Seamless forward-reverse video loops

Patent metadata

Field	Value
Publication number	US-10176845-B2
Application number	US-201715678497-A
Country	US
Kind code	B2
Filing date	Aug 16, 2017
Priority date	Sep 23, 2016
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

Techniques and devices for creating a Forward-Reverse Loop output video and other output video variations. A pipeline may include obtaining input video and determining a start frame within the input video and a frame length parameter based on a temporal discontinuity minimization. The selected start frame and the frame length parameter may provide a reversal point within the Forward-Reverse Loop output video. The Forward-Reverse Loop output video may include a forward segment that begins at the start frame and ends at the reversal point and a reverse segment that starts after the reversal point and plays back one or more frames in the forward segment in a reverse order. The pipeline for the generating Forward-Reverse Loop output video may be part of a shared resource architecture that generates other types of output video variations, such as AutoLoop output videos and Long Exposure output videos.

First claim

The invention claimed is:

1. A non-transitory computer-readable storage medium, on which are stored instructions that, when executed, cause a programmable control device to:
obtain a video;
determine a start frame within the video, a frame length parameter, and a reversal point for a video loop based on a temporal discontinuity minimization for the video, wherein the temporal discontinuity minimization is based on frame differences between expected frames that playback after the reversal point according to the video and actual frames that playback after the reversal point according to a reverse segment of the video loop; and
generate the video loop based on the start frame, frame length parameter, and the reversal point, wherein the video loop includes:
a forward segment that begins at the start frame and ends at the reversal point; and
a reverse segment that starts after the reversal point and plays back one or more frames in the forward segment in a reverse order.

2. The non-transitory computer-readable storage medium of claim 1 , wherein the instructions, when executed, further cause the programmable control device to apply a frame-time normalization on a stabilized video to enforce a constant frame rate on the video.

3. The non-transitory computer-readable storage medium of claim 2 , wherein the instructions to apply a frame-time normalization comprise instructions that, when executed, cause the programmable control device to perform a linear blend for one or more gaps within the stabilized video.

4. The non-transitory computer-readable storage medium of claim 1 , wherein the instructions, when executed, further cause the programmable control device to:
read each frame within the forward segment into a memory;
write each of the frames within the forward segment from the memory to an output file for play back; and
delete each of the frames from the memory after writing each of the frames to the output file.

5. The non-transitory computer-readable storage medium of claim 4 , wherein the instructions, when executed, further cause the programmable control device to:
read, in a forward order, a chunk of frames within the reverse segment into the memory;
write, in the reverse order, each frame within the chunk of frames from the memory to the output file for playback; and
delete each frame within the chunk of frames from the memory after writing each frame within the chunk of frames to the output file for playback.

6. The non-transitory computer-readable storage medium of claim 1 , wherein the temporal discontinuity minimization is further based on frame differences between actual frames that playback after the start frame according to the forward segment and expected frames that playback before the start frame according to the video.

7. The non-transitory computer-readable storage medium of claim 1 , wherein the temporal discontinuity minimization includes a buffer length parameter that indicates the number of expected frames to compare with the actual frames after the reversal point.

8. The non-transitory computer-readable storage medium of claim 1 , wherein the instructions, when executed, further cause the programmable control device to perform playback of the video loop in real-time based on a media framework.

9. The non-transitory computer-readable storage medium of claim 1 , wherein the video loop does not include a crossfade at the reversal point.

10. A computer-implemented method for generating a video loop of frames, comprising:
obtaining a video;
determining a start frame within the video, a frame length parameter, and a reversal point for a video loop based on a temporal discontinuity minimization for the video, wherein the temporal discontinuity minimization is based on frame differences between expected frames that playback after the reversal point according to the video and actual frames that playback after the reversal point according to a reverse segment of the video loop; and
generating the video loop based on the start frame, frame length parameter, and the reversal point, wherein the video loop includes:
a forward segment that begins at the start frame and ends at the reversal point; and
a reverse segment that starts after the reversal point and plays back one or more frames in the forward segment in a reverse order.

11. The computer-implemented method of claim 10 , further comprising applying a frame-time normalization on a stabilized video to enforce a constant frame rate on the video.

12. The computer-implemented method of claim 11 , wherein applying a frame-time normalization comprises performing a linear blend for one or more gaps within the stabilized video.

13. The computer-implemented method of claim 10 , further comprises rendering a video loop that includes reading each frame within the forward segment into a memory;
writing each of the frames within the forward segment from the memory to an output file; and
deleting each of the frames from the memory after writing each of the frames to the output file.

14. The computer-implemented method of claim 13 , wherein rendering a video loop further comprises:
reading, in a forward order, a chunk of frames within the reverse segment into the memory;
writing, in the reverse order, each frame within the chunk of frames from the memory to the output file; and
deleting each of the frames within the chunk of frames from the memory after writing each frame within the chunk of frames to the output file.

15. The computer-implemented method of claim 11 , wherein the temporal discontinuity minimization is further based on the frame differences between actual frames that playback after the start frame according to the forward segment and expected frames that playback before the start frame according to the video.

16. An electronic device comprising:
an image sensor,
a memory comprising instructions stored thereon and operatively coupled to the image sensor, and
one or more processors operatively coupled to the memory and the image sensor, wherein instructions cause the one or more processors to:
obtain a video captured by the image sensor;
determine a start frame within the video, a frame length parameter, and a reversal point for a video loop based on a temporal discontinuity minimization for the video, wherein the temporal discontinuity minimization is based on frame differences between expected frames that playback after the reversal point according to the video and actual frames that playback after the reversal point according to a reverse segment of the video loop; and
generate the video loop based on the start frame, frame length parameter, and the reversal point, wherein the video loop includes:
a forward segment that begins at the start frame and ends at the reversal point; and
a reverse segment that starts after the reversal point and plays back one or more frames in the forward segment in a reverse order.

17. The electronic device of claim 16 , wherein the memory further comprises instructions to cause the one or more processors to apply a frame-time normalization on the video to enforce a constant frame rate prior to determining the start frame, the frame length parameter, and the reversal point.

18. The electronic device of claim 16 , wherein the temporal discontinuity minimization is based on frame differences between actual frames that playback after the start frame according to the forward segment and expected frames that playback before the start frame according to the video.

19. The electronic device of claim 16 , wherein th

Assignees

• Apple Inc

Inventors

• Bradley Arwen V
• Klivington Jason
• Van Der Merwe Rudolph
• Mitchell Douglas P
• Hoffnung Amir
• Manzari Behkish J
• Mezak Charles A
• Stauber Matan
• Margolin Ran
• Guerard Etienne
• Stanczyk Piotr

Classifications

• G11B27/034 Primary

  on discs (G11B27/036, G11B27/038 take precedence) · CPC title

• G09G2340/10

  Mixing of images, i.e. displayed pixel being the result of an operation, e.g. adding, on the corresponding input pixels · CPC title

• G09G5/377

  for mixing or overlaying two or more graphic patterns (G09G5/02, G09G5/397 take precedence) · CPC title

• G11B27/007

  reproducing continuously a part of the information, i.e. repeating · CPC title