Filtering video data using a plurality of filters

An apparatus for decoding video data, the apparatus comprising:

• a video decoding processor configured to decode a unit of pixels of at least one frame, filter selection information, and a plurality of filters embedded in a video data bitstream, the processor is configured to reconstruct pixel values of the pixels of the unit of the at least one frame using one of intra-frame prediction or inter-frame prediction, the pixels comprising first and second pixels of the unit of the at least one frame;
• and
• a memory configured to store the plurality of filters;
• wherein the video decoding processor is further configured to:
• calculate a characteristic of each reconstructed pixel value from the reconstructed pixel values of the first pixels of the unit;
• select a first filter of the plurality of filters to apply to a first reconstructed pixel value from the reconstructed pixel values of the first pixels, wherein selecting the first filter includes comparing a characteristic of the first reconstructed pixel value of the first pixels to a first range of values, a second range of values, and a third range of values defined by the filter selection information, wherein the filter selection information indicates that the first filter is to be applied to reconstructed pixel values that have characteristics within the first range of values, and wherein the first filter is selected, according to the filter selection information, based on the characteristic of the first reconstructed pixel value being within the first range of values;
• calculate a characteristic of each reconstructed pixel value from the reconstructed pixel values of the second pixels of the unit;
• select a second filter of the plurality of filters to apply to a second reconstructed pixel value from the reconstructed pixel values of the second pixels, wherein selecting the second filter includes comparing a characteristic of the second reconstructed pixel value of the second pixels to the first range of values, the second range of values, and the third range of values defined by the filter selection information, wherein the filter selection information indicates that the second filter is to be applied to reconstructed pixel values that have characteristics within the second range of values, wherein the second filter is selected, according to the filter selection information, based on the characteristic of the second reconstructed pixel value being within the second range of values, and wherein the second filter is different than the first filter;
• and
• apply the first filter to the first reconstructed pixel value of the first pixels and the second filter to the second reconstructed pixel value of the second pixels to produce filtered decoded pixel values of the first and second pixels of the unit, wherein filter coefficients of at least one of the first filter or the second filter are quantized to form quantized filter coefficients, and wherein the quantized filter coefficients are subsequently clipped to be within a range after quantization is performed.

An integrated circuit comprising:

• video decoding circuitry configured to:
• decode a signal including video data of a unit of pixels of at least one frame, filter selection information, and a plurality of filters embedded in a video data bitstream, wherein to decode the unit of video data, the video decoding circuitry is configured to reconstruct pixel values of the pixels of the unit of the at least one frame using one of intra-frame prediction or inter-frame prediction, the pixels comprising first and second pixels of the unit of the at least one frame;
• calculate a characteristic of each reconstructed pixel value from the reconstructed pixel values of the first pixels of the unit;
• select a first filter of the plurality of filters to apply to a first reconstructed pixel value from the reconstructed pixel values of the first pixels, wherein selecting the first filter includes comparing a characteristic of the first reconstructed pixel value of the first pixels to a first range of values, a second range of values, and a third range of values defined by the filter selection information, wherein the filter selection information indicates that the first filter is to be applied to reconstructed pixel values that have characteristics within the first range of values, and wherein the first filter is selected, according to the filter selection information, based on the characteristic of the first reconstructed pixel value being within the first range of values;
• calculate a characteristic of each reconstructed pixel value from the reconstructed pixel values of the second pixels of the unit;
• select a second filter of the plurality of filters to apply to a second reconstructed pixel value from the reconstructed pixel values of the second pixels, wherein selecting the second filter includes comparing a characteristic of the second reconstructed pixel value of the second pixels to the first range of values, the second range of values, and the third range of values defined by the filter selection information, wherein the filter selection information indicates that the second filter is to be applied to reconstructed pixel values that have characteristics within the second range of values, wherein the second filter is selected, according to the filter selection information, based on the characteristic of the second reconstructed pixel value being within the second range of values, and wherein the second filter is different than the first filter;
• and
• apply the first filter to the first reconstructed pixel value of the first pixels and the second filter to the second reconstructed pixel value of the second pixels to produce filtered decoded pixel values of the first and second pixels of the unit, wherein filter coefficients of at least one of the first filter or the second filter are quantized to form quantized filter coefficients, and wherein the quantized filter coefficients are subsequently clipped to be within a range after quantization is performed.

