摘要:
A video coding system and method to adjust the sharpening procedures performed during post-processing by analyzing statistics information collected during encoding and decoding. The statistics information collected may be directed to the source of the video data, the operations executed during pre-processing and encoding of the video data, the transmission of the video data from encoder to decoder, or the operations executed during decoding. The statistics information may comprise a collection of data values, calculated statistics, or instructions for the suggested post-processing adjustments. Accumulated supplemental information may be transmitted from the encoder to the decoder via an out-of-band channel, associated with the encoded video sequence transmitted on a communications channel.
摘要:
A system and method for gradually changing the resolution of a video signal to avoid a large spike in the video data transmitted between an encoder and a decoder. Upon detection of a change in the quality of source video, of the quality of the encoding process, or of the channel conditions, any of which may negatively impact the rate of frame transmission from encoder to decoder, or the quality of frames transmitted, a responsive change in the resolution of the video frame may be gradually implemented. To change the resolution by increasing the effective image size, each successive frame in a sequence of frames may contain additional pixel blocks in the expansion image area at the new resolution. In an embodiment, the decoder displays the video image at the original resolution until the resolution switch has been completed.
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:
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:
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:
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 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.