Buffer system for controlled and timely delivery of MPEG-2F data services

• US 6,573,942 B1
• Filed: 07/12/1999
• Issued: 06/03/2003
• Est. Priority Date: 08/17/1998
• Status: Expired due to Fees

• Current Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Crinon, Regis J.
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US09/352,156
• Time in Patent Office: 1,422 Days
• Field of Search: 348/512, 348/714, 348/725, 348/607, 348/497, 348/515, 348/518, 348/718, 375/371, 375/372
• US Class Current: 348/518
• CPC Class Codes: H04N 21/23406 involving management of server-side video buffer
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer

Abstract

A data elementary buffer with underflow and overflow operational constraints is incorporated into a digital televison receiver to regulate the flow of data related to an ancillary data service to be presented in synchronization with a video or audio program element. The data elementary buffer ensures that data is received in time for decoding and presentation in synchronization with the video or audio element. The data elementary buffer also limits the amount of data that the receiver may be required to cache. The minimum size of the data elementary buffer is three times the size of a nominal data access unit or three times the quantity of data that the receiver can receive at the maximum rate in the period that a video element is displayed by the receiver.

Claims

1. A buffer mechanism to regulate delivery of data for synchronized presentation by a digital television receiver that includes a smoothing buffer, said buffer mechanism comprising a data elementary buffer constrained to operate without overflow and underflow of said data, to receive said data from said smoothing buffer, wherein a data capacity of said data elementary buffer is, at least, approximately three times a maximum quantity of said data that can be received by said receiver in a period of display of a video element by said receiver.

2. The buffer mechanism of claim 1 wherein a data capacity of said data elementary buffer is a function of a quantity of said data that can be received by said receiver in a period of display of a video element by said receiver, wherein said video element is a video frame.

3. The buffer mechanism of claim 1 wherein a data capacity of said data elementary buffer is a function of a quantity of said data that can be received by said receiver in a period of display of a video element by said receiver, wherein said video element is a video field.

4. A target system decoder for a synchronized ancillary data service for a digital television receiver comprising:

(a) a transport buffer receiving a first plurality of transport stream data packets for said synchronized ancillary data service from a transport stream demultiplexer;

(b) a smoothing buffer receiving a second plurality of transport stream data packets from said transport buffer at a transport buffer leak rate;

(c) a first-in, first-out data elementary buffer, constrained to operate without overflow and underflow of data, receiving elementary data stream packet data from said smoothing buffer at a smoothing buffer leak rate and aggregating said elementary data stream packet data to reconstruct a data access unit; and

(d) an application decoder receiving said data access unit from said data elementary buffer at a specified admission time, wherein a data capacity of said data elementary buffer is, at least, approximately three times a maximum quantity of said data that can be received by said receiver in a period of display of a video element by said receiver.

5. The target system decoder of claim 4 wherein a data capacity of said data elementary buffer is a function of a quantity of said data that can be received by said receiver in a period of display of a video element by said receiver, wherein said video element is a video frame.

6. The target system decoder of claim 4 wherein a data capacity of said data elementary buffer is a function of a quantity of said data that can be received by said receiver in a period of display of a video element by said receiver, wherein said video element is a video field.

7. A method of buffering data for synchronized presentation with an instant of at least one of a visual and an audio data stream by a digital televison receiver comprising:

(a) setting an appropriate size for a data elementary buffer aggregating data to reconstruct a access unit of data, said data elementary buffer constrained to operate without overflow or underflow of data;

(b) removing said access unit of data from said data elementary buffer for presentation at a removal time correlated with a presentation time stamp included in said at least one of a visual and an audio data stream; and

(c) adding said data to said data elementary buffer from a smoothing buffer, wherein said appropriate size of said data elementary buffer is, at least, approximately three times a maximum quantity of said data that can be received by said receiver in a period of display of a video element by said receiver.

8. The method of claim 7 wherein said video element is a video frame.

9. The method of claim 7 wherein said video element is a video field.