Variable transfer rate control coding apparatus, reproducing apparatus and recording medium

A variable transfer rate information reproducing apparatus for reproducing pieces of moving picture information recorded on a recording medium, comprising:

• information reading means for intermittently reading the pieces of moving picture information from the recording medium at a constant information reading rate, the pieces of moving picture information being recorded coded at a variable transfer rate changing every prescribed time period being recorded;
• buffer means for temporarily storing the pieces of moving picture information read by the information reading means and outputting the pieces of moving picture information at an information decoding rate;
• reading operation controlling means for detecting an occupancy information filling rate representing an occupancy degree of the buffer means and controlling a reading operation performed by the information reading means according to the occupancy information filling rate to prevent an overflow of the pieces of moving picture information stored in the buffer means and an information empty condition of the buffer means;
• and
• decoding means for decoding the pieces of moving picture information output from the buffer means to obtain pieces of reproduced moving picture information.

A variable transfer rate information reproducing apparatus for reproducing pieces of moving picture information recorded on a recording medium, comprising:

• information reading means for intermittently reading at a constant information reading rate the pieces of moving picture information and a piece of reading operation control information from the recording medium, in which the pieces of moving picture information are recorded coded at a variable transfer rate changing every prescribed time period are recorded;
• buffer means for temporarily storing the pieces of moving picture information read by the information reading means and outputting the pieces of moving picture information at an information decoding rate;
• control information separating means for separating the reading operation control information from the pieces of moving picture information read by the information reading means and controlling a reading operation performed by the information reading means according to the reading operation control information to prevent an overflow of the pieces of moving picture information stored in the buffer means and an information empty condition of the buffer means;
• and
• decoding means for decoding the pieces of moving picture information output from the buffer means to obtain pieces of reproduced moving picture information.

A variable transfer rate information reproducing apparatus for reproducing pieces of moving picture of information recorded on a recording medium, comprising:

• information reading means for intermittently reading the pieces of moving picture information and a piece of transfer rate information from the recording medium at a constant information reading rate for each prescribed time period, in which the pieces of moving picture information are recorded coded at a variable transfer rate changing every prescribed time period, are recorded, the transfer rate information indicating the variable transfer rate;
• transfer rate information separating means for separating the transfer rate information from the pieces of moving picture information read by the information reading means;
• buffer means for temporarily storing the pieces of moving picture information read by the information reading means and outputting the pieces of moving picture information at an information decoding rate;
• reading operation controlling means for controlling a reading operation performed by the information reading means according to the transfer rate information obtained by the transfer rate information separating means to prevent an overflow of the pieces of moving picture information stored in the buffer means and to prevent an information empty condition of the buffer means;
• and
• decoding means for decoding the pieces of moving picture information output from the buffer means to obtain pieces of reproduced moving picture information.

A variable transfer rate information reproducing apparatus for reproducing pieces of moving picture information recorder in a packet on a recording medium for each prescribed time period comprising:

• information reading means for intermittently reading the pieces of moving picture information and code amount of the pieces of the moving picture information in one packet from the recording medium at a constant information reading rates for each prescribe time period, in which the pieces of moving picture information are recorded with a changeable amount of code indicating the pieces of the moving picture information in one packet;
• packet code amount detecting means for detecting the code amount of the pieces of moving pictures information in one packet read by the information reading means for each prescribed time period;
• buffer means for temporarily storing the pieces moving picture information in one packet read by the information reading means for each prescribed time period and outputting the pieces of moving picture information at an information decoding rate;
• reading operation controlling means for controlling a reading operation performed by the information reading means according to the code amount obtained by the packet code amount detecting means to prevent an overflow of the pieces of moving picture information stored in the buffer means and an information empty condition of the buffer means;
• and
• decoding means for decoding the pieces of moving picture information output from the buffer means to obtain pieces of reproduced moving picture information.

