ffmpeg读取摄像头并且播放.zip

#include "ffmpeg.h" #include "ui_ffmpeg.h" //#define FFMPEG_MJPEG //#define FFMPEG_H264 #define FFMPEG_YUV #define TIMEMS qPrintable(QTime::currentTime().toString("HH:mm:ss zzz")) ffmpeg::ffmpeg(QWidget *parent) : QThread(parent) { initVideo(); } ffmpeg::~ffmpeg() { } int ffmpeg::initVideo() { //注册库中所有可用的文件格式和解码器 av_register_all(); //注册所有设备,主要用于本地摄像机播放支持 avdevice_register_all(); //初始化网络流格式,使用网络流时必须先执行 avformat_network_init(); qDebug() << TIMEMS << "init ffmpeg lib ok" << " version:" << FFMPEG_VERSION; const char *inputFilename = "/dev/video4"; AVDictionary *options = NULL; AVCodec *videoDecoder = NULL; av_dict_set(&options, "framerate", "25", 0); av_dict_set(&options, "video_size", "1920x1080", 0); #ifdef FFMPEG_MJPEG av_dict_set(&options, "input_format", "mjpeg", 0); #endif #ifdef FFMPEG_YUV av_dict_set(&options, "input_format", "yuyv422", 0); #endif ifmt_ctx = avformat_alloc_context(); AVInputFormat *ifmt = av_find_input_format("video4linux2"); if (nullptr != ifmt) { qDebug("input device name video4linux2！"); } else { qDebug("Null point "); } //打开输入视频流 int result = avformat_open_input(&ifmt_ctx, inputFilename, ifmt, &options); if (result < 0) { qDebug() << TIMEMS << "open input error" << inputFilename; return false; } //获取流信息 result = avformat_find_stream_info(ifmt_ctx, NULL); if (result < 0) { qDebug() << TIMEMS << "find stream info error"; return false; } videoStreamIndex = -1; videoStreamIndex = av_find_best_stream(ifmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &videoDecoder, 0); if (videoStreamIndex < 0) { qDebug() << TIMEMS << "find video stream index error"; return false; } //获取输入视频流 in_stream = ifmt_ctx->streams[videoStreamIndex]; if (!in_stream) { printf("Failed get input stream\n"); return false; } //获取视频流解码器 videoCodec = in_stream->codec; //获取分辨率大小 videoWidth = in_stream->codec->width; videoHeight = in_stream->codec->height; //如果没有获取到宽高则返回 if (videoWidth == 0 || videoHeight == 0) { qDebug() << TIMEMS << "find width height error"; return false; } //获取视频流的帧率 fps,要对0进行过滤,除数不能为0,有些时候获取到的是0 int num = in_stream->codec->framerate.num; int den = in_stream->codec->framerate.den; if (num != 0 && den != 0) { videoFps = num / den ; } QString videoInfo = QString("视频流信息 -> 索引: %1 格式: %2 时长: %3 秒 fps: %4 分辨率: %5*%6") .arg(videoStreamIndex).arg(ifmt_ctx->iformat->name) .arg((ifmt_ctx->duration) / 1000000).arg(videoFps).arg(videoWidth).arg(videoHeight); qDebug() << TIMEMS << videoInfo; //打开视频解码器 result = avcodec_open2(videoCodec, videoDecoder, NULL); if (result < 0) { qDebug() << TIMEMS << "open video codec error"; return false; } avPacket = av_packet_alloc(); avFrame = av_frame_alloc(); avFrame2 = av_frame_alloc(); avFrame3 = av_frame_alloc(); //比较上一次文件的宽度高度,当改变时,需要重新分配内存 if (oldWidth != videoWidth || oldHeight != videoHeight) { int byte = avpicture_get_size(AV_PIX_FMT_RGB32, videoWidth, videoHeight); buffer = (uint8_t *)av_malloc(byte * sizeof(uint8_t)); oldWidth = videoWidth; oldHeight = videoHeight; } //定义像素格式 AVPixelFormat srcFormat = AV_PIX_FMT_YUV420P; AVPixelFormat dstFormat = AV_PIX_FMT_RGB32; #ifdef FFMPEG_MJPEG srcFormat = AV_PIX_FMT_YUV420P; #endif #ifdef FFMPEG_YUV srcFormat = AV_PIX_FMT_YUYV422; #endif #ifdef FFMPEG_H264 srcFormat = AV_PIX_FMT_YUV420P; #endif av_image_fill_arrays(avFrame3->data, avFrame3->linesize, buffer, dstFormat, videoWidth, videoHeight, 1); //默认最快速度的解码采用的SWS_FAST_BILINEAR参数,可能会丢失部分图片数据,可以自行更改成其他参数 int flags = SWS_FAST_BILINEAR; swsContext = sws_getContext(videoWidth, videoHeight, srcFormat, videoWidth, videoHeight, dstFormat, flags, NULL, NULL, NULL); qDebug() << TIMEMS << "init ffmpegVideo ok"; } int ffmpeg::playVideo() { while(true) { if (av_read_frame(ifmt_ctx, avPacket) >= 0) { //判断当前包是视频还是音频 int packetSize = avPacket->size; int index = avPacket->stream_index; in_stream = ifmt_ctx->streams[avPacket->stream_index]; if (index == videoStreamIndex) { avcodec_decode_video2(videoCodec, avFrame2, &frameFinish, avPacket); if (frameFinish) { //将数据转成一张图片 sws_scale(swsContext, (const uint8_t *const *)avFrame2->data, avFrame2->linesize, 0, videoHeight, avFrame3->data, avFrame3->linesize); //以下两种方法都可以 //QImage image(avFrame3->data[0], videoWidth, videoHeight, QImage::Format_RGB32); QImage image((uchar *)buffer, videoWidth, videoHeight, QImage::Format_RGB32); if (!image.isNull()) { emit receiveImage(image); msleep(20); } } av_packet_unref(avPacket); av_freep(avPacket); } } } } void ffmpeg::run() { playVideo(); }