ReadPacketsThread.cpp

#include "ReadPacketsThread.h"
#include "Media.h"
#include <QMutexLocker>
extern "C" {

#include <libavformat\avformat.h>

}
static bool isExit = false;

//************************************
// Method:    run
// FullName:  ReadPacketsThread::run
// Access:    public 
// Returns:   void
// Qualifier:读取音视频包的线程处理函数
//************************************
void ReadPacketsThread::run()
{
	AVPacket packet;
	while (!isExit) {
		QMutexLocker locker(&mutex);
		if (!isPlay) {//还没开始播放
			locker.unlock();
			msleep(100);
			continue;
		}
		Media *media = Media::getInstance();
		if (media->audio == nullptr || media->video == nullptr) {
			break;
		}
		if (isSeek) {//是否跳转视频的标识，在解压音视频读包时进行跳转			 
			int64_t stamp = 0;
			stamp = currentPos * media->video->getVideoStream()->duration;
			 			 
			int ret = av_seek_frame(media->getAVFormatContext(), media->getVideoStreamIndex(),
				stamp, AVSEEK_FLAG_BACKWARD | AVSEEK_FLAG_FRAME);
			media->audio->clearPacket();//要清空所有队列
			media->video->clearPackets();
			media->video->clearFrames();		 	 
			isSeek = false;
		}
		
		bool isInvalid = media->checkMediaSizeValid();//音视队列超过一定量时先不读包，等待包消费
		if (isInvalid) {
			locker.unlock();
			msleep(10);
			continue;
		}
		if (!media->getAVFormatContext()) {
			locker.unlock();
			msleep(10);
			continue;
		}
		int ret = av_read_frame(media->getAVFormatContext(), &packet);//读帧音视频包
		if (ret < 0)
		{
			if (ret == AVERROR_EOF) {//读包出错
				break;
			}
				
			if (media->getAVFormatContext()->pb->error == 0) // 没有错误就等待下次读
			{
				locker.unlock();
				msleep(100);
				continue;
			}
			else {
				break;
			}
				
		}
		if (media->audio!=nullptr&& packet.stream_index == media->getAudioStreamIndex()) // 音频包队列此处入队
		{
			locker.unlock();
			media->enqueueAudioPacket(packet);
		}

		else if (media->video != nullptr&& packet.stream_index == media->getVideoStreamIndex()) // 视频包队列此处入队
		{
			locker.unlock();
			media->enqueueVideoPacket(packet);
		}
		else {
			av_packet_unref(&packet);
		}
		
	}
	if(packet.size>=0)
	    av_packet_unref(&packet);//包没数据不能释放
}

ReadPacketsThread::ReadPacketsThread()
{
}

ReadPacketsThread::~ReadPacketsThread()
{
	QMutexLocker locker(&mutex);
	isExit = true;
	locker.unlock();
	wait();
}

//************************************
// Method:    getIsPlaying
// FullName:  ReadPacketsThread::getIsPlaying
// Access:    public 
// Returns:   bool
// Qualifier: 获取视频播放状态
//************************************
bool ReadPacketsThread::getIsPlaying()
{
	return isPlay;
}

//************************************
// Method:    setPlaying
// FullName:  ReadPacketsThread::setPlaying
// Access:    public 
// Returns:   void
// Qualifier: 设置播放状态
// Parameter: bool isPlaying
//************************************
void ReadPacketsThread::setPlaying(bool isPlaying)
{
	this->isPlay = isPlaying;
}

//************************************
// Method:    receivePos
// FullName:  ReadPacketsThread::receivePos
// Access:    public 
// Returns:   void
// Qualifier: 接收跳转的位置，跳转标识设置true
// Parameter: float pos 视频跳转位置
//************************************
void ReadPacketsThread::receivePos(float pos) {
	currentPos = pos;
	isSeek = true;
}