linux下ffmpeg和SDL可以播放视频文件，也可以直接拉流播放

#include "mainwindow.h" #include "ui_mainwindow.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) , ui(new Ui::MainWindow) { ui->setupUi(this); } MainWindow::~MainWindow() { delete ui; } void MainWindow::on_pushButton_clicked() { AVFormatContext* pFormatCtx = nullptr; AVCodecContext* pCodecCtx = nullptr; AVCodec* pCodec = nullptr; // 解码器 int iVideoIndex = 0, iRet = 0; AVFrame* pFrame = nullptr; AVFrame* pFrameYUV = nullptr; AVPacket* pPacket = nullptr; unsigned char* out_buffer = nullptr; SwsContext* pSwsCtx = nullptr; FILE* fp_yuv = nullptr; int got_picture = 0; // sdl int nScreen_w = 0, nScreen_h = 0; SDL_Window* pScreen = nullptr; // 播放窗口 SDL_Renderer* pRender = nullptr; // 渲染器 SDL_Texture* pSDLTexture = nullptr; // 纹理 char filepath[] = "rtmp://ns8.indexforce.com/home/mystream"; SDLHandle* m_pSDlHandle = nullptr; // ffmpeg av_register_all(); avformat_network_init(); pFormatCtx = avformat_alloc_context(); if (!pFormatCtx) { printf("avformat_alloc_context error!\n"); goto exit; } // 该函数用于打开多媒体数据并且获得一些相关的信息 if (avformat_open_input(&pFormatCtx, filepath, nullptr, nullptr) < 0) { printf("avformat_open_input failed!\n"); goto exit; } // 该函数可以读取一部分视音频数据并且获得一些相关的信息 if (avformat_find_stream_info(pFormatCtx, nullptr) < 0) { printf("avformat_find_stream_info error!\n"); goto exit; } iVideoIndex = -1; for (int i=0; i< pFormatCtx->nb_streams; i++) { if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) { iVideoIndex = i; break; } } if (iVideoIndex == -1) { printf("not find a video stream.\n"); goto exit; } pCodecCtx = pFormatCtx->streams[iVideoIndex]->codec; nScreen_w = pCodecCtx->width; nScreen_h = pCodecCtx->height; pCodec = avcodec_find_decoder(pCodecCtx->codec_id); // 查找解码器 if (pCodec == nullptr) { printf("avcodec_find_decode error.\n"); goto exit; } if (avcodec_open2(pCodecCtx, pCodec, nullptr) < 0) { printf("avcodec_open2 failed!\n"); goto exit; } printf("--------------- File Information ----------------\n"); av_dump_format(pFormatCtx, 0, filepath, 0); printf("-------------------------------------------------\n"); // 解码准备 pFrame = av_frame_alloc(); pFrameYUV = av_frame_alloc(); pPacket = (AVPacket*)av_malloc(sizeof(AVPacket)); // 申请内存 w*h*1.5(Y:w*h U:w*h/4 V:w*h/4) out_buffer = (unsigned char*)av_malloc(av_image_get_buffer_size(AV_PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height, 1)); av_image_fill_arrays(pFrameYUV->data, pFrameYUV->linesize, out_buffer, AV_PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height, 1); pSwsCtx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt,pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_YUV420P, SWS_BICUBIC, nullptr, nullptr, nullptr); m_pSDlHandle = new SDLHandle(pCodecCtx->width, pCodecCtx->height);//(1000,800);//pCodecCtx->width, pCodecCtx->height); if (!m_pSDlHandle->CreateSDLWindow("SDL_TEXT", SDL_WINDOW_OPENGL)) { printf("CreateSDLWindow error:%s\n", SDL_GetError()); goto exit; } // 解码 while (av_read_frame(pFormatCtx,pPacket) >= 0) { if (pPacket->stream_index == iVideoIndex) // 视频packet { iRet = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, pPacket); if (iRet < 0) { printf("avcodec_decode_video2 error!\n"); goto exit; } if (got_picture) { sws_scale(pSwsCtx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data, pFrameYUV->linesize); m_pSDlHandle->UpdateTexture(pFrame); } } av_free_packet(pPacket); } // 解码器虽然读完了 但是还有一些帧缓存 while (true) { iRet = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, pPacket); if (iRet < 0) { break; } if (!got_picture) { break; } sws_scale(pSwsCtx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data, pFrameYUV->linesize); m_pSDlHandle->UpdateTexture(pFrame); } exit: if (m_pSDlHandle) { delete m_pSDlHandle; m_pSDlHandle = nullptr; } if (pSwsCtx) { sws_freeContext(pSwsCtx); } if (pFrame) { av_frame_free(&pFrame); } if (pFrameYUV) { av_frame_free(&pFrameYUV); } if (pCodecCtx) { avcodec_close(pCodecCtx); } if (pFormatCtx) { avformat_close_input(&pFormatCtx); } }