Method and system for encoding video with overlay

Patent metadata

Field	Value
Publication number	US-2020007883-A1
Application number	US-201916452431-A
Country	US
Kind code	A1
Filing date	Jun 25, 2019
Priority date	Jul 2, 2018
Publication date	Jan 2, 2020
Grant date	—

Abstract

Encoding video data comprises receiving an image sequence comprising first and second input image frames, adding an overlay, thereby generating first and second generated image frames, and encoding a video stream containing output image frames with and without overlay. The first input image frame is encoded as an intra-frame to form a first output image frame. The second input image frame is encoded as an inter-frame with reference to the first output image frame to form a second output image frame. The generated image frames are encoded as inter-frames with reference to the first and second output image frames to form first and second overlaid output image frames. A first part of the second generated image frame is encoded with reference to the first overlaid output image frame, and a second part of the second generated image frame is encoded with reference to the second output image frame.

First claim

1 . A method of encoding video data, comprising:
receiving an image sequence comprising a first input image frame and a second input image frame, receiving an overlay to be applied to the image sequence, the overlay comprising a picture element and spatial coordinates for positioning the picture element in the first and second input image frames, adding the picture element to the first and second input image frames in accordance with the spatial coordinates, thereby generating an overlaid image sequence comprising a first generated image frame and a second generated image frame, encoding a video stream containing output image frames without overlay and corresponding output image frames with overlay, wherein: the first input image frame is encoded as an intra-frame to form a first output image frame, the second input image frame is encoded as an inter-frame with reference to the first output image frame to form a second output image frame, the first generated image frame is encoded as an inter-frame with reference to the first output image frame to form a first overlaid output image frame, the second generated image frame is encoded as an inter-frame to form a second overlaid output image frame, wherein a first part of the second generated image frame is encoded with reference to the first overlaid output image frame, and a second part of the second generated image frame is encoded with reference to the second output image frame.

2 . The method according to claim 1 , wherein the first output image frame and the second output image frame are each encoded with a non-display indicator.

3 . The method according to claim 1 , wherein the first part of the second generated frame contains at least a portion of the picture element.

4 . The method according to claim 1 , wherein the second part of the second generated frame is outside the spatial coordinates of the overlay.

5 . The method according to claim 1 , further comprising:
receiving an additional overlay to be applied to the image sequence, the additional overlay comprising an additional picture element and additional spatial coordinates for positioning the additional picture element in the first and second input image frames, adding the additional picture element to the first and second input image frames in accordance with the additional spatial coordinates, thereby generating an additional overlaid image sequence comprising a first additional generated image frame and a second additional generated image frame, wherein encoding a video stream containing output image frames without overlay and corresponding output image frames with overlay additionally comprises encoding corresponding output image frames with additional overlay, wherein: the first additional generated image frame is encoded as an inter-frame with reference to the first output image frame to form a first additional overlaid output image frame, the second additional generated image frame is encoded as an interframe to form a second additional overlaid output image frame, wherein a first part of the second additional generated image frame is encoded with reference to the first additional overlaid output image frame, and a second part of the second additional generated image frame is encoded with reference to the second output image frame.

6 . The method according to claim 5 , wherein the first part of the second additional generated frame contains at least a portion of the additional picture element.

7 . The method according to claim 1 , wherein the second part of the second additional generated frame is outside the additional spatial coordinates of the additional overlay.

8 . A video encoding system comprising:
an image receiver arranged to receive an image sequence comprising a first input image frame and a second input image frame, an overlay receiver arranged to receive an overlay to be applied to the image sequence, the overlay comprising a picture element and spatial coordinates for positioning the picture element in the first and second input image frames, an overlay applicator arranged to add the picture element to the first and second input image frames in accordance with the spatial coordinates, thereby generating an overlaid image sequence comprising a first generated image frame and a second generated image frame, an encoder arranged to encode a video stream containing output image frames without overlay and corresponding output image frames with overlay, wherein: the first input image frame is encoded as an intra-frame to form a first output image frame, the second input image frame is encoded as an inter-frame with reference to the first output image frame to form a second output image frame, the first generated image frame is encoded as an inter-frame with reference to the first output image frame to form a first overlaid output image frame, the second generated image frame is encoded as an inter-frame to form a second overlaid output image frame, wherein a first part of the second generated image frame is encoded with reference to the first overlaid output image frame, and a second part of the second generated image frame is encoded with reference to the second output image frame.

9 . The video encoding system according to claim 8 , wherein the encoder is arranged to encode both of the first output image frame and the first overlaid output image frame with a first picture order count, and to encode both of the second output image frame and the second overlaid output image frame with a second picture order count.

10 . The video encoding system according to claim 8 , wherein the encoder is arranged to encode each of the first output image frame and the second output image frame with a non-display indicator.

11 . The video encoding system according to claim 8 , wherein
the overlay receiver is additionally arranged to receive an additional overlay to be applied to the image sequence, the additional overlay comprising an additional picture element and additional spatial coordinates for positioning the additional picture element in the first and second input image frames, the overlay applicator is additionally arranged to add the additional picture element to the first and second input image frames in accordance with the additional spatial coordinates, thereby generating an additional overlaid image sequence comprising a first additional generated image frame and a second additional generated image frame, and the encoder is arranged to encode the video stream additionally containing corresponding output image frames with additional overlay, wherein: the first additional generated image frame is encoded as an inter-frame with reference to the first output image frame to form a first additional overlaid output image frame, the second additional generated image frame is encoded as an interframe to form a second additional overlaid output image frame, wherein a first part of the second additional generated image frame is encoded with reference to the first additional overlaid output image frame, and a second part of the second additional generated image frame is encoded with reference to the second output image frame.

12 . A video transmission system comprising an encoding system according to claim 8 and a decoding system, the decoding system comprising:
a video receiver arranged to receive the encoded video stream from the encoding system, and
a decoder arranged to decode the encoded video stream.

13 . The video transmission system according to claim 12 , wherein the decoder is arranged to decode the first and second output images with a non-display indicator.

14 . The video tra

Assignees

• Axis Ab

Inventors

• Toresson Alexander

Classifications

• H04N19/46 Primary

  Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) · CPC title

• H04N19/44

  Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder · CPC title

• H04N19/42

  characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation (H04N19/635 takes precedence) · CPC title

• H04N5/265

  Mixing · CPC title

• H04N19/177

  the unit being a group of pictures [GOP] · CPC title