AVC to HEVC transcoder based on quadtree limitation

Abstract

Following the finalization of the state-of-the-art High Efficiency Video Coding (HEVC) standard in January 2013, several new services are being deployed in order to take advantage of the superior coding efficiency (estimated at 50 % less bitrate for the same visual quality) that this standard provides over its predecessor: H.264 / Advanced Video Coding (AVC). However, the switch from AVC to HEVC is not trivial as most video content is still encoded in AVC. Consequently, there is a growing need for fast AVC to HEVC transcoders in the market today. While a trivial transcoder can be made by simply cascading an AVC decoder and an HEVC encoder, fast transcoding cannot be achieved. In this paper, we present an AVC to HEVC transcoder where decoded AVC blocks are first fused according to their motion similarity. The resulting fusion map is then used to limit the quadtree of HEVC coded frames. AVC motion vectors are also used to determine a better starting point for integer motion estimation. Experimental results show that significant transcoder execution time savings of 63 % can be obtained with only a 1.4 % bitrate increase compared to the trivial transcoder.

Machine learning‐based H.264/AVC to HEVC transcoding via motion information reuse and coding mode similarity analysis

“…To show the better performance of the proposed transcoding method in both scenarios, we show the performances both in LP configuration and RA configuration. Among them, Table 5 shows a comparison between the proposed algorithm and two other transcoding methods, namely CSVT2014 [12] and MTA2016 [7]; all compared methods use the LP configuration. It can be seen from Table 5 that the proposed transcoding algorithm reduces complexity by 75.3% on average, and that it outperforms the other two algorithms.…”

“…Peixoto used the similarity of the motion vectors (MVs) in H.264/AVC to decide which HEVC CU partitions should be tested [6]. In [7], Mora et al present an H.264/AVC to HEVC transcoder, in which decoded H.264/AVC blocks are first fused according to their motion similarity. A motion‐homogeneous‐based H.264/AVC to HEVC transcoding method is proposed in [8].…”

Predicting split decisions in MPEG-2 to HEVC video transcoding

“…In [17] a transcoding algorithm is proposed that makes use of intra and inter coding information and MVs in H.264 to accelerate the re-encoding in HEVC. In [18], incoming H.264 blocks are fused according to a motion similarity criterion. The map is used to help in constructing the quadtree of HEVC coded frames.…”

Efficient Software HEVC to AVS2 Transcoding

“…Their algorithms achieved a speedup of 2.31× on average with a BD-rate penalty of 3.4%. Mora et al [20] also proposed an H.264/AVC to HEVC transcoder based on quadtree limitation, where the fusion map generated by the motion similarity of decoded H.264/AVC blocks is used to limit the quadtree of HEVC coded frames. They achieved 63% time saving with only a 1.4% bitrate increase.…”