Wireless video streaming has become an extremely popular application in recent years. Internet video streaming to mobile devices, however, faces several challenges, e.g., unstable wireless connections, long latency, high jitter and etc. Bitrate adaptive streaming and video transcoding solutions are widely used to address the above-mentioned issues, however, there are still several shortcomings of these approaches. Such challenges hinder providing satisfactory quality of video streaming service to the mobile users. We propose a hardware-assisted, real-time video transcoding solution implemented on a commercial off-the-shelf device, Raspberry Pi. We employ the software and hardware coupled architecture in order to improve the performance/quality of video streaming and enhance the user satisfactions in wireless network. Our video transcoding solution can be applied to both the downlink and uplink streaming: for downlink stream, it can provide agile bitrate adaptation to sudden network dynamics and enhance video quality by running our transcoding solution at the wireless edge. It can be used to uplink stream for broadcasting live streams in real-time. We present the design and implementation of our video transcoding system in both cases with practical scenarios. The evaluation results reveal that our transcoding solution enhances the performance of video streaming compared with other adaptive bitrate streamings and it provides higher video quality without causing rebuffering or video stall. We bridge the gap between the wireless channel capacity and the video quality while providing a better streaming experience to end user.

中文翻译：

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无线网络中硬件辅助的低成本视频转码解决方案

近年来，无线视频流已成为一种非常流行的应用。然而，互联网视频流传输到移动设备面临着无线连接不稳定、时延长、抖动高等挑战。比特率自适应流媒体和视频转码解决方案被广泛用于解决上述问题，然而，仍然存在这些方法的几个缺点。这些挑战阻碍了向移动用户提供令人满意的视频流服务质量。我们提出了一种硬件辅助的实时视频转码解决方案，该解决方案在商用现成设备 Raspberry Pi 上实施。我们采用软硬件耦合架构，以提高视频流的性能/质量并提高无线网络中的用户满意度。我们的视频转码解决方案可以应用于下行和上行流：对于下行流，它可以通过在无线边缘运行我们的转码解决方案来为突然的网络动态提供灵活的码率适应并提高视频质量。它可用于上行流实时广播直播流。我们在实际场景中介绍了两种情况下我们的视频转码系统的设计和实现。评估结果表明，与其他自适应比特率流媒体相比，我们的转码解决方案提高了视频流媒体的性能，并提供了更高的视频质量，而不会导致重新缓冲或视频停顿。我们弥合了无线信道容量和视频质量之间的差距，同时为最终用户提供了更好的流媒体体验。