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1.
公开(公告)号:WO2022040012A1
公开(公告)日:2022-02-24
申请号:PCT/US2021/045762
申请日:2021-08-12
Applicant: NETFLIX, INC.
Inventor: CHEN, Li-Heng , BAMPIS, Christos G. , LI, Zhi
IPC: G06K9/00 , H04N17/00 , G06K9/03 , G06T7/00 , H04N21/44 , H04N21/466 , H04N21/475 , H04N19/154 , H04N19/186 , H04N19/115
Abstract: In various embodiments, a training application generates a perceptual video model. The training application computes a first feature value for a first feature included in a feature vector based on a first color component associated with a first reconstructed training video. The training application also computes a second feature value for a second feature included in the feature vector based on a first brightness component associated with the first reconstructed training video. Subsequently, the training application performs one or more machine learning operations based on the first feature value, the second feature value, and a first subjective quality score for the first reconstructed training video to generate a trained perceptual quality model. The trained perceptual quality model maps a feature value vector for the feature vector to a perceptual quality score.
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2.
公开(公告)号:WO2017176656A1
公开(公告)日:2017-10-12
申请号:PCT/US2017/025801
申请日:2017-04-03
Applicant: NETFLIX, INC.
Inventor: AARON, Anne , LI, Zhi , GOODALL, Todd
IPC: H04N19/00
Abstract: In various embodiments, a quality trainer trains a model that computes a value for a perceptual video quality metric for encoded video content. During a pre-training phase, the quality trainer partitions baseline values for metrics that describe baseline encoded video content into partitions based on genre. The quality trainer then performs cross-validation operations on the partitions to optimize hyperparameters associated with the model. Subsequently, during a training phase, the quality trainer performs training operations on the model that includes the optimized hyperparameters based on the baseline values for the metrics to generate a trained model. The trained model accurately tracks the video quality for the baseline encoded video content. Further, because the cross-validation operations minimize any potential overfitting, the trained model accurately and consistently predicts perceived video quality for non-baseline encoded video content across a wide range of genres.
Abstract translation: 在各种实施例中,质量培训师训练计算经编码的视频内容的感知视频质量度量的值的模型。 在预培训阶段,质量培训师根据流派将基准编码视频内容描述的分割基准值分割成分区。 质量培训师然后对分区执行交叉验证操作,以优化与模型相关联的超参数。 随后,在训练阶段期间,质量训练师基于该度量的基线值对包括优化超参数的模型执行训练操作以生成训练模型。 训练好的模型准确地跟踪基线编码的视频内容的视频质量。 此外,由于交叉验证操作使任何潜在的过度拟合最小化,所以经过训练的模型准确且一致地预测跨广泛流派的非基线编码视频内容的感知视频质量。
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公开(公告)号:WO2022026792A1
公开(公告)日:2022-02-03
申请号:PCT/US2021/043836
申请日:2021-07-30
Applicant: NETFLIX, INC.
Inventor: LI, Zhi
IPC: H04N21/466
Abstract: In various embodiments, a data optimization application mitigates scoring inaccuracies in subjective quality experiments. In operation, the data optimization application generates a model that includes a first set of individual scores and a first set of parameters. The first set of parameters includes a first subjective score set and a first set of subjective factor sets. The data optimization application performs one or more optimization operations on the first set of parameters to generate a second set of parameters. The second set of parameters includes a second subjective score set and a second set of subjective factor sets, wherein the second subjective score set compensates for at least a first subjective factor set included in the second set of subjective factor sets. The data optimization application also computes a participant evaluation report based on at least a second subjective factor setsincluded in the second set of subjective factor sets.
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4.
公开(公告)号:WO2020018465A1
公开(公告)日:2020-01-23
申请号:PCT/US2019/041889
申请日:2019-07-15
Applicant: NETFLIX, INC.
Inventor: LI, Zhi , HUANG, Te-Yuan
IPC: H04N21/2343 , H04N21/234 , H04N21/24 , H04N21/44
Abstract: In various embodiments, a hindsight application computes a hindsight metric value for evaluation of a video rate selection algorithm. The hindsight application determines a first encoding option associated with a source chunk of a media title based on a network throughput trace and a buffer trellis. The hindsight application determines that the first encoding option is associated with a buffered duration range. The buffered duration range is also associated with a second encoding option that is stored in the buffer trellis. After determining that the first encoding option is associated with a higher visual quality than the second encoding option, the hindsight application stores the first encoding option instead of the second encoding option in the buffer trellis to generate a modified buffer trellis. Finally, the hindsight application computes a hindsight metric value associated with a sequence of encoded chunks of the media title based on the modified buffer trellis.
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5.
公开(公告)号:WO2019157235A1
公开(公告)日:2019-08-15
申请号:PCT/US2019/017134
申请日:2019-02-07
Applicant: NETFLIX, INC.
