摘要:
A method and system are provided to encode a video sequence into a compressed bitstream. An encoder receives a video sequence from an image-capture device, together with metadata associated with the video sequence, and codes the video sequence into a first compressed bitstream using the metadata to select or revise a coding parameter associated with a coding operation. Optionally, the video sequence may be conditioned for coding by a preprocessor, which also may use the metadata to select or revise a preprocessing parameter associated with a preprocessing operation. The encoder may itself generate metadata associated with the first compressed bitstream, which may be used together with any metadata received by the encoder, to transcode the first compressed bitstream into a second compressed bitstream. The compressed bitstreams may be decoded by a decoder to generate recovered video data, and the recovered video data may be conditioned for viewing by a postprocessor, which may use the metadata to select or revise a postprocessing parameter associated with a postprocessing operation.
摘要:
A method and system are provided to encode a video sequence into a compressed bitstream. An encoder receives a video sequence from an image-capture device, together with metadata associated with the video sequence, and codes the video sequence into a first compressed bitstream using the metadata to select or revise a coding parameter associated with a coding operation. Optionally, the video sequence may be conditioned for coding by a preprocessor, which also may use the metadata to select or revise a preprocessing parameter associated with a preprocessing operation. The encoder may itself generate metadata associated with the first compressed bitstream, which may be used together with any metadata received by the encoder, to transcode the first compressed bitstream into a second compressed bitstream. The compressed bitstreams may be decoded by a decoder to generate recovered video data, and the recovered video data may be conditioned for viewing by a postprocessor, which may use the metadata to select or revise a postprocessing parameter associated with a postprocessing operation.
摘要:
Example embodiments of the present invention provide a method or device for coding source video. The method or device may provide for a segment of video frames from the source video, computing a noise map for the segment of the source video where the noise map is computed from differences among pixels selected from spatially-distributed sampling patterns in the segment, computing control parameter adjustments based on the noise map, and coding the selected segment of source video according to control parameters generated from a default coding policy and the control parameter adjustments, where the default coding policy includes default control parameters of the encoder.
摘要:
Embodiments of the present invention provide systems, methods and apparatuses for generating forward, backward or bi-directional P frames. Prior to encoding a sequence of video frames, P frames within the video sequence can be reordered to include causal and/or non-causal references to one or more reference frames. This allows any block partition of a bi-directional P frame to include a single reference to a reference frame that is temporally displayed either before or after the bi-directional P frame. Compression and visual quality can therefore be improved. Hierarchical frame structures can be constructed using bi-directional P frames to better accommodate low complexity decoding profiles. Multilayered encoded video bitstreams can be generated based on the hierarchical frame structures and can include a first layer of anchor frames and one or more second layers that include bi-directional P frames that reference the anchor frames and/or any frame in any lower level layer.
摘要:
Embodiments of the present invention provides a method and device for processing a source video. The method and device may provide computing an artifact estimation from differences among pixels selected from spatially-distributed sampling patterns in the source video; filtering the source video to produce a filtered version of the source video, computing a blending factor based on the artifact estimation in the source video, and computing an output video by blending the source video and the filtered version of the source video based on the blending factor.
摘要:
A method and device for dithering video from a decoder. The method and device provide: selecting a segment of video frames from the video; computing a noise map for the segment of the video, the noise map computed from differences among pixels selected from spatially-distributed sampling patterns in the segment; determining contours of quantization artifacts within the video frame based on the noise map and a histogram of pixel values in the video frame; computing a gradient measurement of pixel values along the contours; identifying regions along the contours of quantization artifacts to apply dithering based on the noise map and the gradient measurement; determining a dithering strength based on the noise map and the gradient measurement; and applying dithering noise to the identified regions at the determined dithering strength.
摘要:
A video coding system reduces perceptible artifacts introduced to coded video due to selection of disparate coding modes among adjacent partitions of video. When coding modes are assigned to partitions of video that likely would introduce visually perceptible coding artifacts during decode, the partitions may be subject to a coding process in which a selected partition is coded according to coding modes that correspond to neighboring partitions, then decoded. The decoded data of the selected partition may be recoded according to a different coding mode. Coding artifacts that otherwise might be introduced by the different coding mode may be avoided by first coding the corresponding partition in a manner that is consistent with neighboring partitions, then decoding the coded partition and re-coding the decoded data according to the different mode. In an embodiment, a quantization parameter may be reduced between a first code and the recode. The coding technique may be applied to partitions of various scales—e.g., to pixel blocks or frames.
摘要:
A video coding and transmission system may employ techniques for adapting buffered video to network condition changes. Video data may be coded as reference data and non-reference data. According to the embodiments, non-reference frame may be detected in buffered video while awaiting transmission to a network. When network degradation is detected, one or more of the buffered non-reference frames may be dropped when network degradation is detected. Information about the dropped frames may be passed to an encoder for updating buffer parameters for future encoding. In this manner, a video coding system may provide faster responses to changing network conditions than systems without such buffer management techniques.
摘要:
A video coding system and method for increasing a transmitted output bit rate of a video encoding system by altering the content of the bit stream. A video encoder may receive a coding mode signal from a computer application for coding source video data, the coding mode signal indicating a target bit rate having a risk factor related to transmission error associated to the target bit rate. The coded bitstream may be modified based on the risk factor indicated in the coding mode signal. A modified coded bitstream may be outputted at the target bit rate and at a reduced coding efficiency, and the channel may be tested for transmission errors. Based on the test results, a revised coding mode signal indicating the same target bit rate, but a revised risk factor may be provided. The coded bitstream may be revised by removing the modifications previously made to the coded bitstream and a revised coded bitstream having greater coding efficiency may be output at the target bit rate.
摘要:
Systems and methods for streaming video over multiple HTTP channels are provided. The client may have control over the channels, allowing the client to control the amount and source of data received. Data requested by the client may be separated into a set of layers, with each layer being assigned to a separate channel. The client may adjust the number of layers requested based on a variety of factors. Layers may be requested from multiple remote sources, providing the client with additional control over the specific bandwidth profile of received data.