Abstract: A method and apparatus is disclosed herein for decoding data (e.g., video data) using transforms. In one embodiment, the decoding process comprises scaling a block of coefficients using a scaling factor determined for each coefficient by computing an index for said each coefficient and indexing a look-up table (LUT) using the index. The index is based on a quantization parameter, a size of the block of coefficients, and a position of said each coefficient within the block. The method also comprises applying a transform to the block of scaled coefficients.

Abstract: An apparatus for processing a video signal and method thereof are disclosed. The present invention includes receiving the video signal, extracting discrete cosine transform information from the video signal, and performing inverse discrete cosine transform using the discrete cosine transform information, wherein the discrete cosine transform information indicates a rearrangement mode of blocks in the discrete cosine transform. Accordingly, a video signal processing method of the present invention, improves efficiency of discrete cosine transform in a manner of rearranging blocks of video signal by considering a prediction mode prior to performing discrete cosine transform. The present invention enhances coding efficiency by using a row or column shifted matrix and shift information including information relevant to the row or column shifted matrix and by directly performing RRU (reduced resolution update) scheme on a discrete cosine transform/inverse discrete cosine transform domain.

Abstract: This disclosure describes the use of non-dyadic discrete cosine transform (DCT) sizes for performing a DCT. Similarly, this disclosure describes the use of non-dyadic inverse discrete cosine transform (IDCT) sizes for performing an IDCT. Using non-dyadic transform sizes may be less computationally expensive compared to using conventional dyadic transform sizes. Aspects of this disclosure may be useful in any device or system that performs a DCT or IDCT.

Abstract: A unified solution to coding/decoding of different video formats such as 4:2:0, 4:2:2 and 4:4:4 is provided. A method of video coding includes transforming a first m×n macro block of residual chrominance pixel values of moving pictures by a first integer-transform function generating a corresponding second m×n macro block of integer-transform coefficients, further transforming DC values of the integer-transform coefficients by a second integer-transform function to generate a third block of integer-transformed DC coefficients. The method further includes generating the second m×n macro block of integer-transform coefficients by utilizing a k×k integer-transform function on each k×k sub-block of the first m×n macro block, wherein n and m are each a multiple of k, and generating the third block of coefficients by utilizing a second ixj integer-transform function on the DC values resulting in a (m/k)×(n/k) third block of integer-transformed DC coefficients.

Abstract: A method and apparatus is disclosed for efficiently encoding data representing a video image, thereby reducing the amount of data that must be transferred to a decoder. The method includes transforming data sets utilizing a tensor product wavelet transform which is capable of transmitting remainders from one subband to another. Collections of subbands, in macro-block form, are weighted, detected, and ranked enabling prioritization of the transformed data. A motion compensation technique is performed on the subband data producing motion vectors and prediction errors which are positionally encoded into bit stream packets for transmittal to the decoder. Subband macro-blocks and subband blocks which are equal to zero are identified as such in the bit stream packets to further reduce the amount of data that must be transferred to the decoder.

Abstract: A compression method and a compression system for display frames of QFHD (quad full high definition) resolution are provided and applied to the image encoding/decoding environment of the H.264/AVC image encoding standard of the QFHD resolution and the effective dictionary base compression and de-compression algorithm, the image data compression rate can be tremendously raised at the resolution of 1080 HD (High Definition) content and the average memory data rate is greatly decreased. Hence only a bus with a lower frequency as 57 MHz can be done for the real-time of the resolution of 1080 HD content.

Abstract: A method of fast mode decision of an enhancement layer using a bitrate-distortion cost in an SVC encoder includes: calculating a bitrate-distortion cost for a current macro block of an enhancement layer and a bitrate-distortion cost for a previous macro-block of the current macro block of an enhancement layer based on an optimal motion mode and an motion vector for a macro block of a base layer of a current frame; correcting the bitrate-distortion cost for the previous macro block calculated at the calculating by a correction value for reflecting relationship with the previous frame to calculate a final bitrate-distortion cost for the previous macro block; and comparing the bitrate-distortion cost for the current macro block calculated at the calculating with the final bitrate-distortion cost calculated at the correcting and selecting a motion mode that will be removed from the current macro block according to the comparison result.

