capture video with sound, and the audio part and video part are digitally synchronized and played synchronously. Video capture card, video capture card and video signal are stored on the hard disk in the form of data files collected in the computer. This is an indispensable hardware device for video processing. Through it, we can transfer the video signal from the camera box to the computer, use the video editing software, edit the digital video signal in the later stage, such as cutting the picture, adding filter, subtitles and audio, setting transition effects and adding various video effects, and finally complete the transformation of the edited video signal into standard VCD, DVD and online streaming media formats. /> Edit this paragraph to classify
video capture cards, which can be divided into digital capture cards (using digital interfaces) and analog capture cards according to video signal sources.
video capture card video capture cards can be divided into external capture cards (boxes) according to the installation links, and have built-in boards. According to video compression and video acquisition card, it can be divided into soft compression card (consuming CPU resources) and hardware compression card. According to the input and output interfaces of video signals, video capture cards, 1394 capture cards, USB capture cards, HDMI capture cards, VGA video capture cards, graphics cards, PCI and PCI-E video capture cards can be divided into. According to the performance role of video capture card, it can be divided into TV card, image capture card, DV capture card, computer video card, monitoring capture card, multi-screen card, component capture card of streaming media capture card, HD capture card, laptop capture card, video capture card, VCD card and nonlinear editing card (hereinafter referred to as nonlinear editing card). According to its intended use, it can be divided into broadcast-quality video capture cards, professional-grade video capture cards, commercial-grade video capture cards, and video capture cards that collect image quality. Between the collected images, their main difference indicators. More basic video image acquisition methods can be divided into two categories: digital signal acquisition and analog signal acquisition. General image acquisition card, digital acquisition card and analog acquisition card, and several types of AV+DV two-in-one acquisition card. Usually, the video acquisition card with the highest broadcast quality has a collection resolution of 768X576 (root mean square value) PAL system, or 72X576(CCIR-61 value) PAL system with 25 frames per second, or the minimum compression ratio of 64X48/72X48 NTSC 3 frames per second is usually less than 4:1. This type of product is characterized by a set of images, high resolution, and high video signal-to-noise ratio. The disadvantage is a large video file with a data volume of at least 2MB per minute. The performance level of the video capture card is slightly lower than that of the professional video capture card with broadcast quality, and the resolution of the two cards is the same, but the compression ratio with the lowest compression ratio is less than 6:1, and the input and output interface AV is combined with a slightly larger video and S-Video. The general dynamic resolution of civil video acquisition card is as high as 384X288, and the PAL system is 25 frames per second.
video (video) multiple still images (image frames) and continuous audio information are mixed in the media on the time axis, and the changes of the multi-frame images move synchronously with the passage of time. Therefore, in a sense, it is called the video of moving images. The video stored and processed in different ways can be divided into two types: analog video and digital video. The signals from analog video sources are captured and processed, converted into digital signals ( and 1), and the digital information is stored in a computer program on the hard disk. Analog/digital conversion is carried out through the acquisition chip of video acquisition card. On the computer, an analog video signal can be received through a video capture card, which collects the video input signal, quantizes it into a digital signal, and then compresses the encoded digital to analog and converts it into a digital video capture card. br/>; Most video cards and the hardware on the first card compress and collect video signals, which are compressed and then transmitted to the host through the compressed video data of PCI interface. The general PC video capture card adopts intra-frame compression algorithm, and the digitized video is stored as AVI file. The high-end video capture card directly collects digital video data and compresses it into MPEG-1 file in real time. Because of the analog video input, it can provide uninterrupted information source, and each frame in the analog video sequence collected by the video acquisition card is before the data of the PC system collects the next frame of image. Therefore, the key to real-time acquisition is the processing time required for each frame. If the processing time of each video image is between two adjacent data loss intervals, they also lose frames. The first compression processing of the video sequence obtained by the acquisition card, and then the access and compression of the video sequence stored in the hard disk device are completed together, eliminating the inconvenience of recompression processing. Different grades of acquisition cards have different quality of acquisition and compression performance. The analog signal in the video capture chip is converted into a digital signal and then sent to the temporary memory of the board. The compression algorithm of the own video compression chip is implemented to compress the huge video signal by the card. Finally, these compressions are directly or later stored in the hard disk to the PCI, PCI bridge chip. The latter adopts general video A/D converter to realize image acquisition, which is characterized by taking up CPU time, requiring high processor speed, low cost and easy implementation, and can meet the needs of some image acquisition systems. Recording high-definition video shooting, VGA image acquisition card is a high-end product with the rapid development of digital information technology industry and the requirement of VGA signal acquisition in many areas to improve the appearance. Nowadays, machine vision system is widely used in industrial field or teaching, which includes some computer hardware and software technologies, more related image processing, artificial intelligence and other fields. Video image acquisition card is an important part of machine vision system. Its main functions are real-time acquisition of video data output by camera and high-speed interface. PC video acquisition card is an indispensable video processing hardware, and it is an indispensable hardware for digital video editing and post-production. Video capture card, we can dump the video signal from the camera box to the computer, use video editing software and the digital video signal in the post-editing process, such as cutting the picture, adding ytterbium, subtitles and audio, setting the transition effect and adding various video effects, etc., and finally complete the conversion of the edited video signal into standard VCD, DVD and online streaming media formats, which is convenient for dissemination and preservation.
