公开(公告)号：JP2001189662A

公开(公告)日：2001-07-10

申请号：JP2000349015

申请日：2000-11-16

Applicant: ST MICROELECTRONICS SRL

Inventor： PAU DANILO ,  BORTOT LUCA ,  SACCHI MARIA LUISA

IPC: G06T9/00 ,  H03M7/30 ,  H03M7/40 ,  H04N7/26

Abstract: PROBLEM TO BE SOLVED: To provide technology for easily changing the bit rate of the data stream of a video picture. SOLUTION: An input bit stream is divided into the sequence of encoded data and the sequence of a control bit. The output sequence of the control bit is generated by correcting the sequence of the control bit by the function of a different bit rate in a desired output bit stream. The intermediate sequence of data is generated by decoding the sequence of the code data. The output sequence of the encoded data is generated by quantizing data in a previously established step and encoding the intermediate data of these data. These output sequences are joined and the output stream having the desired bit rate is generated.

公开(公告)号：JP2001119698A

公开(公告)日：2001-04-27

申请号：JP2000273887

申请日：2000-09-08

Applicant: ST MICROELECTRONICS SRL

Inventor： PAU DANILO ,  BORTOT LUCA ,  SACCHI MARIA LUISA

IPC: H03M7/30 ,  H04N7/26 ,  H04N7/30 ,  H04N7/50

Abstract: PROBLEM TO BE SOLVED: To reduce complexity on calculation in the case of calculating the action of the macroblock of a video picture. SOLUTION: A predictive error calculation is performed in a spatial frequency domain obtained by discrete cosine transform instead of performing a calculation about the macro block arranged on a source picture, in the case of calculating the action of the macrobloek of the video picture.

公开(公告)号：DE69940506D1

公开(公告)日：2009-04-16

申请号：DE69940506

申请日：1999-09-08

Applicant: ST MICROELECTRONICS SRL

Inventor： PAU DANILO ,  BORTOT LUCA ,  SACCHI MARIA LUISA

IPC: H04N7/50 ,  H03M7/30 ,  H04N7/26 ,  H04N7/30

Abstract: A method of measuring the activity of a macroblock of a picture in the direct cosine transform domain of values assumed by a selected component of the video signal comprises a) separately storing in a memory blocks of data into which is divided a macroblock in the discrete cosine transform domain before quantization; b) reading from said memory the data of each of the blocks constituting said macroblock representing said selected component in the discrete cosine transform domain obtaining the respective coefficients; c) multipliying the absolute value of said coefficients by a selected mask of words of a number not exceeding the number of words constituting the block; d) summing the results of said moltiplications producing an activity coefficient for each of the blocks constituting said macroblock; e) calculating a first activity coefficient of the macroblock (actj) as the sum of said activity coefficients produced for each block; f) calculating a normalized activity value of the macroblock as the ratio between the sum of the double of said activity coefficient (actj) with a mean activity (mean_actj) relative to the preceding coded frame and the sum of the double of the coefficient mean_actj with the activity coefficient actj.