System for digital stream transmission and method thereof

• US 20020178274A1
• Filed: 03/06/2001
• Published: 11/28/2002
• Est. Priority Date: 03/06/2001
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: ATI Technologies ULC (Advanced Micro Devices, Inc.)
• Inventors: Kovacevic, Branko D.
• Granted Patent: US 7,047,330 B2
• Time in Patent Office: Days
• US Class Current: 709/231
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/752 adapting media to network capabilities
• CPC Class Codes: H04L 65/762 at the source reformatting of additional data in video distribution servers H04N21/2355
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A system and methods are shown for generating a transport stream. An application reads a transport stream file stored in memory. The application provides access to the transport stream file to a graphics card using a multimedia peripheral port (MPP). The MPP is used to provide data from the transport stream file to a transport stream demultiplexer. The application determines a desired transmission rate from the data present between program clock references in the transport stream file. The application suspends transmissions to the transport stream demultiplexer to allow a transmission bit-rate to match the desired bit-rate. The application also suspends transmission when the receiving transport demultiplexer determines its buffers are nearly full.

Claims

1. A method comprising the steps of:

reading a first data representing a first portion of a transport stream;

providing a representation of the first data to a transport stream handler, wherein the representation of the first data is provided in a transport stream format; and

receiving a bit-rate indicator based upon the first data, wherein the bit-rate indicator is used to adjust a transmit bit rate at which a second portion of the transport stream is provided.

2. The method as in claim 1, wherein the transport stream format includes a data signal and a clock signal.

3. The method as in claim 1, wherein the bit-rate indicator is based on an amount of the representation of the first data which has been received by the transport stream handler.

4. The method as in claim 1, wherein the bit-rate indicator is based on the fullness of a data FIFO (First In First Out) memory associated with the transport stream handler.

5. A method comprising the steps of:

reading data from a file;

setting a transmit bit-rate to a first bit-rate;

sending a transport stream based on the data to a demultiplexer at the transmit bit rate;

determining a number of transmitted bits between two program clocks referenced in a common program stream, wherein the program clock references are read from the transport stream;

determine a desired elapsed time between the two program clock;

determining a desired bit-rate based on the desired elapsed time and the number of transmitted bits; and

setting the transmit bit-rate to the desired bit-rate.

6. The method as in claim 5, wherein the transmit bit-rate is determined by calculating an average number of bits associated with the transport stream sent to the demultiplexer per unit time.

7. The method as in claim 5, wherein the common program stream is determined by parsing program stream information tables to determine a program identifier of a particular program stream.

8. The method as in claim 5, wherein the common program stream is determined by parsing program map tables to determine a program identifier of a particular program stream.

9. The method as in claim 5, wherein the step of setting the transmit bit-rate to the desired bit-rate includes indicating that transmission of a portion of the transport stream should be delayed.

10. A method comprising the steps of:

determining a desired bit-rate of a received transport stream;

determining a current bit-rate of the received transport stream;

determining a throttle amount based on the desired bit-rate and the current bit-rate; and

providing an indicator requesting the throttle amount.

11. The method as in claim 10, wherein the desired bit-rate is based on calculating a desired elapsed time between consecutive program clock references included in the received transport stream.

12. The method as in claim 10, wherein the throttle amount includes an amount of time to wait before transmitting a portion of the transport stream.

13. The method as in claim 10, wherein the throttle includes an amount of data to hold to alter the current bit-rate.

14. The method as in claim 10, wherein the desired bit-rate and the current bit-rate indicate a number of bits per millisecond.

15. The method as in claim 10, wherein the desired bit-rate and the current bit-rate indicate a number of bits per microsecond.

16. The method as in claim 10, wherein the indicator includes a providing a signal via hardware signal.

17. The method as in claim 16, wherein the signal is used to apply a value to a particular register.

18. The method as in claim 16, wherein the signal includes an interrupt.

19. The method as in claim 10, wherein the indicator includes a software signal.

20. The method as in claim 10, wherein the step of providing the indicator is only performed when a difference between the desired bit-rate and the current bit-rate is greater than a predetermined value.

21. The method as in claim 10, further including the steps of:

determining if the throttle time is larger than a threshold;

reading new data from a file when the time is larger than the threshold; and

determining a new desired bit-rate based on the new data, when the time is larger than the threshold.

22. A method comprising the steps of:

receiving data from a multimedia stream at a buffer;

determining a fullness of the buffer; and

providing an indicator to request a transmitting source to reduce a data rate of the multimedia stream when the fullness is greater than a predetermined amount.

23. The method as in claim 22, wherein the buffer includes a first-in-first-out memory array.

24. The method as in claim 22, wherein the data is related to video data.

25. The method as in claim 22, wherein the data is related to audio data.

26. The method as in claim 22, wherein reducing the data rate of the multimedia stream includes suspending transmission of a portion of the multimedia stream.

28. The method as in claim 27, wherein the transport stream portion includes an indicator for selecting between parallel and serial transmission of the representation of the transport stream.

30. The method as in claim 29, wherein the desired bit-rate is determined based on an amount of data between consecutive program clock references within the received transport stream.

31. The method as in claim 29, wherein the throttle amount is an amount of time to suspend a transmission of the received transport stream.

27. A system comprising:

a data processor having an I/O buffer;

a memory having an I/O buffer coupled to the I/O buffer of the data processor, the memory capable of storing code to control said data processor to;

read data related to a transport stream from a file;

a multimedia port including;

a buss to provide data and an address to communicate with a first external device;

a set of general purpose I/O lines for communicating with a second external device;

a TVO transmit portion to transmit TVO data; and

a transport stream transmit portion to transmit a representation of the transport stream.

29. A computer readable medium tangibly embodying a program of instructions to manipulate a data processor to:

determine a desired bit-rate of a received transport stream;

determine a current bit-rate of the received transport stream;

determine a throttle amount based on the desired bit-rate and the current bit-rate; and

provide an indicator requesting the throttle amount.

32. A system comprising:

a means to determine a desired bit-rate of a received transport stream;

a means to determine a current bit-rate of the received transport stream;

a means to determine a throttle amount based on the desired bit-rate and the current bit-rate; and

a means to provide an indicator requesting the throttle time.

33. A system comprising:

a means to receive data from a multimedia stream at a buffer;

a means to determine a fullness of the buffer; and

a means to provide an indicator to request a transmitting source to reduce a data rate of the multimedia stream when the fullness is greater than a predetermined amount.