在VS2017下FFmpeg+SDL编写最简单的视频播放器

1.下载ShiftMediaProject/FFmpeg

2.下载SDL2

3.新建VC++控制台应用

3.配置include和lib

4.把FFmpeg和SDL的dll 复制到工程Debug目录下，并设置调试命令

5.复制一下mp4视频到工程Debug目录下（复制一份到*.vcxproj同一目录，用于调试）

6.编写代码

#include <stdio.h>
#include <stdlib.h>
#include <iostream>

extern "C" {
#include "libavcodec\avcodec.h"
#include "libavformat\avformat.h"
#include "libavutil\avutil.h"
#include "SDL.h"
}

SDL_Window *window;
SDL_Texture* texture;
SDL_Renderer* renderer;
SDL_Rect rect;
int width;
int height;

void display(AVFrame* frame);
void iniSdl();

#undef main
int main()
{
	int ret = -1;
	AVFormatContext* ctx = avformat_alloc_context();

	ret = avformat_open_input(&ctx, "my.mp4", NULL, NULL);
	ret = avformat_find_stream_info(ctx, NULL);

	int videoindex = -1;
	for (int i = 0; i < ctx->nb_streams; i++)
	{
		if (ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
		{
			videoindex = i;
			break;
		}
	}

	const AVCodec* codec = avcodec_find_decoder(ctx->streams[videoindex]->codecpar->codec_id);
	AVCodecContext* avcc = avcodec_alloc_context3(codec);
	ret = avcodec_parameters_to_context(avcc, ctx->streams[videoindex]->codecpar);
	ret = avcodec_open2(avcc, codec, NULL);

	width = avcc->width;
	height = avcc->height;
	rect.x = 0;
	rect.y = 0;
	rect.h = height;
	rect.w = width;
	iniSdl();

	AVFrame* frame = av_frame_alloc();
	AVPacket* packet = av_packet_alloc();
	while (true)
	{
		ret = av_read_frame(ctx, packet);
		if (ret >=0)
		{
			if (packet->stream_index == videoindex)
			{
				ret = avcodec_send_packet(avcc, packet);
				while (ret >= 0)
				{
					ret = avcodec_receive_frame(avcc, frame);
					if (ret >= 0)
					{
						display(frame);
						av_frame_unref(frame);
					}
					else
					{
						av_frame_unref(frame);
						break;
					}
				}
			}			
		}
		else
		{
			av_packet_unref(packet);
			break;
		}
	}

	SDL_DestroyWindow(window);
	std::cout << "finish\n";
}

void display(AVFrame* frame)
{
	SDL_UpdateYUVTexture(texture, &rect, frame->data[0], frame->linesize[0], frame->data[1], frame->linesize[1], frame->data[2], frame->linesize[2]);
	SDL_RenderClear(renderer);
	SDL_RenderCopy(renderer, texture, NULL, NULL);
	SDL_RenderPresent(renderer);
}

void iniSdl()
{
	SDL_Init(SDL_INIT_VIDEO);
	window = SDL_CreateWindow("test", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, width, height, SDL_WINDOW_RESIZABLE);
	renderer = SDL_CreateRenderer(window, -1, 0);
	texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, width, height);
}