结合ffmpeg用SDL播放YUV实现简易播放器

通过解码之后得到的yuv视频数据我们直接可以进行播放，本篇使用SDL来实现视频播放。

SDL环境配置：https://blog.csdn.net/furzoom/article/details/53992124

SDL视频播放基础教程: https://blog.csdn.net/xuyankuanrong/article/details/77574152

有了上一篇文章的解码的基础，代码看着就很轻松了。

代码上写的很详细了，具体看代码

#include "stdafx.h"
#include <iostream>

// LNK2019	无法解析的外部符号 SDL_main，该符号在函数 main_utf8 中被引用
#define SDL_MAIN_HANDLED 

//Refresh Event
#define SFM_REFRESH_EVENT     (SDL_USEREVENT + 1)
#define SFM_BREAK_EVENT       (SDL_USEREVENT + 2)

extern "C" {
	#include <libavformat/avformat.h>   
	#include <libavcodec/avcodec.h>   
	#include <libavutil/imgutils.h>
	#include <libswscale/swscale.h>
	#include <libsdl/SDL.h>
}



void log_s(const char * msg, int d = -1123) {
	if (d == -1123) {
		printf_s("%s\n", msg);
	}
	else {
		printf_s("%s  %d \n", msg, d);
	}
}


int thread_exit = 0;
int thread_pause = 0;

int sfp_refresh_thread(void *opaque) {
	while (!thread_exit) {
		if (!thread_pause) {
			SDL_Event event;
			event.type = SFM_REFRESH_EVENT;
			SDL_PushEvent(&event);
		}
		SDL_Delay(10);
	}
	thread_exit = 0;
	thread_pause = 0;
	//Break
	SDL_Event event;
	event.type = SFM_BREAK_EVENT;
	SDL_PushEvent(&event);

	return 0;
}

int play(const char*  filePath) {
	AVFormatContext * pFmtCtx = NULL;
	AVCodecContext *pCodecCtx = NULL;
	AVFrame *pFrame = NULL;
	AVFrame *pFrameYUV = NULL;
	uint8_t *outBuffer = NULL;
	AVPacket *pPacket = NULL;
	SwsContext *pSwsCtx = NULL;

	//SDL
	int screen_w, screen_h;
	SDL_Window *screen=NULL;
	SDL_Renderer* sdlRenderer = NULL;
	SDL_Texture* sdlTexture = NULL;
	SDL_Rect sdlRect;
	SDL_Thread *video_tid = NULL;
	SDL_Event event;


	//1. 初始化
	av_register_all();
	avformat_network_init();
	//2. AVFormatContext获取
	pFmtCtx = avformat_alloc_context();
	//3. 打开文件
	if (avformat_open_input(&pFmtCtx, filePath, NULL, NULL) != 0) {
		log_s("Couldn't open input stream.\n");
		return -1;
	}
	//4. 获取文件信息
	if (avformat_find_stream_info(pFmtCtx, NULL)<0) {
		log_s("Couldn't find stream information.");
		return -1;
	}
	//5. 获取视频的index
	int i = 0, videoIndex = -1;
	for (; i < pFmtCtx->nb_streams; i++) {
		if (pFmtCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
			videoIndex = i;
			break;
		}
	}

	if (videoIndex == -1) {
		log_s("Didn't find a video stream.");
		return -1;
	}
	//6. 获取解码器并打开
	pCodecCtx = avcodec_alloc_context3(NULL);
	if (avcodec_parameters_to_context(pCodecCtx, pFmtCtx->streams[videoIndex]->codecpar) < 0) {
		log_s("Didn't parameters to contex.");
		return -1;
	}
	AVCodec *pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
	if (pCodec == NULL) {
		log_s("Codec not found.");
		return -1;
	}
	if (avcodec_open2(pCodecCtx, pCodec, NULL)<0) {//打开解码器
		log_s("Could not open codec.");
		return -1;
	}
	//7. 解码播放开始准备工作
	pFrame = av_frame_alloc();
	pFrameYUV = av_frame_alloc();

