该代码参考了雷神的博客 [总结]FFMPEG视音频编解码零基础学习方法
#include <iostream> #include <highgui.h> #include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> #include <opencv2/imgproc/imgproc.hpp> #define __STDC_CONSTANT_MACROS extern "C" { #include <libavutil/opt.h> #include <libavcodec/avcodec.h> #include <libavutil/channel_layout.h> #include <libavutil/common.h> #include <libavutil/imgutils.h> #include <libavutil/mathematics.h> #include <libavutil/samplefmt.h> #include "libavformat/avformat.h" #include <libavformat/avformat.h> #include <libswscale/swscale.h> #include <SDL.h> }; #pragma comment(lib,"avcodec.lib") #pragma comment(lib,"avdevice.lib") #pragma comment(lib,"avfilter.lib") #pragma comment(lib,"avformat.lib") #pragma comment(lib,"avutil.lib") #pragma comment(lib,"postproc.lib") #pragma comment(lib,"swresample.lib") #pragma comment(lib,"swscale.lib") using namespace std; using namespace cv; #define OUTPUT_YUV420P 0 #define SWS_BICUBIC 4 #define SDL_INIT_VIDEO 0x00000020u #define SDL_INIT_AUDIO 0x00000010u #define SDL_INIT_TIMER 0x00000001u #define SDL_WINDOWPOS_UNDEFINED (0x1FFF0000|0) void DisplayYUV(int w, int h, int fps, FILE* pFileIn) { printf("yuv file w: %d, h: %d \n", w, h); //设置文件指针为文件末尾 fseek(pFileIn, 0, SEEK_END); int frame_count = 0; //求文件帧数，对于MxN（rows x cols，M行N列）的BGR图像（CV_8UC3)，其对应的YUV420图像大小是(3M/2)xN（CV_8UC1） //frame_count = (int)((long long)ftell(pFileIn) / ((w * h * 3) / 2)); // ftell 用于求文件大小,fetell对大于2.1G的文件会出错 //printf("frame num is %d \n", frame_count); fseek(pFileIn, 0, SEEK_SET);//文件内位置定位到文件头 int bufLen = w * h * 3 / 2; unsigned char* pYuvBuf = new unsigned char[bufLen]; for (int i = 0; i < 14315/*frame_count*/; i++) { fread(pYuvBuf, bufLen * sizeof(unsigned char), 1, pFileIn); Mat yuvImg; yuvImg.create(h * 3 / 2, w, CV_8UC1); memcpy(yuvImg.data, pYuvBuf, bufLen * sizeof(unsigned char)); Mat rgbImg; //颜色空间转换 cvtColor(yuvImg, rgbImg, CV_YUV2BGR_I420); //imshow("yuv", yuvImg); imshow("rgb", rgbImg); waitKey(1000 / fps); printf("cnt: %d \n", i); } delete[] pYuvBuf; fclose(pFileIn); } int main(int argc, char* argv[]) { AVFormatContext* pFormatCtx; int i, videoindex; AVCodecContext* pCodecCtx; AVCodec* pCodec; //存放yuv AVFrame* pFrame, * pFrameYUV; unsigned char* out_buffer; //存放h264 AVPacket* packet; struct SwsContext* img_convert_ctx; int y_size; FILE* fp_yuv; int ret, got_picture; char filepath[] = "c:/users/37075/source/repos/ffmpeg_learn/h264/output2.h264"; //初始化 av_register_all(); avformat_network_init(); pFormatCtx = avformat_alloc_context(); //打开文件 if (avformat_open_input(&pFormatCtx, filepath, NULL, NULL) != 0) { printf("Couldn't open input stream.\n"); return -1; } //获取流的信息 if (avformat_find_stream_info(pFormatCtx, NULL) < 0) { printf("Couldn't find stram information.\n"); return -1; } videoindex = -1; for (i = 0; i < pFormatCtx->nb_streams; i++) //判断是否是视频 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; } //获取解码器 pCodecCtx = pFormatCtx->streams[videoindex]->codec; if ((pCodec = avcodec_find_decoder(pCodecCtx->codec_id)) == NULL) { printf("Codec not found.\n"); return -1; } //打开解码器 if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) { printf("Could not open codec.\n"); return -1; } FILE* fp = fopen("c:/users/37075/source/repos/ffmpeg_learn/info/output.txt", "wb+"); fprintf(fp, "Duration: %d\n", pFormatCtx->duration); fprintf(fp, "Long Name: %s\n", pFormatCtx->iformat->long_name); fprintf(fp, "Width*Height: %d*%d\n", pFormatCtx->streams[videoindex]->codec->width, pFormatCtx->streams[videoindex]->codec->height); fclose(fp); //申请AVFrame结构，申请内存 pFrame = av_frame_alloc(); pFrameYUV = av_frame_alloc(); //申请内存 out_buffer = (unsigned char*)av_malloc(av_image_get_buffer_size(AV_PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height, 1)); //设置data和linesize 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)); printf("--------------- File Information ----------------\n"); // Dump information about file onto standard error 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); fp_yuv = fopen("c:/users/37075/source/repos/ffmpeg_learn/yuv/output.yuv", "wb+"); //FILE* fp_h264 = fopen("c:/users/37075/source/repos/ffmpeg_learn/h264/test.h264", "wb+"); //读取整个视频流，解码成帧，转换为yuv并保存 //输入一个AVFrame，输出一个AVPacket while (av_read_frame(pFormatCtx, packet) >= 0) { // Is this a packet from the video stream? if (packet->stream_index == videoindex) { //fwrite(packet->data, 1, packet->size, fp_h264); //解码 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); 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 } } av_free_packet(packet); } //fclose(fp_h264); //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); // 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 //} //ifstream fp_in; //fp_in.open("c:/users/37075/source/repos/ffmpeg_learn/yuv/output.yuv", ios_base::in | ios_base::binary); //if (fp_in.fail()) { // cout << "the file is error" << endl; // return -1; //} sws_freeContext(img_convert_ctx); DisplayYUV(pCodecCtx->width, pCodecCtx->height, 25, fp_yuv); fclose(fp_yuv); av_frame_free(&pFrameYUV); av_frame_free(&pFrame); avcodec_close(pCodecCtx); avformat_close_input(&pFormatCtx); return 0; }