FrameQueue.cpp
1.52 KB
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#include "FrameQueue.h"
FrameQueue::FrameQueue(/* args */)
{
for (size_t i = 0; i < Maxsize; i++)
{
base[i] = av_frame_alloc();
}
front = rear = 0;//头指针和尾指针置为零，队列为空
}
FrameQueue::~FrameQueue()
{
if (base)
{
for (size_t i = 0; i < Maxsize; i++)
{
if (base[i])
{
av_frame_free(&base[i]);
}
}
}
rear = front = 0;
}
//循环队列的入队
AVFrame* FrameQueue::getTail()
{
//插入一个元素e为Q的新的队尾元素
if ((rear + 1) % Maxsize == front)
return nullptr;//队满
return base[rear];//获取队尾元素
}
// 将队尾元素添加到队列中
void FrameQueue::addTail()
{
rear = (rear + 1) % Maxsize;//队尾指针加1
}
//循环队列的出队
AVFrame* FrameQueue::deQueue()
{
//删除Q的队头元素，用e返回其值
if (front == rear)
return nullptr;//队空
AVFrame* e = base[front];//保存队头元素
front = (front + 1) % Maxsize;//队头指针加1
return e;
}
//取循环队列的队头元素
AVFrame* FrameQueue::getHead()
{
//返回Q的队头元素，不修改队头指针
if (front == rear)
return nullptr;//队列为空，取元素失败
return base[front];
}
void FrameQueue::addHead()
{
front = (front + 1) % Maxsize;//队头指针加1
}
int FrameQueue::length()
{
return (rear - front + Maxsize) % Maxsize;
}
bool FrameQueue::isEmpty()
{
if (front == rear)
return true;
return false;
}
void FrameQueue::clearQueue()
{
rear = front = 0;
}