Inventor: LI, Zhi , BAMPIS, Christos
IPC: H04N19/154 , H04N19/136 , G06K9/62 , G06N3/02 , G06T7/00
CPC classification number: H04N19/154 , G06K9/00744 , G06K9/036 , G06K9/6269 , G06N3/08 , G06N20/20 , G06T7/0002 , G06T2207/10016 , G06T2207/30168 , H04N19/136 , H04N19/91 , H04N21/235
Abstract: In various embodiments, an ensemble prediction application computes a quality score for re-constructed visual content that is derived from visual content. The ensemble prediction application computes a first quality score for the re-constructed video content based on a first set of values for a first set of features and a first model that associates the first set of values with the first quality score. The ensemble prediction application computes a second quality score for the re-constructed video content based on a second set of values for a second set of features and a second model that associates the second set of values with the second quality score. Subsequently, the ensemble prediction application determines an overall quality score for the re-constructed video content based on the first quality score and the second quality score. The overall quality score indicates a level of visual quality associated with streamed video content.
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公开(公告)号:WO2019157234A2
公开(公告)日:2019-08-15
申请号:PCT/US2019/017133
申请日:2019-02-07
Applicant: NETFLIX, INC.
Inventor: LI, Zhi , BAMPIS, Christos
IPC: H04N17/02 , H04N17/04 , H04N19/154
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公开(公告)号:WO2018111655A1
公开(公告)日:2018-06-21
申请号:PCT/US2017/064975
申请日:2017-12-06
Applicant: NETFLIX, INC.
Inventor: LI, Zhi , AARON, Anne , MOORTHY, Anush , BAMPIS, Christos
IPC: H04N19/154 , H04N19/59 , H04N19/00
Abstract: In various embodiments, a perceptual quality application computes an absolute quality score for encoded video content. In operation, the perceptual quality application selects a model based on the spatial resolution of the video content from which the encoded video content is derived. The model associates a set of objective values for a set of objective quality metrics with an absolute quality score. The perceptual quality application determines a set of target objective values for the objective quality metrics based on the encoded video content. Subsequently, the perceptual quality application computes the absolute quality score for the encoded video content based on the selected model and the set of target objective values. Because the absolute quality score is independent of the quality of the video content, the absolute quality score accurately reflects the perceived quality of a wide range of encoded video content when decoded and viewed.
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8.
公开(公告)号:WO2019226481A1
公开(公告)日:2019-11-28
申请号:PCT/US2019/032863
申请日:2019-05-17
Applicant: NETFLIX, INC.
Inventor: HUANG, Te-Yuan , EKANADHAM, Chaitanya , BERGLUND, Andrew J. , LI, Zhi
IPC: H04N19/184 , H04N21/2343 , H04N21/845
Abstract: In various embodiments, a hindsight application computes a total download size for a sequence of encoded chunks associated with a media title for evaluation of at least one aspect of a video streaming service. The hindsight application computes a feasible download end time associated with a source chunk of the media title based on a network throughput trace and a subsequent feasible download end time associated with a subsequent source chunk of the media title. The hindsight application then selects an encoded chunk associated with the source chunk based on the network throughput trace, the feasible download end time, and a preceding download end time associated with a preceding source chunk of the media title. Subsequently, the hindsight application computes the total download size based on the number of encoded bits included in the first encoded chunk. The total download size correlates to an upper bound on visual quality.
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公开(公告)号:WO2022173687A1
公开(公告)日:2022-08-18
申请号:PCT/US2022/015455
申请日:2022-02-07
Applicant: NETFLIX, INC.
Inventor: MOORTHY, Anush , LI, Zhi , GUO, Liwei , MAVLANKAR, Aditya , AARON, Anne
IPC: H04N21/234 , H04N19/10 , H04N21/2343 , H04N21/2662 , H04N21/845
Abstract: In various embodiments, an encoding ladder application generates encoding ladders for encoding media titles. In operation, the encoding ladder application generates a first convex hull representing encoding tradeoffs between quality and bitrate when encoding a media title at a first resolution. The encoding ladder application generates a second convex hull representing encoding tradeoffs between quality and bitrate when encoding the media title at a second resolution. Based on the first convex hull and the second convex hull, the encoding ladder application generates an overall convex hull. Subsequently, the encoding ladder application generates an encoding ladder for the media title based on at least the overall convex hull and a ladder requirement. Advantageously, the tradeoffs between quality and bitrate represented by the encoding ladder are customized for the media title. Consequently, encoding inefficiencies attributable to conventional fixed-bitrate ladders can be reduced.
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公开(公告)号:WO2019183280A1
公开(公告)日:2019-09-26
申请号:PCT/US2019/023256
申请日:2019-03-20
Applicant: NETFLIX, INC.
Inventor: BAMPIS, Christos , LI, Zhi , SHARAN, Lavanya , NOVAK, Julie , TINGLEY, Martin
IPC: H04N21/25 , G06K9/62 , H04N17/00 , H04N19/147 , H04N19/154 , G06N20/20
Abstract: In various embodiments, a bootstrapping training subsystem performs sampling operation(s) on a training database that includes subjective scores to generate resampled dataset. For each resampled dataset, the bootstrapping training subsystem performs machine learning operation(s) to generate a different bootstrap perceptual quality model. The bootstrapping training subsystem then uses the bootstrap perceptual quality models to quantify the accuracy of a perceptual quality score generated by a baseline perceptual quality model for a portion of encoded video content. Advantageously, relative to prior art solutions in which the accuracy of a perceptual quality score is unknown, the bootstrap perceptual quality models enable developers and software applications to draw more valid conclusions and/or more reliably optimize encoding operations based on the perceptual quality score.