ffmpeg+sdl解码h264数据流程

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我在分析网上大神的博客后使用ffmpeg + sdl 成功地播放了h264数据，所以做了下面的记录.

解码h264数据为yuv240p

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ffmpeg 头文件
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"


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   AVFormatContext	*pFormatCtx; 
int				i, videoindex;
AVCodecContext	*pCodecCtx;
AVCodec			*pCodec;
AVFrame	*pFrame, *pFrameYUV;
uint8_t *out_buffer;
AVPacket *packet;
int y_size;
int ret, got_picture;
struct SwsContext *img_convert_ctx;

创建这些变量,结构体

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//注册ffmpeg编解码器
   av_register_all();
avformat_network_init();
pFormatCtx = avformat_alloc_context();
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if (avformat_open_input(&pFormatCtx, filepath, NULL, NULL) != 0) {
		printf("Couldn't open input stream.\n"); //打开h264文件
		return -1;
	}
	if (avformat_find_stream_info(pFormatCtx, NULL)<0) {
		printf("Couldn't find stream information.\n"); //检测流
		return -1;
	}
	videoindex = -1;
	for (i = 0; i<pFormatCtx->nb_streams; i++)//找到视频流
		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;
	}
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   pFrame = av_frame_alloc(); //初始化
pFrameYUV = av_frame_alloc();//初始化
out_buffer = (uint8_t *)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height));//分配内存空间
avpicture_fill((AVPicture *)pFrameYUV, out_buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);//分配内存空间
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, PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);//转码的信息
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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 uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height,
					pFrameYUV->data, pFrameYUV->linesize);//转码一帧数据

SDL

初始化SDL

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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;
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SDL_UpdateYUVTexture(sdlTexture, &sdlRect,
					pFrameYUV->data[0], pFrameYUV->linesize[0],
					pFrameYUV->data[1], pFrameYUV->linesize[1],
					pFrameYUV->data[2], pFrameYUV->linesize[2]);

				SDL_RenderClear(sdlRenderer);
				SDL_RenderCopy(sdlRenderer, sdlTexture, NULL, &sdlRect);
				SDL_RenderPresent(sdlRenderer);
				//SDL End-----------------------
				//Delay 40ms
				SDL_Delay(40);
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 //最后将所有的资源释放掉
SDL_Quit();

	av_frame_free(&pFrameYUV);
	av_frame_free(&pFrame);
	avcodec_close(pCodecCtx);
	avformat_close_input(&pFormatCtx);

tips

在编译完成后，我点击运行，没有什么反应，但是我点击生成的exe却可以执行
当时我觉得很奇怪，在试错之后明白了，是filepath[]的问题，编译的是cpp的路径，
执行的exe在Debug下面，它们不一样.
感觉这是不人性化的设置