Abstract: A method and a device for approximating a DC coefficient of a first block of pixels of a first frame are proposed. The method comprises: calculating a luminance DC average value based on DC coefficients of first frame's macro-blocks without an approximation error; and determining the DC coefficient of the first block based on the DC coefficient of a second block, wherein the second block is a part of a second frame, which is a reference frame of the first frame, the second block overlapping with a reference block of the first block and having the closest DC coefficient to the luminance DC average value.

Abstract: A system and method is provided for improving efficiency when entropy coding a block of quantized transform coefficients in video coding. Quantized coefficients are coded in two separate coding modes, namely, a run mode to a level mode coding mode. “Rules” for switching between these two modes are provided, and various embodiments are realized by allowing an entropy coder to adaptively decide when to switch between the two coding modes based on context information, the rules and/or by explicitly signaling the position of switching (e.g., whether or not it should switch coding modes).

Abstract: An image information decoding method for decoding compressed image information which has been coded via a process including dividing an input image signal into blocks, performing an orthogonal transform on the blocks on a block-by-block basis, and quantizing resultant orthogonal transform coefficients. The decoding process includes performing dequantization such that a quantization parameter is weighted by an addition operation, and the dequantization is performed on each chroma components of the quantized coefficients using said weighted quantization parameter, and performing an inverse orthogonal transform.

Abstract: A method of creating a bitstream comprises receiving video data, receiving auxiliary data, translating the auxiliary data according to a defined scheme, encoding the translated auxiliary data as one or more video frames, each frame substantially consisting of the encoded translated auxiliary data, and combining the video data and the encoded video frames into a bitstream. A device for carrying out the creation of the bitstream is disclosed, along with a corresponding handling method and device arranged to receive the bitstream.

Abstract: Adjustment of hardware acceleration level in a video decoder utilizing hardware acceleration is described. Errors are detected in a bitstream as it is decoded using different levels of error detection based on decoding characteristics. A statistical analysis is performed on the error values as they are detected. In one technique, if the bitstream is categorized as fitting a high error rate state in a bitstream model, then hardware acceleration is dropped. In another technique, error statistics based on run-lengths of good and bad bitstream units are kept, and compared to predetermined thresholds. If the thresholds are exceeded, the hardware acceleration level is dropped. The level is dropped in order to take advantage of superior error handing abilities of software-based decoding over hardware-accelerated decoding.

Abstract: A method and an arrangement for processing data in a digital input image include a decoder configured to decode encoded data. A detector is configured to detect the decoded data and a correction device is configured to correct the detected data. A predicted maximum frequency is calculated based on first and second data sets transformed by first and second transform, respectively. A real maximum frequency is calculated based on data transformed by an overall transform of a data set corresponding to the concatenation of the first and second data sets. A grid is determined by comparing the real and predicted maximum frequencies for a portion of the digital input image.

Abstract: A method and apparatus for encoding surveillance video where one or more regions of interest are identified and the encoding parameter values associated with those regions are specified in accordance with intermediate outputs of a video analytics process. Such an analytics-modulated video compression approach allows the coding process to adapt dynamically based on the content of the surveillance images. In this manner, the fidelity of the region of interest is increased relative to that of a background region such that the coding efficiency is improved, including instances when no target objects appear in the scene. Better compression results can be achieved by assigning different coding priority levels to different types of detected objects.

