Method and apparatus for efficiently processing an audio and video data stream

• US 6,546,426 B1
• Filed: 03/21/1997
• Issued: 04/08/2003
• Est. Priority Date: 03/21/1997
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Post, Lauren Lee
• Primary Examiner(s): Rinehart, Mark H.
• Assistant Examiner(s): Thompson, Marc D.
• Application Number:
  US08/821,938
• Time in Patent Office: 2,209 Days
• Field of Search: 709/219, 709/231, 709/248, 725/89
• US Class Current: 709/231
• CPC Class Codes: H04N 21/23406 involving management of server-side video buffer
• CPC Class Codes: H04N 21/2368 Multiplexing of audio and video streams
• CPC Class Codes: H04N 21/4341 Demultiplexing of audio and video streams
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4392 involving audio buffer management
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer

Abstract

A method and apparatus for processing a data stream including audio and video data in which high data rates and throughput is required. Thresholds are employed to control the processing of video and audio data in a data stream. Video data is decoded in response to a comparison of audio and video data to threshold values. Additionally, another threshold value is employed to control buffers storing audio data in response to an underflow of audio data.

Claims

1. A method in a data processing system for dynamically synchronizing a data stream, the method comprising:

receiving the data stream;

parsing the data stream into packets to form a plurality of packets, wherein the plurality of packets includes audio packets and video packets;

comparing the plurality of packets to a threshold as packets are added to the plurality of packets; and

selectively decoding of audio packets and video packets based on a result from the comparison of the plurality of packets to the threshold.

2. The method of claim 1, wherein the threshold includes a first threshold value and a second threshold value and wherein the comparing step comprises comparing the audio packets to the first threshold value and comparing the video packets to the second threshold value.

3. The method of claim 2, wherein the decoding of audio packets and video packets comprises decoding a video packet if a number of audio packets is greater than the first threshold and if the number of video packets is greater than the second threshold value.

4. The method of claim 1, wherein the data stream is a MPEG-1.

5. The method of claim 1, wherein the data stream is a MPEG-2 data stream.

6. The method of claim 1 further comprises:

halting parsing of the data stream in response to comparing the plurality of packets to a threshold as packets are added to the plurality of packets.

7. A method in a data processing system for dynamically synchronizing a data stream, the method comprising:

receiving a data stream;

parsing the data stream into a plurality of packets;

identifying a number of video packets within the plurality of packets while parsing the data stream into the plurality of packets;

comparing the number of video packets to a video threshold value; and

decoding the video packets in response to the number of video packets being greater than the video threshold value.

8. The method of claim 7, wherein the data processing system includes an amount of processing resources and further comprising:

identifying the amount of processing resources within the data processing system; and

adjusting the video threshold value in response to the identified amount of processing resources within the data processing system.

9. The method for claim 7 further comprising:

monitoring the plurality of packets for audio packets;

identifying a number of audio packets within the plurality of packets;

determining whether the number of audio packets is greater than an audio threshold value in response to a determination that the number of video packets is greater than the video threshold value; and

starting the decoding step when the number of video packets is greater than the audio threshold value.

10. The method of claim 9, wherein the data processing system includes an amount of processing resources and further comprises:

identifying the amount of processing resources within the data processing system; and

adjusting the video threshold value and the audio threshold value in response to the identified amount of processing resources within the data processing system.

11. The method of claim 10, further comprising:

identifying a number of audio packets within the plurality of packets;

storing data from the audio packets in a number of available buffers;

comparing the number of available buffers to a threshold value; and

processing the data stored in the available buffers in response to the number of available buffers being greater than the threshold value.

12. The method of claim 11 further comprising:

flushing data from the available buffers in response to the number of available buffers being less than or equal to the threshold value.

13. The method of claim 7 further comprises:

halting parsing of the data stream in response to comparing the plurality of packets to a threshold as packets are added to the plurality of packets.

14. An apparatus for decoding a data stream comprising:

input means for receiving the data stream;

processing means for parsing the data stream into a number of video data packets and a number of audio data packets;

video decoding means for decoding the number of video data packets;

audio decoding means for decoding the number of audio data packets; and

processing control means for controlling the processing means, wherein the processing means is halted in response to the number of video data packets being greater than a first threshold value.

15. The apparatus of claim 14, wherein the data processing system includes an amount of processing resources and further comprises:

identification means for identifying the amount of processing resources within the apparatus; and

adjustment means for adjusting the video threshold value in response to the identified amount of processing resources within the apparatus.

16. The apparatus of claim 14 further comprising:

monitoring means for monitoring the plurality of data packets for a presence of audio data packets;

identification means for identifying a number of audio data packets within the plurality of data packets in response to the monitoring means detecting a presence of audio packets;

determination means for determining whether the number of audio packets is greater than an audio threshold value in response to a determination that the number of video packets is greater than the video threshold value; and

second processing control means for starting decoding of video packets in response to a determination that the number of video packets is less than or equal to the audio threshold value.

17. The apparatus of claim 14, wherein the apparatus is a data processing system.

18. The apparatus of claim 14, wherein the apparatus is an audio/visual adapter.

19. The apparatus of claim 14, wherein the data stream is a MPEG-1 data stream.

20. The apparatus of claim 14, wherein the data stream is a MPEG-2 data stream.

21. A method in a data processing system for decoding a multimedia data stream, the method comprising:

receiving the multimedia data stream;

parsing the multimedia data stream into packets to form a plurality of packets, wherein the plurality of packets includes audio packets and video packets;

comparing the plurality of packets to a threshold as packets are added to the plurality of packets; and

selectively decoding of audio packets and video packets based on a result from the comparison of the plurality of packets to the threshold.

22. A method in a data processing system for decoding a multimedia data stream of claim 21, further comprising:

halting parsing of the data stream in response to comparing the plurality of packets to a threshold as packets are added to the plurality of packets.

23. A computer program product for use with a data processing system for processing a data stream, the computer program product comprising:

a computer useable medium;

first instructions for receiving a data stream;

second instructions for parsing the data stream into data packets to form a plurality of packets;

third instructions for comparing the plurality of packets to a threshold as data packets are added to the plurality of packets;

fourth instructions for selectively decoding audio and video packets based on a result from the comparison of the plurality of packets; and

wherein the instructions are embodied within the computer useable medium.

24. A computer program product for use with a data processing system for processing a data stream of claim 23, further comprising:

fifth instructions for halting parsing of the data stream.

25. A method in a data processing system for dynamically, synchronizing a data stream, the method comprising:

receiving the data stream;

parsing the data stream into packets to form a plurality of packets, wherein the plurality of packets includes audio packets and video packets;

comparing the audio packets to a first threshold as packets are added to the plurality of packets;

comparing the video packets to a second threshold as packets are added to the plurality of packets;

halting parsing of the data stream based on a result from the comparison of the plurality of packets to the thresholds; and

selectively decoding of audio packets and video packets based on a result from the comparison of the plurality of packets to the thresholds.