Client for video stream play and method thereof

• US 20050232290A1
• Filed: 04/04/2005
• Published: 10/20/2005
• Est. Priority Date: 04/02/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Rhim, Eun-hee, Mathew, Manu
• Granted Patent: US 7,602,812 B2
• Time in Patent Office: Days
• US Class Current: 370/412
• CPC Class Codes: H04N 21/23406 involving management of server-side video buffer
• CPC Class Codes: H04N 21/23608 Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/4344 Remultiplexing of multiplex streams, e.g. by modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer
• CPC Class Codes: H04N 21/4425 Monitoring of client processing errors or hardware failure
• CPC Class Codes: H04N 21/6332 directed to client
• CPC Class Codes: H04N 21/654 Transmission by server directed to the client

Abstract

A client for playing a video stream and a method thereof adaptively control the video play in accordance with variable communication environments and the size of the video stream to be transmitted. The client includes a demultiplexer for generating elementary stream (ES) packets by demultiplexing a video stream; a FIFO buffer for temporarily storing the ES packets; a play timing modification unit for reducing a gap of a play time caused by a burst error by modifying time stamps of the ES packets that exist in the FIFO buffer if it is judged that the burst error occurs; and a video decoder for generating an output video by decoding the ES packets of which the time stamps are modified. The client can relatively improve the quality of the video streaming in multimedia communications through a wireless or wire network.

Claims

1. A client terminal for playing a video stream, the client comprising:

a demultiplexer which generates elementary stream (ES) packets by a demultiplexing video stream;

a FIFO buffer which temporarily stores the ES packets;

a play timing modification unit which reduces a gap of a play time caused by a burst error by modifying time stamps of the ES packets that are stored in the FIFO buffer if it is judged that the burst error occurs; and

a video decoder which generates an output video by decoding the ES packets of which the time stamps are modified.

2. The client terminal as claimed in claim 1, wherein the time stamps are presentation time stamps (PTS).

3. The client terminal as claimed in claim 1, wherein the play timing modification unit reduces the gap of the play time by modifying the time stamps so that play times of the ES packets existing in the FIFO buffer are arranged at equal intervals.

4. The client terminal as claimed in claim 1, wherein the play timing modification unit reduces the gap of the play time by modifying the time stamps so that play times of the ES packets existing in the FIFO buffer are arranged at smaller intervals as a packet loss part becomes more distant.

5. The client terminal as claimed in claim 4, wherein the modifying the time stamp is performed by performing a forward correction routine with respect to the ES packets before the burst error occurrence among the ES packets stored in the FIFO buffer and performing a reverse correction routine with respect to the ES packets after the burst error occurrence.

6. The client terminal as claimed in claim 1, wherein judgment of the burst error occurrence is based on whether a difference between the time stamps of adjacent packets exceeds a specified threshold value.

7. A method for playing a video stream, the method comprising:

generating elementary stream (ES) packets by demultiplexing a video stream;

temporarily storing the ES packets;

reducing a gap of a play time caused by a burst error by modifying time stamps of the ES packets which are stored if it is judged that the burst error occurs; and

generating an output video by decoding the ES packets of which the time stamps are modified.

8. The method as claimed in claim 7, wherein the burst error occurs by partly dropping the packets of the complete video stream through a server side that provides the video stream.

9. The method as claimed in claim 8, wherein the packets are partly dropped if a bit rate of the complete video stream is larger than an available bandwidth of a transmitter side.

10. The method as claimed in claim 7, wherein the time stamps are presentation time stamps (PTS).

11. The method as claimed in claim 7, wherein the reducing the gap of the play time is performed by modifying the time stamps so that play times of the ES packets are arranged at equal intervals.

12. The method as claimed in claim 7, wherein the reducing the gap of the play time is performed by modifying the time stamps so that play times of the ES packets are arranged at smaller intervals as a packet loss part becomes more distant.

13. The method as claimed in claim 12, wherein the modifying the time stamps is performed by performing a forward correction routine with respect to the ES packets before the burst error occurrence among the ES packets which are temporarily stored and performing a reverse correction routine with respect to the packets after the burst error occurrence.

14. The method as claimed in claim 7, wherein judgment of the burst error occurrence is based on whether a difference between the time stamps of adjacent ES packets exceeds a specified threshold value.

15. A recording medium in which a method for playing a video stream is recorded as a program readable by a computer, the method comprising:

generating elementary stream (ES) packets by demultiplexing a video stream;

temporarily storing the ES packets;

reducing a gap of a play time caused by a burst error by modifying time stamps of the ES packets which are stored if it is judged that the burst error occurs; and

generating an output video by decoding the ES packets of which the time stamps are modified.