ffmpeg录屏
作者：互联网
qt + ffmpeg屏幕录制软件
完整工程链接：https://download.csdn.net/download/weixin_42538789/85013858
测试代码
#include <QtCore/QCoreApplication>
#include "screencapture.h"
#include <iostream>
using namespace std;
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
ScreenCapture* capture = new ScreenCapture();
capture->start();
while (true)
{
string str;
cin >> str;
if (str == "q")
{
capture->setStop(true);
break;
}
}
return a.exec();
}
头文件screencapture.h
#ifndef SCREEN_CAPTURE_H
#define SCREEN_CAPTURE_H
#include <QThread>
#include <QTcpSocket>
extern "C"
{
#include "libavformat/avformat.h"
#include "libavutil/ffversion.h"
#include "libavcodec/avcodec.h"
#include "libswscale/swscale.h"
#include "libavutil/imgutils.h"
#include "libavdevice/avdevice.h"
}
class ScreenCapture : public QThread
{
Q_OBJECT
public:
explicit ScreenCapture(QWidget *parent = 0, QString savefile = "record.mp4");
protected:
void run();
private:
AVFrame* avFrameRgb; //解码帧对象RGB
AVFrame* avFrameYuv; //解码帧对象YUV
AVStream* in_stream; //输入视频流
AVStream* out_stream; //输出视频流
AVCodecContext* deCodecCtx; //解码器上下文
AVCodecContext* enCodecCtx; //解码器上下文
SwsContext* swsContextYuvtoRgb; //格式转换上下文（YuvtoRgb）
SwsContext* swsContextRgbtoYuv; //格式转换上下文（RgbtoYuv）
AVFormatContext *ifmt_ctx; //输入格式对象
AVFormatContext *ofmt_ctx; //输出格式对象
AVOutputFormat *ofmt; //输出格式
AVPacket *avDePacket; //包对象
AVPacket* avEnPacket; //包对象
AVPixelFormat srcFormat; //像素格式
AVPixelFormat dstFormat; //像素格式
QString url; //视频流地址
QString fileName; //保存文件名称
bool stop; //线程停止标志
int videoStreamIndex; //视频流索引
int videoWidth; //视频宽度
int videoHeight; //视频高度
int videoFps; //视频帧率
int videoIndex; //视频索引
uint64_t frameCount; //帧计数
private:
bool intiDeContext();
bool initDecoder();
bool initEncoder();
bool initOutputStream();
bool initSwsContext();
void memoryAlloc();
bool initmodules();
signals:
void initFinished();
public:
void setStop(bool stop);
};
#endif // SCREEN_CAPTURE_H
源文件screencapture.cpp
#include <QDateTime>
#include <QThread>
#include <QTimer>
#include <QDebug>
#include "screencapture.h"
#define TIMEMS qPrintable(QTime::currentTime().toString("HH:mm:ss zzz"))
ScreenCapture::ScreenCapture(QWidget* parent, QString savefile) : QThread()
{
stop = false;
fileName = savefile;
frameCount = 0;
}
bool ScreenCapture::initmodules()
{
/* 各个模块的初始化顺序不能变 */
if (!intiDeContext()) return false;
if (!initDecoder()) return false;
if (!initEncoder()) return false;
if (!initOutputStream()) return false;
if (!initSwsContext()) return false;
memoryAlloc();
return true;
}
void ScreenCapture::run()
{
int err = 0;
if (!initmodules())
{
return;
}
qDebug() << TIMEMS << "start capture screen ...";
while (!stop)
{
if ((av_read_frame(ifmt_ctx, avDePacket)) >= 0)
{
err = 0;
int index = avDePacket->stream_index;
in_stream = ifmt_ctx->streams[index];
if (index == videoStreamIndex)
{
int frameFinish = 0;
avcodec_decode_video2(deCodecCtx, avFrameRgb, &frameFinish, avDePacket);
