The patent's assignee for patent number 8774272 is
News editors obtained the following quote from the background information supplied by the inventors: "The invention relates to data processing systems and methods, and in particular to video encoding systems and methods.
"Commonly-used video encoding methods are based on MPEG (
"Each frame is typically divided into multiple non-overlapping rectangular blocks. Blocks of 16.times.16 pixels are commonly termed macroblocks. Other block sizes used in encoders using the H.264 standard include 16.times.8, 8.times.16, 8.times.8, 8.times.4, 4.times.8, and 4.times.4 pixels. For each block in an inter-frame, a typical MPEG encoder searches for a corresponding, similar block in that inter-frame's anchor frame(s). If a sufficiently similar block is not found in the anchor frames, then the current block is intra-coded. If a similar block is found, the MPEG encoder stores residual data representing differences between the current block and the similar block in the anchor frame, as well as motion vectors identifying the difference in position between the blocks. The difference data is converted to the frequency domain using a transform such as a discrete cosine transform (DCT). The resulting frequency-domain data is quantized and variable-length (entropy) coded before storage/transmission.
"Quantizing the data involves reducing the precision used to represent various frequency coefficients, usually through division and rounding operations. Quantization can be used to exploit the human visual system's different sensitivities to different frequencies by representing coefficients for different frequencies with different precisions. Quantization is generally lossy and irreversible. A quantization scale factor MQuant or quantization parameter Q can be used to control system bitrates as the visual complexity of the encoded images varies. Such bitrate control can be used to maintain buffer fullness within desired limits, for example. The quantization parameter is used to scale a quantization table, and thus the quantization precision. Higher quantization precisions lead to locally increased bitrates, and lower quantization precisions lead to decreased bitrates.
"MPEG frames are typically organized in groups-of-pictures (GOPs). A
"FIG. 1 illustrates an exemplary frame sequence 20, shown in display order, including a closed
"Inter-coded (P- and B-) frames may include both intra-coded and inter-coded blocks. For any given inter-frame block, the encoder can calculate the bit cost of encoding the block as an intra-coded block or as an inter-coded block. In some instances, for example in parts of fast-changing video sequences, inter-encoding may not provide encoding cost savings for some blocks, and such blocks can be intra-encoded. If inter-encoding provides desired encoding cost savings for a block, the block is inter-encoded.
"Each inter-encoded block in a P-frame may be encoded with reference to a block in a preceding or subsequent frame, in display (temporal) order. Each inter-encoded block in a B-frame may be encoded with reference to one or two other frames. The reference frames can be before and/or after the frame to be encoded, in display order. If two reference frames are used, several temporal order combinations are possible: one past and one future reference frame, two past reference frames, and two future reference frames.
"While MPEG-based video coding methods can yield remarkably-accurate representations of motion pictures, the human visual system can sometimes detect imperfections or artifacts in MPEG-encoded video sequences. Such artifacts can become particularly noticeable at relatively low system bandwidths."
As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventor's summary information for this patent: "According to one aspect, a video data encoding method comprises controlling a set of block encoding modes in a plurality of inter video frames in a group of pictures according to a frame position in the group of pictures to generally decrease a forward inter-encoded frame content with the frame position in the group of pictures. The plurality of inter frames are encoded according to the set of block encoding modes.
"According to another aspect, a video data encoding method comprises receiving video data for a plurality of inter frames in a group of pictures; making an encoding mode determination for each of a plurality of encoding blocks in each of the plurality of inter frames according to a position of said each of the plurality of inter frames in the group of pictures; and encoding each of the plurality of encoding blocks according to the encoding mode determination.
"According to another aspect, a video data encoding method comprises receiving video data for a plurality of inter frames in a group of pictures; and controlling an intra-encoded content of the plurality of inter-frames according to a frame position in the group of pictures to increase the intra-encoded content with the frame position in the group of pictures.
"According to another aspect, a video data encoding method comprises receiving video data for a plurality of inter frames in a group of pictures; and controlling a backward-predicted content of the plurality of inter-frames according to a frame position in the group of pictures to increase the backward-predicted content with the frame position in the group of pictures.
"According to another aspect, a video data encoder integrated on a chip comprises a mode decision processor configured to make an encoding mode determination for each of a plurality of encoding blocks in each of a plurality of inter frames in a group of pictures according to a position of said each of the plurality of inter frames in the group of pictures; and video encoding logic connected to the mode decision processor and configured to encode said each of the plurality of encoding blocks according to the encoding mode determination."
For additional information on this patent, see: Chen, Lulin. Video Quality by Controlling Inter Frame Encoding According to Frame Position in
Keywords for this news article include: Electronics,
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