Adaptive resolution transcoding for optimal visual quality

Patent metadata

Field	Value
Publication number	US-9615098-B1
Application number	US-62766009-A
Country	US
Kind code	B1
Filing date	Nov 30, 2009
Priority date	Nov 30, 2009
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

An adaptive resolution transcoding system and method adaptively transcodes a source video with an optimized resolution and visual quality based on the video coding complexity (VCC) of the source video. The transcoding system is configured to receive a source video in its native format, and to obtain the video coding complexity score of the source video from a video coding complexity engine. The transcoding system is further configured to set a resolution adjustment level based on the complexity score. Based on the resolution adjustment level, the transcoding system determines an optimal output resolution for the source video for each video output format supported by the transcoding system. Responsive to a user selection of video output format, the transcoding system determines an optimal output resolution for the source video and encodes the source video with the determined optimal output resolution.

First claim

What is claimed is:

1. A method for adaptively transcoding a source video of a video hosting service with an optimized resolution, the method comprising:
receiving the source video having a first video format and a first resolution;
encoding the source video into an intermediate video in an intermediate video format;
calculating a video coding complexity score of the source video based on spatial and temporal features of the encoded intermediate video, wherein the spatial and temporal features of the encoded intermediate video are normalized using a reference frame resolution and a reference frame rate, the reference frame resolution and the reference frame rate are independent from frame resolution and frame rate of the source video and target frame resolution and target frame rate of the source video, and the video coding complexity score represents a measure of complexity to encode the source video;
selecting a second resolution of the source video from a plurality of predetermined resolutions based on the video coding complexity score; and
encoding the source video into an output video having the selected second resolution and a predetermined video output format, wherein the second resolution is different from the first resolution, and the video output format is different from the first video format.

2. The method of claim 1 , wherein the intermediate video format is a H.263 video format.

3. The method of claim 1 , wherein determining the second resolution of the source video comprises setting a resolution adjustment level based on the video coding complexity score of the source video.

4. The method of claim 3 , wherein determining the second resolution of the source video further comprises mapping the resolution adjustment level to one of a plurality of predetermined resolutions.

5. A method for adaptively transcoding a source video of a video hosting service with an optimized resolution and video output format, the method comprising:
receiving the source video having a first video format and a first resolution;
encoding the source video into an intermediate video in an intermediate video format;
calculating a video coding complexity score of the source video based on spatial and temporal features of the encoded intermediate video, wherein the spatial and temporal features of the encoded intermediate video are normalized using a reference frame resolution and a reference frame rate, the reference frame resolution and the reference frame rate are independent from frame resolution and frame rate of the source video and target frame resolution and target frame rate of the source video, and the video coding complexity score represents a measure of complexity to encode the source video;
selecting a second resolution of the source video from a plurality of predetermined resolutions based on the video coding complexity score for each of a plurality of video output formats;
receiving a selection of video output format; and
encoding the source video into an output video having the selected second resolution and the selected video output format, wherein the second resolution is different from the first resolution, and the video output format is different from the first video format.

6. A computer system for adaptively transcoding a source video of a video hosting service with an optimized resolution, the system comprising:
a resolution determination module configured to:
receive the source video having a first video format and a first resolution;
encode the source video into an intermediate video in an intermediate video format;
calculate a video coding complexity score of the source video based on spatial and temporal features of the encoded intermediate video, wherein the spatial and temporal features of the encoded intermediate video are normalized using a reference frame resolution and a reference frame rate, the reference frame resolution and the reference frame rate are independent from frame resolution and frame rate of the source video and target frame resolution and target frame rate of the source video, and the video coding complexity score represents a measure of complexity to encode the source video; and
select a second resolution of the source video from a plurality of predetermined resolutions based on the video coding complexity; and

an adaptive video encoder configured to encode the source video into an output video having the selected second resolution and a predetermined video output format, wherein the second resolution is different from the first resolution, and the video output format is different from the first video format.

7. The system of claim 6 , wherein the intermediate video format is a H.263 video format.

8. The system of claim 6 , wherein the resolution determination module is further configured to set a resolution adjustment level based on the video coding complexity score of the source video.

9. The system of claim 8 , wherein the resolution determination module is further configured to map the resolution adjustment level to one of a plurality of predetermined resolutions.

10. A computer system for adaptively transcoding a source video of a video hosting service with an optimized resolution and output format, the system comprising:
a resolution determination module configured to:
receive the source video having a first video format and a first resolution;
encode the source video into an intermediate video in an intermediate video format;
calculate a video coding complexity score of the source video based on spatial and temporal features of the encoded intermediate video, wherein the spatial and temporal features of the encoded intermediate video are normalized using a reference frame resolution and a reference frame rate, the reference frame resolution and the reference frame rate are independent from frame resolution and frame rate of the source video and target frame resolution and target frame rate of the source video, and the video coding complexity score represents a measure of complexity to encode the source video; and
select a second resolution of the source video from a plurality of predetermined resolutions based on the video coding complexity score for each of a plurality of video output formats; and

an adaptive video encoder configured to:
receive a selection of video output format; and
encode the source video into an output video having the selected second resolution and the selected video output format, wherein the second resolution is different from the first resolution, and the video output format is different from the first video format.

11. A non-transitory computer-readable storage medium having executable computer modules for adaptively transcoding a source video of a video hosting service with an optimized resolution, comprising:
a resolution determination module configured to:
receive the source video having a first video format and a first resolution;
encode the source video into an intermediate video in an intermediate video format;
calculate a video coding complexity score of the source video based on spatial and temporal features of the encoded intermediate video, wherein the spatial and temporal features of the encoded intermediate video are normalized using a reference frame resolution and a reference frame rate, the reference frame resolution and the reference frame rate are independent from frame resolution and frame rate of the source video and target frame resolution and target frame rate of the source video, and the video coding complexity score represents a measure of complexity to encode the source video;
selecting a second resolution of the source video from a plurality of predetermined resolutions based on

Assignees

• Yi Xioquan
• Wang Huisheng
• Shastri Vijnan
• Google Inc

Inventors

• Yi Xioquan
• Wang Huisheng
• Shastri Vijnan

Classifications

• H04N19/102

  characterised by the element, parameter or selection affected or controlled by the adaptive coding · CPC title

• H04N19/134 Primary

  characterised by the element, parameter or criterion affecting or controlling the adaptive coding · CPC title

• H04N19/132 Primary

  Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking · CPC title

• H04N19/14

  Coding unit complexity, e.g. amount of activity or edge presence estimation (H04N19/146 takes precedence) · CPC title

• H04N19/40

  using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream · CPC title