A variable transfer rate information reproducing apparatus for reproducing pieces of moving picture information recorded on a recording medium, comprising:

• information reading means for intermittently reading at a constant information reading rate the pieces of moving picture information from the recording medium, the pieces of moving picture information being classified into pieces of first information coded at a fixed transfer rate and recorded on the recording medium at a fixed transfer rate and pieces of second information coded at a variable transfer rate changing every prescribed time period and recorded on the recording medium at a variable transfer rate changing every prescribed time period, at a constant information reading rate;
• demultiplexing means for demultiplexing the pieces of moving picture information read by the information reading means to the pieces of first information and the pieces of second information;
• first buffer means for temporarily storing the pieces of first information demultiplexed by the demultiplexing means and outputting the pieces of first information at an information decoding rate;
• second buffer means for temporarily storing the pieces of second information demultiplexed by the demultiplexing means and outputting the pieces of second information at the information decoding rate;
• fixed transfer rate detecting means for detecting the fixed transfer rate from the pieces of first information;
• reading operation controlling means for controlling a reading operation performed by the information reading means according to the fixed transfer rate detected by the fixed transfer rate detecting means to prevent an overflow of the pieces of first information stored in the first buffer means and to prevent an information empty condition of the first buffer means;
• first decoding means for decoding the pieces of first information output from the first buffer means to obtain pieces of reproduced first information;
• and
• second decoding means for decoding the pieces of second information output from the second buffer means to obtain pieces of reproduced second information, pieces of reproduced moving picture information being composed of the pieces of reproduced first information obtained by the first decoding means and the pieces of second information.

A recording medium on which codes are recorded, comprising:

• a recording region having a prescribed storing capacity value;
• and
• information of a plurality of moving picture signals in a total data stream being stored in the recording medium so that a sum of a plurality of real variable length codes indicating the moving picture signals in the total data stream is equal to the prescribed storing capacity value, wherein each of the moving picture signals in the total data stream is quantized according to a temporary quantization step width which is determined according to each of activities of the moving picture signals to produce a plurality of temporary quantized signals which are changed to a plurality of temporary variable length codes, a temporary transfer rate indicating an amount of temporary variable length codes in one prescribed time period being calculated for each of prescribed time periods, a plurality of target transfer conversion characteristics respectively indicating the conversion of each of the temporary transfer rates to a target transfer rate indicating an amount of target codes in one prescribed time period are prepared, a particular target transfer conversion characteristic being selected from the plurality of target transfer conversion characteristics on condition that a total amount of target codes which are determined by a plurality of target transfer rates obtained by converting the temporary transfer rates corresponding to the moving picture signals in the total data stream according to the particular target transfer conversion characteristic is the prescribed storing capacity value of the recording region, one target transfer rate being calculated from each of the temporary transfer rates according to the particular target transfer conversion characteristic on condition that the plurality of target transfer rates for the prescribed time periods are variable with time, a buffer in which codes are temporarily stored, the codes are output at one corresponding target transfer rate for each prescribed time period on condition that the target transfer rates for the prescribed time periods are variable with time and that a buffer filling rate indicating a filling rate of the codes in the buffer is output is prepared, each of the moving picture signals in the total data stream being quantized according to a real quantization step width which is determined according to each of the activities of the moving picture signals and the buffer filling rate output from the buffer to produce a plurality of real quantized signals on condition that a volume of variable length codes obtained from each of the real quantized signals is increased or decreased with the decrease or increase of the buffer filling rate and that a total sum of variable length codes obtained from the real quantized signals becomes the prescribed storing capacity value of the recording region, the real quantized signals being changed to the plurality of real variable length codes of which a total volume is equal to the prescribed storing capacity value of the recording region, the real variable length codes being temporarily stored in the buffer one after another, and the real variable length codes stored in the buffer are recorded in the recording region of the recording medium at one corresponding target transfer rate for each prescribed time period on condition that the plurality of target transfer rates for the prescribed time periods are variable with time.

