L-CUT STREAM STARTUP

• US 20120281965A1
• Filed: 05/02/2011
• Published: 11/08/2012
• Est. Priority Date: 05/02/2011
• Status: Active Grant

• Current Assignee: Netflix, Inc.
• Original Assignee: Netflix, Inc.
• Inventors: HUNT, Neil D., KAISER, Christian
• Granted Patent: US 8,682,139 B2
• Time in Patent Office: Days
• US Class Current: 386/241
• CPC Class Codes: G11B 27/10 Indexing; Addressing; Timing or synchronising; Measuring tape travel
• CPC Class Codes: H04N 5/76 Television signal recording
• CPC Class Codes: H04N 5/772 the recording apparatus and the television camera being placed in the same enclosure
• CPC Class Codes: H04N 9/8205 involving the multiplexing of an additional signal and the colour video signal

Abstract

One embodiment of the present invention sets forth a technique for starting playback of an audio portion of digital media content before a video portion of the digital media content is received. An advantage of the disclosed technique is that the perceived delay from the time when a user selects the digital media content to when playback of the digital media content begins is reduced. The audio may be faded-in and one or more still frames of video data may be displayed while the video stream is retrieved. Additionally, a license for DRM (Digital Rights Management) encryption of the title content may be retrieved before starting playback of the video stream, so that the digital media content that is retrieved is also protected.

Claims

1. A method for playback of an audio stream before synchronized playback of the audio stream with a video stream, the method comprising:

receiving, when playback of digital media content is initiated, an audio playback point within the digital media content including the audio stream and the video stream which are each encoded as a sequence of intervals;

retrieving a first interval of the audio stream beginning at the audio playback point;

initiating retrieval of one or more additional intervals of the audio stream that are subsequent to the first interval;

playing the first interval of the audio stream without yet playing any interval of the video stream;

determining a video start transfer point that occurs subsequent to the audio playback point; and

initiating retrieval of the video stream beginning at the video start transfer point.

2. The method of claim 1, further comprising:

determining that the audio stream and the video stream can be played synchronously; and

synchronously playing the audio stream and the video stream.

3. The method of claim 1, wherein the first interval of the audio stream comprises a modulated version of an original audio stream.

4. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause a computer system to play an audio stream before beginning synchronized playback of the audio stream with a video stream, by performing the steps of:

receiving, when playback of digital media content is initiated, an audio playback point within the digital media content including the audio stream and the video stream which are each encoded as a sequence of intervals;

retrieving a first interval of the audio stream beginning at the audio playback point;

initiating retrieval of one or more additional intervals of the audio stream that are subsequent to the first interval;

playing the first interval of the audio stream without yet playing any interval of the video stream;

determining a video start transfer point that occurs subsequent to the audio playback point; and

initiating retrieval of the video stream beginning at the video start transfer point.

5. The non-transitory computer-readable storage medium of claim 4, further comprising:

determining that the audio stream and the video stream can be played synchronously; and

synchronously playing the audio stream and the video stream.

6. The non-transitory computer-readable storage medium of claim 5, wherein determining that the audio stream and the video stream can be played synchronously comprises determining that a decoded interval of video corresponding to a next interval of the video stream is available for playback at the start of the next interval.

7. The non-transitory computer-readable storage medium of claim 4, wherein one or more intervals of the video stream are retrieved in reverse order beginning at the video start transfer point and progressing towards the audio playback point.

8. The non-transitory computer-readable storage medium of claim 7, further comprising:

determining that the audio stream and the video stream may be synchronized;

synchronously playing the audio stream and the video stream; and

in response, retrieving one or more intervals of the video stream in forward order beginning at the video start transfer point and progressing away from the audio playback point.

9. The non-transitory computer-readable storage medium of claim 4, further comprising determining an interval boundary closest to a selected playback location in the audio stream as the audio playback point.

10. The non-transitory computer-readable storage medium of claim 4, wherein the first interval of the audio stream comprises a modulated version of an original audio stream.

11. The non-transitory computer-readable storage medium of claim 4, wherein the video start transfer point is computed as the sum of the audio playback point and a duration in time of one or more intervals of the video stream.

12. The non-transitory computer-readable storage medium of claim 4, wherein intervals of the video stream are retrieved in forward order beginning at the video start transfer point and progressing away from the audio playback point.

13. The non-transitory computer-readable storage medium of claim 4, wherein the audio stream comprises a fade-in audio stream that is generated as a version of an original audio stream that starts at a low volume level and increases the volume level across the first interval of the audio stream.

14. The non-transitory computer-readable storage medium of claim 4, further comprising displaying a still video frame while playing the first interval of the audio stream.

15. The non-transitory computer-readable storage medium of claim 4, wherein the audio stream is precomputed.

16. The non-transitory computer-readable storage medium of claim 4, wherein the audio stream is generated in real-time.

17. A system for playing an audio stream before beginning synchronized playback of the audio stream with a video stream, the system comprising:

a network interface that is coupled to a communications network and configured to receive digital media content;

a memory configured to store a playback application; and

a processor that is coupled to the memory and configured to execute the playback application that is configured to;

receive=, when playback of digital media content is initiated, an audio playback point within the digital media content including the audio stream and the video stream which are each encoded as a sequence of intervals;

retrieve a first interval of the audio stream beginning at the audio playback point;

initiate retrieval of one or more additional intervals of the audio stream that are subsequent to the first interval;

play the first interval of the audio stream without yet playing any interval of the video stream;

determine a video start transfer point that occurs subsequent to the audio playback point; and

initiate retrieval of the video stream beginning at the video start transfer point.

18. The system of claim 17, wherein the playback application is further configured to:

determine that the audio stream and the video stream can be played synchronously; and

synchronously play the audio stream and the video stream.

19. The system of claim 17, wherein the first interval of the audio stream comprises a modulated version of an original audio stream.

20. The system of claim 17, wherein one or more intervals of the video stream are retrieved in reverse order beginning at the video start transfer point and progressing towards the audio playback point.