Moving picture coding, coded-moving picture bitstream conversion and coded-moving picture bitstream multiplexing

• US 7,697,607 B2
• Filed: 09/12/2005
• Issued: 04/13/2010
• Est. Priority Date: 03/15/2000
• Status: Active Grant

• Current Assignee: JVC Kenwood Corporation
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Inventors: Sugiyama, Kenji
• Primary Examiner(s): DIEP, NHON THANH
• Application Number:
  US11/222,805
• Publication Number:
  US 20060062297A1
• Time in Patent Office: 1,674 Days
• Field of Search: None
• US Class Current: 375/240.01
• CPC Class Codes: H04N 19/105 Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
• CPC Class Codes: H04N 19/126 Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/15 by monitoring actual compressed data size at the memory before deciding storage at the transmission buffer
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/503 involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 19/587 involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 21/234381 by altering the temporal resolution, e.g. decreasing the frame rate by frame skipping
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/2401 Monitoring of the client buffer
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/4347 Demultiplexing of several video streams

Abstract

First pictures as reference for inter-picture prediction of an incoming moving-picture and second pictures are coded. The first pictures are coded by intra-picture or unidirectional inter-picture predictive coding. The second pictures are coded by bidirectional inter-picture predictive coding by referring the first or their locally-decoded pictures to obtain a moving-picture bitstream. The bitstream is multiplexed with obtained motion activity information. Incoming first bitstreams are multiplexed into a bitstream at a rate lower than a total bit rate of the incoming first bitstreams. Each bitstream has first bitstreams of the first and second pictures. A code amount of the multiplexed bitstream is obtained for each reproduction period as virtual buffer occupancy, according to which a decimation rate is set on the second pictures. The second pictures bitstreams are decimated from the incoming first bitstreams according to the decimation rate to obtain second bitstreams, which are multiplexed to obtain the multiplexed bitstream.

Claims

1. A bitstream multiplexing apparatus for multiplexing a plurality of incoming first moving-picture bitstreams into a moving-picture bitstream at a bit rate lower than a total bit rate of the incoming first moving-picture bitstreams, each incoming first moving-picture bitstream having first moving-picture bitstreams of first pictures used as reference pictures for inter-picture prediction and bitstreams of second pictures other than the first pictures, the apparatus comprising:

a decimation controller to set a decimation rate on the second pictures of the incoming first moving-picture bitstreams according to virtual buffer occupancy to the multiplexed moving-picture bitstream;

a bitstream decimator to decimate the bitstreams of the second pictures from the incoming first moving-picture bitstreams at a predetermined interval according to the decimation rate, thus obtaining second bitstreams;

a multiplexer to multiplex the second bitstreams to obtain the multiplexed bitstream; and

virtual buffer means for obtaining a code amount of the multiplexed bitstream for each reproduction period as the virtual buffer occupancy.

2. The bitstream multiplexing apparatus according to claim 1, further comprising a motion amount detector to obtain motion activity on each incoming first moving-picture bitstream, the motion activity being used for setting the decimation rate.

3. A method of multiplexing a plurality of incoming first moving-picture bitstreams into a moving-picture bitstream at a bit rate lower than a total bit rate of the incoming first moving-picture bitstreams, each incoming first moving-picture bitstream having first moving-picture bitstreams of first pictures used as reference pictures for inter-picture prediction and bitstreams of second pictures other than the first pictures, the method comprising the steps of:

obtaining a code amount of the multiplexed bitstream for each reproduction period as virtual buffer occupancy;

setting a decimation rate on the second pictures of the incoming first moving-picture bitstreams according to the virtual buffer occupancy;

decimating the bitstreams of the second pictures from the incoming first moving-picture bitstreams at a predetermined interval according to the decimation rate, thus obtaining second bitstreams; and

multiplexing the second bitstreams to obtain the multiplexed bitstream.

4. The multiplexing method according to claim 3, further comprising the step of obtaining motion activity on each incoming first moving-picture bitstream, the motion activity being used for setting the decimation rate.