TMS320C50组成的水下视频图像数字化系统的软件设计

SYSTEM SOFTWARE DESIGN OF DIGITALIZING UNDERWATER VIDEO SIGNAL USING TMS320C50

由 ＤＳＰ（数字信号处理器）芯片 ＴＭＳ３２０Ｃ５０构成的视频图像数字化系统较好地解 决了模拟视频图像在复杂的海洋声信道传输的信源编码问题。由 Ｃ５０汇编语言设计的系统 软件，充分利用 Ｃ５０芯片的阴影寄存器，将视频信号的行、场信号作为 Ｃ５０的外部中断 １和 ３的申请信号，快速完成了视频图像的实时数据采集。采用查表法在 １２８ ｕｓ的时间内完成一 个 ８×８子块的 ＤＣＴ变换。这种软件设计方法使系统即使在采集高密度（６４ Ｋ×８ｂｉｔ）图像 时也能在规定的时间内完成模拟图像的数字化和数字化后的数据处理。

We use DSP chip-TMS320C50 to construct a system of digitalizing underwater video signal to solve the information source coding problem of transmitting analog video signal in the complex underwater acoustic channel. The software is designed by using C50's assemble language. It makes full use of the shadow register of C50. The horizontal and vertical sync generate the No 1 and 3 interrupts of C50 respectively to accomplish real time gathering video signal. It can finish DCT(Discrete Cosine Transform) for a 8 × & sub-block in 128 us using the method of searching table. The technology we used in this software enable our system digitalize analog video signal, processes gathered data and transfers the pro cessed data in limited time even for high density image(64 K × 8bit).