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|Title: ||New architecture for dynamic frame-skipping transcoder|
|Authors: ||Fung, Kai-tat|
|Subjects: ||Compressed domain processing|
|Issue Date: ||Aug-2002 |
|Citation: ||IEEE Transactions on image processing, Aug. 2002, v. 11, no. 8, p. 886-900.|
|Abstract: ||Transcoding is a key technique for reducing the bitrate of a previously compressed video signal. A high transcoding ratio may result in an unacceptable picture quality when the full frame rate of the incoming video bitstream is used. Frame skipping is often used as an efficient scheme to allocate more bits to the representative frames, so that an acceptable quality for each frame can be maintained. However, the skipped frame must be decompressed completely, which might act as a reference frame to nonskipped frames for reconstruction. The newly quantized discrete cosine transform (DCT) coefficients of the prediction errors need to be re-computed for the nonskipped frame with reference to the previous nonskipped frame; this can create undesirable complexity as well as introduce re-encoding errors. In this paper, we propose new algorithms and a novel architecture for frame-rate reduction
to improve picture quality and to reduce complexity. The proposed architecture is mainly performed on the DCT domain to achieve a transcoder with low complexity. With the direct addition of DCT coefficients and an error compensation feedback loop, re-encoding errors are reduced significantly. Furthermore, we propose a frame-rate control scheme which can dynamically adjust the number of skipped frames according to the incoming
motion vectors and re-encoding errors due to transcoding such that
the decoded sequence can have a smooth motion as well as better
transcoded pictures. Experimental results show that, as compared to the conventional transcoder, the new architecture for frameskipping transcoder is more robust, produces fewer requantization errors, and has reduced computational complexity.|
|Rights: ||© 2002 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.|
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|Type: ||Journal/Magazine Article|
|Appears in Collections:||EIE Journal/Magazine Articles|
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