摘要:
Various techniques are provided herein for processing raw image data acquired using a digital image sensor in an image processing pipeline of an image signal processing system. In one embodiment, the image processing pipeline may first process the raw image data (e.g., Bayer image data) for the detection and correction of defective pixels. Next, the image processing pipeline may process the raw image data to reduce noise. Thereafter, the image processing pipeline may correct lens shading distortion in the raw image data and, subsequently, apply a demosaicing algorithm to convert the raw image data into full color image data (e.g., RGB image data). The color image data may be further processed by the image processing pipeline to correct color and gamma properties prior to being converted into a luma and chroma color space (e.g., YCbCr color space).
摘要:
A method for transcoding from an H.264 format to an MPEG-2 format is disclosed. The method generally comprises the steps of (A) decoding an input video stream in the H.264 format to generate a picture having a plurality of macroblock pairs that used an H.264 macroblock adaptive field/frame coding; (B) determining a mode indicator for each of the macroblock pairs; and (C) coding the macroblock pairs into an output video stream in the MPEG-2 format using one of (i) an MPEG-2 field mode coding and (ii) an MPEG-2 frame mode coding as determined from the mode indicators.
摘要:
A method for transcoding from an MPEG-2 format to an H.264 format is disclosed. The method generally comprises the steps of (A) decoding an input video stream in the MPEG-2 format to generate a plurality of macroblocks; (B) determining a plurality of indicators from a pair of the macroblocks, the pair of the macroblocks being vertically adjoining; and (C) coding the pair of the macroblocks into an output video stream in the H.264 format using one of (i) a field mode coding and (ii) a frame mode coding as determined from the indicators.
摘要:
An encoder circuit, a task scheduler circuit and a decoder circuit. The encoder circuit may be configured to (i) generate one or more first status signals in response to one or more report signals and (ii) perform video encoding tasks based on available central processing unit (CPU) cycles and memory bandwidth. The task scheduler circuit may be configured to (i) generate a control signal and the one or more report signals in response to the one or more first status signals. The decoder circuit may be configured to (i) generate one or more second status signals and (ii) perform concurrent decoding while the encoder circuit performs adaptive video encoding tasks in response to the control signal.
摘要:
A method for implementing B-frame prediction in video compression comprising the steps of (A) setting a prediction flag (i) “off” if B-frames are used for block prediction and (ii) “on” if B-frames are not used for block prediction, (B) if the prediction flag is off, generating an output video signal in response to an input video signal by performing an inverse quantization step and an inverse transform step in accordance with a predefined coding specification and (C) if the prediction flag is on, bypassing the inverse quantization step and the inverse transform step.
摘要:
A method for coefficient bitdepth limitation in an encoder and/or bitstream generation apparatus including the steps of (A) generating one or more residual block coefficients in response to a video signal and one or more coding parameters and (B) manipulating the one or more coding parameters such that the one or more residual block coefficients are prevented from having values greater than a bitdepth of the video signal plus a predefined number of bits.
摘要:
A method for image decoding is disclosed. The method generally includes the steps of (A) receiving from a medium (1) an encoded signal and (2) transform data comprising at least one of (i) encoding statistics embedded in the encoded signal, (ii) encoding information and (iii) pre-processing information, wherein (a) the encoding statistics are created by an encoder in encoding an intermediate input signal to create the encoded signal, (b) the encoding information is producible by the encoder in the encoding and (c) the pre-processing information is producible by a pre-processor in converting an image input signal into the intermediate input signal, (B) generating an intermediate output signal by decoding the encoded signal and (C) generating an image output signal by processing the intermediate output signal in response to the transform data.
摘要:
A video encoder including an encoder circuit, a quantizer circuit and a control circuit. The encoder circuit may be configured to generate a plurality of coefficient values and motion vectors in response to a video stream, a first control signal, a second control signal, and a number of quantized values. The control circuit may be configured to (i) generate the first control signal, the second control signal, and a quantizer index signal and (ii) set two or more quantization dead zones and two or more offsets to different values, where the quantization dead zones and the offsets are independently programmable. The quantizer circuit may be configured to generate the number of quantized values in response to the coefficient values, the quantizer index signal, the two or more quantization dead zones and the two or more offsets. A first coefficient value may be quantized using a first quantization dead zone and a first offset. A second coefficient value may be quantized using a second quantization dead zone and a second offset. The first and second quantization dead zones generally have different values. The first and second offsets generally have different values. Quantization calculations determining each quantized value take into account respective quantization dead zones and offsets.
摘要:
A method for deinterlacing a picture is disclosed. The method generally includes the steps of (A) calculating a potential sample at a location interfaced with a first field of the picture by temporal filtering, (B) evaluating a protection condition in a current region around the location after inclusion of the potential sample and (C) calculating an interpolated sample at the location by vertical spatial filtering the first field in response to the protection condition indicating a significant increase in a vertical activity within the current region due to the potential sample.
摘要:
A method of signaling additional chroma QP offset values that are specific to quantization groups is provided, in which each quantization group explicitly specifies its own set of chroma QP offset values. Alternatively, a table of possible sets of chroma QP offset values is specified in the header area of the picture, and each quantization group uses an index to select an entry from the table for determining its own set of chroma QP offset values. The quantization group specific chroma QP offset values are then used to determine the chroma QP values for blocks within the quantization group in addition to chroma QP offset values already specified for higher levels of the video coding hierarchy.