Bandwidth adaptive stream selection

Abstract

An apparatus and corresponding method are provided for selecting one of several alternate input streams for transmission, the method including determining bandwidth requirements for each of the alternate input streams, measuring bandwidth currently available for transmission, and selecting for transmission one of the alternate input streams that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.

1 . A method for selecting one of a plurality of alternate input streams for transmission, the method comprising: 
 determining bandwidth requirements for each of the plurality of alternate input streams;    measuring bandwidth currently available for transmission; and    selecting for transmission one of the plurality of alternate input streams that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       2 . A method as defined in  claim 1 , further comprising: 
 sub-sampling an alternate input stream;    measuring the bandwidth requirement of the sub-sampled alternate input stream;    selecting for transmission the sub-sampled alternate input stream if it has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       3 . A method as defined in  claim 1 , further comprising: 
 sub-sampling each of the plurality of alternate input streams;    measuring the bandwidth requirements of each of the sub-sampled alternate input streams;    selecting for transmission the sub-sampled alternate input stream that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       4 . A method as defined in  claim 1  wherein an input stream comprises at least one group of pictures (GOP), the method further comprising: 
 sub-sampling the alternate input stream by filtering one picture from each GOP to form a first sub-sampled input stream;    sub-sampling the alternate input stream by filtering two pictures from each GOP to form a second sub-sampled input stream;    sub-sampling the alternate input stream by filtering three pictures from each GOP to form a third sub-sampled input stream;    sub-sampling the alternate input stream by filtering four pictures from each GOP to form a fourth sub-sampled input stream;    measuring the bandwidth requirements of each of the sub-sampled alternate input streams;    selecting for transmission the sub-sampled alternate input stream that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       5 . A method as defined in  claim 1  wherein an input stream comprises I, P and B pictures, the method further comprising: 
 sub-sampling the alternate input stream by filtering at least one picture from each GOP to form a sub-sampled alternate input stream, wherein B pictures are filtered before P pictures, and P pictures are filtered before I pictures;    measuring the bandwidth requirements of the sub-sampled alternate input stream;    selecting for transmission the sub-sampled alternate input stream if it has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       6 . An apparatus for selecting one of a plurality of alternate input streams for transmission, the apparatus comprising: 
 input determination means for determining bandwidth requirements for each of the plurality of alternate input streams;    output measurement means for measuring bandwidth currently available for transmission; and    stream selection means for selecting for transmission one of the plurality of alternate input streams that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       7 . An apparatus as defined in  claim 6 , further comprising: 
 an encoder in signal communication with the input determination means;    a sub-sampler in signal communication between the input determination means and the stream selection means; and    a receiver in signal communication with the output measurement means.    
   
   
       8 . An apparatus as defined in  claim 7  wherein the encoder provides at least one input stream to the sub-sampler.  
   
   
       9 . An apparatus as defined in  claim 7  wherein the encoder provides a plurality of alternate input streams to the sub-sampler.  
   
   
       10 . An apparatus as defined in  claim 7 , the encoder comprising: 
 an input terminal;    a prediction unit in signal communication with the input terminal;    a transform unit in signal communication with the prediction unit;    a quantization unit in signal communication with the transform unit; and    a variable length coding unit in signal communication with the quantization unit.    
   
   
       11 . An apparatus as defined in  claim 10 , the encoder further comprising: 
 an inverse quantization unit in signal communication with the quantization unit;    an inverse transform unit in signal communication with the inverse quantization unit;    a reference picture unit in signal communication with the inverse transform unit;    a motion estimation unit in signal communication with each of the reference picture unit and the input terminal;    a motion compensation unit in signal communication with each of the reference-picture unit and the motion estimation unit; and    a summing unit having a negative input in signal communication with the motion compensation unit, a positive input in signal communication with the input terminal, and an output in signal communication with the transform unit.    
   
   
       12 . An apparatus as defined in  claim 6 , further comprising: 
 means for sub-sampling an alternate input stream;    means for measuring the bandwidth requirement of the sub-sampled alternate input stream; and    means for selecting for transmission the sub-sampled alternate input stream if it has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       13 . An apparatus as defined in  claim 6 , further comprising: 
 means for sub-sampling each of the plurality of alternate input streams;    means for measuring the bandwidth requirements of each of the sub-sampled alternate input streams; and    means for selecting for transmission the sub-sampled alternate input stream that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       14 . An apparatus as defined in  claim 6  wherein an input stream comprises at least one group of pictures (GOP), the apparatus further comprising: 
 means for sub-sampling the alternate input stream by filtering one picture from each GOP to form a first sub-sampled input stream;    means for sub-sampling the alternate input stream by filtering two pictures from each GOP to form a second sub-sampled input stream;    means for sub-sampling the alternate input stream by filtering three pictures from each GOP to form a third sub-sampled input stream;    means for sub-sampling the alternate input stream by filtering four pictures from each GOP to form a fourth sub-sampled input stream;    means for measuring the bandwidth requirements of each of the sub-sampled alternate input streams; and    means for selecting for transmission the sub-sampled alternate input stream that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       15 . An apparatus as defined in  claim 6  wherein an input stream comprises I, P and B pictures, the apparatus further comprising: 
 means for sub-sampling the alternate input stream by filtering at least one picture from each GOP to form a sub-sampled alternate input stream, wherein B pictures are filtered before P pictures, and P pictures are filtered before I pictures;    means for measuring the bandwidth requirements of the sub-sampled alternate input stream; and    means for selecting for transmission the sub-sampled alternate input stream if it has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       16 . A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform program steps for selecting one of a plurality of alternate input streams for transmission, the program steps comprising: 
 determining bandwidth requirements for each of the plurality of alternate input streams;    measuring bandwidth currently available for transmission; and    selecting for transmission one of the plurality of alternate input streams that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       17 . A program storage device as defined in  claim 16 , the program steps further comprising: 
 sub-sampling an alternate input stream;    measuring the bandwidth requirement of the sub-sampled alternate input stream;    selecting for transmission the sub-sampled alternate input stream if it has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       18 . A program storage device as defined in  claim 16 , the program steps further comprising: 
 sub-sampling each of the plurality of alternate input streams;    measuring the bandwidth requirements of each of the sub-sampled alternate input streams;    selecting for transmission the sub-sampled alternate input stream that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       19 . A program storage device as defined in  claim 16  wherein an input stream comprises at least one group of pictures (GOP), the program steps further comprising: 
 sub-sampling the alternate input stream by filtering one picture from each GOP to form a first sub-sampled input stream;    sub-sampling the alternate input stream by filtering two pictures from each GOP to form a second sub-sampled input stream;    sub-sampling the alternate input stream by filtering three pictures from each GOP to form a third sub-sampled input stream;    sub-sampling the alternate input stream by filtering four pictures from each GOP to form a fourth sub-sampled input stream;    measuring the bandwidth requirements of each of the sub-sampled alternate input streams;    selecting for transmission the sub-sampled alternate input stream that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.    
   
   
       20 . A program storage device as defined in  claim 16  wherein an input stream comprises I, P and B pictures, the program steps further comprising: 
 sub-sampling the alternate input stream by filtering at least one picture from each GOP to form a sub-sampled alternate input stream, wherein B pictures are filtered before P pictures, and P pictures are filtered before I pictures;    measuring the bandwidth requirements of the sub-sampled alternate input stream;    selecting for transmission the sub-sampled alternate input stream if it has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.