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Widely-used Rate Control (RC) algorithms, such as those in the H.264 encoder, have certain shortcomings for time-sensitive applications such as High Definition Video Conferencing (HDVC): they either respond too slowly to available bandwidth variations, causing degradation in the perceived quality of the video session, or do not optimize video quality for a given available bandwidth. To overcome these...
This paper introduces an open-source HEVC video call application called Kvazzup. This academic proposal is the first HEVC-based end-to-end video call system with a user-friendly Graphical User Interface for call management. Kvazzup is built on the Qt framework and it makes use of four open-source tools: Kvazaar for HEVC encoding, OpenHEVC for HEVC decoding, Opus codec for audio coding, and Live555...
This paper demonstrates the usage of Kvazaar open-source HEVC intra encoder in 4K real-time video encoding. In this setup, a raw 4K video is shot by an action camera, captured by an HDMI capture card, encoded in real-time by Kvazaar ultrafast preset on a 22-core Intel Xeon processor, sent to a laptop, and decoded by OpenHEVC decoder for playback. The encoding process is visualized on the fly by Kvazaar...
Given the significant industrial growth of demand for virtual reality (VR), 360º video streaming is one of the most important VR applications that require cost-optimal solutions to achieve widespread proliferation of VR technology. Because of its inherent variability of data-intensive content types and its tiled-based encoding and streaming, 360º video requires new encoding ladders in adaptive streaming...
Video summarization is an important multimedia task for applications such as video indexing and retrieval, video surveillance, human-computer interaction and video "storyboarding". In this paper, we present a new approach for automatic summarization of video collections that leverages a structured minimum-risk classifier and efficient submodular inference. To test the accuracy of the predicted...
This paper presents a real-time Kvazaar HEVC intra encoder for 4K Ultra HD video streaming. The encoder is implemented on Nokia AirFrame Cloud Server featuring a 2.4 GHz dual 14-core Intel Xeon processor and Arria 10 PCI Express FPGA accelerator card. In our HW/SW partitioning scheme, the data-intensive Kvazaar coding tools including intra prediction, DCT, inverse DCT, quantization, and inverse quantization...
Virtual reality (VR) applications target high-quality and zero-latency scene navigation to provide users with a full-immersion sensation within a scene. From a network perspective, this requires transmission of the omnidirectional content in its entirety, at a high resolution, which is not always feasible in bandwidth-limited networks. In this work, we propose an optimal transmission strategy for...
Virtual reality applications make use of 360-degree panoramic or omnidirectional video with high resolution and high frame rate in order to create the immersive experience to the user. The user views only a portion of the captured 360-degree scene at each time instant, hence streaming the whole omnidirectional video in highest quality is not efficient. In order to alleviate the problem of bandwidth...
Virtual view synthesis is a key component of multi-view imaging systems that enable visual immersion environments for emerging applications, e.g., virtual reality and 360-degree video. Using a small collection of captured reference view-points, this technique reconstructs any view of a remote scene of interest navigated by a user, to enhance the perceived immersion experience. We carry out a convexity...
Good user experience with interactive cloud-based multimedia applications, such as cloud gaming and cloud-based VR, requires low end-to-end latency and large amounts of downstream network bandwidth at the same time. In this paper, we present a foveated video streaming system for cloud gaming. The system adapts video stream quality by adjusting the encoding parameters on the fly to match the player's...
Currently, more and more 360-degree videos (or 360 videos for short) are being provided via the Internet. This kind of videos can render a virtual reality (VR) environment via a head-mounted display (HMD). However, understanding the quality of experience (QoE) of 360 videos is a big challenge because user experience in VR is a very complex phenomenon. In this paper, the QoE of 360 videos is considered...
Interactive video streaming requires very low latency and high throughput. Traditional latency based congestion control algorithm performs poorly in fairness. This results in very poor video quality to adaptive video streaming. Software defined networks (SDN) enables us to solve the problem by designing a network controller in the routers. This paper presents a SDN-centric TCP where sending rate of...
This paper examines the 4kUHD video quality from streaming over an IEEE 802.11ac wireless channel, given measured levels of packet loss. Findings suggest that there is a strong content dependency to loss impact upon video quality but that, for short-range transmission, the quality is acceptable, making 4kUHD feasible on head-mounted displays.
The rapid growth of the volume of multimedia data necessitates efficient compression and transmission of videos, which are requested in divergent bitrates owing to the diverse network bandwidth constraints or end device resolution/complexity requirements. Scalable video coding (SVC) is a coding paradigm that allows once-encoded video to be adapted to any desired bitrate or quality level, and thus...
The use of Recurrent Neural Networks for video captioning has recently gained a lot of attention, since they can be used both to encode the input video and to generate the corresponding description. In this paper, we present a recurrent video encoding scheme which can discover and leverage the hierarchical structure of the video. Unlike the classical encoder-decoder approach, in which a video is encoded...
The latest High Efficiency Video Coding (HEVC) has been increasingly used to generate video streams over Internet. However, the decoded HEVC video streams may incur severe quality degradation, especially at low bit-rates. Thus, it is necessary to enhance visual quality of HEVC videos at the decoder side. To this end, we propose in this paper a Decoder-side Scalable Convolutional Neural Network (DS-CNN)...
HTTP adaptive streaming (HAS) has become the de-facto standard for video streaming to ensure continuous multimedia service delivery under irregularly changing network conditions. Many studies already investigated the detrimental impact of various playback characteristics on the Quality of Experience of end users, such as initial loading, stalling or quality variations. However, dedicated studies tackling...
Panoramic streaming enables users to interactively navigate through high-spatial resolution videos and create an immersive and personalized user experience. Since transmission of high-resolution videos in desirable quality is not feasible given the limited throughput of access and home network links, our work is based on tile-based streaming, where only a spatial subset of the video is transmitted...
Many video streaming services employ the dynamic adaptive streaming over HTTP (DASH) technique to achieve better user's QoE. Named-data Networking (NDN) can bring many benefits to the video distribution with in-network cache and stateful forwarding. However, simply applying DASH technique to NDN causes problems. First, in-network cache may affect download time which makes bitrate adaptation a difficult...
This paper presents an algorithm that achieves high quality video compression with low memory bandwidth of reference frame data and latency due to computation in motion estimation for screen content. Efficiency is attained by content-adaptive placement of the search windows within the reference frames. In our scheme, the center location of the search window is decided by k most prominent motion vectors...
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