开发一个简单的视频播放器？

VideoStreamer/ ├── Core/ # 核心引擎 │ ├── MediaEngine # 音视频解码（QMediaPlayer+FFmpeg） │ └── AIRecommender # 推荐算法（Python集成） ├── Network/ # 网络模块 │ ├── RTSP_Server # 实时流协议服务端 │ └── P2P_Module # 点对点传输优化 ├── UI/ # 交互层 │ ├── PlayerWidget # 播放控件（QVideoWidget扩展） │ └── Dashboard # 数据监控面板 └── Utils/ # 工具库 ├── ThreadPool # 线程池管理 └── CacheSystem # 本地缓存（SQLite+QList）

QT += multimedia multimediawidgets network concurrent CONFIG += c++17 python_embed

void MediaEngine::initDecoder() { #ifdef Q_PROCESSOR_X86 // Intel QuickSync硬件加速 av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_QSV, NULL, NULL, 0); #else // FFmpeg CPU解码 codec = avcodec_find_decoder(AV_CODEC_ID_H264); #endif // Qt多媒体框架集成 player = new QMediaPlayer(this); player->setVideoOutput(videoWidget); connect(player, &QMediaPlayer::mediaStatusChanged, this, &onBuffering); }

qint64 syncOffset = (t2 - t1 - (t4 - t3)) / 2; player->setPosition(masterPos + syncOffset);

// 同步报文结构 #pragma pack(push, 1) struct SyncPacket { quint64 timestamp; // NTP时间戳 qint64 mediaPosition; // 媒体位置(ms) quint32 sequence; // 序列号 quint8 syncType; // 同步类型 }; #pragma pack(pop) // 时间戳同步算法 qint64 calculateOffset(const SyncPacket &server, const SyncPacket &client) { qint64 t1 = server.timestamp; qint64 t2 = client.timestamp; qint64 t3 = QDateTime::currentMSecsSinceEpoch(); return ((t2 - t1) + (t3 - t2)) / 2; }

void AdaptiveStreaming::checkBandwidth() { qint64 bandwidth = downloadSpeed(); qint64 bufferLevel = player->bufferStatus(); if(bandwidth < currentBitrate * 0.8 && bufferLevel < 5000) { switchToLowerBitrate(); } else if(bandwidth > currentBitrate * 1.2 && bufferLevel > 10000) { switchToHigherBitrate(); } }

class MediaThread : public QThread { Q_OBJECT protected: void run() override { QElapsedTimer timer; while(!isInterruptionRequested()) { timer.restart(); AVFrame *frame = decoder->getFrame(); if(frame) { emit frameReady(frame); } int remaining = 40 - timer.elapsed(); // 25FPS if(remaining > 0) msleep(remaining); } } };

QVideoSurfaceFormat format( QSize(width, height), QVideoFrame::Format_NV12, QAbstractVideoBuffer::GLTextureHandle ); QOpenGLContext *glContext = QOpenGLContext::currentContext(); glContext->functions()->glBindTexture(GL_TEXTURE_2D, textureId); glContext->functions()->glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB8, width, height, 0, GL_BGRA, GL_UNSIGNED_BYTE, nullptr );

void PrefetchManager::schedulePrefetch() { QNetworkRequest request; request.setUrl(nextSegmentUrl); request.setAttribute( QNetworkRequest::Attribute::User, QVariant(PrefetchPriority) ); QNetworkReply *reply = manager->get(request); connect(reply, &QNetworkReply::finished, [=](){ cache->store(reply->url(), reply->readAll()); }); }