Method and system for staggered statistical multiplexing

• US 20060018379A1
• Filed: 10/27/2003
• Published: 01/26/2006
• Est. Priority Date: 11/15/2002
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Thomson Licensing SA (Vantiva SA)
• Inventors: Cooper, Jeffrey Allen
• Granted Patent: US 9,084,010 B2
• Time in Patent Office: Days
• US Class Current: 375/240.120
• CPC Class Codes: H04N 19/114 Adapting the group of pictures [GOP] structure, e.g. number of B-frames between two anchor frames H04N19/107 takes precedence
• 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 21/23655 Statistical multiplexing, e.g. by controlling the encoder to alter its bitrate to optimize the bandwidth utilization
• CPC Class Codes: H04N 21/26275 for distributing content or additional data in a staggered manner, e.g. repeating movies on different channels in a time-staggered manner in a near video on demand system
• 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

In a multi-channel video transmission system in which channel video segments are operated on by corresponding channel video encoders to encode the video segments into frames organized into groups of defined frame types, an apparatus and method to cause a temporal staggering for the processing of a specific frame type among the various channels. In one preferred embodiment, the apparatus includes a frame counter to synchronize reset signals associated with the corresponding channel video encoders and a means for providing a timing offset to channel video encoders corresponding to a selected frame stagger for a particular corresponding channel.

Claims

1. In a multi-channel video transmission system wherein channel video segments are operated on by corresponding channel video encoders to encode said video segments into pluralities of frames organized into groups having defined frame patterns, an apparatus to effect a temporal staggering of corresponding ones of said frame groups among said channels comprising:

a frame counter to synchronize reset signals associated with said corresponding channel video encoders; and

means for providing a timing offset to ones of said channel video encoders corresponding to a selected frame stagger for given ones of said channels.

2. The apparatus of claim 1 further comprising:

a plurality of registers, ones of said registers being loaded with frame offset values corresponding to said selected frame stagger for an associated channel.

3. The apparatus of claim 2 further comprising:

a plurality of comparators, ones of said comparators being functionally associated with ones of said video encoders, said comparators being operative to receive as inputs an output of associated registers and of a frame rate counter (70), and to provide a timing signal as an output corresponding to said selected frame stagger for an associated channel.

4. The apparatus of claim 3 further comprising:

a plurality of gates adapted to receive as inputs an encoder reset signal level and an output of ones of said comparators and to provide as an output a reset signal for an associated encoder, wherein ones of said encoders are reset at a timing point corresponding to the selected frame stagger for given encoders.

5. In a video transmission system in which video segments are encoded into a plurality of frame types, a method for arranging frame transmission alignment among a plurality of channels concurrently transmitted via a common transmission medium, comprising:

identifying a specified frame type in each of said plurality of channels; and

causing ones of said specified frame type to be arranged so as to avoid temporal alignment with other ones of said specified frame type in corresponding other ones of said plurality of channels.

6. The method of claim 5 wherein said ones of said specified frame type and other ones of said specified frame type are temporally displaced, relative to one another.

7. The method of claim 5 wherein said specified frame type in successive ones of said plurality of channels are displaced by one frame position relative to a location of said frame type in a preceding channel.

8. The method of claim 5 wherein said video segments include a fixed number of frame positions and said fixed number of frame positions is an integer multiple of the number of said plurality of channels.

9. The method of claim 5 wherein each of said plurality of channels is synchronized to a common frame rate and phase.

10. The method of claim 5 wherein said plurality of frame types include a high priority frame type and a low priority frame type.

11. The method of claim 5 wherein said plurality of frame types include at least one intermediate priority frame type.

12. The method of claim 11 wherein said video segments are encoded using an MPEG coding methodology and further wherein said high, intermediate and low priority frame types correspond respectively to MPEG Intra-coded, Predictive, and Bi-directionally Predictive frames.

13. The method of claim 10 wherein ones of said low priority frame type are optionally dropped to reduce required transmission bandwidth.

14. The method of claim 5 wherein said video segments are encoded using an MPEG coding methodology and correspond to an MPEG Group of Pictures.