Streaming of variable bit rate multimedia content

• US 7,391,717 B2
• Filed: 06/30/2003
• Issued: 06/24/2008
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Klemets, Anders E., Chou, Philip A., Weiss, Rebecca C., Ribas-Corbera, Jordi
• Primary Examiner(s): Wilson; Robert W
• Application Number:
  US10/611,115
• Publication Number:
  US 20040264489A1
• Time in Patent Office: 1,821 Days
• Field of Search: None
• US Class Current: 370/216
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 67/61 taking into account QoS or priority requirements
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Systems and methods for improved streaming of variable bit rate multimedia content are described. The described systems and methods solve some streaming problems by streaming the variable bit rate content at a constant bit rate that is negotiated between a server and a client. As a result, a transmission channel from server to client is utilized in an efficient manner. If the client is able to buffer the streamed content (to a hard drive, for example) the content can be streamed at a rate that is significantly less than its peak bit rate, even at a rate that is less than its average bit rate.

Claims

1. A method, comprising:

encoding multimedia data for processing, said multimedia data including at least one data stream;

storing the encoded multimedia data in a data file for streaming to one or more clients;

selecting at least two possible bit rate values at which the data file may be streamed;

calculating a client buffer size value for each possible bit rate value, each client buffer size value being a client buffer size for the possible bit rate value corresponding to the client buffer size value;

for each data stream, calculating an average bit rate value, a peak bit rate value, an average buffer size value corresponding to the average bit rate value and a peak buffer size value corresponding to the peak bit rate value;

storing the bit rate values and the buffer size values in the data file; and

wherein the bit rate values and the buffer size values can be used to determine an optimal client buffer size for a client receiving the multimedia data at a particular constant bit rate.

2. The method as recited in claim 1, wherein the one or more data streams further comprise at least one audio stream and one video stream.

3. The method as recited in claim 1, further comprising setting a variable bit rate flag in the data file if the encoded multimedia data in the data file contains variable bit rate data.

4. The method as recited in claim 1, wherein the average bit rate value, the peak bit rate value, the average buffer size value and the peak buffer size value are approximations.

5. The method as recited in claim 1, wherein the data file is an Advance System Format (ASF) file.

6. The method as recited in claim 1, wherein the calculating the bit rate values and the buffer size values further comprises using a leaky bucket method to calculate the bit rate values and the buffer size values.

7. The method as recited in claim 1, further comprising transmitting at least a portion of the data file to a client.

8. The method as recited in claim 7, wherein the transmitting at least a portion of the data file further comprises transmitting at least a portion of the data file that includes the buffer size values and the bit rate values.

9. A system, comprising:

one or more processors;

a compression module comprising computer-executable instructions encoded on one or more computer-readable storage media that when executed on the one or more processors, compress multimedia data for streaming to one or more clients by encoding the multimedia data into a streaming format and storing the encoded multimedia data in a data file;

a buffer size calculation module comprising computer-executable instructions encoded on one or more computer-readable storage e media that when executed on the one or more processors;

select one or more possible bit rates at which the data file may be streamed to the one or more clients and to calculate a client buffer size corresponding to each possible bit rate,

calculate for each of the one or more streams included in the data file a first buffers size value and a second buffer size value that correspond, respectively, to a first bit rate value and a second bit rate value associated with the stream;

store the bit rate values and the corresponding buffer size values in the data file; and

wherein the one or more clients can utilize the bit rate values and the buffer size values to calculate an optimal client buffer size for receiving the data file at a particular bit rate.

10. The system as recited in claim 9, wherein the one or more streams further comprise at least one audio stream and at least one video stream.

11. The system as recited in claim 9, further comprising a variable bit rate module comprising computer-executable instructions encoded on one or more computer-readable storage media that, when executed on the one or more processors set a variable bit rate flag in the data file if the data file contains variable bit rate data.

12. The system as recited in claim 9, wherein the data file is an Advance System Format file.

13. The system as recited in claim 9, wherein the buffer size calculation module is configured to calculate the bit rate values and the buffer values using a leaky bucket interpolation method.

14. The system as recited in claim 9, further comprising a content buffer comprising computer-executable instructions encoded on one or more computer-readable storage media that, when executed on the one or more processors, store a portion of the data file as a previously stored portion of the data file is streamed to the one or more clients.

15. One or more computer-readable storage media containing computer-executable instructions that, when executed on a computer, perform the following steps:

selecting one or more possible bit rate values that each denote a bit rate at which a multimedia data file can be streamed to at least a client;

calculating a client buffer size for each possible bit rate value;

determining a first buffer size for a first bit rate associated with each of one or more streams in the multimedia data file;

determining a second buffer size for a second bit rate associated with each of one or more streams in the multimedia data file;

storing the buffer values and the bit rate values in a location associated with the multimedia data file; and

wherein the bit rate values and the buffer vales can be used by a client to determine an optimal streaming rate at which to receive the multimedia data file, and to calculate an optimal buffer size associated with the streaming bit rate.

16. The one or more computer-readable storage media recited in claim 15, further comprising computer executable instructions that, when executed on a computer, perform the step of creating the multimedia data file by encoding multimedia data.

17. The one or more computer-readable storage media recited in claim 15, wherein the first bit rate is less than the second bit rate.

18. The one or more computer-readable storage media recited in claim 15, wherein the first bit rate is an approximate average bit rate and the second bit rate is an approximate peak bit rate.

19. The one or more computer-readable storage media recited in claim 15, wherein the multimedia data file includes at least one audio stream and at least one video stream.

20. The one or more computer-readable storage media recited in claim 15, further comprising computer executable instructions that, when executed on a computer, perform the step of providing an indication in the multimedia data file that the multimedia data file contains a variable bit rate data if the multimedia data file contains variable bit rate data.

21. The one or more computer-readable storage media recited in claim 15, wherein the multimedia data file further comprises a file in ASF format.

22. The one or more computer-readable storage media recited in claim 15, wherein the determination steps are accomplished using a leaky bucket method.

23. The one or more computer-readable storage media recited in claim 15, further comprising computer executable instructions that, when executed on a computer, perform the step of streaming client-selected streams of the multimedia data file to the client.