Abstract: A method and system for minimizing bus traffic in a video decoder is disclosed. A method and system for processing a portion of a reference picture includes designating the reference picture, selecting a display picture within the reference picture, transmitting a display picture size, and sending a display picture offset. A method and system for compressing IDCT coefficients corresponding to a macroblock, the macroblock having a plurality of blocks, includes locating each non-zero IDCT coefficient corresponding to one of the plurality of blocks, assigning an index to the non-zero IDCT coefficient, the index designating a location within the one of the plurality of blocks, packing the non-zero IDCT coefficient in little endian format, and specifying a terminator bit corresponding to the non-zero coefficient, the terminator bit indicating the end of all non-zero IDCT coefficients for the one of the plurality of blocks.

Abstract: A method and system for performing a 2D transform is disclosed. The 2D transform may include a row transform and/or a column transform. When performing the row or column transform, it may be determined whether each of different subsets of the data values including a partition of a row or column includes at least one zero value, whether each of different subsets of a first subset of the partition includes at least one zero value, and whether each of different subsets of at least one other subset of the partition includes at least one zero value. When performing the row or column transform, at least one transformation operation on at least one zero value may be bypassed or performed in a reduced-power manner, where such transformation operation would otherwise be performed in a manner consuming full power if the zero value were a non-zero value.

Abstract: An embodiment is a method and apparatus to process video frames. An entropy decoder performs entropy decoding on a bitstream of a video frame extracted from a network frame. The entropy decoder generates discrete cosine transform (DCT) coefficients representing a picture block in the video frame. The entropy decoder is configured for serial operations. A graphics processing unit (GPU) performs image decoding using the DCT coefficients. The GPU is configured for parallel operations. One disclosed feature of the embodiments is a technique to decode a video frame. A GPU performs image encoding of a video frame computing quantized DCT coefficients representing a picture block in the video frame. The GPU is configured for parallel operations. An entropy encoder performs entropy encoding on the quantized DCT coefficients. The entropy encoder is configured for serial operations.

Abstract: A method for transmitting video information is shown, in which at least a first bit-stream (510) and a second bit-stream are formed. The first bit-stream (510) includes a video frame, and the second bit-stream (520) includes a predictive video frame (524). Different encoding parameters are used with encoding of the frames of the first bit-stream (510) and the second bit-stream (520). A frame of the first bit-stream (510) is transmitted, and the transmission is switched over from the first (510) to the second bit-stream (520) during which a secondary switching frame (550) is transmitted encoded using the encoding parameters of the second bit-stream (520) and at least one reference frame from the first bit-stream (510). The secondary switching frame (550) is used as a reference frame in the reconstruction of the predictive video frame (524) of the second set of video frames.

Abstract: A video encoding method comprises selecting one combination, for each block of an input video signal, from a plurality of combinations each including a predictive parameter and at least one reference picture number determined in advance for the reference picture, generating a prediction picture signal in accordance with the reference picture number and predictive parameter of the selected combination, generating a predictive error signal representing an error between the input video signal and the prediction picture signal, and encoding the predictive error signal, information of the motion vector, and index information indicating the selected combination.

Abstract: The invention presents a scalable solution to encode the whole 12-bit raw video once to generate one bitstream that contains an H.264/AVC compatible base layer and a scalable enhancement layer. If a color bit depth scalable decoder is available at the client end, both the base layer and the enhancement layer sub-bitstreams will be decoded to obtain the 12-bit video and it can be viewed on a high quality display that supports more than eight bit; otherwise only the base layer sub-bitstream is decoded using an H.264/AVC decoder and the decoded 8-bit video can be viewed on a conventional 8-bit display. The enhancement layer contains a residual based on a prediction from the base layer, which is either based on bit-shift or based on an advanced bit depth prediction is utilized, wherein the advanced bit depth prediction method is a Smoothed Histogram method or a Localized Polynomial Approximation method.

