Script-based video rendering using alpha-blended images

• US 9,143,826 B2
• Filed: 05/30/2012
• Issued: 09/22/2015
• Est. Priority Date: 08/16/2011
• Status: Active Grant

• Current Assignee: Destiny Software Productions Incorporated (Destiny Media Technologies Incorporated)
• Original Assignee: Che-Wai Tsui, Shaoning Tu, Steven Erik Vestergaard
• Inventors: Vestergaard, Steven Erik, Tsui, Che-Wai, Tu, Shaoning
• Primary Examiner(s): Paula, Cesar
• Assistant Examiner(s): NGUYEN, LUU-PHUONG T
• Application Number:
  US13/484,064
• Publication Number:
  US 20130047074A1
• Time in Patent Office: 1,210 Days
• Field of Search: 715/234
• US Class Current: 1/1
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G06F 9/445 Program loading or initiating bootstrapping G06F9/4401; security arrangements for program loading or initiating G06F21/57
• CPC Class Codes: G11B 27/034 on discs G11B27/036, G11B27/038 take precedence
• CPC Class Codes: G11B 27/10 Indexing; Addressing; Timing or synchronising; Measuring tape travel
• CPC Class Codes: G11B 27/28 by using information signals recorded by the same method as the main recording G11B27/22 takes precedence
• CPC Class Codes: H04N 19/15 by monitoring actual compressed data size at the memory before deciding storage at the transmission buffer
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/436 using parallelised computational arrangements
• CPC Class Codes: H04N 19/587 involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence
• CPC Class Codes: H04N 21/234309 by transcoding between formats or standards, e.g. from MPEG-2 to MPEG-4 or from Quicktime to Realvideo conversion of standards in analog television systems H04N7/01
• CPC Class Codes: H04N 21/234381 by altering the temporal resolution, e.g. decreasing the frame rate by frame skipping
• CPC Class Codes: H04N 21/43072 of multiple content streams on the same device
• CPC Class Codes: H04N 21/4341 Demultiplexing of audio and video streams
• CPC Class Codes: H04N 21/44 Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer
• CPC Class Codes: H04N 21/440218 by transcoding between formats or standards, e.g. from MPEG-2 to MPEG-4 conversion of standards in analogue television systems H04N7/01
• CPC Class Codes: H04N 21/440281 by altering the temporal resolution, e.g. by frame skipping television signal recording using magnetic recording on tape for reproducing at a rate different from the recording rate H04N5/783
• CPC Class Codes: H04N 21/6125 involving transmission via Internet transmission by internet of broadcast information H04H60/82
• CPC Class Codes: H04N 21/8543 using a description language, e.g. Multimedia and Hypermedia information coding Expert Group [MHEG], eXtensible Markup Language [XML] information retrieval of semistructured data, the underlying structure being taken into account, e.g. mark-up language structure data G06F16/80
• CPC Class Codes: H04N 5/272 : Means for inserting a foreground image in a background image, i.e. inlay, outlay

Abstract

Systems and methods are provided for cross-platform rendering of video content on a user-computing platform that is one type of a plurality of different user-computing platform types. A script is transmitted to the user-computing platform and is interpreted by an application program compiled to operate on any one of the plurality of user-computing platform types. Transmitting the script causes the script to be interpreted by the application program operating on the user-computing platform to cause the interpreted script to directly decode encoded video data transmitted or otherwise accessible to the user-computing platform into decoded video data and to further cause the rendering of the decoded video data.

Claims

1. A method performed by a computer system for rendering video content on a user-computing platform that is one type of a plurality of different user-computing platform types, the method comprising:

transmitting a script to the user-computing platform, the script configured to be interpreted by an application program operating on any one of the plurality of user-computing platform types;

wherein transmitting the script causes the script to be interpreted by the application program operating on the user-computing platform to cause the interpreted script to directly decode encoded video data accessible to the user-computing platform into decoded video data comprising one or more frame images;

wherein transmitting the script causes the script to be interpreted by the application program to cause the interpreted script to directly decode encoded audio data accessible to the user-computing platform into decoded audio data;

wherein transmitting the script causes the script to be interpreted by the application program to;

natively render the decoded video data by displaying the one or more frame images on the user-computing platform; and

natively render the decoded audio data by playing back the decoded audio data;

wherein rendering the video data by displaying the one or more frame images comprises, at each of one or more times between displaying a first one of the frame images and displaying a second one of the frame images, displaying an alpha-blended image comprising an alpha-blend of the first one of the frame images and the second one of the frame images;

at each of the one or more times between displaying the first one of the frame images and displaying the second one of the frame images, displaying the alpha-blended image comprises alpha-blending the second one of the frame images onto a preceding displayed image using an alpha-blending coefficient α

provided by;

α

=[β

+1−

mod(f#,β

)]<sup>−

1</sup>

where;

β

is a down-sampling factor equal to a number of the one or more times +1;

f# is an index referring to a number of a current one of the one or more times; and

mod(x,y) is a modulo operator which returns the whole number remainder of x divided by y.

2. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to natively display the one or more frame images on the user-computing platform.

3. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to:

render the decoded video data by displaying the one or more frame images on the user-computing platform; and

render the decoded audio data by playing back the decoded audio data on the user computing platform.

4. A method according to claim 3 wherein transmitting the script causes the script to be interpreted by the application program to simulate a multi-threaded execution environment by iteratively scheduling and performing a method which, on each iteration makes one or more logical inquiries into one or more corresponding conditions and, in dependence on the one or more of the corresponding conditions, selects and performs one of:

a first simulated thread which comprises directly decoding the encoded video data into the frame images;

a second simulated thread which comprises rendering the video data by displaying the frame images;

a third simulated thread which comprises directly decoding the encoded audio data into the decoded audio data;

a fourth simulated thread which comprises implementing an audio renderer interface which provides the decoded audio data to an audio renderer.

5. A method according to claim 1 wherein the video data and audio data are associated with one another as parts of a video content item, the one or more frame images comprise a plurality of frame images and wherein transmitting the script causes the script to be interpreted by the application program to cause the interpreted script to directly synchronize the displaying of the frame images with the playback of the decoded audio data.

6. A method according to claim 1 wherein the video data and audio data are associated with one another as parts of a video content item, wherein the one or more frame images comprise a plurality of frame images and wherein transmitting the script causes the script to be interpreted by the application program to ascertain an audio playback time reference associated with the playback of the decoded audio data and causes the interpreted script to directly synchronize the displaying of the frame images with the playback of the decoded audio data based on the audio playback time reference.

7. A method according to claim 6 wherein synchronizing the displaying of the frame images with the playback of the decoded audio data comprises at least one of:

advancing the display of frame images out of order by skipping the display of one or more frame images based on a determination that the rendering of the video data is behind the audio playback time reference by a first threshold amount of time; and

causing one or more frame images to be displayed for time periods longer than those dictated by a frame rate of the video data based on a determination that the rendering of the video data is ahead of the audio playback time reference by a second threshold amount of time.

8. A method according to claim 6 wherein synchronizing the displaying of the frame images with the playback of the decoded audio data comprises:

using the audio playback time reference to determine a current frame index; and

if the frame image associated with the current frame index is ready to be displayed, displaying the frame image associated with the current frame index.

9. A method according to claim 8 wherein synchronizing the displaying of the frame images with the playback of the decoded audio data comprises determining that the frame image associated with the current frame index is behind one or more other frame images in a frame image queue and if so skipping the displaying of the one or more other frame images.

10. A method according to claim 8 wherein synchronizing the displaying of the frame images with the playback of the decoded audio data comprises determining that the frame image associated with the current frame index is not ready to be displayed and, in dependence on such determination, initiating a drop frame action, the drop frame action comprising one or more of:

recording an indication that the frame image associated with the current frame index was not ready for rendering;

causing the playback of decoded audio data to be paused or slowed;

causing a rate of decoding of the encoded video data to be increased;

causing a switch to video data having a lower frame rate;

causing a switch to effective down-sampling of the video data by decoding a subset of the image frames.

11. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to simulate a multi-threaded execution environment by:

iteratively scheduling and performing a first simulated thread which comprises directly decoding the encoded video data into the frame images; and

iteratively scheduling and performing a second simulated thread which comprises rendering the video data by displaying the frame images.

12. A method according to claim 11 wherein transmitting the script causes the script to be interpreted by the application program to simulate a multi-threaded execution environment by:

iteratively scheduling and performing a third simulated thread which comprises directly decoding the encoded audio data into the decoded audio data; and

iteratively scheduling and performing a fourth simulated thread which comprises implementing an audio renderer interface which supplies decoded audio data to an audio renderer.

13. A method according to claim 11 wherein performing the first simulated thread comprises:

dividing the first simulated thread into a plurality of sub-components;

between the performance of pairs of sub-components, making one or more logical inquiries into one or more corresponding conditions and, in dependence on the one or more corresponding conditions, temporarily interrupting the first simulated thread to select and perform an iteration of one of;

the second simulated thread; and

another simulated thread which involves implementing an audio renderer interface which provides decoded audio data to an audio renderer.

14. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to cause the interpreted script to directly implement at least a portion of a video data queue monitor which directly monitors a video data queue to determine its status and, in dependence on the determined status of the video data queue, determines whether to fetch more encoded video data.