edited video capture
capture analog video
capture analog video 1) video capture card in analog video capture environment
MPC (or PowerMac of Apple) of analog video sources (such as camcorders, cameras, VCD players, DVD players, etc.) is equipped with a video capture card to connect the hardware environment of analog video capture. 2) Install audio-visual audio-visual video capture software X2) Set to use video capture (1)(2) Video capture software to capture and play video from video source equipment (3)/>; Capture digital video
Digital video capture digital video can also use the IEEE1394 interface connected to the video signal of DV, and the completion of the multimedia computer system with the DV signal acquisition function of the digital camera creates the first hardware environment, including the wireless transmission system. Install IEEEl394 (Firewire or i.Link) interface card and cable to connect the DV camera. DV connects the interfaces at both ends of the cable, with a 4-pin port at one end for connecting the 6-pin port of the digital camera and an IEEE 1394 acquisition card at the other end. The optional audio mixer adjusts the sound output of your DV camera. To install external speakers, you need to install video processing software installed by other hardware and software or optionally
edit the system requirements in this paragraph: at the same time, the current video acquisition card means that the computer is compressed into MPG format video stream at the same time. This process requires a PC and a high-speed CPU, a large enough memory, a high-speed hard disk drive, and opening the system bus ...... The computing power of the CPU is enough to meet our requirements, and the board of directors suggests to choose a cascade control with RAID. But now the multi-core and large-capacity hard disks are basically enough for video capture. Now the price of memory has basically fallen to the bottom. Buying a brand of memory can provide enough memory bandwidth and scale to capture images and convert data. Hard disk is the key to this configuration, which requires not only large storage capacity but also faster storage speed. The cache requirement will be at least 2M, and the hard disk drive can reach this cache capacity. Of course, the bigger the better. Graphic video shooting doesn't seem so important, so you can choose a general 32M AGP display card. Sound cards are generally not enough to buy an ordinary family, but they are generally not needed.
Editing the technical indicators in this paragraph
There are various specifications, according to different applications, different application environments and technical indicators, video capture cards. From the PCI-ETC212 video capture card, the main functions and technical indicators of the performance parameters of the PC hardware environment of the video capture card can be summarized as follows:
Function
The video capture card on the PC can receive the video input of analog video signals, collect the signals, quantize them into digital signals, and then compress and encode them into digital video sequences. When most video capture cards and the hardware on the first card compress and collect video signals, the video signals are compressed and then transmitted to the host through the compressed video data of PCI interface. General acquisition card adopts intra-frame compression algorithm, the digitized video is stored as AVI file, high-end video acquisition card (hardware compression card), and the directly collected digital video data is compressed into MPEG-1 format file in real time.
