VS2008+ffmpeg_sdk 3.2 + sdl 播放视频

这次的笔记是基于我上一个笔记的基础上做的，主要是不要重复搭建环境，如果有不懂的，请先做 VS2008+ffmpeg SDK3.2调试tutorial01

第1步：

     下载SDL-devel-1.2.15-VC.zip，下载地址：点击下载，我也上传了一份到115网盘http://115.com/file/an923mtd，并解压。

第2步：

将解压得到的sdl目录下的include文件夹拷到test.cpp同目录下，并将include文件夹改名为sdl

将sdl中的.h文件添加到工程的头文件。

第3步：

将解压的sdl目录下的lib/x86文件夹下的SDL.lib、SDLmain.lib拷贝至工程目录下的lib文件夹

在VS2008中，单击项目属性->链接器->输入,在附加依赖项中将SDL.lib、SDLmain.lib加入。

本来是还要将SDL.dll拷进debug目录的，但我看到里面本来就有了，就省了这一步，如果没有的，复制进去就可以了。

第4步：编写代码，测试

tes.cpp代码

#include 
#include 

#ifdef __cplusplus
extern "C" {
#endif
	#include "libavcodec/avcodec.h"
	#include "libavformat/avformat.h"
	#include "libswscale/swscale.h"
#ifdef __cplusplus
}
#endif

#include "sdl\SDL.h"
#include "sdl\SDL_thread.h"

#ifdef __MINGW32__
#undef main /* Prevents SDL from overriding main() */
#endif

void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame) {
  FILE *pFile;
  char szFilename[32];
  int  y;
  
  // Open file
  sprintf(szFilename, "frame%d.ppm", iFrame);
  pFile=fopen(szFilename, "wb");
  if(pFile==NULL)
    return;
  
  // Write header
  fprintf(pFile, "P6\n%d %d\n255\n", width, height);
  
  // Write pixel data
  for(y=0; ydata[0]+y*pFrame->linesize[0], 1, width*3, pFile);
  
  // Close file
  fclose(pFile);
}

int main() {
  AVFormatContext *pFormatCtx;
  int             i, videoStream;
  AVCodecContext  *pCodecCtx;
  AVCodec         *pCodec;
  AVFrame         *pFrame; 
  AVFrame         *pFrameRGB;
  AVPacket        packet;
  int             frameFinished;
  int             numBytes;
  uint8_t         *buffer;
  float           aspect_ratio;
  SDL_Overlay     *bmp;
  SDL_Surface     *screen;
  SDL_Rect        rect;
  SDL_Event       event;
  static struct SwsContext *img_convert_ctx;
  char * filePath="test.mp4";
  // Register all formats and codecs
  av_register_all();

  if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
    fprintf(stderr, "Could not initialize SDL - %s\n", SDL_GetError());
    exit(1);
  }

    // Open video file
  if(av_open_input_file(&pFormatCtx, filePath, NULL, 0, NULL)!=0)
    return -1; // Couldn't open file
  
  // Retrieve stream information
  if(av_find_stream_info(pFormatCtx)<0)
    return -1; // Couldn't find stream information
  
  // Dump information about file onto standard error
  dump_format(pFormatCtx, 0, filePath, 0);
    // Find the first video stream
  videoStream=-1;
  for(i=0; inb_streams; i++)
    if(pFormatCtx->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO) {
      videoStream=i;
      break;
    }
  if(videoStream==-1)
    return -1; // Didn't find a video stream
	  // Get a pointer to the codec context for the video stream
  pCodecCtx=pFormatCtx->streams[videoStream]->codec;

    // Find the decoder for the video stream
  pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
  if(pCodec==NULL) {
    fprintf(stderr, "Unsupported codec!\n");
    return -1; // Codec not found
  }
	  // Open codec
  if(avcodec_open(pCodecCtx, pCodec)<0)
    return -1; // Could not open codec

    // Allocate video frame
  pFrame=avcodec_alloc_frame();
  
  // Allocate an AVFrame structure
  pFrameRGB=avcodec_alloc_frame();
  if(pFrameRGB==NULL)
    return -1;


  // Make a screen to put our video
#ifndef __DARWIN__
        screen = SDL_SetVideoMode(pCodecCtx->width, pCodecCtx->height, 0, 0);
#else
        screen = SDL_SetVideoMode(pCodecCtx->width, pCodecCtx->height, 24, 0);
#endif
  if(!screen) {
    fprintf(stderr, "SDL: could not set video mode - exiting\n");
    exit(1);
  }



   // Allocate a place to put our YUV image on that screen
  bmp = SDL_CreateYUVOverlay(pCodecCtx->width,
				 pCodecCtx->height,
				 SDL_YV12_OVERLAY,
				 screen);

    
  // Determine required buffer size and allocate buffer
  numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width,
			      pCodecCtx->height);
  buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));

    // Assign appropriate parts of buffer to image planes in pFrameRGB
  // Note that pFrameRGB is an AVFrame, but AVFrame is a superset
  // of AVPicture
  avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24,
		 pCodecCtx->width, pCodecCtx->height);

  // Read frames and save first five frames to disk
  i=0;
  while(av_read_frame(pFormatCtx, &packet)>=0) {
		    if(packet.stream_index==videoStream) {
				      // Decode video frame
				 avcodec_decode_video(pCodecCtx, pFrame, &frameFinished,packet.data, packet.size);
				   if(frameFinished) {


									SDL_LockYUVOverlay(bmp);

							AVPicture pict;
							pict.data[0] = bmp->pixels[0];
							pict.data[1] = bmp->pixels[2];
							pict.data[2] = bmp->pixels[1];

							pict.linesize[0] = bmp->pitches[0];
							pict.linesize[1] = bmp->pitches[2];
							pict.linesize[2] = bmp->pitches[1];


							// Convert the image from its native format to RGB
						img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height,PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
						// Convert the image from its native format to RGB
sws_scale(img_convert_ctx, pFrame->data, pFrame->linesize,0, pCodecCtx->height, pict.data, pict.linesize);
			

							SDL_UnlockYUVOverlay(bmp);
	
							rect.x = 0;
							rect.y = 0;
							rect.w = pCodecCtx->width;
							rect.h = pCodecCtx->height;
							SDL_DisplayYUVOverlay(bmp, &rect);

				   }
			}
			    // Free the packet that was allocated by av_read_frame
		av_free_packet(&packet);
		SDL_PollEvent(&event);
		 switch(event.type) {
			case SDL_QUIT:
			SDL_Quit();
			exit(0);
			break;
			default:
			break;
		 }


  }
  // Free the RGB image
  av_free(buffer);
  av_free(pFrameRGB);
  
  // Free the YUV frame
  av_free(pFrame);
  
  // Close the codec
  avcodec_close(pCodecCtx);
  
  // Close the video file
  av_close_input_file(pFormatCtx);
  
  printf("执行完毕\n");
  system("pause");
  return 0;
}

按F7编译，F5运行

写完收工，

由于没有调整帧，播放速度超快，下一步目标是调整速度，并调出声音。