sws_scale(swsContextRgbtoYuv, (const uint8_t* const*)avFrameRgb->data, avFrameRgb->linesize, \
0, videoHeight, avFrameYuv->data, avFrameYuv->linesize);
int base = 90000 / videoFps;
avFrameYuv->pts = frameCount++;
frameCount = frameCount + base;
/* 这里设定每隔一秒钟打印一次帧号 */
if (frameCount / base % videoFps == 0)
{
qDebug() << "framCount = " << frameCount / base;
}
int ret = avcodec_send_frame(enCodecCtx, avFrameYuv);
if (ret != 0)
{
qDebug() << "avcodec_send_frame failed.";
continue;
}
ret = avcodec_receive_packet(enCodecCtx, avEnPacket);
if (ret != 0)
{
qDebug() << "avcodec_receive_packet failed.";
continue;
}
ret = av_write_frame(ofmt_ctx, avEnPacket);
if (ret < 0)
{
av_packet_unref(avEnPacket);
av_freep(avEnPacket);
qDebug() << "av_write_frame failed.";
continue;
}
}
av_packet_unref(avDePacket);
av_freep(avDePacket);
}
else
{
qDebug() << "av_read_frame failed";
av_packet_unref(avDePacket);
av_freep(avDePacket);
err++;
/* 连续N次读取失败则跳出循环 */
if (err > 3)
{
err = 0;
break;
}
}
}
av_write_trailer(ofmt_ctx);
/* close output */
if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
{
avio_close(ofmt_ctx->pb);
}
avformat_close_input(&ifmt_ctx);
avformat_free_context(ofmt_ctx);
avformat_free_context(ifmt_ctx);
qDebug() << TIMEMS << "stop ffmpeg thread";
}
bool ScreenCapture::intiDeContext()
{
av_register_all();
/* 注册编解码器 */
avcodec_register_all();
avdevice_register_all();
AVDictionary* options = NULL;
/* 指定录屏的分辨率 */
av_dict_set(&options, "video_size", "1920x1080", 0);
av_dict_set(&options, "pix_fmt", "yuv420p", 0);
ifmt_ctx = avformat_alloc_context();
if (!ifmt_ctx)
{
qDebug() << "avformat_alloc_context failed.";
return false;
}
AVInputFormat* ifmt = av_find_input_format("gdigrab");
if (avformat_open_input(&ifmt_ctx, "desktop", ifmt, &options) != 0) {
qDebug() << TIMEMS << "open input error" << url;
return false;
}
/* 释放设置参数 */
if (options != NULL) {
av_dict_free(&options);
}
/* 获取流信息 */
bool result = avformat_find_stream_info(ifmt_ctx, NULL);
if (result < 0) {
qDebug() << TIMEMS << "find stream info error";
return false;
}
AVCodec* videoDecoder = NULL;
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)
{
qDebug() << "Failed get input stream.";
return false;
}
/* 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";
avformat_free_context(ofmt_ctx);
avformat_free_context(ifmt_ctx);
return false;
}
/* 获取视频流的帧率 fps,要对0进行过滤 */
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("保存视频流信息 -> 索引: %1 解码: %2 格式: %3 时长: %4 秒 fps: %5 分辨率: %6*%7 rtsp地址: %8")
.arg(videoStreamIndex).arg(videoDecoder->name).arg(ifmt_ctx->iformat->name)
.arg((ifmt_ctx->duration) / 1000000).arg(videoFps).arg(videoWidth).arg(videoHeight).arg(url);
qDebug() << TIMEMS << videoInfo;
return true;
}
bool ScreenCapture::initDecoder()
{
AVCodec* deCodec = NULL;
deCodecCtx = in_stream->codec;
deCodec = avcodec_find_decoder(deCodecCtx->codec_id);
int result = avcodec_open2(deCodecCtx, deCodec, NULL);
if (result < 0) {
