US2006062293A1PendingUtilityA1

Pre-processing of bit rate allocation in a multi-channel video encoder

41
Individually held — no corporate assignee on recordPriority: Jun 16, 1998Filed: Nov 10, 2005Published: Mar 23, 2006
Est. expiryJun 16, 2018(expired)· nominal 20-yr term from priority
Inventors:James E. KayePaul HaskellArthur C. Manansala
H04N 19/149H04N 19/61H04N 19/115H04N 19/176H04N 19/179H04N 19/137H04N 21/23655H04N 21/2365H04N 19/85H04N 19/15H04N 19/14H04N 19/152H04N 19/87H04N 19/142H04N 21/4347H04N 19/162H04N 19/436
41
PatentIndex Score
0
Cited by
0
References
0
Claims

Abstract

A method and apparatus for bit rate allocation, or statistical multiplexing, in a multi-channel video data encoder. A pre-processor in each channel determines a bit rate need prior to compression and encoding. A control processes the bit rate need in each channel to arrive at an allocated bit rate for each channel. The video data is then compressed and encoded according to the allocated bit rate. The bit rate demand accounts for various characteristics of the current picture data in each channel, including spatial activity, temporal activity, image size, frame rate, scene change, brightness, flash, fade, and horizontal pixel resolution. The system also biases the bit rate allocation according to inter-frame distance, whether the average spatial activity level is below a lower threshold, whether the inter-frame distance is above an upper threshold or below a lower threshold, whether the quantization of previous frames is above an upper threshold, the length of the Group of Pictures (GOP), and a user-selectable priority factor. The system also allocates any surplus bit rate among the channels to avoid having unused bandwidth.

Claims

exact text as granted — not AI-modified
1 . A method for determining a bit rate need of a plurality of variable rate video channels in a video encoder, comprising the steps of: 
 processing video data from a current picture in each respective channel to determine at least a spatial activity and a temporal activity thereof;    determining an initial bit rate demand for each current picture according to the associated spatial activity and temporal activity; and    for at least one current picture, determining whether the associated spatial activity is below a lower threshold, and if so, increasing the associated temporal activity thereof, and adjusting the initial bit rate demand thereof according to the increased temporal activity thereof.    
   
   
       2 . A method in accordance with  claim 25 , comprising the further step of: 
 adjusting said initial bit rate demand for each current picture according to whether a scene change is detected for the current picture.    
   
   
       3 . A method in accordance with  claim 25 , comprising the further step of: 
 adjusting said initial bit rate demand for each current picture according to whether a fade is detected for the current picture.    
   
   
       4 . A method in accordance with  claim 25 , comprising the further step of: 
 adjusting said initial bit rate demand for each current picture according to whether a flash is detected for the current picture.    
   
   
       5 . A method in accordance with  claim 25 , comprising at least one of the further steps of, for at least one current picture: 
 adjusting the initial bit rate demand thereof upwards when the associated temporal activity exceeds an upper threshold; and    adjusting the initial bit rate demand thereof downwards when the associated temporal activity is less than a lower threshold.    
   
   
       6 . A method in accordance with  claim 25 , comprising the further step of: 
 for at least one current picture, adjusting the initial bit rate demand thereof upwards when a quantization level of at least one previous picture associated therewith of a same picture type exceeds an upper threshold.    
   
   
       7 . A method in accordance with  claim 25 , comprising at least one of the further steps of, for at least one current picture: 
 adjusting the initial bit rate demand thereof downwards when a length of an associated group of pictures exceeds a nominal level; and    adjusting the initial bit rate demand thereof upwards when a length of an associated group of pictures is less than a nominal level.    
   
   
       8 . A method in accordance with  claim 31 , comprising the further step of, for the at least one current picture: 
 tempering the upwards or downward adjusting of the initial bit rate demand thereof when the temporal activity thereof exceeds an upper threshold.    
   
   
       9 . A method in accordance with  claim 25 , comprising the further step of: 
 for at least one current picture, adjusting the initial bit rate demand thereof according to whether a horizontal pixel resolution thereof exceeds or is less than a nominal level.    
   
   
       10 . A method in accordance with  claim 25 , comprising the further step of: 
 for at least one current picture, adjusting the initial bit rate demand thereof upwards when an associated brightness level is less than a lower threshold.    
   
   
       11 . A method in accordance with  claim 25 , comprising the further step of: 
 for at least one current picture, adjusting the initial bit rate demand thereof according to a priority factor thereof which indicates a relative importance of the at least one current picture in the multiplexed data stream.    
   
   
       12 . An apparatus for determining a bit rate need of a plurality of variable rate video channels in a video encoder, comprising: 
 means for processing video data from a current picture in each respective channel to determine at least a spatial activity and a temporal activity thereof;    means for determining an initial bit rate demand for each current picture according to the associated spatial activity and temporal activity; and    means for determining, for at least one current picture, whether the associated spatial activity is below a lower threshold, and if so, increasing the associated temporal activity thereof, and adjusting the initial bit rate demand thereof according to the increased temporal activity thereof.    
   
