1.libx264是一个*的H.264编码库，是x264项目的一部分，使用广泛，ffmpeg的H.264实现就是用的libx264。ffmpeg 中带有264的解码,没有编码,需要添加x264。

去官网下载一个libx264的压缩文件。
我用的是x264-snapshot-20171212-2245
x264官方网站
解压文件

mkdir /opt/x264
配置： ./configure --prefix=/opt/x264 --enable-shared --disable-asm
make
make install

2.SDL2
我用的是SDL2-2.0.10
SDL2官方网站

mkdir /opt/SDL2
配置： ./configure --prefix=/opt/SDL2 --enable-shared
make
make install

3.ffmpeg
我用的是ffmpeg-3.4.5
ffmpeg官方网站

mkdir /opt/ffmpeg
配置： ./configure --prefix=/opt/ffmpeg --target-os=linux --enable-gpl --enable-nonfree --extra-cflags="-I/opt/x264/include -I/opt/SDL2/include/SDL2" --extra-ldflags=" -L/opt/x264/lib -L/opt/SDL2/lib" --enable-libx264 --pkg-config-flags=–static --extra-libs="-ldl -fpic -shared -lSDL2" --enable-shared --disable-x86asm
make
make install

装好之后可用代码测试，以下用雷神的代码
雷神博客

/**
 * 最简单的基于FFmpeg的视频播放器 2
 * Simplest FFmpeg Player 2
 *
 * 雷霄骅 Lei Xiaohua
 * leixiaohua1020@126.com
 * 中国传媒大学/数字电视技术
 * Communication University of China / Digital TV Technology
 * http://blog.csdn.net/leixiaohua1020
 *
 * 第2版使用SDL2.0取代了第一版中的SDL1.2
 * Version 2 use SDL 2.0 instead of SDL 1.2 in version 1.
 *
 * 本程序实现了视频文件的解码和显示(支持HEVC，H.264，MPEG2等)。
 * 是最简单的FFmpeg视频解码方面的教程。
 * 通过学习本例子可以了解FFmpeg的解码流程。
 * This software is a simplest video player based on FFmpeg.
 * Suitable for beginner of FFmpeg.
 *
 */
 
 
 
#include <stdio.h>
 
#define __STDC_CONSTANT_MACROS
 
#ifdef _WIN32
//Windows
extern "C"
{
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"
#include "libavutil/imgutils.h"
#include "SDL2/SDL.h"
};
#else
//Linux...
#ifdef __cplusplus
extern "C"
{
#endif
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>
#include <SDL2/SDL.h>
#include <libavutil/imgutils.h>
#ifdef __cplusplus
};
#endif
#endif
 
//Output YUV420P data as a file 
#define OUTPUT_YUV420P 0
 
int main(int argc, char* argv[])
{
	AVFormatContext	*pFormatCtx;
	int				i, videoindex;
	AVCodecContext	*pCodecCtx;
	AVCodec			*pCodec;
	AVFrame	*pFrame,*pFrameYUV;
	unsigned char *out_buffer;
	AVPacket *packet;
	int y_size;
	int ret, got_picture;
	struct SwsContext *img_convert_ctx;
 
	char filepath[]="bigbuckbunny_480x272.h265";
	//SDL---------------------------
	int screen_w=0,screen_h=0;
	SDL_Window *screen; 
	SDL_Renderer* sdlRenderer;
	SDL_Texture* sdlTexture;
	SDL_Rect sdlRect;
 
	FILE *fp_yuv;
 
	av_register_all();
	avformat_network_init();
	pFormatCtx = avformat_alloc_context();
 
	if(avformat_open_input(&pFormatCtx,filepath,NULL,NULL)!=0){
		printf("Couldn't open input stream.\n");
		return -1;
	}
	if(avformat_find_stream_info(pFormatCtx,NULL)<0){
		printf("Couldn't find stream information.\n");
		return -1;
	}
	videoindex=-1;
	for(i=0; i<pFormatCtx->nb_streams; i++) 
		if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){
			videoindex=i;
			break;
		}
	if(videoindex==-1){
		printf("Didn't find a video stream.\n");
		return -1;
	}
 
	pCodecCtx=pFormatCtx->streams[videoindex]->codec;
	pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
	if(pCodec==NULL){
		printf("Codec not found.\n");
		return -1;
	}
	if(avcodec_open2(pCodecCtx, pCodec,NULL)<0){
		printf("Could not open codec.\n");
		return -1;
	}
	
	pFrame=av_frame_alloc();
	pFrameYUV=av_frame_alloc();
	out_buffer=(unsigned char *)av_malloc(av_image_get_buffer_size(AV_PIX_FMT_YUV420P,  pCodecCtx->width, pCodecCtx->height,1));
	av_image_fill_arrays(pFrameYUV->data, pFrameYUV->linesize,out_buffer,
		AV_PIX_FMT_YUV420P,pCodecCtx->width, pCodecCtx->height,1);
	
	packet=(AVPacket *)av_malloc(sizeof(AVPacket));
	//Output Info-----------------------------
	printf("--------------- File Information ----------------\n");
	av_dump_format(pFormatCtx,0,filepath,0);
	printf("-------------------------------------------------\n");
	img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, 
		pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL); 
 
