Stmicroelectronics S.r.l.

Gianluca Filippini

Fabrizio Simone Rovati

Emiliano Mario Piccinelli

Danilo Pietro Pau

Bruno Biffi

Emiliano Mario Angelo Piccinelli

Transcoder apparatus for transcoding an input video bit-stream having a first encoding profile (e.g., MPEG-2) into an output video bit-stream having a second encoding profile (e.g., H.264), the first encoding profile including motion estimation information, the apparatus including: a front-end for extracting the motion estimation information from the input video bit-stream, and a back-end for constructing the output bit-stream. The front-end and the back-end of the apparatus are interconnected (e.g., via a buffer) to pass the motion estimation information from the front-end to the back-end, thereby avoiding motion estimation in constructing the output bit-stream at the apparatus back-end.

Method for transcoding compressed video signals, related apparatus and computer program product therefor

A moving-image signal, such as typically a luminance signal organized in blocks of pixels is coded via a technique that envisages the steps of: comparing a block to be coded with a plurality of candidate prediction blocks; determining, for each candidate prediction block, a respective value of an index representing the difference between the block to be coded and each candidate prediction block; and choosing between the candidate prediction blocks, as a function of the respective value of the aforesaid index, a prediction block to be used for coding of the block to be coded. The signal is sampled pixel by pixel on the block to be coded and on the plurality of candidate prediction blocks, thus generating respective surfaces representing the pattern of the signal in the block to be coded and in the candidate prediction blocks. Chosen as an index is an index of the parallelism between the aforesaid respective surfaces.

Method and system for coding moving image signals, corresponding computer program product

Digital signals are converted between a first and second format by a conversion process including generating coefficients representing the digital signals. The coefficients may be discrete cosine transform coefficient generated during encoding/transcoding of MPEG signals. The coefficients are subject to quantization by generating a dither signal that is added to the coefficients before quantization to generate a quantized signal. Preferably, each coefficient is first subject to a first quantization in the absence of any dither signal added to generate an undithered quantized coefficient. If the undithered quantized signal is equal to zero the undithered quantized coefficient is taken as the output quantized signal. If the undithered quantized coefficient is different from zero, the dither signal is added and the dithered coefficient thus obtained is subject to quantization to generate the output quantized signal.

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Lodi, Italy

Gianluca Filippini