Bit rate allocation in joint bit rate transcoding

Abstract

The present invention relates to a multiplexing system comprising a set of transcoders (TC[ 1] to TC[n]), a controller (CONT) and a multiplexer (MUX). The set of transcoders comprises n transcoders, each transcoder (TC[i]) allowing an input compressed data signal (ICS[i]) encoded at an input bit rate (Rin[i]) to be converted into an output compressed data signal (OCS[i]) encoded at an output bit rate (Rout[i]). The controller (CONT) receives from each transcoder parametric information on the regulation process and the video coding complexity and subsequently computes the bit rate allocated (Rout[i]) to each transcoder (TC[i]) according to a total bit rate capacity available at the output of the multiplexer. The controller receives also parametric information derived from the input compressed data signal (ICS[i]), this information being used to improve the bit rate allocation strategy. Finally, the multiplexer (MUX) provides a multiplexed data signal (MS) by multiplexing of the output compressed data signals (OCS[ 1] to OCS[n]).

1 - 6 . (canceled) 
   
   
       7 . A method for controlling a set of transcoding channels, each transcoding channel configured to convert an input compressed data signal encoded at an input bit rate into an output compressed data signal encoded at an output bit rate, the method comprising:
 computing, by a transcoder controller, an indicator of a compressed data quality for each respective transcoding channel, the indicator being computed from the input compressed data signal, and   allocating, by the transcoder controller, the output bit rate to each transcoding channel from a total output bit rate, based on the indicators of the compressed data quality.   
   
   
       8 . The method of  claim 7 , wherein allocating the output bit rate to each transcoding channel is based on the transcoding channel's indicator and a sum of the indicators. 
   
   
       9 . The method  claim 7 , wherein each indicator is based on an average, over a set of encoded pictures, of a function of one or more quantization scales over each picture, and a number of bits used to encode the picture. 
   
   
       10 . The method of  claim 7 , wherein the indicator is based on a weighted average of a set of the averages calculated over the set of encoded pictures. 
   
   
       11 . A controller for controlling a set of transcoders, each transcoder being configured to convert an input compressed data signal encoded at an input bit rate into an output compressed data signal encoded at an output bit rate, the controller being configured to:
 compute an indicator of a compressed data quality for each respective transcoder, the indicator being computed from the input compressed data signal, and   allocate the output bit rate to each transcoder from a total output bit rate based on the indicators of the compressed data quality.   
   
   
       12 . The controller of  claim 11 , wherein the controller is configured to allocate the output bit rate to each transcoder based on the transcoder's corresponding indicator and a sum of the indicators. 
   
   
       13 . The controller of  claim 11 , wherein each indicator is based on an average, over a set of encoded pictures, of a function of one or more quantization scales over each picture, and a number of bits used to encode the picture. 
   
   
       14 . The controller of  claim 11 , wherein the indicator is based on a weighted average of a set of the averages calculated over the set of encoded pictures. 
   
   
       15 . A data multiplexing system comprising:
 a set of transcoders that are configured to convert input compressed data signals encoded at an input bit rate into output compressed data signals encoded at an output bit rate,   a controller for controlling the set of transcoders that is configured to:
 determine an indicator of a compressed data quality for each respective transcoder, the indicator being computed from the corresponding input compressed data signal, 
 allocate the output bit rate to each transcoder based on the indicators of the compressed data quality, and 
   a multiplexer that is configured to multiplex the output compressed data signals to provide an output multiplexed data signal.   
   
   
       16 . The system of  claim 15 , wherein the controller is configured to allocate the output bit rate of each transcoder based on the transcoder's corresponding indicator and a sum of the indicators. 
   
   
       17 . The system of  claim 15 , wherein each indicator is based on an average, over a set of encoded pictures, of a function of one or more quantization scales over each picture, and a number of bits used to encode the picture. 
   
   
       18 . The system of  claim 15 , wherein the indicator is based on a weighted average of a set of the averages calculated over the set of encoded pictures. 
   
   
       19 . A computer-readable medium that stores a computer program that enables a controller to control a plurality of transcoders, the computer program causing the controller to:
 compute an indicator of a compressed data quality for each transcoder of the plurality of transcoders, the indicator being computed from an input compressed data signal to each of the plurality of transcoders, and   allocate a output bit rate to each transcoder from a total output bit rate, based on the indicators.   
   
   
       20 . The medium of  claim 19 , wherein the program causes the controller to allocate the output bit rate to each transcoders based on the transcoder's corresponding indicator and a sum of the indicators. 
   
   
       21 . The medium of  claim 19 , wherein each indicator is based on an average, over a set of encoded pictures, of a function of one or more quantization scales over each picture, and a number of bits used to encode the picture. 
   
   
       22 . The medium of  claim 19 , wherein the indicator is based on a weighted average of a set of the averages calculated over the set of encoded pictures.