h264測試文件--從h.264文件讀取單獨幀C語言版本

測試服務器需要一個h264流，從h264文件讀取流的函數實現： c語言版本

注意需要h264文件開頭即爲00 00 00 01

/***

***20190828 canok

*** output: complete frames

**/

#include<stdio.h>
#include<stdlib.h>	
#include <unistd.h>
#include <string.h>

typedef unsigned char   uint8_t;     //無符號8位數

#define CACH_LEN (1024*500)//緩衝區不能設置太小，如果出現比某一幀比緩衝區大，會被覆蓋掉一部分
static uint8_t *g_cach[2] = {NULL,NULL};
static FILE* fp_inH264 = NULL;
static int icach = 0;
static int ioffset = 0;
int init()
{	
	if(g_cach[0] == NULL)
	{
		g_cach[0] = (uint8_t*)malloc(CACH_LEN);
	}
	if(g_cach[1] == NULL)
	{
		g_cach[1] = (uint8_t*)malloc(CACH_LEN);
	}
	
	if(fp_inH264 == NULL)
	{
		fp_inH264 = fopen("./test.h264","r");
		if(fp_inH264 == NULL)
		{
			printf("fope erro [%d%s]\n",__LINE__,__FUNCTION__);
			return -1;
		}
	}
	
	if(fread(g_cach[icach], 1,CACH_LEN,fp_inH264 )<CACH_LEN)
	{
		printf("intpufile too short [%d%s]\n",__LINE__,__FUNCTION__);
		return -1;
	}
	return 0;
}
int deinit()
{
	if(g_cach[0])
	{
		free(g_cach[0]);
		g_cach[0] = NULL;
	}
	if(g_cach[1])
	{
		free(g_cach[1]);
		g_cach[1] = NULL;
	}
	
	if(fp_inH264)
	{
		fclose(fp_inH264);
		fp_inH264 = NULL;
	}
	
	
}

int checkHead(uint8_t *buffer, int offset) 
{
	static uint8_t mMark[4] = {0x00,0x00,0x00,0x01};
	return !memcmp(buffer+offset,mMark,4);
}
//獲取一幀數據到 buf, bufLen表示緩衝區最大可以容納的數據
//返回實際的幀數據長度
int getOneFrame(uint8_t *buf, int bufLen)
{
	int i =0;
	int startpoint = ioffset;
	int endpoint = ioffset;
	for (i = ioffset+4; i <= CACH_LEN - 4; i++) {
		if (checkHead(g_cach[icach], i)){
			startpoint = ioffset;
			endpoint = i;
		}
	}
	if(endpoint - startpoint > 0)
	{
		memcpy(buf,g_cach[icach]+startpoint, (endpoint - startpoint));
		ioffset = endpoint;
		return endpoint - startpoint;
	}
	else
	{
		int oldLen =CACH_LEN -startpoint;
	    memcpy(g_cach[(icach+1)%2],g_cach[icach]+startpoint, oldLen );
		
		int newLen = 0;
		newLen = fread(g_cach[(icach+1)%2]+oldLen, 1,CACH_LEN -(oldLen),fp_inH264);
		if(newLen <CACH_LEN -(oldLen) )
		{
			return -1;
		}
		
		ioffset = 0;
		icach = (icach+1)%2;
		
		return getOneFrame(buf,bufLen);
	}
	
}

int main()
{
	if(init())
	{
		return -1;
	}
	uint8_t *buffer = (uint8_t*)malloc(CACH_LEN);
	int len =0;
	FILE *fp_out = fopen("out.h264","w+");
	while((len = getOneFrame(buffer,CACH_LEN) )> 0)
	{
		printf("get a fram :%d\n",len);
		fwrite(buffer,1,len,fp_out);
	}
	fclose(fp_out);
	free(buffer);
	deinit();
}