//

// Created by frank on 2018/2/3.

//

#include "AVpacket_queue.h"

#include <stdlib.h>

#include <libavcodec/avcodec.h>

AVPacketQueue* queue_init(int size){

AVPacketQueue* queue = malloc(sizeof(AVPacketQueue));

queue->size = size;

queue->next_to_read = 0;

queue->next_to_write = 0;

int i;

queue->packets = malloc(sizeof(*queue->packets) * size);

for(i = 0; i < size; i++){

queue->packets[i] = malloc(sizeof(AVPacket));

}

return queue;

}

void queue_free(AVPacketQueue *queue){

int i;

for(i=0; i<queue->size; i++){

free(queue->packets[i]);

}

free(queue->packets);

free(queue);

}

int queue_next(AVPacketQueue* queue, int current){

return (current+1) % queue->size;

}

void* queue_push(AVPacketQueue* queue, pthread_mutex_t* mutex, pthread_cond_t* cond){

int current = queue->next_to_write;

int next_to_write;

for(;;){

next_to_write = queue_next(queue, current);

//写的不等于读的，跳出循环

if(next_to_write != queue->next_to_read){

break;

}

pthread_cond_wait(cond, mutex);

}

queue->next_to_write = next_to_write;

pthread_cond_broadcast(cond);

return queue->packets[current];

}

void* queue_pop(AVPacketQueue* queue, pthread_mutex_t* mutex, pthread_cond_t* cond){

int current = queue->next_to_read;

for(;;){

//写的不等于读的，跳出循环

if(queue->next_to_write != queue->next_to_read){

break;

}

pthread_cond_wait(cond, mutex);

}

queue->next_to_read = queue_next(queue, current);

pthread_cond_broadcast(cond);

return queue->packets[current];

}