qDebug() << TIMEMS << "open video codec error :" << result;
return false;
}
return true;
}
void ScreenCapture::memoryAlloc()
{
//分配AVFram及像素存储空间
avFrameRgb = av_frame_alloc();
avFrameRgb->format = srcFormat;
avFrameRgb->width = videoWidth;
avFrameRgb->height = videoHeight;
av_frame_get_buffer(avFrameRgb, 32);
avFrameYuv = av_frame_alloc();
avFrameYuv->format = dstFormat;
avFrameYuv->width = videoWidth;
avFrameYuv->height = videoHeight;
av_frame_get_buffer(avFrameYuv, 32);
avEnPacket = av_packet_alloc();
av_init_packet(avEnPacket);
avDePacket = av_packet_alloc();
av_init_packet(avDePacket);
}
bool ScreenCapture::initSwsContext()
{
/* 定义像素格式 */
srcFormat = AV_PIX_FMT_BGRA;
dstFormat = AV_PIX_FMT_YUV420P;
/* 默认最快速度的解码采用的SWS_FAST_BILINEAR参数 */
int flags = SWS_FAST_BILINEAR;
/* 格式转换上下文(RgbtoYuv) */
swsContextRgbtoYuv = sws_getContext(videoWidth, videoHeight, srcFormat, \
videoWidth, videoHeight, dstFormat, \
flags, NULL, NULL, NULL);
return true;
}
bool ScreenCapture::initOutputStream()
{
/* 设置输出封装格式上下文 */
avformat_alloc_output_context2(&ofmt_ctx, 0, "mpegts", fileName.toLatin1().data());
ofmt = ofmt_ctx->oformat;
/* 封装格式上下文中增加视频流信息 */
out_stream = avformat_new_stream(ofmt_ctx, NULL);
/* 设置封装器参数 */
out_stream->id = 0;
out_stream->codecpar->codec_tag = 0;
avcodec_parameters_from_context(out_stream->codecpar, enCodecCtx);
av_dump_format(ofmt_ctx, 0, fileName.toLatin1().data(), 1);
/* 写MP4头 */
avio_open(&ofmt_ctx->pb, fileName.toLatin1().data(), AVIO_FLAG_WRITE);
int ret = avformat_write_header(ofmt_ctx, NULL);
if (ret < 0)
{
qDebug() << "Failed to avformat_write_header.";
return false;
}
return true;
}
bool ScreenCapture::initEncoder()
{
/* 找到编码器对象 */
AVCodec* encodec = avcodec_find_encoder(AV_CODEC_ID_H264);
if (!encodec)
{
qDebug() << "Failed to find encoder.";
return false;
}
/* 分配编码器上下文 */
enCodecCtx = avcodec_alloc_context3(encodec);
if (!enCodecCtx)
{
qDebug() << "Failed to alloc context3.";
return false;
}
/* 设置编码器参数 */
enCodecCtx->bit_rate = 400000;
enCodecCtx->width = videoWidth;
enCodecCtx->height = videoHeight;
enCodecCtx->time_base = { 1,videoFps };
enCodecCtx->framerate = { videoFps,1 };
enCodecCtx->gop_size = 50;
enCodecCtx->keyint_min = 20;
enCodecCtx->max_b_frames = 0;
enCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
enCodecCtx->codec_id = AV_CODEC_ID_H264;
enCodecCtx->flags |= AV_CODEC_FLAG2_LOCAL_HEADER;
enCodecCtx->thread_count = 8;
/* 量化因子,范围越大，画质越差，编码速度越快 */
enCodecCtx->qmin = 20;
enCodecCtx->qmax = 30;
AVDictionary* param = 0;
av_dict_set(¶m, "preset", "superfast", 0);
av_dict_set(¶m, "tune", "zerolatency", 0);
/* 打开编码器 */
int ret = avcodec_open2(enCodecCtx, encodec, ¶m);
if (ret < 0)
{
qDebug() << "Failed to open enCodecCtx.";
return false;
}
qDebug() << TIMEMS;
return true;
}
void ScreenCapture::setStop(bool stop)
{
this->stop = stop;
}
标签：ffmpeg,int,ctx,录屏,enCodecCtx,av,qDebug,include 来源： https://blog.csdn.net/weixin_42538789/article/details/123642875