Abstract: The present invention relates to a video signal decoding method for adding an intra prediction mode as a sub-macroblock type to prediction of a macroblock in coding a video signal. The present invention includes obtaining a macroblock type, obtaining a sub-macroblock type when a macroblock includes a plurality of coded sub-macroblocks according the macroblock type, obtaining flag information indicating a DC (discrete cosine) transform size, determining the DC transform size of the coded sub-macroblock based on the flag information, when the sub-macroblock is intra prediction coded based on the sub-macroblock type, determining a prediction size of the intra prediction coded sub-macroblock based on the determined DC transform size, obtaining prediction direction information from a block adjacent to the sub-macroblock based on the prediction size of the sub-macroblock, and obtaining a prediction value of the sub-macroblock based on the prediction direction information.

Abstract: The present invention relates to a method for transmitting video information, in which a bitstream is formed comprising a set of frames comprising macroblocks. At least one switching frame is formed into the bitstream, macroblocks of the switching frame are arranged into a first and a second group of macroblocks, each macroblock of the first group of macroblocks are encoded by a first encoding method to provide a switching point for continuing the transmission of video information with another bitstream formed from the video information; and macroblocks of the second group of macroblocks are encoded by another encoding method. Errors in transmission of video information are reduced by forming at least one SP-encoded frame by predictively encoding the macroblocks; replacing part of the SP-encoded macroblocks with intra encoded blocks; and transmitting the encoded frame containing both predictively and intra encoded macroblocks instead of the SP-encoded frame.

Abstract: Inverse discrete cosine transform (type-III DCT), used in video/image and audio coding, is implemented in the form of FFT to lower computational complexity.

Abstract: Tools and techniques for applying scan patterns during encoding and decoding of interlaced video are described. For example, a video decoder scans transform coefficients from a one-dimensional array to a two-dimensional block according to a scan pattern. The block is 4×4, and the scan pattern biases the vertical direction by starting with the DC coefficient and three AC coefficients of the lowest horizontal frequency. Or, the block is 8×4, and the scan pattern biases the vertical direction by starting with the DC coefficient and three AC coefficients of the lowest horizontal frequency. Or, the block is 4×8, and the scan pattern biases the horizontal direction for the lowest frequency AC coefficients in the horizontal and vertical directions but biases the vertical direction for at least some other AC coefficients. A corresponding video encoder applies the scan patterns to scan transform coefficients from two-dimensional blocks to one-dimensional arrays.

Abstract: A method of and an apparatus for predicting discrete cosine transform coefficients. A discrete cosine transform coefficient prediction method and apparatus performs a discrete cosine transform on a row and column of pixel blocks nearest to a transform coefficient to be predicted in a discrete cosine transform block to be predicted among pixel blocks adjacent to the discrete cosine transform block to create a prediction coefficient for the transform coefficient to be predicted, and predict the transform coefficient to be predicted using the created prediction coefficient. By using prediction coefficients with higher correlation to a transform coefficient of a discrete cosine transform block to be predicted, an image may be efficiently compressed.

Abstract: A unified solution to coding/decoding of different video formats such as 4:2:0, 4:2:2 and 4:4:4 is provided. A method of video coding includes transforming a first m×n macro block of residual chrominance pixel values of moving pictures by a first integer-transform function generating a corresponding second m×n macro block of integer-transform coefficients, further transforming DC values of the integer-transform coefficients by a second integer-transform function to generate a third block of integer-transformed DC coefficients. The method further includes generating the second m×n macro block of integer-transform coefficients by utilizing a k×k integer-transform function on each k×k sub-block of the first m×n macro block, wherein n and m are each a multiple of k, and generating the third block of coefficients by utilizing a second i×j integer-transform function on the DC values resulting in a (m/k)×(n/k) third block of integer-transformed DC coefficients.

Abstract: A video encoding method comprises selecting one combination, for each block of an input video signal, from a plurality of combinations each including a predictive parameter and at least one reference picture number determined in advance for the reference picture, generating a prediction picture signal in accordance with the reference picture number and predictive parameter of the selected combination, generating a predictive error signal representing an error between the input video signal and the prediction picture signal, and encoding the predictive error signal, information of the motion vector, and index information indicating the selected combination.

