Abstract: The invention relates to a method for dynamic quantization of an image stream including transformed blocks, the method comprising a step for establishing a relationship (V12, V10, V20) between at least one temporal predictive encoding source block (330, 323) of a first image (B1, P2) and one or more reference blocks (311, 312, 313, 314, 316, 321, 322, 323, 324) belonging to other images (I0, P2), the method comprising, for at least one of said transformed blocks, a step of quantization of said block wherein the level of quantization applied to this block is chosen (402) at least partly as a function of the relationship or relationships (V12, V10, V20) established between this block and blocks belonging to other images. The invention applies notably to the improvement of video compression in order to improve the visual rendition of encoded videos.

Abstract: The process is characterized in that, the zoomed image being defined by its horizontal and vertical homothety ratio with respect to the coded image, it performs the following steps: calculation of the horizontal and vertical sizes of an initial display rectangle from which would be obtained the sizes of the target display rectangle as defined by the profile and level information by applying the horizontal and vertical homothety ratios, storage in the display_horizontal_size and display_vertical_size fields of an MPEG2 video data stream of the horizontal and vertical sizes of the initial display rectangle.

Abstract: The invention reduces the time required for automatically searching for channels on a device receiving channels of various widths. The invention proposes a channel detection process which carries out successive passes with frequency spacings corresponding to channels of a specific width. During each pass, only the channels corresponding to the specific width are searched for. The invention also pertains to a multichannel reception device comprising the means required for the operation of the process.

Abstract: The system comprises a separate unit for calculating quality parameters relating to results obtained from video test sequences by means of the device to be tested and nonlinear as a function of these results. It also comprises a unit for comparing, over time, these parameters and corresponding quality parameters, the latter being associated with reference results relating to video test sequences. The comparison unit produces binary results corresponding respectively to the quality parameters by means of predetermined tolerance margins, thereby allocating to each of the binary results corresponding to one of the quality parameters a first value when the quality parameter associated with the device to be tested remains within the tolerance margin around the quality parameter associated with the reference results, over time, and otherwise, a second value. Application to an IRD.

Abstract: The process is characterized in that, the zoomed image being defined by its horizontal and vertical homothety ratio with respect to the coded image (1, 7), it performs the following steps:

Abstract: The invention reduces the time required for automatically searching for channels on a device receiving channels of various widths. The invention proposes a channel detection process which carries out successive passes with frequency spacings corresponding to channels of a specific width. During each pass, only the channels corresponding to the specific width are searched for. The invention also pertains to a multichannel reception device comprising the means required for the operation of the process.