摘要:
The invention, in a first aspect, is a method for mitigating edge effects in a decompressed video image. The method comprises first reads an N×N group of pixels defining a vertical edge between two blocks in a video frame row by row into N registers, wherein N is a predetermined number defining the length of a filter. The content of the N registers is then transposed and then filtered in the filter. The filtered content of the N registers is then transposed and stored back from where it was read. In other aspects, the invention is a program storage device encoded with instructions that, when executed by a computer, perform such a method; a computer programmed to perform such a method; and a computing system capable of performing such a method.
摘要:
A method is disclosed for performing an inverse discrete cosine transform (IDCT) using a microprocessor having an instruction set that includes SIMD floating-point instructions. In one embodiment, the method includes: (1) receiving a block of integer data having C columns and R rows; and (2) for each row, (a) loading the row data into registers; (b) converting the row data into floating-point form so that the registers each hold two floating-point row data values; and (c) using SIMD floating-point instructions to perform weighted-rotation operations on the values in the registers. Suitable SIMD floating-point instructions include the pswap, pfmul, and pfpnacc instructions. For the row-IDCT, the data values are preferably ordered in the registers so as to permit the use of these instructions. For the column-IDCT, two columns are preferably processed concurrently using SIMD instructions to improve computational efficiency. An intermediate buffer may be used to avoid unnecessary conversions between integer and floating-point format.
摘要:
An efficient finite length POW10 calculation for MPEG audio encoding. A method for encoding an audio input signal includes storing a plurality of predetermined tonal values corresponding to a plurality of predetermined power levels. The method also includes receiving a plurality of input values each representative of a power level of a spectral component of the audio input signal at a corresponding frequency sub-band and accessing at least one corresponding tonal value of the plurality of predetermined tonal values. The method further includes generating an encoded output signal representative of the audio input signal by using at least one corresponding tonal value for each of the plurality of input values. Further, the storing of the plurality of predetermined tonal values is performed prior to the receiving of the plurality of input values.
摘要:
An adaptive region-based, multi-scale, motion compensated video compression algorithm design for transmission over hostile communication channels. The algorithm is embodied in a video encoder that extracts spatial information from video frames to create video regions that are then decomposed into sub-bands of different perceptual importance before being compressed and transmitted independently. The system further uses unequal error protection, prioritized transmission and reconstruction to guarantee a minimum spatial and temporal resolution at the receiver. In particular, the region segmented frames bound both spatial and temporal error propagation within frames. A connection-level inter-region statistical multiplexing scheme is also employed to ensure optimal utilization of reserved transmission bandwidth.
摘要:
A method is disclosed for performing a discrete cosine transform (DCT) using a microprocessor having an instruction set that includes SIMD floating point instructions. In one embodiment, the method includes: (1) receiving a block of integer data having C columns and R rows; and (2) for each row, (a) loading the row data into registers; (b) converting the row data into floating point form so that the registers each hold two floating point row data values; and (c) using SIMD floating point instructions to perform weighted-rotation operations on the values in the registers. Suitable SIMD floating point instructions include the pswap, pfmul, and pfpnacc instructions. For the row-DCT, the data values are preferably ordered in the registers so as to permit the use of these instructions. For the column-DCT, two columns are preferably processed in parallel using SIMD instructions to improve computational efficiency. An intermediate buffer may be used to avoid unnecessary conversions between integer and floating point format.
摘要:
An improved form of half pixel accuracy motion estimation/compensation using the MPEG recommended half pixel approach resides in method and system. In the inventive method, an interpolated reference image is created before coding so that it can be preloaded into a cache memory and used whenever needed, without having to create it each time. To avoid redundant processing during accessing of subsampled interpolated data, the interpolated image using half pixel method is partitioned into four areas. The four areas are defined based on where in a 2×2 square region the pixels fall.
摘要:
A method for making a voice communications link is implemented using local and remote computers, each of which operates in an instant messenger environment and is connected to a data network. The local computer is equipped with a call forwarding device for connecting to a telephone network. The method includes: a) in response to an incoming phone call placed by a calling party and received by the local computer through the call forwarding device, enabling activation of the instant messenger function of the local computer for paging the remote computer; and b) in response to an acknowledge message issued by the remote computer to accept establishment of the voice communications link and received by the local computer through the data network, activating the instant messenger function of the local and remote computers for establishing the voice communications link.
摘要:
Methods and system provide for the encoding of video frames using a plurality of processors. In one example, a first processor provides a location of a plurality of non-stationary pixels in a current frame by comparing pixel data in the current frame with corresponding pixel data in a previous frame for use by a second processor. The first processor also provides pixel data describing substantially only non-stationary pixels in the current frame, for use by the second processor. The second processor calculates motion vector data for the plurality of non-stationary pixels based on the non-stationary pixel location information and the pixel data describing substantially only non-stationary pixels. The first processor encodes the current frame using the motion vector data for the plurality of non-stationary pixels from the second processor.
摘要:
In a multimedia compression system such as is used in compressing data in a video stream, “zero blocks” from an MPEG block array are identified prior to encoding and subjecting blocks to the process of quantized discrete cosine transform (DCT). A zero block as understood herein is an MPEG video data block that results when an unencoded block of video data is identical to an adjacent un-encoded block of video data, i.e., when there is little or no change between consecutive frames of video. The efficiency of the compression system is increased in this invention by not having to perform the functions of DCT, quantization, dequantization or inverse DCT on the identified zero blocks, but simply directly encoding zero blocks.
摘要:
A method of quantizing multiple input values in parallel using SIMD instructions is disclosed. In one embodiment, the method comprises (1) receiving a set of input values Xi; (2) operating on the set of input values to produce a set of binary mask values Ki that are related to the input values Xi by Ki=−1 if Xi>0, and Ki=0 if Xi 0, and Yi=Xi−Q/2 if Xi≦0. The prequantization values may then be converted to floating point format, divided by Q, and restored to integer format to obtain the desired quantization values. Each of these operations can be performed in parallel on each of the values in the set using SIMD instructions.