Abstract: A video encoding method comprises selecting one combination, for each block of an input video signal, from a plurality of combinations each including a predictive parameter and at least one reference picture number determined in advance for the reference picture, generating a prediction picture signal in accordance with the reference picture number and predictive parameter of the selected combination, generating a predictive error signal representing an error between the input video signal and the prediction picture signal, and encoding the predictive error signal, information of the motion vector, and index information indicating the selected combination.

Abstract: A multi-sensor network camera providing up to 360 degrees angle of view. The includes multiple image sensors with individual optics, one or more image processors, compression units and network interfaces mounted in the single housing. The image sensors are positioned in non-parallel planes, cumulatively providing panoramic field of view and image streams originating from all sensors share the same image compression and network interface hardware, providing for low cost implementation. The images from all sensors are transmitted over the network simultaneously via packet interleaving, with appropriate bandwidth reduction achieved by image decimation. Simultaneously with transmission of decimated images from all sensors, full resolution window or entire image of one or more sensors may also transmitted, where the selection of contents is based on motion detection or user setting.

Abstract: A method of processing a video signal is disclosed. The present invention includes obtaining a DC (discrete cosine) transform coefficient for a current macroblock and partition information of a DC (direct current) component block from a bitstream, obtaining transform size information of each partition of the DC component block based on the partition information of the DC component block, performing an inverse DC transform or a Hadamard transform based on the transform size information of the partition of the DC component block, performing inverse quantization on a result value from the transform and an AC (alternating current) component, and reconstructing a residual block by performing an inverse DC transform on a result value from the inverse quantization, wherein the residual block includes a block indicating a pixel value difference between an original picture and a predicted picture.

Abstract: A video encoding method comprises selecting one combination, for each block of an input video signal, from a plurality of combinations each including a predictive parameter and at least one reference picture number determined in advance for the reference picture, generating a prediction picture signal in accordance with the reference picture number and predictive parameter of the selected combination, generating a predictive error signal representing an error between the input video signal and the prediction picture signal, and encoding the predictive error signal, information of the motion vector, and index information indicating the selected combination.

Abstract: A video encoding method comprises selecting one combination, for each block of an input video signal, from a plurality of combinations each including a predictive parameter and at least one reference picture number determined in advance for the reference picture, generating a prediction picture signal in accordance with the reference picture number and predictive parameter of the selected combination, generating a predictive error signal representing an error between the input video signal and the prediction picture signal, and encoding the predictive error signal, information of the motion vector, and index information indicating the selected combination.

Abstract: Provided are an apparatus for multi-stage transforming a plurality of unit blocks in multi-dimension that can improve compression efficiency of video data by collecting Discrete Cosine Transforming (DCT) coefficients of neighboring blocks and performing an additional transformation based on the DCT coefficients of an original picture and a differential picture. The method includes the steps of: performing a Discrete Cosine Transform (DCT) on inputted picture data and selecting R blocks of a predetermined size from DCT picture data, where R is a natural number equal to or greater than 2; arranging DCT coefficients of each of the selected R blocks according to each frequency in one-dimension; and performing one-dimensional transformation again on the DCT coefficients arranged in one-dimension.

Abstract: A server at the edge of a broadband network distributes multimedia content streams to clients, while ensuring that the first data delivered to each client is key data (milestones) needed for correctly decoding the stream content. This is obtained by buffering the packets in the incoming stream and transmitting the packets from the buffer in an outgoing stream, starting with the most recent milestone placed in the buffer before a request to join the respective incoming stream is received. As the writing to and reading from the buffer are performed at different rates, the incoming and outgoing streams are eventually synchronized, at which point the client may be switched to receive the incoming stream directly.