   
       13 . Apparatus in accordance with  claim 36 , further comprising: 
 means for adjusting said initial bit rate demand for each current picture according to whether a scene change is detected for the current picture.    
   
   
       14 . Apparatus in accordance with  claim 36 , further comprising: 
 means for adjusting said initial bit rate demand for each current picture according to whether a fade is detected for the current picture.    
   
   
       15 . Apparatus in accordance with  claim 36 , further comprising: 
 means for adjusting said initial bit rate demand for each current picture according to whether a flash is detected for the current picture.    
   
   
       16 . Apparatus in accordance with  claim 36 , wherein, for at least one current picture, the apparatus further comprises: 
 means for adjusting the initial bit rate demand thereof upwards when the associated temporal activity exceeds an upper threshold; and    means for adjusting the initial bit rate demand thereof downwards when the associated temporal activity is less than a lower threshold.    
   
   
       17 . Apparatus in accordance with  claim 36 , further comprising: 
 means for adjusting, for at least one current picture, the initial bit rate demand thereof upwards when a quantization level of at least one previous picture associated therewith of a same picture type exceeds an upper threshold.    
   
   
       18 . Apparatus in accordance with  claim 36 , wherein, for at least one current picture, the apparatus further comprises: 
 means for adjusting the initial bit rate demand thereof downwards when a length of an associated group of pictures exceeds a nominal level; and    means for adjusting the initial bit rate demand thereof upwards when a length of an associated group of pictures is less than a nominal level.    
   
   
       19 . Apparatus in accordance with  claim 42 , wherein, for the at least one current picture, the apparatus further comprises: 
 means for tempering the upward or downward adjusting of the initial bit rate demand thereof when the temporal activity thereof exceeds an upper threshold.    
   
   
       20 . Apparatus in accordance with  claim 36 , further comprising: 
 means for adjusting, for at least one current picture, the initial bit rate demand thereof according to whether a horizontal pixel resolution thereof exceeds or is less than a nominal level.    
   
   
       21 . Apparatus in accordance with  claim 36 , further comprising: 
 means for adjusting, for at least one current picture, the initial bit rate demand thereof upward when an associated brightness level is less than a lower threshold.    
   
   
       22 . Apparatus in accordance with  claim 36 , further comprising: 
 means for adjusting, for at least one current picture, the initial bit rate demand thereof according to a priority factor thereof which indicates a relative importance of the at least one current picture in the multiplexed data stream.    
   
   
       23 . A method for determining a bit rate need of a plurality of variable rate video channels in a video encoder, comprising the steps of: 
 processing video data from a current picture in each respective channel to determine at least a spatial activity and a temporal activity thereof;    determining an initial bit rate demand for each current picture according to the associated spatial activity and temporal activity; and    for at least one current picture, adjusting the initial bit rate demand thereof upwards when an associated brightness level is less than a lower threshold.    
   
   
       24 . A method in accordance with claim  47 , comprising the further step of: 
 adjusting said initial bit rate demand for each current picture according to whether a scene change is detected for the current picture.    
   
   
       25 . A method in accordance with claim  47 , comprising the further step of: 
 adjusting said initial bit rate demand for each current picture according to whether a fade is detected for the current picture.    
   
   
       26 . A method in accordance with claim  47 , comprising the further step of: 
 adjusting said initial bit rate demand for each current picture according to whether a flash is detected for the current picture.    
   
   
       27 . A method in accordance with claim  47 , comprising the further step of: 
 for at least one current picture, determining whether the associated spatial activity is below a lower threshold, and if so, increasing the associated temporal activity thereof, and adjusting the initial bit rate demand thereof according to the increased temporal activity thereof.    
   
   
       28 . A method in accordance with claim  47 , comprising at least one of the further steps of, for at least one current picture: 
 adjusting the initial bit rate demand thereof upwards when the associated temporal activity exceeds an upper threshold; and    adjusting the initial bit rate demand thereof downwards when the associated temporal activity is less than a lower threshold.    
   
   
       29 . A method in accordance with claim  47 , comprising the further step of: 
 for at least one current picture, adjusting the initial bit rate demand thereof upwards when a quantization level of at least one previous picture associated therewith of a same picture type exceeds an upper threshold.    
   
   
       30 . A method in accordance with claim  47 , comprising at least one of the further steps of, for at least one current picture: 
 adjusting the initial bit rate demand thereof downwards when a length of an associated group of pictures exceeds a nominal level; and    adjusting the initial bit rate demand thereof upwards when a length of an associated group of pictures is less than a nominal level.    
   
   
       31 . A method in accordance with claim  54 , comprising the further step of, for the at least one current picture: 
 tempering the upwards or downward adjusting of the initial bit rate demand thereof when the temporal activity thereof exceeds an upper threshold.    
   
