Coding

Abstract

Coding is provided in which a multi-media object is coded to obtain a bit-stream, and quality information is added to the bit-stream, which quality information indicates a quality of the object in relation to a given position in (or a given part of) the bit-stream. By adding quality information to the bit-stream, jointly storing or transmitting multiple coded objects can be optimized in that the quality of the object can be easily taken into account.

1 . A method of coding a multi-media object, the method comprising the steps of: 
 coding the object to obtain a bit-stream, and    adding quality information to the bit-stream, which quality information indicates a quality of the object in relation to a given position in (or a given part of) the bit-stream.    
     
     
         2 . A method as claimed in  claim 1 , wherein the coding step is a scalable coding step to obtain a scalable bit-stream.  
     
     
         3 . A method as claimed in  claim 1  or  2 , wherein the quality information relates to an object reproduction quality.  
     
     
         4 . A method as claimed in  claim 3 , wherein the quality information is based on a signal to noise ratio value.  
     
     
         5 . A method as claimed in any of the preceding claims, wherein quality tags are added at given locations in the bit-stream, indicating a quality of the object when the bit-stream is truncated just after (or alternatively just before) the given location in the bit-stream.  
     
     
         6 . A method as claimed in  claim 1 , wherein the quality information is incorporated in existing fields of a given scalable coding standard.  
     
     
         7 . A method as claimed in  claim 2 , wherein the scalable bit-stream includes several layers and wherein respective layers include respective quality information.  
     
     
         8 . A method as claimed in  claim 1 , wherein the bit-stream is encrypted and the quality information is unencrypted.  
     
     
         9 . A method of controlling at least one bit-stream representing a multi-media object in which bit-stream quality information has been added, the quality information indicating a quality of the object in relation to a given position in (or a given part of) the bit-stream, the method comprising the steps of: 
 receiving the at least one bit-stream,    extracting the quality information from the bit-stream,    transcoding or truncating the at least one bit-stream in the case a desired combination of bit-rate and quality of the at least one bit-stream differs from a current combination of bit-rate and quality of the at least one received bit-stream,    providing the at least one bit-stream at the desired combination of bit-rate and quality.    
     
     
         10 . A method of transmitting at least one multi-media object, the method comprising the steps of: 
 coding the object to obtain a bit-stream,    adding quality information to the bit-stream, which quality information indicates a quality of the object in relation to a given position in (or a given part of) the bit-stream, and    transmitting the bit-stream in which the quality information has been added.    
     
     
         11 . A method of receiving at least one bit-stream representing a multi-media object in which bit-stream quality information has been added, the quality information indicating a quality of the object in relation to a given position in (or a given part of) the bit-stream, the method comprising the steps of: 
 extracting the quality information from the bit-stream,    transcoding or truncating the at least one bit-stream in the case a desired combination of bit-rate and quality of the at least one bit-stream differs from a current combination of bit-rate and quality of the at least one received bit-stream,    providing the at least one bit-stream at the desired combination of bit-rate and quality, and    decoding the at least one bit-stream at the desired combination of bit-rate and quality.    
     
     
         12 . A method of receiving at least one bit-stream representing a multi-media object in which bit-stream quality information has been added, the quality information indicating a quality of the object in relation to a given position in (or a given part of) the bit-stream, the method comprising the steps of: 
 extracting the quality information from the bit-stream;    decoding the bit-stream to obtain a decoded multi-media object; and    processing the multi-media object in dependence on the extracted quality.    
     
     
         13 . A device of coding a multi-media object, the device comprising: 
 means for coding the object to obtain a bit-stream, and    means for adding quality information to the bit-stream, which quality information indicates a quality of the object in relation to a given position in (or a given part of) the bit-stream.    
     
     
         14 . A transmitter comprising a device as claimed in  claim 13 .  
     
     
         15 . A controller for controlling at least one bit-stream representing a multi-media object in which bit-stream quality information has been added, the quality information indicating a quality of the object in relation to a given position in (or a given part of) the bit-stream, the controller comprising: 
 means for receiving the at least one bit-stream,    means for extracting the quality information from the bit-stream,    means for truncating the at least one bit-stream in the case a desired combination of bit-rate and quality of the at least one bit-stream differs from a current combination of bit-rate and quality of the at least one received bit-stream,    means for providing the at least one bit-stream at the desired combination of bit-rate and quality.    
     
     
         16 . A receiver comprising a controller as claimed in  claim 15 .  
     
     
         17 . A receiver for receiving at least one bit-stream representing a multi-media object in which bit-stream quality information has been added, the quality information indicating a quality of the object in relation to a given position in (or a given part of) the bit-stream, the receiver comprising: 
 means for extracting the quality information from the bit-stream;    means for decoding the bit-stream to obtain a decoded multi-media object; and    means for processing the multi-media object in dependence on the extracted quality.    
     
     
         18 . A multiplexer or network node comprising a controller as claimed in  claim 15 .  
     
     
         19 . A bit-stream representing a multi-media object in which bit-stream quality information has been added, the quality information indicating a quality of the object in relation to a given position in (or a given part of) the bit-stream  
     
     
         20 . A storage medium on which a signal as claimed in  claim 19  has been stored.