Abstract: A method for interference-free, centrally controlled switchover from a first to a second program channel in a data transmission system for distributing encoded program data streams to multiple subscribers includes delivering at least two program data streams, each of which is associated with a separate program channel, to a separate, controllable encoder. The program data streams are encoded in the associated encoders. The encoded first and second program data streams are fed into a distribution network. One encoded program data stream is delivered through a routing device to at least one target subscriber. Control parameters are provisioned in a central control device which permits a synchronized activation of the controllable encoders and at least one switching device for interference-free switchover of the program channels. An interference-free switchover from the first to the second program channel is executed.

Abstract: A head end application server is coupled to a photo-sharing server having an Internet interface. A video content network is coupled to the head end application server, and a terminal is coupled to the video content network at a location remote from the head end application server and the photo-sharing server. The photo-sharing server is configured to accept upload of digital still images via the Internet interface, and the digital still images are in a format other than MPEG I-frames. The head end application server is configured to receive a request from the terminal and, responsive to the request, to fetch the digital still images from the photo-sharing server, transcode the digital still images into MPEG I-frames, and make the MPEG I-frames available, over the video content network, for selective display via the terminal. The system can advantageously function without use of a video-on-demand server.

Abstract: When a quantized DCT coefficient and a quantization parameter are input from an entropy decoder, a controller outputs them to a switch and gives a load detector an instruction to detect system load. The load detector requests system load information from OS. If the system load is light, the load detector controls the switch to execute first inverse quantization of general load by a general processor and obtain a DCT coefficient. If the system load is heavy, the load detector controls the switch to execute second inverse quantization whose processing load is lighter than the first inverse quantization by a specific processor and obtain a DCT coefficient.

Abstract: An encoding circuit transforms a picture signal into blocks of, for example, 8*8 coefficients, in which each block of coefficients is read motion- adaptively. In the case of motion within a sub-picture, the block of coefficients is read in such an order that the obtained series of coefficients includes, as it were, two interleaved sub-series. The first series starts with a dc component. In a first embodiment, the second series starts with the most relevant motion coefficient. In a second embodiment, two interlaced sub-fields are separately transformed and the second series also starts with a dc coefficient. As a result, the coefficients are transmitted as much as possible in their order of significance. This particularly produces the largest possible clusters of zero value coefficients. Such clusters are transmitted as one compact run-length code so that an effective bit rate reduction is achieved, also for moving pictures.

Abstract: A method for transcoding between videostreams using different entropy coding, comprising the steps of (A) decoding a first videostream using a first set of entropy codes, and (B) generating a second videostream by entropy encoding the decoded first videostream using a second set of entropy codes. The first set of entropy codes and the second set of entropy codes are configured to represent all valid coefficient values of the first videostream.

Abstract: A video predictive decoding method and apparatus for predicting a current block of a picture. The method includes storing at least one previous product in a memory. The previous product corresponds to a block of a plurality of blocks of the picture. The previous product is the product of a quantized AC coefficient and a quantization scale of the block that the previous product corresponds to. The method further includes determining which block to use as a prediction block from the plurality of blocks, reading from the memory at least one previous product corresponding to the prediction block, and calculating at least one quantized AC coefficient of the current block using the at least one previous product read from the memory.

Abstract: A method and apparatus is disclosed herein for decoding data (e.g., video data) using transforms. In one embodiment, the decoding process comprises scaling a block of coefficients using a scaling factor determined for each coefficient by computing an index for said each coefficient and indexing a look-up table (LUT) using the index. The index is based on a quantization parameter, a size of the block of coefficients, and a position of said each coefficient within the block. The method also comprises applying a transform to the block of scaled coefficients.

Abstract: Video encoding apparatuses and methods with decoupled data dependency are provided. An embodiment of a method for video encoding with decoupled data dependency contains at least steps as follows. Data generated from a macroblock of a previous frame is acquired. At least one reference parameter for a macroblock of a current frame is determined according to the acquired data. The macroblock of the current frame is encoded according to the determined reference parameter to generate an output bitstream.

