{'fraction_non_alphanumeric': 0.026126126126126126, 'fraction_numerical': 0.0018018018018018018, 'mean_word_length': 5.0710382513661205, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Novel SVC VoD System with Rate Adaptation and Error Concealment over GPRS/EDGE Network

Considering the high packet losses and low, varying bandwidth of GPRS/EDGE network and limited computation power of handheld devices, we present and implement a novel SVC video-on-demand system for hand-held devices over GPRS/EDGE network. For the purpose of handling varying bitrate, we propose a priority based layer switching (PLS) adaptation scheme for SVC stream, which not only performs online 3-D adaptation more quickly by a simple parser, but also optimizes the video quality in a R-D sense under the bandwidth constraint. To resist packet losses, a motion-detection based adaptive error concealment (MDA) algorithm is proposed, which can achieve a PSNR gain of up to 3dB comparing to existing methods, while maintaining low complexity. Moreover, our proposed system was implemented and tested over existing GPRS/EDGE network deployed in China. The test results demonstrate that the proposed system and schemes have performance advantage in terms of quicker data rate adaptation, higher PSNR and lower overhead.