  The paper presents quantitative analysis of the video quality losses in the
homogenous HEVC video transcoder. With the use of HM15.0 reference software and
a set of test video sequences, cascaded pixel domain video transcoder (CPDT)
concept has been used to gather all the necessary data needed for the analysis.
This experiment was done for wide range of source and target bitrates. The
essential result of the work is extensive evaluation of CPDT, commonly used as
a reference in works on effective video transcoding. Until now no such
extensively performed study have been made available in the literature. Quality
degradation between transcoded video and the video that would be result of
direct compression of the original video at the same bitrate as the transcoded
one have been reported. The dependency between quality degradation caused by
transcoding and the bitrate changes of the transcoded data stream are clearly
presented on graphs.
