Adaptive video transcoding and streaming over wireless channels
Journal of Systems and Software - Special issue: Adaptive multimedia computing
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
A Frame-Activity-Based Dynamic Frame-Skipping Transcoder
Wireless Personal Communications: An International Journal
Client-centered multimedia content adaptation
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)
Motion information exploitation in H.264 frame skipping transcoding
ACIVS'07 Proceedings of the 9th international conference on Advanced concepts for intelligent vision systems
Parabolic Motion-Vector Re-estimation Algorithm for Compressed Video Downscaling
Journal of Signal Processing Systems
An efficient compressed domain spatial transcoding scheme for adaptive video content delivery
PCM'10 Proceedings of the Advances in multimedia information processing, and 11th Pacific Rim conference on Multimedia: Part II
Fast transcoding algorithm from MPEG2 to h.264
PSIVT'06 Proceedings of the First Pacific Rim conference on Advances in Image and Video Technology
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In multimedia applications, it is often necessary to adapt the bit rates of the coded video bit streams to the available bandwidths of various communication channels. Because different networks may have different bandwidths, a gateway can include a transcoder to adapt the video bit rates in order to provide video services to users on different networks. In transcoding, motion estimation is usually not performed in the transcoder because of its heavy computational complexity. To speed up the operation, a video transcoder usually reuses the decoded motion vectors (MVs) from the incoming bitstream. Previously, the bilinear interpolation and forward dominant vector selection methods were proposed to compose the missing MVs for reuse. We propose a new algorithm, called the activity dominant vector selection, which utilizes the quantized discrete cosine transform coefficients of residual blocks for composing a MV from the incoming ones. In addition, a motion-vector refinement algorithm called variable step-size search is presented. The performance can be improved while maintaining low computational complexity for a reduced frame-rate video transcoder