: Complementary metal oxide semiconductor, like CCD, is a semiconductor that can record light changes in digital cameras. At the same resolution, CMOS is cheaper than CCD, but the image quality produced by CMOS devices is lower than CCD. So far, most consumer-grade and high-end digital cameras on the market use CCD as sensors; CMOS sensors are used as low-end products in some cameras, but some high-end products also use special CMOS as optical sensors, such as several high-end CMOS models of Sony. 2. Number of sensors: the number of single CCD and 3CCD image sensors, that is, the number of CCD or CMOS photosensitive devices of digital cameras. Most digital cameras are digital cameras.

A single CCD is used as its photosensitive device, while some high-end digital cameras use 3CCD as its photosensitive device. Single CCD means that there is only one CCD in the camera, which is used for photoelectric conversion of brightness signal and color signal. Because a CCD completes the conversion of luminance signal and chrominance signal at the same time, the captured image can not meet the high requirements in color reproduction. 3CCD, as its name implies, is a camera that uses three ccds. We know that if light passes through a special prism, it will be divided into three colors: red, green and blue, and these three colors are the three primary colors used in our TV. Through these three primary colors, all TV signals including brightness signals can be generated. If a CCD is used to receive each color and convert it into an electrical signal, and then an image signal is generated through circuit processing, a 3CCD system can be formed, which can display the primary colors of the image almost completely, and there will be no color error caused by camera deduction.