frame dropping
analog video input can provide a continuous source of information, and the video acquisition card captures the data of each frame in the analog video sequence before acquiring the next frame image and transmits it to the computer system. Therefore, the key to real-time acquisition is the processing time required for each frame. If the processing time of each video image is between two adjacent data loss intervals, they also lose frames. The first compression processing of the video sequence obtained by the acquisition card, and then the access and compression of the video sequence stored in the hard disk device are completed together, eliminating the inconvenience of recompression processing. Different grades of acquisition cards have different quality of acquisition and compression performance. Drive
video capture card driver: video capture cards are generally equipped with hardware driver to PC control and data capture card communication. According to the needs of different acquisition cards, each driver is different in the operating system environment. Only when the acquisition card is inserted into the expansion slot of the computer motherboard and the correct driver is installed can it work normally. However, the compatibility of video capture card is strong, and basically no additional driver is installed.
video editing software
video capture card application (editing software): the capture card is generally equipped with a collection application program to control and operate the acquisition process. There are also some general acquisition programs, digital video editing software, and the latest version of audio-visual X2 capture, editing, format conversion, burning and other functions. The hardware of the acquisition card is used together, that is, only the hardware of the acquisition card is installed and used normally to drive. Of course, the basic acquisition card now supports commonly used video editing software and nonlinear editing software.
Edit the basic types of software compression cards and hard compression cards in this paragraph
Soft compression cards and video capture cards. The circuit board is compressed by one or more video capture chips and a video capture card whose periphery is also called components, circuits and circuits
compared with simple hardware. This card is only responsible for collecting video, video compression, decompression, and other video processing is realized by CPU operation. Basic principle of soft compression video acquisition card: the analog video signal of camera is input to DVR card, and the analog signal of video acquisition chip is converted into digital signal, which is then directly inserted into PCI or PCI bridge chip, and then transferred to the memory and graphics, which is executed by CPU. DVR software compression algorithm, huge video signals are compressed and stored in hard disk. Hardware compression card, also known as video capture and compression card, circuit board and software compression card, is a part of the circuit structure of video compression and decompression. Video compression is processed by the CPU of the computer, but it is processed by the DSP chip. The basic principle of hardware compression video capture card: the analog video signal of the camera is input to DVR card, and the analog signal of the video capture chip is converted into digital signal, and then it spreads to the board of directors' own temporary memory card and video compression chip for compression algorithm, which makes the huge video signal compression smaller, and the last one is directly compressed or inserted into PCI, and the PCI bridge chip is stored on the hard disk. In video compression ability, hardware compression ratio software compression. Software compression card consumes computer resources because of CPU compression, so it is the key to reasonably configure the soft compression DVR of computer for long-term stable operation. Video capture card and a wide variety of bulk non-commercial amateur video capture and processing, hardware compression function, cheap video capture card or TV card acquisition function and 3D graphics card are completely sufficient. In terms of software efforts, you can get the processing results of quite expensive and high-end video capture cards. Of course, the post-comparison of video files in the production process will take you more time. Usually too simple video capture software is cheap or card-driven, especially in the real-time file archiving engine, it is often difficult to directly use these simple video capture software for video capture and processing.
analog capture card and digital capture card
point is the interface between video source and capture card. Video capture cards are divided into two categories: one is analog capture card, and the other is digital capture card. When the analog video signal is collected to PC through AV or S-Video, the analog signal is converted into digital signal, and the analog capture card of the video signal source of analog camera, TV signal and analog video recorder. The digital acquisition card adopts the digital form of IEEE1394 digital interface, and the digital video signals are collected to the video sources of digital devices such as PC and DV (Digital Camera) without loss. It is an important difference from the digital analog acquisition card: using the digital acquisition card, the video signal is not lost in the acquisition process, and the same effect can be guaranteed. The original video source, video signal and analog acquisition card are lost to some extent. Someone made an image metaphor: analog acquisition is to use a tape recorder to open the video tape, and it is always better to grasp the similar sub-bands. If the sub-bands are used, the effect will be even worse; The number of times a digital acquisition computer copies a data file, whether you copy the original file, the file is exactly the same, without any difference. Two-in-one acquisition card refers to digital analog acquisition card and AV+DV acquisition card. Digital input and output, analog interface input (DV/AV/S- video), interface board.
external collection box and built-in acquisition card
external USB video acquisition card and built-in PCI interface video receiving card. T31 professional USB video capture card
These two things have advantages and disadvantages. If you don't have enough money, we suggest you choose a built-in PCI video receiving card. Card with PCI interface is recommended. It also has the following advantages: first, it is definitely much cheaper.