Patent ID: 8107530
Filing Date: 2012-01-31
Classification: H04L,H04N

Abstract:
1. A video transcoder comprising: a decoding unit decoding compressed video to generate a video header, a motion vector, and a DCT (discrete cosine transform) coefficient for each frame of the compressed video; a single description/multiple description determining unit determining whether to perform transcoding into a single description or multiple descriptions based on the possibility of errors occurring in a transmission channel of the compressed video; and a transcoding unit performing transcoding into the single description by coding the DCT coefficient together with the video header and the motion vector when the single description/multiple description determining unit determines to perform transcoding into the single description and performing transcoding into the multiple descriptions by dividing the DCT coefficient into a plurality of DCT coefficients and coding each of the DCT coefficients together with the video header and the motion vector when the single description/multiple description determining unit determines to perform transcoding into the multiple descriptions; wherein the transcoding unit comprises: where a is the number of pixels included in a macroblock for which the DCT coefficient is calculated, b=2a, 0<Start position<(a−1), and PLR is a packet loss rate in the transmission channel.