Abstract: An apparatus for converting a resolution of video including a decoding unit configured to convert a first resolution of a video signal to a second resolution according to a predetermined ratio, to scale a motion vector extracted from the video signal based on the predetermined ratio, and to compensate the scaled motion vector. Also included is a coding unit configured to code a signal output from the decoding unit.

Abstract: A system and method for providing video processing and implementing signal-to-noise ratio scalability is provided. The apparatus comprises a first coder and a second coder. The first coder codes inputted image data utilizing a first quantization step for outputting quantized discrete cosine transform coefficients of the first coder. A second coder codes inputted image data utilizing a second quantization step for generating a difference between discrete cosine transform coefficients from the second coder and the quantized discrete cosine transform coefficients of the first coder.

Abstract: A streaming contents recording method of a mobile terminal including comparing a length of streaming contents with a remaining memory capacity of the mobile terminal, and recording the streaming contents by omitting a specific frame type if the length of the streaming contents is greater than the memory capacity. Further, the omitted specific frame types include a B-frame type or a B-frame type and a P-frame type.

Abstract: A method for judging a lost block characteristic in a video processing system including certifying whether a lost block exists among transmitted video blocks, calculating a temporal difference cost1 between neighborhood pixels of the lost block in a present frame and a previous frame, and calculating a motion vector distribution value cost2 of peripheral blocks of the lost video block. The method also includes comparing the temporal difference cost1 and the motion vector distribution value cost2 with preset threshold values, and determining a characteristic of the lost block based on a result of the comparison. The automatically judged characteristic of the lost block is utilized as information for recovering the lost block to thereby reproduce a recovery video close to the original video.

Abstract: A method for extracting a macro block at a high speed is disclosed to re-set a motion vector in a DCT (Discrete Cosine Transform) region. A macro block is extracted by using an overlap phenomenon where a previously extracted macro block information and macro block information to be currently extracted overlap with each other, so that the amount of calculation can be considerably reduced.

Abstract: A digital video signal processing apparatus for providing video conferencing services in a mobile communication system includes a plurality of mobile terminals each having a video camera and a MCU (multipoint control unit) for mixing video signals received from the video conference terminals to generate a composite signal and for transmitting the composite signal to each of the terminals.

Abstract: An HTTP based video streaming apparatus and method of a mobile communication system is disclosed. A memory, such as a storing disk, stores content files received from a server of a transmitting party, a random access searching unit searches the random access point in the memory and transmits a content file request message to the transmitting server if the random access point does not exist in the memory, and a display unit displays the files from the random access point. Therefore, HTTP streaming service from a random point required by a user can be provided when the streaming has begun, and the random access function can be supported by even if the part required by the user has not yet been transmitted to receiving party.

Abstract: A motion vector and macroblock type determining method is provided. The method comprises receiving a high frame-rate video stream having N frames; skipping a frame N−1; allocating a motion vector to a macroblock of frame N according to a macroblock type of the skipped frame N−1; allocating a macroblock type to a macroblock type of frame N according to a macroblock type of the skipped frame N−1; and outputting a low frame-rate video stream.

Abstract: Apparatus and method for adaptively controlling a bit rate of a video transcoder are disclosed. Logarithmic R-Q characteristics obtaining the adaptive R-Q characteristics suitable to characteristics of an inputted image are proposed, and the parameter (&bgr;) compensating the difference between the coding efficiency of MPEG-1 and the coding efficiency of MPEG-4 is not fixed as a specific value but changed adaptively according to the characteristics of an image. Accordingly, an accurate quantization parameter of MPEG-4 is generated. Thus, on the basis of the proposed concepts, the bit rate is adaptively controlled when the bit stream of MPEG-1 is converted into a bit stream of MPEG-4, so that the picture quality (PSNR) can be heightened and more accurate output bit rate can be obtained.

Abstract: A transcoding method and apparatus for converting a digital bitstream complying with a certain compression method into a digital bitstream complying with a different (or the same) compression method is provided. The transcoding apparatus performs conversion between compressed bitstreams having at least syntax elements and video elements corresponding to video data.

Abstract: A method selects a requantization step size which abruptly changes a bit-rate in a piecewise linearly decreasing model and controls the bit-rate.