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Real-time video compressing under DSP/BIOS (EI CONFERENCE) 会议论文
MIPPR 2009 - Medical Imaging, Parallel Processing of Images, and Optimization Techniques: 6th International Symposium on Multispectral Image Processing and Pattern Recognition, October 30, 2009 - November 1, 2009, Yichang, China
Chen Q.-P.; Li G.-J.
收藏  |  浏览/下载:18/0  |  提交时间:2013/03/25
This paper presents real-time MPEG-4 Simple Profile video compressing based on the DSP processor. The programming framework of video compressing is constructed using TMS320C6416 Microprocessor  the architecture level optimizations are used to improve software pipeline. The system used DSP/BIOS to realize multi-thread scheduling. The whole system realizes high speed transition of a great deal of data. Experimental results show the encoder can realize real-time encoding of 768*576  TDS510 simulator and PC. It uses embedded real-time operating system DSP/BIOS and the API functions to build periodic function  25 frame/s video images. 2009 Copyright SPIE - The International Society for Optical Engineering.  tasks and interruptions etcs. Realize real-time video compressing. To the questions of data transferring among the system. Based on the architecture of the C64x DSP  utilized double buffer switched and EDMA data transfer controller to transit data from external memory to internal  and realize data transition and processing at the same time  
High power VCSEL device with periodic gain active region (EI CONFERENCE) 会议论文
Optoelectronic Materials and Devices II, November 2, 2007 - November 5, 2007, Wuhan, China
Ning Y. Q.; Qin L.; Sun Y. F.; Li T.; Cui J. J.; Peng B.; Liu G. Y.; Zhang Y.; Liu Y.; Wang L. J.; Cui D. F.; Xu Z. Y.
收藏  |  浏览/下载:20/0  |  提交时间:2013/03/25
High power vertical cavity surface emitting lasers with large aperture have been fabricated through improving passivation  lateral oxidation and heat dissipation techniques. Different from conventional three quantum well structure  a periodic gain active region with nine quantum wells was incorporated into the VCSEL structure  with which high efficiency and high power operation were expected. The nine quantum wells were divided into three groups with each of them located at the antinodes of the cavity to enhance the coupling between the optical field and the gain region. Large aperture and bottom-emitting configuration was used to improve the beam quality and the heat dissipation. A maximum output power of 1.4W was demonstrated at CW operation for a 400m-diameter device. The lasing wavelength shifted to 995.5nm with a FWHM of 2nm at a current of 4.8A due to the internal heating and the absence of active water cooling. A ring-shape farfield pattern was induced by the non-homogeneous lateral current distribution in large diameter device. The light intensity at the center of the ring increased with increasing current. A symmetric round light spot at the center and single transverse mode operation with a divergence angle of 16 were observed with current beyond 4.8A.  


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