Scalable video transcoding for mobile communications

Mobile multimedia contents have been introduced in the market and their demand is growing every day due to the increasing number of mobile devices and the possibility to watch them at any moment in any place. These multimedia contents are delivered over different networks that are visualized in mobile terminals with heterogeneous characteristics. To ensure a continuous high quality it is desirable that this multimedia content can be adapted on-the-fly to the transmission constraints and the characteristics of the mobile devices. In general, video contents are compressed to save storage capacity and to reduce the bandwidth required for its transmission. Therefore, if these compressed video streams were compressed using scalable video coding schemes, they would be able to adapt to those heterogeneous networks and a wide range of terminals. Since the majority of the multimedia contents are compressed using H.264/AVC, they cannot benefit from that scalability. This paper proposes a technique to convert an H.264/AVC bitstream without scalability to a scalable bitstream with temporal scalability as part of a scalable video transcoder for mobile communications. The results show that when our technique is applied, the complexity is reduced by 98 % while maintaining coding efficiency

Video transcoding for mobile digital television

Mobile digital television is one of the new services introduced recently by telecommunications operators. Due to the possibilities of personalization and interaction provided, together with the increasing demand for this type of portable services, it will undoubtedly be a successful technology in the near future. Multimedia content is generally encoded by reducing the storage capacity necessary and bandwidth consumption in order to be transmitted. In order to adapt to the different characteristics of the networks and the varying capabilities of the devices, scalable video coding schemes have been proposed that provide temporal, spatial, and quality scalability, or a combination of these. Most of the existing video content is compressed using H.264/AVC, which is a single-layer codec, so these contents cannot benefit from the scalability tools due to the lack of intrinsic scalability provided in the bitstream at encoding time. This paper proposes a technique to convert from the single-layer H.264/AVC bitstream to a scalable bitstream with temporal scalability. Applying this approach, a reduction of 60% in coding complexity is achieved while maintaining the coding efficiency