A variable transfer rate coding apparatus for coding a plurality of moving picture signals in a total data stream, comprising:

• temporary coding means for quantizing each of the moving picture signals in the total data stream according to a temporary quantization step width which is determined according to each of activities of the moving picture signals to produce a plurality of temporary quantized signals, changing the temporary quantized signals to a plurality of temporary variable length codes according to a variable length coding and calculating a temporary transfer rate indicating an amount of temporary variable length codes in one prescribed time period for each of prescribed time periods, the plurality of temporary transfer rates being variable with time;
• target transfer rate setting means for setting a target transfer rate from each of the temporary transfer rates calculated by the temporary coding means so that a maximum value of each of the target transfer rates is lower than a prescribed constant value, and so as to provide a prescribed value for a total amount of target codes which are determined by a plurality of the target transfer rates corresponding to the moving picture signals in the total data stream, the plurality of target transfer rates being variable with time, and each target transfer rate corresponding to one prescribed time period;
• buffer means for temporarily storing codes, outputting the codes at one corresponding target transfer rate for each prescribed time period, the target transfer rates for the prescribed time periods being variable with time, and outputting occupancy information representing an occupancy degree of the codes in the buffer means;
• and
• real coding means for quantizing each of the moving picture signals in the total stream according to a real quantization step width which is determined according to each of the activities of the moving picture signals and the occupancy information output from the buffer means to produce a plurality of real quantized signals so that a volume of variable length codes obtained from each of the real quantized signals according to the variable length coding is increased or decreased with the decrease or increase of the occupancy information and so that a total sum of variable length codes obtained from the real quantized signals becomes the prescribed value, changing the real quantized signals to a plurality of real variable length codes having a total volume which is equal to the prescribed value according to the variable length coding, and outputting the real variable length codes to the buffer means one after another to output the real variable length codes from the buffer means at the one corresponding target transfer rate for each prescribed time period, the target transfer rates for the prescribed time periods being variable with time.

A variable transfer rate coding method for coding a plurality of moving picture signals in a total data stream, comprising:

• a temporary coding step of quantizing each of the moving picture signals in the total data stream according to a temporary quantization step width which is determined according to each of activities of the moving picture signals to produce a plurality of temporary quantized signals, changing the temporary quantized signals to a plurality of temporary variable length codes according to a variable length coding and calculating a temporary transfer rate indicating an amount of temporary variable length codes in one prescribed time period for each of prescribed time periods, the plurality of temporary transfer rates being variable with time;
• a target transfer rate setting step of setting a target transfer rate from each of the temporary transfer rates calculated by the temporary coding step so that a maximum value of each of the target transfer rates is lower than a prescribed constant value, and so as to provide a prescribed value for a total amount of target codes which are determined by a plurality of the target transfer rates corresponding to the moving picture signals in the total data stream, the plurality of target transfer rates being variable with time, and each target transfer rate corresponding to one prescribed time period;
• a buffering steps of temporarily storing codes, outputting the codes at one corresponding target transfer rate for each prescribed time period, the target transfer rates for the prescribed time periods being variable with time, and outputting occupancy information representing an occupancy degree of the codes in the buffering step;
• and
• a real coding step of quantizing each of the moving picture signals in the total stream according to a real quantization step width which is determined according to each of the activities of the moving picture signals and the occupancy information output from the buffering step to produce a plurality of real quantized signals so that a volume of variable length codes obtained from each of the real quantized signals according to the variable length coding is increased or decreased with the decrease or increase of the occupancy information and so that a total sum of variable length codes obtained from the real quantized signals becomes the prescribed value, changing the real quantized signals to a plurality of real variable length codes having a total volume which is equal to the prescribed value according to the variable length coding, and performing the buffering step on the real variable length codes one after another to output the real variable length codes from the buffering step at one corresponding target transfer rate for each prescribed time period, the target transfer rates for the prescribed time periods being variable with time.