#if OUTPUT_YUV420P 
    fp_yuv=fopen("output.yuv","wb+");  
#endif  
	
	if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {  
		printf( "Could not initialize SDL - %s\n", SDL_GetError()); 
		return -1;
	} 
 
	screen_w = pCodecCtx->width;
	screen_h = pCodecCtx->height;
	//SDL 2.0 Support for multiple windows
	screen = SDL_CreateWindow("Simplest ffmpeg player's Window", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
		screen_w, screen_h,
		SDL_WINDOW_OPENGL);
 
	if(!screen) {  
		printf("SDL: could not create window - exiting:%s\n",SDL_GetError());  
		return -1;
	}
 
	sdlRenderer = SDL_CreateRenderer(screen, -1, 0);  
	//IYUV: Y + U + V  (3 planes)
	//YV12: Y + V + U  (3 planes)
	sdlTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING,pCodecCtx->width,pCodecCtx->height);  
 
	sdlRect.x=0;
	sdlRect.y=0;
	sdlRect.w=screen_w;
	sdlRect.h=screen_h;
 
	//SDL End----------------------
	while(av_read_frame(pFormatCtx, packet)>=0){
		if(packet->stream_index==videoindex){
			ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);
			if(ret < 0){
				printf("Decode Error.\n");
				return -1;
			}
			if(got_picture){
				sws_scale(img_convert_ctx, (const unsigned char* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, 
					pFrameYUV->data, pFrameYUV->linesize);
				
#if OUTPUT_YUV420P
				y_size=pCodecCtx->width*pCodecCtx->height;  
				fwrite(pFrameYUV->data[0],1,y_size,fp_yuv);    //Y 
				fwrite(pFrameYUV->data[1],1,y_size/4,fp_yuv);  //U
				fwrite(pFrameYUV->data[2],1,y_size/4,fp_yuv);  //V
#endif
				//SDL---------------------------
#if 0
				SDL_UpdateTexture( sdlTexture, NULL, pFrameYUV->data[0], pFrameYUV->linesize[0] );  
#else
				SDL_UpdateYUVTexture(sdlTexture, &sdlRect,
				pFrameYUV->data[0], pFrameYUV->linesize[0],
				pFrameYUV->data[1], pFrameYUV->linesize[1],
				pFrameYUV->data[2], pFrameYUV->linesize[2]);
#endif	
				
				SDL_RenderClear( sdlRenderer );  
				SDL_RenderCopy( sdlRenderer, sdlTexture,  NULL, &sdlRect);  
				SDL_RenderPresent( sdlRenderer );  
				//SDL End-----------------------
				//Delay 40ms
				SDL_Delay(40);
			}
		}
		av_free_packet(packet);
	}
	//flush decoder
	//FIX: Flush Frames remained in Codec
	while (1) {
		ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);
		if (ret < 0)
			break;
		if (!got_picture)
			break;
		sws_scale(img_convert_ctx, (const unsigned char* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, 
			pFrameYUV->data, pFrameYUV->linesize);
#if OUTPUT_YUV420P
		int y_size=pCodecCtx->width*pCodecCtx->height;  
		fwrite(pFrameYUV->data[0],1,y_size,fp_yuv);    //Y 
		fwrite(pFrameYUV->data[1],1,y_size/4,fp_yuv);  //U
		fwrite(pFrameYUV->data[2],1,y_size/4,fp_yuv);  //V
#endif
		//SDL---------------------------
		SDL_UpdateTexture( sdlTexture, &sdlRect, pFrameYUV->data[0], pFrameYUV->linesize[0] );  
		SDL_RenderClear( sdlRenderer );  
		SDL_RenderCopy( sdlRenderer, sdlTexture,  NULL, &sdlRect);  
		SDL_RenderPresent( sdlRenderer );  
		//SDL End-----------------------
		//Delay 40ms
		SDL_Delay(40);
	}
 
	sws_freeContext(img_convert_ctx);
 
#if OUTPUT_YUV420P 
    fclose(fp_yuv);
#endif 
 
	SDL_Quit();
 
	av_frame_free(&pFrameYUV);
	av_frame_free(&pFrame);
	avcodec_close(pCodecCtx);
	avformat_close_input(&pFormatCtx);
 
	return 0;
}

编译命令

gcc test.c -I/opt/ffmpeg/include -I/opt/x264/include -I/opt/SDL2/include/SDL2/ -lavcodec -lavformat -lswscale -lavdevice -lavfilter -lavutil -lpostproc -lswresample -lx264 -lSDL2 -L/opt/x264/lib -L/opt/ffmpeg/lib -L/opt/SDL2/lib

如果运行出现Could not initialize SDL，建议将SDL2再装一次。这一次不指定目录

配置： ./configure
make
make instal