A video decoder comprising:

• means for decoding video data of a unit of pixels of at least one frame, filter selection information, and a plurality of filters embedded in a video data bitstream, the means for decoding comprising means for reconstructing pixel values of the pixels of the unit of the at least one frame using one of intra-frame prediction or inter-frame prediction, the pixels comprising first and second pixels of the unit of the at least one frame;
• means for calculating, at the video decoder, a characteristic of each reconstructed pixel value from the reconstructed pixel values of the first pixels of the unit;
• means for selecting, at the video decoder, a first filter of the plurality of filters to apply to a first reconstructed pixel value from the reconstructed pixel values of the first pixels, wherein selecting the first filter includes comparing a characteristic of the first reconstructed pixel value of the first pixels to a first range of values, a second range of values, and a third range of values defined by the filter selection information, wherein the filter selection information indicates that the first filter is to be applied to reconstructed pixel values that have characteristics within the first range of values, and wherein the first filter is selected, according to the filter selection information, based on the characteristic of the first reconstructed pixel value being within the first range of values;
• means for calculating, at the video decoder, a characteristic of each reconstructed pixel value from the reconstructed pixel values of the second pixels of the unit;
• means for selecting, at the video decoder, a second filter of the plurality of filters to apply to a second reconstructed pixel value from the reconstructed pixel values of the second pixels, wherein selecting the second filter includes comparing a characteristic of the second reconstructed pixel value of the second pixels to the first range of values, the second range of values, and the third range of values defined by the filter selection information, wherein the filter selection information indicates that the second filter is to be applied to reconstructed pixel values that have characteristics within the second range of values, wherein the second filter is selected, according to the filter selection information, based on the characteristic of the second reconstructed pixel value being within the second range of values, and wherein the second filter is different than the first filter;
• and
• means for applying, at the video decoder, the first filter to the first reconstructed pixel value of the first pixels and the second filter to the second reconstructed pixel value of the second pixels to produce filtered decoded pixel values of the first and second pixels of the unit, wherein filter coefficients of at least one of the first filter or the second filter are quantized to form quantized filter coefficients, and wherein the quantized filter coefficients are subsequently clipped to be within a range after quantization is performed.

A non-transitory computer-readable medium having instructions stored thereon that, when executed, cause one or more processors to:

• decode, at a video decoder, a unit of pixels of at least one frame, filter selection information, and a plurality of filters embedded in a video data bitstream at the video decoder, wherein to decode the unit of pixels the processor is configured to reconstruct pixel values of the pixels of the unit of the at least one frame using one of intra-frame prediction or inter-frame prediction, the pixels comprising first and second pixels of the unit of the at least one frame;
• calculate, at the video decoder, a characteristic of each reconstructed pixel value from the reconstructed pixel values of the first pixels of the unit;
• select, at the video decoder, a first filter of the plurality of filters to apply to a first reconstructed pixel value from the reconstructed pixel values of the first pixels, wherein selecting the first filter includes comparing a characteristic of the first reconstructed pixel value of the first pixels to a first range of values, a second range of values, and a third range of values defined by the filter selection information, wherein the filter selection information indicates that the first filter is to be applied to reconstructed pixel values that have characteristics within the first range of values, and wherein the first filter is selected, according to the filter selection information, based on the characteristic of the first reconstructed pixel value being within the first range of values;
• calculate, at the video decoder, a characteristic of each reconstructed pixel value from the reconstructed pixel values of the second pixels of the unit;
• select, at the video decoder, a second filter of the plurality of filters to apply to a second reconstructed pixel value from the reconstructed pixel values of the second pixels, wherein selecting the second filter includes comparing a characteristic of the second reconstructed pixel value of the second pixels to the first range of values, the second range of values, and the third range of values defined by the filter selection information, wherein the filter selection information indicates that the second filter is to be applied to reconstructed pixel values that have characteristics within the second range of values, wherein the second filter is selected, according to the filter selection information, based on the characteristic of the second reconstructed pixel value being within the second range of values, and wherein the second filter is different than the first filter;
• and
• apply, at the video decoder, the first filter to the first reconstructed pixel value of the first pixels and the second filter to the second reconstructed pixel value of the second pixels to produce filtered decoded pixel values of the first and second pixels of the unit, wherein filter coefficients of at least one of the first filter or the second filter are quantized to form quantized filter coefficients, and wherein the quantized filter coefficients are subsequently clipped to be within a range after quantization is performed.