In this paper, we present a DCT domain watermarking approach for H.264/AVC video coding standard. This scheme is resilient to compressed-domain temporal adaptation. A cryptographic hash function is used to generate a semi-fragile watermark to provide content-based authentication. The embedded watermark can withstand frame-dropping due to temporal adaptation, yet it is able to detect malicious attacks such as content modification, transcoding etc. Simulation results demonstrate that the watermarking scheme is computationally efficient and suitable for practical use.

In this demo, we present a working system that we have built for metadata-based compressed-domain spatio-temporal video adaptation of H.264/AVC videos. Our approach is in contrast to most existing approaches that do adaptation in a series of cascaded decode/re-encode procedures. We show that by applying compressed-domain operations, adaptation can be expedited for real-time application scenarios like news/sports broadcasting. Moreover, the system can be applied as a tool box for distributed adaptation within P2P video distribution applications to support heterogeneous devices.

In this paper, we present a metadata-based compressed-domain spatial adaptation scheme for H.264/AVC video. We have enhanced the H.264/AVC encoder with our proposed adaptation strategies in order to reduce video size by cropping individual frames in an intermediary node prior to transmitting that video to heterogeneous devices. In this regard, we exploit the sliced architecture of the video frames within the first version of the H.264/AVC specification and devise different slicing strategies. The compressed-domain bitstream modification is performed at the intermediary nodes, avoiding the need for any cascaded operations. Here, we briefly present our adaptation scheme as well as evaluation results showing the effectiveness of the slicing strategies on the bitrate reduction and processing time. A comparison of our approach with an existing cropping scheme is also presented.