帮我用ffmpeg写一篇视频播放器代码

我可以为你提供一些参考代码，但最终实现取决于你。下面是一个使用ffmpeg播放视频的例子：#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavutil/avutil.h>
#include <libswscale/swscale.h>int main() {
AVFormatContext *pFormatCtx = NULL;
int i, videoStream;
AVCodecContext *pCodecCtx = NULL;
AVCodec *pCodec = NULL;
AVFrame *pFrame = NULL;
AVPacket packet;
int frameFinished;
float aspect_ratio;

av_register_all(); // Register all available file formats and codecs with the library

// Open video file
if(avformat_open_input(&pFormatCtx, "video.mp4", NULL, NULL)!=0)
return -1; // Couldn't open file

// Retrieve stream information
if(avformat_find_stream_info(pFormatCtx, NULL)<0)
return -1; // Couldn't find stream information

// Dump information about file onto standard error
av_dump_format(pFormatCtx, 0, "video.mp4", 0);

// Find the first video stream
videoStream=-1;
for(i=0; i<pFormatCtx->nb_streams; i++)
if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_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_open2(pCodecCtx, pCodec, NULL)<0)
return -1; // Could not open codec

// Allocate video frame
pFrame=av_frame_alloc();

// Read frames and save first five frames to disk
i=0;
while(av_read_frame(pFormatCtx, &packet)>=0) {
// Is this a packet from the video stream?
if(packet.stream_index==videoStream) {
// Decode video frame
avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished,
&packet);

// Did we get a video frame?
if(frameFinished) {
// Save the frame to disk
}
}

// Free the packet that was allocated by av_read_frame
av_free_packet(&packet);
}

// Free the RGB image
av_free(buffer);
av_free(pFrame);

// Free the YUV frame
av_free(pFrameRGB);

// Close the codec
avcodec_close(pCodecCtx);

// Close the video file
avformat_close_input(&pFormatCtx);

return 0;
}