Digital TV video and audio synchronous measuring method

Abstract

The invention relates to a video and audio synchronization test signal of a digital TV and a measuring method thereof, and belongs to the technical field of audio and video signal detection. The test signal is composed of a video signal and an audio signal. The waveform of the video signal is a rectangular curve, forming a cycle signal with full bright and full dark phase jumps; The video light and dark transitions have the same repetition period; the time difference between the video's rising edge and the midpoint of the audio duration is the test result of the video and audio synchronization. The measurement method is to first generate image and sound data according to the requirements of the video and audio waveform of the test signal; generate video and audio basic stream data through compression coding, and form composite TS stream signal data; select the corresponding test equipment for the tested equipment; The device reads the measurement correctly. The measurement result of the invention is correct and reliable, the precision of the detection equipment itself is not high, the measurement operation is simplified, and human error can also be avoided.

Description

technical field [0001] The invention belongs to the technical field of detection of audio and video signals, in particular to a test signal and a measurement method for the synchronization of video signals and audio signals in a digital television system Background technique [0002] A TV program contains both video and audio signals. In the whole process from production and transmission to reception and reproduction, the two signals are combined in some stages, but processed separately in some stages. When they are processed separately, in principle, there is anisochronism, which reduces their synchronization, so that the action and sound are not at the same time. As for the analog TV system, the work of the circuit is real-time, and the time difference caused by the circuits of different channels is in the order of ns at most to μs. The storage and playback of TV signals involves electromagnetic processes and mechanical processes. Even if the mechanical process has a slig...

AI Technical Summary

Problems solved by technology

[0005] The disadvantage of this method is that a relatively expensive dual-trace digital storage readout oscilloscope must be used, and the measurement accuracy is affected by the oscilloscope's own scanning time base accuracy and the correctness of the reading line adjustment

Images