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1
Parallel Deblocking Filtering in MPEG-4 AVC/H.264 on Massively Parallel Architectures

Pieters, Bart,Hollemeersch, Charles-Frederik J,De Cock, Jan,Lambert, Peter,De Neve, Wesley,Van de Walle, Rik IEEE 2011 IEEE transactions on circuits and systems for vide Vol.21 No.1
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<P>The deblocking filter in the MPEG-4 AVC/H.264 standard is computationally complex because of its high content adaptivity, resulting in a significant number of data dependencies. These data dependencies interfere with parallel filtering of multiple macroblocks (MBs) on massively parallel architectures. In this letter, we introduce a novel MB partitioning scheme for concurrent deblocking in the MPEG-4 AVC/H.264 standard, based on our idea of deblocking filter independency, a corrected version of the limited error propagation effect proposed in the letter. Our proposed scheme enables concurrent MB deblocking of luma samples with limited synchronization effort, independently of slice configuration, and is compliant with the MPEG-4 H.264/AVC standard. We implemented the method on the massively parallel architecture of the graphics processing unit (GPU). Experimental results show that our GPU implementation achieves faster-than real-time deblocking at 1309 frames per second for 1080p video pictures. Both software-based deblocking filters and state-of-the-art GPU-enabled algorithms are outperformed in terms of speed by factors up to 10.2 and 19.5, respectively, for 1080p video pictures.</P>
2
Esophageal Bolus Domain Pressure and Peristalsis Associated With Experimental Induction of Esophagogastric Junction Outflow Obstruction

( Wei-yi Lei ),( Taher Omari ),( Tso-tsai Liu ),( Ming-wun Wong ),( Jui-sheng Hung ),( Chih-hsun Yi ),( Shu-wei Liang ),( Charles Cock ),( Chien-lin Chen ) 대한소화기기능성질환·운동학회 2022 Journal of Neurogastroenterology and Motility (JNM Vol.28 No.1
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- 복사/대출신청
Background/Aims Intrabolus pressures are important for esophageal bolus transport and may detect obstructed bolus flow. This study measured the effect esophageal outflow obstruction experimentally induce by a leg-lift protocol. Methods Twenty-five gastroesophageal reflux disease patients referred for esophageal manometry and a normal motility diagnosis were included. Supine liquid swallows were tested. Leg-lift protocol generated esophageal outflow obstruction by increasing abdominal pressure. Esophageal pressure topography and intrabolus pressure metrics were calculated. These included, (1) mid-domain bolus distension pressure during esophageal emptying (DPE, mmHg) and (2) ramp pressure (mmHg/sec), generated by compression of the bolus between the peristaltic contraction and esophagogastric junction (EGJ). Results EGJ relaxation pressure was increased by leg-lift from 13 (11-17) to 19 (14-30) mmHg (P < 0.005) and distal contractile integral also increased from 1077 (883-1349) to 1620 (1268-2072) mmHgㆍcmㆍsec (P < 0.001) as a physiological response to obstruction. All bolus pressures were increased by leg lift; DPE increased from 17 (15-20) to 27 (19-32) mmHg (P < 0.001), and ramp pressure increased from 3 (1-4) to 5 (2-9) mmHg/sec (P < 0.05). Conclusion Measuring pressures within the intrabolus domain can quantify changes related to obstruction to outflow and may serve as adjunct measures for confirming a diagnosis EGJ outflow obstruction. (J Neurogastroenterol Motil 2022;28:62-68)