Fast start-up for digital video streams

• US 7,636,934 B2
• Filed: 12/05/2005
• Issued: 12/22/2009
• Est. Priority Date: 06/13/2003
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Baldwin, James Armand, Green, Dustin L., Grossman, John H. IV
• Primary Examiner(s): Kelley; Christopher
• Assistant Examiner(s): HOSSAIN, FARZANA E
• Application Number:
  US11/275,047
• Publication Number:
  US 20060117359A1
• Time in Patent Office: 1,478 Days
• Field of Search: 725/101, 725/86
• US Class Current: 725/101
• CPC Class Codes: H04N 21/21 Server components or server architectures
• CPC Class Codes: H04N 21/23 Processing of content or additional data; Elementary server operations; Server middleware
• CPC Class Codes: H04N 21/23424 involving splicing one content stream with another content stream, e.g. for inserting or substituting an advertisement
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/2389 Multiplex stream processing, e.g. multiplex stream encrypting
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/4331 Caching operations, e.g. of an advertisement for later insertion during playback
• CPC Class Codes: H04N 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
• CPC Class Codes: H04N 21/4385 Multiplex stream processing, e.g. multiplex stream decrypting
• CPC Class Codes: H04N 21/44016 involving splicing one content stream with another content stream, e.g. for substituting a video clip
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18
• CPC Class Codes: H04N 21/8455 involving pointers to the content, e.g. pointers to the I-frames of the video stream

Abstract

Described herein is a technology facilitating the presentation of digital video streams. An implementation, described herein, reduces the effective start-up delay in the presentation of the first frames of the video content that occurs when a system tunes into a video stream. This abstract itself is not intended to limit the scope of this patent. The scope of the present invention is pointed out in the appending claims.

Claims

1. A computer storage medium having computer-executable instructions that, when executed by a computer, perform a method comprising:

selecting a lead-in video stream, wherein the lead-in stream corresponds to a portion of a particular main video-stream transmission, the portion of the particular main video-stream transmission being encoded at a first bit-rate, the selected lead-in video-stream transmission being encoded at a second bit-rate, wherein the second bit-rate represents a lower number of bits per frame than a number of bits per frame represented by the first bit-rate, wherein the lead-in video stream is scheduled for transmission during the scheduled transmission of the portion of the particular main video-stream transmission, wherein the second bit-rate is determined by a function based at least in part on a request time and a next access point transmission time, the request time corresponding to a request to receive the particular main video-stream transmission, the next access point transmission time corresponding to transmission of a next access point in the particular main video-stream following the request time, wherein if a first difference between a first request time and the next access point transmission time is less than a second difference between a second request time and the next access point transmission time, a first calculated bit-rate associated with the first difference is smaller than a second calculated bit-rate associated with the second difference;

receiving the selected lead-in video-stream transmission;

presenting content of the selected lead-in video stream transmission;

switching reception from the lead-in to the main video-stream transmission;

switching presentation from the content of the lead-in to the content of the main video-stream transmission.

2. A medium as recited in claim 1, wherein the selected lead-in video stream of the selecting is chosen from one of multiple lead-in video streams.

3. A medium as recited in claim 1, wherein the switching occurs on or about the occurrence of an access point transmitted in the main video-stream transmission.

4. A medium as recited in claim 1, wherein the switching occurs just before the occurrence of an access point transmitted in the main video-stream transmission.

5. A medium as recited in claim 1, wherein the access point of each of the multiple lead-in video-stream transmissions are scheduled for phase-staggered transmission relative to each other.

6. A medium as recited in claim 1, wherein the video-stream transmissions are multicast.

7. A medium as recited in claim 1, wherein an available access point is an anchor frame.

8. A computer storage medium having computer-executable instructions that, when executed by a computer, perform a method comprising:

choosing a particular main video-stream transmission for reception and presentation;

before the transmission of the next access point transmitted in the main video-stream transmission, temporarily receiving a lead-in video stream that corresponds to the particular main video-stream transmission, the particular main video-stream transmission being encoded at a first bit-rate, the lead-in video-stream being encoded at a second bit-rate, wherein the second bit-rate represents a lower number of bits per frame than a number of bits per frame represented by the first bit-rate, wherein the second bit-rate is determined by a function based at least in part on a request time and a next access point transmission time, the request time corresponding to choosing the particular main video-stream transmission, the next access point transmission time corresponding to transmission of the next access point transmitted in the main video-stream transmission following the request time, wherein if a first difference between a first request time and the next access point transmission time is less than a second difference between a second request time and the next access point transmission time, a first calculated bit-rate associated with the first difference is smaller than a second calculated bit-rate associated with the second difference;

switching reception from the lead-in to the main video-stream transmission.

9. A medium as recited in claim 8 further comprising

presenting content of the lead-in video stream transmission;

after switching reception to the main video-stream, presenting the content of the main video-stream transmission.

10. A medium as recited in claim 8, wherein the switching is performed on or about the transmission of an access point in the main video-stream transmission.

11. A medium as recited in claim 8, wherein the switching is performed on or about the transmission of the next access point to occur during the main video-stream transmission.

12. A medium as recited in claim 8, wherein the video-stream transmissions are multicast.

13. A medium as recited in claim 8, wherein an available access point is an anchor frame.

14. A medium as recited in claim 8 further comprising:

selecting one of multiple lead-in video-stream transmissions for reception, where each lead-in stream corresponds to a particular main video-stream transmission, wherein the one lead-in transmission selected is the lead-in transmission that is temporarily received;

presenting content of the selected lead-in video stream transmission;

switching reception from the lead-in to the main video-stream transmission and doing so on or about the occurrence of an access point transmitted in the main video-stream transmission;

switching presentation from the content of the lead-in to the content of the main video-stream transmission.

15. A medium as recited in claim 14, wherein the access point of each of the multiple lead-in video-stream transmissions are scheduled for phase-staggered transmission relative to each other.

16. A computer storage medium having computer-executable instructions that, when executed by a computer, perform a method comprising:

preparing multiple video-streams based upon the same original video content for an overlapping transmission schedule so that the access point of each is phase-staggered, wherein a bit-rate is determined for each of the multiple video streams based at least in part on a set of request times and a next access point transmission time, the set of request times corresponding to times at which if a request for a main video-stream transmission occurs, the corresponding one of the multiple video-streams is transmitted, the next access point transmission time corresponding to transmission of the next access point transmitted in the main video-stream transmission following the set of request times, wherein a smaller difference between the set of request times and the next access point transmission time corresponds to a smaller bit-rate, the multiple video-streams being lead-in video streams corresponding to a portion of the main video-stream;

transmitting one of more of the multiple video-streams over a communications network in accordance with the overlapping transmission schedule.

17. A medium as recited in claim 16, wherein the transmission of the group-of-pictures (GOP) of each of the multiple streams ends on or about the same point in the transmission schedule.

18. A medium as recited in claim 16, wherein the multiple video-streams comprise a main stream and a lead-in stream.