	//根据需要解码的类型，获取需要的buffer，不要忘记free
	outBuffer = (uint8_t *)av_malloc(av_image_get_buffer_size(AV_PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height, 1) * sizeof(uint8_t));
	//根据指定的图像参数和提供的数组设置数据指针和行数 ，数据填充到对应的pFrameYUV里面
	av_image_fill_arrays(pFrameYUV->data, pFrameYUV->linesize, outBuffer, AV_PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height, 1);

	pPacket = av_packet_alloc();
	log_s("--------------- File Information ----------------");
	av_dump_format(pFmtCtx, 0, filePath, 0);
	log_s("-------------------------------------------------");
	//获取SwsContext
	pSwsCtx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt,
		pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_YUV420P, NULL, NULL, NULL, NULL);
	//----------------------------------------------------------------------------------------------------------------
	// 8. SDL相关初始化
	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
		log_s("Could not initialize SDL - ");
		log_s(SDL_GetError());
		return -1;
	}
	screen_w = pCodecCtx->width;
	screen_h = pCodecCtx->height;
	screen = SDL_CreateWindow("WS ffmpeg player", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
		pCodecCtx->width/2, pCodecCtx->height/2, SDL_WINDOW_OPENGL);
	if (!screen) {
		log_s("SDL: could not create window - exiting");
		log_s(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;

	video_tid = SDL_CreateThread(sfp_refresh_thread, NULL, NULL);
	//----------------------------------------------------------------------------------------------------------------


	int count = 0;

	//9.读取数据播放
	for (;;) {
		//Wait
		SDL_WaitEvent(&event);
		if (event.type == SFM_REFRESH_EVENT) {
			if (av_read_frame(pFmtCtx, pPacket) == 0) {
				if (pPacket->stream_index == videoIndex) {
					if (avcodec_send_packet(pCodecCtx, pPacket) != 0) {//解码一帧压缩数据
						log_s("Decode end or Error.");
						break;
					}
					else {//处理解码数据
						avcodec_receive_frame(pCodecCtx, pFrame);

						if (sws_scale(pSwsCtx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height,
							pFrameYUV->data, pFrameYUV->linesize) == 0) {
							continue;
						}

						count++;

						//SDL播放---------------------------
						SDL_UpdateTexture(sdlTexture, NULL, pFrameYUV->data[0], pFrameYUV->linesize[0]);
						SDL_RenderClear(sdlRenderer);
						//SDL_RenderCopy( sdlRenderer, sdlTexture, &sdlRect, &sdlRect);  
						SDL_RenderCopy(sdlRenderer, sdlTexture, &sdlRect, NULL);
						SDL_RenderPresent(sdlRenderer);
						//SDL End-----------------------

						log_s("Succeed to play frame!", count);
					}
				}
			}else {
				//退出线程
				thread_exit = 1;
				av_packet_unref(pPacket);
			}
		}
		else if (event.type == SDL_KEYDOWN) {
			log_s("Pause");
			//Pause
			if (event.key.keysym.sym == SDLK_SPACE)
				thread_pause = !thread_pause;
		}
		else if (event.type == SDL_QUIT) {
			log_s("quit");
			thread_exit = 1;
			break;
		}
		else if (event.type == SFM_BREAK_EVENT) {
			log_s("break");
			break;
		}
	}
	//sdl退出
	SDL_Quit();

	//回收
	if (pSwsCtx != NULL) {
		sws_freeContext(pSwsCtx);
	}
	if (outBuffer != NULL) {
		av_free(outBuffer);
	}
	if (pFrameYUV != NULL) {
		av_frame_free(&pFrameYUV);
	}
	if (pFrame != NULL) {
		av_frame_free(&pFrame);
	}
	if (pCodecCtx != NULL) {
		avcodec_close(pCodecCtx);
	}
	if (pFmtCtx != NULL) {
		avformat_close_input(&pFmtCtx);
	}
}


int main()
{
	play("F:/视频资源/gxsp.mp4");
	getchar();
	return 0;
}

参考链接：https://blog.csdn.net/king1425/article/details/71171142