Cost effective transcoding for QoS adaptive multimedia streaming
Proceedings of the 2004 ACM symposium on Applied computing
Event on demand with MPEG-21 video adaptation system
MULTIMEDIA '06 Proceedings of the 14th annual ACM international conference on Multimedia
Effective algorithms for fast transcoding of AVS to H.264/AVC in the spatial domain
Multimedia Tools and Applications
MPEG-4 to H.264 transcoding with frame rate reduction
Multimedia Tools and Applications
Variable frame rate video for mobile devices
MobiMedia '06 Proceedings of the 2nd international conference on Mobile multimedia communications
Personalized video adaptation based on video content analysis
Proceedings of the 9th International Workshop on Multimedia Data Mining: held in conjunction with the ACM SIGKDD 2008
Mixed architectures for H.264/AVC digital video transrating
Multimedia Tools and Applications
A Frame-Activity-Based Dynamic Frame-Skipping Transcoder
Wireless Personal Communications: An International Journal
Compressed-domain techniques for error-resilient video transcoding using RPS
IEEE Transactions on Image Processing
Journal of Visual Communication and Image Representation
A New Dual-bitstream Video Streaming System with VCR Functionalities Using SP/SI-frames
Journal of Signal Processing Systems
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Transcoding is a key technique for reducing the bit rate 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 frame-skipping transcoder is more robust, produces fewer requantization errors, and has reduced computational complexity.