| 摘要 |
A frame receiving unit calculates the number of a frame to be compressed and gets an image data from the frame. A frame checking unit checks the type of the frame and allocates required code memory. When the frame is an I frame, a frequency conversion unit converts the image to a spatial frequency, a quantization unit quantizes the spatial frequency, and a variable-length coding unit performs variable-length coding. At the same time, a reverse quantization unit performs reverse-quantization and a reverse frequency conversion unit performs reverse-conversion to create a reference image. When the frame is a P frame, a motion search unit searches for a motion of the image. The frequency conversion unit converts a difference between the image and the reference image to the spatial frequency, the quantization unit performs quantization, and the variable-length coding unit performs variable-length coding. At the same time, the reverse quantization unit performs reverse-quantization, the reverse frequency conversion unit performs reverse frequency conversion to return the reverse conversion result to the difference of the images, and a motion compensation unit combines the result with a motion-compensated reference image. When the frame is a B frame, a code indicating that the frame is the same as the reference frame is generated. The generated code is output to the allocated code memory.
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