Abstract: An image processing apparatus capable of controlling the amount of codes in the image data of one image through one-pass encoding, without changing a quantization table. A Discrete Cosine Transformation (DCT) unit performs discrete cosine transformation on each MCU of the image data of the image. A quantizer quantizes DCT coefficients resulted from the discrete cosine transformation, using the quantization table. A code amount controller sets a threshold value for each MCU based on a target amount of codes for one image and the amount of codes usable for the unprocessed MCUs, reduces the quantized DCT coefficients based on the threshold value, in order to adjust the amount of codes to be generated in the MCU.

Abstract: Systems and methods for video communication are described. In one aspect, network bandwidth conditions are estimated. Bi-level or full-color video is then transmitted over the network at transmission bit rates that are controlled as a function of the estimated bandwidth conditions. To this end, network bandwidth capability is periodically probed to identify similar, additional, or decreased bandwidth capabilities as compared to the estimated bandwidth conditions. Decisions to hold, decrease, or increase the video transmission bit rate are made based on the estimated bandwidth conditions in view of the probing operations. When the transmission bit rate is increased or decreased, the transmission bit rate is calculated to target an upper or lower bit rate, both of which are indicated by the estimated bandwidth conditions. Bi-level video communication is switched to full-color video transmission, or vice versa, when the video transmission bit rate respectively reaches the upper bit rate or the lower bit rate.

Abstract: A method of generating a spatial prediction of a target block of pixels in a target image includes generating a spatial vector for a target block of pixels, using the spatial vector to construct a spatial reference block, and using the spatial reference block to generate the spatial prediction of the target block.

Abstract: Methods and apparatus for implementing a reduced cost HDTV/SDTV video decoder are disclosed. The described joint video decoder is capable of decoding HDTV pictures at approximately the resolution of standard definition television pictures and can be used to decode HDTV and/or SDTV pictures. The described video decoder may be used as part of a picture-in-picture decoder circuit for providing picture-in-picture capability without providing multiple full resolution video decoders. The reduction in decoder circuit complexity is achieved through the use of a plurality of data reduction techniques including the use of a preparser, downsampling, and truncating pixel values.

Abstract: A system having a video pipeline that includes a variation calculation portion is disclosed. The variance calculation portion calculates a plurality of variance values for a macroblock. A DCT-type indicator for the macroblock is determined based upon the plurality of variance values.

Abstract: The discrete cosine transform (DCT) is mapped to a graphics processing unit (GPU) instead of a central processing unit (CPU). The DCT can be implemented using a shader-based process or a host-based process. A matrix is applied to a set of pixel samples. The samples are processed in either rows or columns first, and then the processing is performed in the opposite direction. The number of times a shader program is changed is minimized by processing all samples that use a particular shader (e.g., the first shader) at the same time (e.g., in sequence).

Abstract: Low complexity edge detection and DCT type selection method to improve the visual quality of H.264/AVC encoded video sequence is described. Encoding-generated information is reused to detect an edge macroblock. Variance and Mean Absolute Difference (MAD) of one macroblock shows a certain relationship that is able to be used to differentiate the edge macroblock and the non-edge macroblock. Also, the variance difference of neighbor macroblocks provides a hint for edge existence. Then, a block-based edge detection method uses this information. To determine the DCT type for each block, the detected edges are differentiated as visual obvious edge, texture-like edge, soft edge and strong edge. 8×8 DCT is used for texture-like edges and the 4×4 DCT is used for all the other edges. The result is an efficient and accurate edge detection and transform selection method.

Abstract: An encoded bit stream having a frame rate of 24 Hz or 23.976 Hz and a progressive format for both NTSC and PAL is recorded on a recording medium. An encoded stream reproduced from the recording medium is supplied to a decoder 20. In the decoder 20, the encoded stream is decoded and 24 p or 23.976 p video is obtained. A video converting portion 25 converts the reproduced video into a display video in accordance with the display format of a monitor 26. For the NTSC range, 29.97 i or 59.94 p display format can be used. For the PAL range, 25 i or 50 p display format can be used.