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A video coding format [a] (or sometimes video compression format) is a content representation format of digital video content, such as in a data file or bitstream. It typically uses a standardized video compression algorithm, most commonly based on discrete cosine transform (DCT) coding and motion compensation .
Intra-frame coding is a data compression technique used within a video frame, enabling smaller file sizes and lower bitrates, with little or no loss in quality. Since neighboring pixels within an image are often very similar, rather than storing each pixel independently, the frame image is divided into blocks and the typically minor difference between each pixel can be encoded using fewer bits.
Three types of pictures (or frames) are used in video compression: I, P, and B frames. An I‑frame (intra-coded picture) is a complete image, like a JPG or BMP image file. A P‑frame (Predicted picture) holds only the changes in the image from a previous frame. For example, in a scene where a car moves across a stationary background, only the ...
Free and open-source software portal; libavcodec is a free and open-source [4] library of codecs for encoding and decoding video and audio data. [5]libavcodec is an integral part of many open-source multimedia applications and frameworks.
Where MaxDpbMbs is a constant value provided in the table below as a function of level number, and PicWidthInMbs and FrameHeightInMbs are the picture width and frame height for the coded video data, expressed in units of macroblocks (rounded up to integer values and accounting for cropping and macroblock pairing when applicable). This formula ...
Motion compensation exploits the fact that, often, for many frames of a movie, the only difference between one frame and another is the result of either the camera moving or an object in the frame moving. In reference to a video file, this means much of the information that represents one frame will be the same as the information used in the ...
In inter-frame coding, individual frames of a video sequence are compared from one frame to the next, and the video compression codec records the differences to the reference frame. If the frame contains areas where nothing has moved, the system can simply issue a short command that copies that part of the previous frame into the next one.
VP8 is a traditional block-based transform coding format. It has much in common with H.264, e.g. some prediction modes. [8] At the time of first presentation of VP8, according to On2 the in-loop filter [9] and the Golden Frames [10] were among the novelties of this iteration.