   
       32 . A method in accordance with claim  47 , comprising 4 the further step of: 
 for at least one current picture, adjusting the initial bit rate demand thereof according to whether a horizontal pixel resolution thereof exceeds or is less than a nominal level.    
   
   
       33 . A method in accordance with claim  47 , comprising the further step of: 
 for at least one current picture, adjusting the initial bit rate demand thereof according to a priority factor thereof which indicates a relative importance of the at least one current picture in the multiplexed data stream.    
   
   
       34 . An apparatus for determining a bit rate need of a plurality of variable rate video channels in a video encoder, comprising: 
 means for processing video data from a current picture in each respective channel to determine at least a spatial activity and a temporal activity thereof;    means for determining an initial bit rate demand for each current picture according to the associated spatial activity and temporal activity; and    means for adjusting, for at least one current picture, the initial hit rate demand thereof upward when an associated brightness level is less than a lower threshold.    
   
   
       35 . Apparatus in accordance with claim  58 , further comprising: 
 means for adjusting said initial bit rate demand for each current picture according to whether a scene change is detected for the current picture.    
   
   
       36 . Apparatus in accordance with claim  59 , further comprising: 
 means for adjusting said initial bit rate demand for each current picture according to whether a fade is detected for the current picture.    
   
   
       37 . Apparatus in accordance with claim  58 , further comprising: 
 means for adjusting said initial bit rate demand for each current picture according to whether a flash is detected for the current picture.    
   
   
       38 . Apparatus in accordance with claim  58 , further comprising: 
 means for determining, for at least one current picture, whether the associated spatial activity is below a lower threshold, end if so, increasing the associated temporal activity thereof, and adjusting the initial bit rate demand thereof according to the increased temporal activity thereof.    
   
   
       39 . Apparatus in accordance with claim  59 , wherein, for at least one current picture, the apparatus further comprises: 
 means for adjusting the initial bit rate demand thereof upwards when the associated temporal activity exceeds an upper threshold; and    means for adjusting the initial bit rate demand thereof downwards when the associated temporal activity is less than a lower threshold.    
   
   
       40 . Apparatus in accordance with claim  58 , further comprising: 
 means for adjusting, for at least one current picture, the initial bit rate demand thereof upwards when a quantization level of at least one previous picture associated therewith of a same picture type exceeds an upper threshold.    
   
   
       41 . Apparatus in accordance with claim  58 , wherein, for at least one current picture, the apparatus further comprises: 
 means for adjusting the initial bit rate demand thereof downwards when a length of an associated group of pictures exceeds a nominal level; and    means for adjusting the initial bit rate demand thereof upwards when a length of an associated group of pictures is less than a nominal level.    
   
   
       42 . Apparatus in accordance with claim  65 , wherein, for the at least one current picture, the apparatus further comprises: 
 means for tempering the upward or downward adjusting of the initial bit rate demand thereof when the temporal activity thereof exceeds an upper threshold.    
   
   
       43 . Apparatus in accordance with claim  58 , further comprising: 
 means for adjusting, for at least one current picture, the initial hit rate demand thereof according to whether a horizontal pixel resolution thereof exceeds or is less than a nominal level.    
   
   
       44 . Apparatus in accordance with claim  58 , further comprising: 
 means for adjusting, for at least one current picture, the initial bit rate demand thereof according to a priority factor thereof which indicates a relative importance of the at least one current picture in the multiplexed data stream.    
   
   
       69 . (canceled)  
   
   
       70 . (canceled)  
   
   
       71 . (canceled)  
   
   
       72 . (canceled)  
   
   
       73 . (canceled)  
   
   
       74 . (canceled)  
   
   
       75 . (canceled)  
   
   
       76 . A method in accordance with  claim 69 , comprising at least one of the further steps of, for at least one current picture: 
 adjusting the initial bit rate demand thereof downwards when a length of an associated group of pictures exceeds a nominal level; and    adjusting the initial bit rate demand thereof upwards when a length of an associated group of pictures is less than a nominal level.    
   
   
       77 . (canceled)  
   
   
       78 . (canceled)  
   
   
       79 . (canceled)  
   
   
       80 . (canceled)  
   
   
       81 . (canceled)  
   
   
       82 . (canceled)  
   
   
       83 . (canceled)  
   
   
       84 . (canceled)  
   
   
       85 . (canceled)  
   
   
       86 . (canceled)  
   
   
       87 . (canceled)  
   
   
       88 . (canceled)  
   
   
       89 . (canceled)  
   
   
       90 . (canceled)  
   
   
       91 . (canceled)  
   
   
       92 . (canceled)

Join the waitlist — get patent alerts

Track US2006062293A1 — get alerts on status changes and closely related new filings.

We store only your email — no account needed. See our privacy policy.