15. A method according to claim 14 wherein transmitting the script causes the script to be interpreted by the application program to implement a second portion of the video queue monitor which fetches more encoded video data using an AJAX XMLHttpRequest object.

16. A method according to claim 14 wherein transmitting the script causes the script to be interpreted by the application program to implement a second portion of the video queue monitor which fetches more encoded video data by alternatingly using a plurality of AJAX XMLHttpRequest objects.

17. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to directly de-multiplex the video data from the audio data.

18. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to cause the interpreted script to directly implement a frame buffer monitor which monitors a frame image buffer to determine its status and, in dependence on the determined status of the frame image buffer, determines whether to decode more of the encoded video data.

19. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to cause the interpreted script to directly convert an image file format of at least one of the frame images from a first image file format into a second image file format, the second image file format capable of being natively rendered by the application program.

20. A method according to claim 1 comprising transmitting the encoded video data to the user-computing platform.

21. A method according to claim 20 comprising encoding the video content into the encoded video data prior to transmitting the encoded video data to the user-computing platform and wherein encoding the video content comprises:

converting an image file format of at least one of the frame images from a first image file format into a second image file format, the second image file format capable of being natively rendered by the application program operating on the user-computer platform.

22. A method according to claim 20 comprising encoding the video content into the encoded video data prior to transmitting the encoded video data to the user-computing platform and wherein encoding the video content comprises:

for at least a first one of the frame images provided in a first file format;

analyzing content of the first one of frame images;

selecting one among a plurality of secondary image file formats based on the analysis of the content of the first one of the frame images; and

if the first file format differs from the selected one of the secondary image file formats, converting the image file format of the first one of the frame images into the selected one of the secondary file formats; and

for at least a second one of frame images provided in a second file format;

analyzing content of the second one of frame images;

selecting a different one among the plurality of secondary image file formats based on the analysis of the content of the second one of the frame images; and

if the second file format differs from the selected different one of the secondary image file formats, converting the image file format of the first one of the frame images into the selected different one of the secondary file formats;

wherein each of the plurality of secondary image file formats is capable of being natively rendered by the application program.

23. A method according to claim 20 comprising encoding the video content into the encoded video data prior to transmitting the encoded video data to the user-computing platform and wherein encoding the video content comprises:

encoding at least one of the frame images in a content-transfer format whereby the content-transfer encoded frame images can be passed by a script interpreter interpreting the script to the application program.

24. A method according to claim 20 comprising encoding the video content into the encoded video data prior to transmitting the encoded video data to the user-computing platform and wherein encoding the video content comprises:

for each of the plurality of frame images;

encoding the frame image in a content-transfer format whereby the content-transfer encoded frame images can be passed by a script interpreter interpreting the script to the application program; and

padding the content-transfer encoded frame image to a particular size with padding data unrelated to the frame image.

25. A method according to claim 20 comprising encoding video content into the encoded video data prior to transmitting the encoded video data to the user-computing platform and wherein encoding the encoded video data comprises:

encoding at least one of the frame images in a base64 content-transfer format.

26. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to cause the interpreted script to directly convert at least one of the frame images into a content-transfer format, the content-transfer format capable of being passed by a script interpreter interpreting the script to the application program.

27. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to cause the interpreted script to directly convert at least one of the frame images into a base64 content-transfer format.

28. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to natively convert at least one of the frame images into a corresponding image object capable of being natively rendered by the application program.

29. A method according to claim 1 wherein the application program comprises an internet browser.

30. A method according to claim 1 wherein the script is embedded in a HTML document.

31. A method according to claim 1 wherein the one or more frame images comprise a plurality of frame images and wherein transmitting the script causes the script to be interpreted by the application program to:

render the audio data by playing back the decoded audio data; and

render the video data by selecting a subset of the plurality of frame images and displaying the selected subset of the plurality of frame images.

32. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to query one or more characteristics of the user-computing platform and to change a file comprising the encoded video data accessible to the user-computing platform in dependence on the one or more queried characteristics of the user-computing platform.

33. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to query one or more characteristics of the user-computing platform and, in dependence on the one or more queried characteristics of the user-computing platform, to modify at least one characteristic of one or more of:

the decoding of the encoded video data and the displaying of the one or more frame images.

34. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to determine a data rate at which the encoded video data is transmitted to the user-computing platform and to change a file comprising the encoded video data transmitted to the user-computing platform in dependence on the determination.

35. A method according to claim 1 wherein transmitting the script causes the script to be interpreted by the application program to determine a data rate at which the encoded video data is transmitted to the user-computing platform and, in dependence on the determination, to modify at least one characteristic of one or more of:

the decoding of the encoded video data and the displaying of the frame images.

