公开(公告)号：US20160014421A1

公开(公告)日：2016-01-14

申请号：US14331091

申请日：2014-07-14

Applicant: APPLE INC.

Inventor： Guy Cote ,  Xiaojin Shi

IPC: H04N19/196 ,  H04N19/176 ,  H04N19/124 ,  H04N19/139 ,  G06K9/46 ,  G06T1/20

CPC classification number: H04N19/196 ,  G06K9/325 ,  G06K9/4642 ,  G06T1/20 ,  H04N19/124 ,  H04N19/139 ,  H04N19/14 ,  H04N19/176 ,  H04N19/42

Abstract: A block input component of a video encoding pipeline may, for a block of pixels in a video frame, compute gradients in multiple directions, and may accumulate counts of the computed gradients in one or more histograms. The block input component may analyze the histogram(s) to compute block-level statistics and determine whether a dominant gradient direction exists in the block, indicating the likelihood that it represents an image containing text. If text is likely, various encoding parameter values may be selected to improve the quality of encoding for the block (e.g., by lowering a quantization parameter value). The computed statistics or selected encoding parameter values may be passed to other stages of the pipeline, and used to bias or control selection of a prediction mode, an encoding mode, or a motion vector. Frame-level or slice-level parameter values may be generated from gradient histograms of multiple blocks.

Abstract translation: 对于视频帧中的像素块，视频编码流水线的块输入分量可以在多个方向上计算梯度，并且可以在一个或多个直方图中累积计算的梯度的计数。 块输入组件可以分析直方图以计算块级统计，并确定块中是否存在显性梯度方向，指示它代表包含文本的图像的可能性。 如果文本很可能，则可以选择各种编码参数值以提高块的编码质量（例如，通过降低量化参数值）。 所计算的统计量或所选择的编码参数值可以被传递到流水线的其他阶段，并且用于偏置或控制预测模式，编码模式或运动矢量的选择。 可以从多个块的梯度直方图生成帧级或片级参数值。

公开(公告)号：US08675740B2

公开(公告)日：2014-03-18

申请号：US13731819

申请日：2012-12-31

Applicant: Apple Inc.

Inventor： Hsi-Jung Wu ,  Barin Geoffry Haskell ,  Xiaojin Shi ,  James Oliver Normile

IPC: H04N7/12

CPC classification number: H04N19/44 ,  H04N19/149 ,  H04N19/152

Abstract: Disclosed is a system and method of controlling a video decoder, including a reviewing channel data representing coded video data generated by an encoder to identify parameters of a hypothetical reference decoder (HRD) used by the encoder during coding operations. A parameter representing an exit data rate requirement of a coded picture buffer (CPB) of the HRD is compared against exit rate performance of the video decoder. If the exit rate performance of the video coder matches the exit rate requirement of the HRD, the coded video data is decoded, otherwise, a certain decoding degradation scheme can be applied, including disabling decoder from decoding the coded video data.

Abstract translation: 公开了一种控制视频解码器的系统和方法，包括：代表由编码器产生的编码视频数据的查看频道数据，以识别由编码器在编码操作期间使用的假设参考解码器（HRD）的参数。 将表示HRD的编码图像缓冲器（CPB）的退出数据速率要求的参数与视频解码器的退出速率性能进行比较。 如果视频编码器的退出速率性能与HRD的退出率要求相匹配，则编码的视频数据被解码，否则可以应用某种解码劣化方案，包括禁止解码器解码编码的视频数据。

公开(公告)号：US20130182778A1

公开(公告)日：2013-07-18

申请号：US13731819

申请日：2012-12-31

Applicant: Apple Inc.

Inventor： Hsi-Jung WU ,  Barin Geoffry Haskell ,  Xiaojin Shi ,  James Oliver Normile

IPC: H04N7/26

CPC classification number: H04N19/44 ,  H04N19/149 ,  H04N19/152

Abstract: Disclosed is a system and method of controlling a video decoder, including a reviewing channel data representing coded video data generated by an encoder to identify parameters of a hypothetical reference decoder (HRD) used by the encoder during coding operations. A parameter representing an exit data rate requirement of a coded picture buffer (CPB) of the HRD is compared against exit rate performance of the video decoder. If the exit rate performance of the video coder matches the exit rate requirement of the HRD, the coded video data is decoded, otherwise, a certain decoding degradation scheme can be applied, including disabling decoder from decoding the coded video data.