源文件:

#include <iostream>
#include <fstream>
using namespace std;
extern "C" { //指定函数是c语言函数，函数名不包含重载标注
//引用ffmpeg头文件
#include <libavcodec/avcodec.h>
}
//预处理指令导入库
#pragma comment(lib,"avcodec.lib")
#pragma comment(lib,"avutil.lib")
int main(int argc, char* argv[])
{//1 分割h264 存入AVPacket// ffmpeg -i v1080.mp4 -s 400x300 test.h264string filename = "test.h264";ifstream ifs(filename, ios::binary);if (!ifs)return -1;unsigned char inbuf[4096] = { 0 };//用于存储h264编码流AVCodecID codec_id = AV_CODEC_ID_H264;//1 找解码器auto codec = avcodec_find_decoder(codec_id);//2 创建解码器上下文auto c = avcodec_alloc_context3(codec);//3 打开上下文avcodec_open2(c, NULL, NULL);//分割上下文auto parser = av_parser_init(codec_id);auto pkt = av_packet_alloc();auto frame = av_frame_alloc();while (!ifs.eof()){ifs.read((char*)inbuf, sizeof(inbuf));//将h264编码的流读入inbuf中，一次读4096int data_size = ifs.gcount();// 读取的字节数，inbuf中的字节数if (data_size <= 0)break;auto data = inbuf;while (data_size > 0) //一次有多帧数据{//通过0001 截断输出到AVPacket 返回帧大小int ret = av_parser_parse2(parser, c,&pkt->data, &pkt->size, //截断后输出到AVpacket的data中data, data_size,        //h264编码流，待处理数据AV_NOPTS_VALUE, AV_NOPTS_VALUE, 0);//返回消耗的输入数据字节数ret。如果所有输入数据都被消耗，则返回值等于 buf_size。如果解析过程中出现错误，则返回负数。data += ret;//data指针向前移动 ret个字节,继续处理inbuf未处理的数据data_size -= ret; //待处理的数据大小if (pkt->size){//cout << pkt->size << " "<<flush;//发送packet到解码线程ret = avcodec_send_packet(c, pkt);//把avpacket给解码器进行解码if (ret < 0)break;//获取多帧解码数据while (ret >= 0){//每次回调用av_frame_unref ret = avcodec_receive_frame(c, frame);//拿到解码后的数据if (ret < 0)break;cout << frame->format << " " << flush;}}}}///取出缓存数据,防止丢帧int ret = avcodec_send_packet(c, NULL);while (ret >= 0){ret = avcodec_receive_frame(c, frame);if (ret < 0)break;cout << frame->format << "-" << flush;}av_parser_close(parser);avcodec_free_context(&c);av_frame_free(&frame);av_packet_free(&pkt);getchar();return 0;
}