Method of content adaptive video encoding

• US 7,773,670 B1
• Filed: 06/05/2001
• Issued: 08/10/2010
• Est. Priority Date: 06/05/2001
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Inventors: Civanlar, Mehmet Reha, Puri, Atul
• Primary Examiner(s): WONG, ALLEN C
• Application Number:
  US09/874,872
• Time in Patent Office: 3,353 Days
• Field of Search: 375/240, 375/240.01, 375/240.02, 375/240.03, 375/240.12, 375/240.16, 375/240.25, 382/243, 382/173
• US Class Current: 375/240.01
• CPC Class Codes: H04N 19/119 Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
• CPC Class Codes: H04N 19/12 Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/16 for a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 19/162 User input
• CPC Class Codes: H04N 19/167 Position within a video image, e.g. region of interest [ROI]
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/179 the unit being a scene or a shot
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 19/80 Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation H04N19/635, H04N19/86 take precedence
• CPC Class Codes: H04N 19/86 involving reduction of coding artifacts, e.g. of blockiness
• CPC Class Codes: H04N 19/87 involving scene cut or scene change detection in combination with video compression

Abstract

A method of content adaptive encoding video is disclosed. The method comprises segmenting video content into segments based on predefined classifications or models. Examples of such classifications include action scenes, slow scenes, low or high detail scenes, and brightness of the scenes. Based on the segment classifications, each segment is encoded with a different encoder chosen from a plurality of encoders. Each encoder is associated with a model. The chosen encoder is particularly suited to encoding the unique subject matter of the segment. The coded bit-stream for each segment includes information regarding which encoder was used to encode that segment. A matching decoder of a plurality of decoders is chosen using the information in the coded bitstream to decode each segment using a decoder suited for the classification or model of the segment. If scenes exist which do not fall in a predefined classification, or where classification is more difficult based on the scene content, these scenes are segmented, coded and decoded using a generic coder and decoder.

Claims

1. A method of encoding video content, the method comprising:

assigning a predefined quantization model to each of at least two regions of interest of video content, wherein a respective region of interest of the at least two regions of interest comprises a rectangular-based region covering less than a full frame identified on a frame-by-frame basis by a first descriptor associated with top left corner coordinates of a first sub-segment in the respective region of interest and a second descriptor associated with a last sub-segment in the region of interest, wherein the first descriptor and the last descriptor define a defined structure of the respective region of interest based on a number of sub-segments in the respective region of interest, wherein the respective region of interest includes an arbitrarily shaped object in a portion of the respective region of interest that is smaller than the defined structure of the respective region of interest; and

encoding at an encoder of a plurality of encoders each of the at least two regions of interest based on the predefined quantization model assigned to the defined structure of the respective region of interest, the encoder using quantization model information to encode each of the at least two regions of interest differently based on the assigned predefined quantization model.

2. The method of claim 1, wherein the assigning a predefined quantization model to each of at least two regions of interest of the video content further comprises assigning a different predefined quantization model to each of the at least two regions of interest of the video content.

3. The method of claim 1, wherein the region of interest information is found in a header.

4. The method of claim 1, wherein the region of interest information indicates a boundary of the region of interest.

5. The method of claim 1, further comprising assigning another predefined quantization content model to a portion of the full frame not covered by the at least two regions of interest.

6. The method of claim 1, further comprising encoding in a header data regarding the which predefined quantization content model a decoder should use to decode each respective region of interest.

7. A method of encoding video content, the method comprising:

assigning a predefined content model to a region of interest in video content, wherein the region of interest comprises a rectangular-based region covering less than a full frame identified on a frame-by-frame basis by a first descriptor associated with top left corner coordinates of a first sub-segment in the respective region of interest and a second descriptor associated with a last sub-segment in the region of interest; and

encoding at an encoder of a plurality of encoders the region of interest differently from a portion of the full frame not covered by the region of interest based on the assigned predefined content model, each encoder of the plurality of encoders having an associated predefined content model that is different from other encoders of the plurality of encoders, the encoder adding header information to instruct a decoder of a plurality of decoders how to decode the region of interest based on the assigned predefined content model.

8. The method of claim 7, wherein the predefined content model is associated with adaptive quantization.

9. A method of decoding video content, the method causing a decoder to perform steps comprising:

receiving header information associated with an assigned predefined content model for a region of interest in video content, wherein the region of interest comprises a rectangular-based region covering less than a full frame identified on a frame-by-frame basis by a first descriptor associated with top left corner coordinates of a first sub-segment in the respective region of interest and a second descriptor associated with a last sub-segment in the region of interest; and

based on the header information and the assigned predefined content model, decoding the region of interest at a decoder of a plurality of decoders, the decoder decoding the region of interest differently from a portion of the full frame not covered by the region of interest and wherein each decoder of the plurality of decoders has an associated predefined content model that is different from other decoders of the plurality of decoders.

10. The method of claim 9, wherein the assigned predefined model causes the decoder to adaptively dequantize the region of interest.