Multi-thread audio and video synchronization control method and system

Abstract

The invention relates to a multi-thread audio and video synchronization control method and system. The method comprises the steps of establishing a demultiplexing thread, an audio and video decoding thread and an audio and video synchronous output thread; starting the demultiplexing thread to finish the demultiplexing processing of a transport stream or a program stream, respectively inserting audio and video elementary streams into tails of audio and video elementary stream queues, and activating the audio and video decoding thread; starting the audio and video decoding thread to respectively decode bit streams in the audio and video elementary stream queues, and respectively inserting time information and audio data and image data obtained after decoding into audio and video output queues; according to difference between a timestamp after decoding and a local system clock, starting the audio and video synchronous output thread, and selecting and outputting data which conforms to output time; and according to the difference between the timestamps of video and audio, conducting repetition and frame skipping processing to video playing to enable the audio and the video to be synchronously output. The multi-thread audio and video synchronization control method and system provided by the invention have the advantages that a large memory space is not needed for buffering data, the operating efficiency is high, the realization complexity is low and the method and the system are applicable to embedded operating systems.

Description

technical field [0001] The invention belongs to the technical field of digital audio and video, and relates to a multi-thread audio and video synchronization control method and system. Background technique [0002] Currently popular video codec standards, such as MPEG-1, MPEG-2, MPEG-4, H.26x, etc., all adopt the traditional hybrid coding structure, which uses time and space prediction, transformation, quantization and entropy coding methods , encode video frames into different frame types: intra-frame prediction frame (I frame), inter-frame prediction frame (P frame) and bi-directional prediction frame (B frame), which will inevitably cause video decoding speed to vary due to video content Different, but the playback frame rate of the video is fixed, which leads to problems such as the mismatch between the video decoding speed and the display speed, and the audio and video are encoded and transmitted separately, and synchronous output is required during playback. If it is n...

AI Technical Summary

Problems solved by technology

Due to the uncertainty of the image content, it is difficult to determine the size of the buffer. If the buffer is too small, the data will overflow, and if the buffer is too large, the memory space will be wasted.

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