Sharp Kabushiki Kaisha Corporation

Masaaki Hyodo

Hiroshi Kusao

Hiroyuki Katata

Yoji Noguchi

Yoichi Fujiwara

Tadao Matsuura

Necessary coded data only can be read out at random accessing even with recording medium having coded data recorded thereon but whose code quantity is out of proportion to time. Once a recording medium was loaded into a recorder-player connected with a coded-data control device, the device reads control data from the recording medium and stores the data in a coded data control portion. At random accessing, the control data is read-out from the coded-data control portion and entered into a recording medium controller which in turn controls the recording medium to read-out only desired data according to the information inputted from the coded data control portion. In random access playback, fast playback from the midway of a video-sequence can be realized by accessing coded data of a video frame by using control data.

Coded data control device

The invention is directed to provide a code-amount control device for use in video-coding device, which controls the generated code-amount of each block (block length) after variable-length coding in the video-coding process to surely be less than the designated target code-amount. The code amount control device is provided with a rate control circuit for setting a target code-amount of each of blocks to be encoded, a rounding circuit for converting a sequence of quantized values into a set of the number of continuous zeroes and following thereto non-zero quantized values and a code-length table containing variable code-length values to be allocated to respective sets of the number of continuous zeroes and non-zero values. Before variable-length encoding of the image block, the rounding circuit estimates by accumulating the code length of each block with reference to the code-length table and outputs the quantized values as they are to a variable-length coding circuit when the accumulated code-length does not exceed the target code-amount. If the estimated code-length exceeds the target code-amount, the rounding circuit outputs the quantized values after rounding off the excessive portion thereof.

Code-amount control device and video coding device including the

A device reads control data from a recording medium and stores the data in a coded data control portion. At random accessing, the control data is read-out from the coded-data control portion and entered into a recording medium controller which in turn controls the recording medium to read-out only desired data according to the information inputted from the coded data control portion. In random access playback, fast playback from the midway of a video-sequence can be realized by accessing coded data of a video frame by using control data.

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Chiba, Japan

Masaaki Hyodo