36. A computer system comprising one or more computers operatively connected using a data communications network adapted to perform the method of claim 1.

37. A non-transitory computer-readable medium comprising computer executable code that, when executed by a computer system comprising one computer or a plurality of computers operatively connected using a data communications network, causes the computer system to perform the methods of claim 1.

38. A method executed on a user-computing platform for rendering video content, the method comprising:

receiving a script at the user-computing platform, the script configured to be interpreted by an application program operating on the user-computing platform;

interpreting the script using the application program on the computer platform;

wherein interpreting the script causes the interpreted script to directly decode encoded video data accessible to the user-computing platform into decoded video data comprising one or more frame images;

wherein interpreting the script causes the interpreted script to directly decode encoded audio data accessible to the user-computing platform into decoded audio data;

wherein interpreting the script causes the interpreted script to;

natively render the decoded video data by displaying the one or more frame images on the user-computing platform; and

natively render the decoded audio data by playing back the decoded audio data;

wherein rendering the video data by displaying one or more frame images comprises, at each of one or more times between displaying a first one of the frame images and displaying a second one of the frame images, displaying an alpha-blended image comprising an alpha-blend of the first one of the frame images and the second one of the frame images; and

at each of the one or more times between displaying the first one of the frame images and displaying the second one of the frame images, displaying the alpha-blended image comprises alpha-blending the second one of the frame images onto a preceding displayed image using an alpha-blending coefficient α

provided by;

α

=[β

+1−

mod(f#,β

)]<sup>−

1</sup>

where;

β

is a down-sampling factor equal to a number of the one or more times +1;

f# is an index referring to a number of a current one of the one or more times; and

mod(x,y) is a modulo operator which returns the whole number remainder of x divided by y.

39. A system for rendering video content on a user-computing platform that is one type of a plurality of different user-computing platform types, the system comprising:

a server computing device for transmitting a script to the user-computing platform, the script configured to be interpreted by an application program compiled to operate on any one of the plurality of user-computing platform types; and

wherein transmitting the script causes the script to be interpreted by the application program operating on the user-computing platform to cause the interpreted script to directly decode encoded video data accessible to the user-computing platform into decoded video data comprising one or more frame images;

wherein the transmitted script causes the script to be interpreted by the application program to cause the interpreted script to directly decode encoded audio data accessible to the user-computing platform into decoded audio data;

wherein the transmitted script causes the script to be interpreted by the application program to;

natively render the decoded video data by displaying the one or more frame images on the user-computing platform; and

natively render the decoded audio data by playing back the decoded audio data;

wherein rendering the video data by displaying the one or more frame images comprises, at each of one or more times between displaying a first one of the frame images and displaying a second one of the frame images, displaying an alpha-blended image comprising an alpha-blend of the first one of the frame images and the second one of the frame images; and

at each of the one or more times between displaying the first one of the frame images and displaying the second one of the frame images, displaying the alpha-blended image comprises alpha-blending the second one of the frame images onto a preceding displayed image using an alpha-blending coefficient α

provided by;

α

=[β

+1−

mod(f#,β

)]<sup>−

1</sup>

where;

β

is a down-sampling factor equal to a number of the one or more times +1;

f# is an index referring to a number of a current one of the one or more times; and

mod(x,y) is a modulo operator which returns the whole number remainder of x divided by y.

40. A system for rendering video content on a user-computer platform, the system comprising a processor configured to provide:

a decoding element for decoding encoded video data accessible to the user-computing platform into decoded video data comprising one or more frame images; and

wherein the processor is configured to provide the decoding element by executing an application program on the user-computing platform, the application program interpreting a cross-platform script which causes the interpreted script to directly decode the video data;

the application program interpreting the script to cause the interpreted script to directly decode encoded audio data accessible to the user-computing platform into decoded audio data;

the application program interpreting the script to;

natively render the decoded video data by displaying the one or more frame images on the user-computing platform; and

natively render the decoded audio data by playing back the decoded audio data;

wherein rendering the video data by displaying the one or more frame images comprises, at each of one or more times between displaying a first one of the frame images and displaying a second one of the frame images, displaying an alpha-blended image comprising an alpha-blend of the first one of the frame images and the second one of the frame images; and

at each of the one or more times between displaying the first one of the frame images and displaying the second one of the frame images, displaying the alpha-blended image comprises alpha-blending the second one of the frame images onto a preceding displayed image using an alpha-blending coefficient α

provided by;

α

=[β

+1−

mod(f#,β

)]<sup>−

1</sup>

where;

β

is a down-sampling factor equal to a number of the one or more times +1;

f# is an index referring to a number of a current one of the one or more times; and

mod(x,y) is a modulo operator which returns the whole number remainder of x divided by y.