Minimum-delay jitter smoothing device and method for packet video communications
First Claim
1. A device in a receiving node of a packet video communication system for converting a received digital video packet stream into a continuous bitstream for transmission to a video decoder, the device comprising:
- (A) a video depacketizer, operably coupled to receive and depacketize digital video packets of the received digital video packet stream into video information bits;
(B) a video information buffer, operably coupled to the video depacketizer for storing the video information bits;
(C) a decoder buffer verifier (DBV), operably coupled to the video information buffer, for determining a number of transmitted information bits for a video frame, and for monitoring a fullness of a hypothetical decoder buffer (HDB);
(D) a bitstream generator, operably coupled to the video information buffer and to the DBV, for transmitting the video information bits from the video information buffer at a predetermined rate and for inserting a number of stuffing bits into the video information bitstream wherein the number of stuffing bits is determined according to a predetermined scheme for minimizing buffering jitter to provide a continuous bitstream with a substantially minimized smoothing delay.
3 Assignments
0 Petitions
Accused Products
Abstract
The method and device of the present invention provide a mechanism at a network node to compensate for variable delays or delay jitters of video packets transported over a packet-switched network, such as an ATM network, and generate a continuous bitstream to an external decoder. The received video packets with variable delays are first depacketized and stored in a video information buffer and then are sent to the external decoder through another constant or variable bit-rate channel. Based on a hypothetical decoder buffer verifier condition, stuffing bits are inserted into the output video bitstream to prevent the decoder buffer from overflowing. Stuffing bits are sent if one of the following two cases occurs: A) the condition of the hypothetical decoder buffer verifier is violated; B) the video information buffer is empty. A minimum number of stuffing bits are sent each time to minimize the incurred delay and concurrently make the following three conditions satisfied: 1) overflow of the decoder buffer is avoided; 2) idleness of the channel is avoided; 3) the stuffing bits must comply with the syntax of the video bitstream.
-
Citations
35 Claims
-
1. A device in a receiving node of a packet video communication system for converting a received digital video packet stream into a continuous bitstream for transmission to a video decoder, the device comprising:
-
(A) a video depacketizer, operably coupled to receive and depacketize digital video packets of the received digital video packet stream into video information bits; (B) a video information buffer, operably coupled to the video depacketizer for storing the video information bits; (C) a decoder buffer verifier (DBV), operably coupled to the video information buffer, for determining a number of transmitted information bits for a video frame, and for monitoring a fullness of a hypothetical decoder buffer (HDB); (D) a bitstream generator, operably coupled to the video information buffer and to the DBV, for transmitting the video information bits from the video information buffer at a predetermined rate and for inserting a number of stuffing bits into the video information bitstream wherein the number of stuffing bits is determined according to a predetermined scheme for minimizing buffering jitter to provide a continuous bitstream with a substantially minimized smoothing delay. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method in a network receiving node of a packet video communication system for converting a received digital video packet bitstream into a continuous bitstream for transmission to a video decoder, the method comprising the steps of:
-
(A) receiving the digital video packet stream and storing the information bits contained in said packets; (B) monitoring a fullness of a hypothetical decoder buffer by a decoder buffer verifier (DBV); and (C) reading, by a bitstream generator, video information bits from the video information buffer at a predetermined rate and inserting, by the bitstream generator, a number of stuffing bits into the video information bitstream wherein the number of stuffing bits is determined according to a predetermined scheme for minimizing buffering jitter to provide a continuous bitstream with a substantially minimized smoothing delay. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
-
-
24. A hypothetical buffer-based jitter smoothing device for minimizing smoothing delay in a packet video communication system, the device comprising:
-
A) a video depacketizer, operably coupled to receive and depacketize digital video packets of a received digital video packet stream into video information bits, B) an information buffer, operably coupled to the depacketizing means, for storing the video information bits, C) hypothetical buffer-based smoothing means, operably coupled to the information buffer, for utilizing a hypothetical buffer to generate and transmit a continuous stuffed video information bitstream at a predetermined rate and minimize buffering jitter. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
-
Specification