DECODING METHOD AND DECODER WITH ROUNDING MEANS

• US 20100135394A1
• Filed: 06/07/2006
• Published: 06/03/2010
• Est. Priority Date: 06/10/2005
• Status: Active Grant

• Current Assignee: Goodix Technology Co., Ltd. (Shenzhen Goodix Technology Co., Ltd.)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Valente, Stephane, Vanhaelewyn, Nicolas
• Granted Patent: US 8,199,808 B2
• Time in Patent Office: Days
• US Class Current: 375/240.160
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/513 Processing of motion vectors
• CPC Class Codes: H04N 19/523 with sub-pixel accuracy
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

The present invention relates to a video decoder (DEC) for decoding a bit stream (BS) corresponding to pictures (FR) of a video signal. The invention is such that, motion vectors (MV1) having values coded at a nominal resolution in the bit stream, said video decoder includes a rounding unit (RND) for rounding decoded nominal motion vectors (MV1) to a resolution different from the nominal resolution in a way that minimizes the error accumulation along prediction path by giving to rounded successive motion vectors (MV2) along the prediction path, successive values such that their average value is equal to the value of the nominal motion vector.

Claims

1. A video decoder for decoding a bit stream corresponding to pictures of a video signal, characterized by motion vectors having values coded at a nominal resolution in the bit stream, said video decoder comprising means for rounding decoded nominal motion vectors to a resolution different from the nominal resolution in a way that minimizes the error accumulation along prediction path by giving to rounded successive motion vectors along the prediction path, successive values such that their average value is equal to the value of the nominal motion vector.

2. A video decoder as claimed in claim 1, in which said means for rounding nominal motion vectors alternates at least two motion vector rounding policies from one picture to the other picture of the same type.

3. A video decoder as claimed in claim 1, in which said means for rounding nominal motion vectors alternates at least two motion vector rounding policies from one reference picture to the other reference picture.

6. A mobile device including a video decoder as claimed in claim 1.

4. A method for decoding a bit stream corresponding to pictures of a video signal, characterized by motion vectors having values coded at a nominal resolution in the bit stream, said decoding method includes a rounding step for rounding decoded nominal motion vectors to a resolution different from the nominal resolution in a way that minimizes the error accumulation along prediction path by giving to rounded successive motion vectors along the prediction path, successive values such that their average value is equal to the value of the nominal motion vector.

5. A computer program product comprising program instructions for implementing, when said program is executed by a processor, a decoding method as claimed in claim 4.