Methods of and arrangements for processing an encoded bit stream

Abstract

In a method for extracting information from an encoded bit stream, the extracted information may be used for improving bit stream quality assessment, or for adapting a decoding sub-system. From an encoded bit stream, received from a bit stream source, complexity related information that is indicative of the complexity of the encoding of said bit stream is extracted. On the basis of said extracted complexity related information one or more data settings are then selected, after which the data settings may be used as an input for improving bit stream quality assessment at a decoding device or a network node, or for adapting a bit stream decoding sub-system at a decoding device.

1 . A method for use in determining a bit stream quality score in a multimedia system, said method comprising the steps of:
 receiving an encoded bit stream from a bit stream source;   extracting complexity related information from said encoded bit stream, said complexity related information being indicative of the complexity of the encoding at said bit stream source;   comparing the complexity related information that was extracted to a set of pre-defined complexity levels;   selecting at least one data setting for a bit stream quality model in response to the comparing; and   calculating a bit stream quality score for said encoded bit stream using said bit stream quality model and in response to said selected at least one data setting.   
     
     
         2 . A method according to  claim 1 , wherein said extracting step further comprises:
 extracting additional quality related information from said bit stream, and wherein said selecting step further comprises:   selecting at least one data setting on the basis of said extracted complexity related information in combination with said additional quality related information.   
     
     
         3 . A method according to  claim 1 , wherein said extracting step further comprises a step of retrieving, from said encoded bit stream, one or more complexity related parameters indicative of macro block partition size, motion vector resolution, skipped macro blocks, or number of used reference pictures of at least a part of said encoded bit stream. 
     
     
         4 . A method according to  claim 3 , wherein said one or more complexity related parameters is carrying information on at least: the existence of, the distribution of, or the relative amount of the respective information type indicated by the respective parameter. 
     
     
         5 . A method according to  claim 1 , wherein said encoded bit stream is a video bit stream. 
     
     
         6 . An arrangement for use in determining a bit stream quality score in a multimedia system, said arrangement comprising:
 at least one processor;   at least one memory coupled to the at least one processor and comprising computer readable program code that when executed by the at least one processor causes the at least one processor to perform operations comprising:
 extracting complexity related information from an encoded bit stream received from a bit stream source, said complexity related information being indicative of the complexity of the encoding at said bit stream source, 
 selecting at least one data setting on the basis of said extracted complexity related information in response to comparing the complexity related information that was extracted to a set of pre-defined complexity levels, and 
 calculating a bit stream quality score for said bit stream, in response to the selecting the at least one data setting. 
   
     
     
         7 . An arrangement according to  claim 6 , wherein the at least one processor is further configured to extract additional quality related information from said encoded bit stream and wherein the at least one processor is further configured to select said one or more data settings on the basis of both said extracted complexity related information and said extracted additional quality related information. 
     
     
         8 . An arrangement according to  claim 7 , further comprising a complexity level database for storing a set of pre-defined complexity levels. 
     
     
         9 . An arrangement according to  claim 1 , wherein said arrangement is implemented in a cellular telephone, a set-top box, a PC, and/or a laptop. 
     
     
         10 . An arrangement according to  claim 1 , wherein said arrangement is implemented in a network node. 
     
     
         11 . An arrangement according to  claim 1 , wherein said encoded bit stream is a video bit stream.