基于 FFMPEG 的视频编码 源码（libavcodec，C++ Qt)
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基于 FFMPEG 的视频编码 源码（libavcodec，C++ Qt)
昨晚把源代码好好整理了一下，加入了视频时间限制功能。源码放这里，大家随便用。
关于代码的解释可以看我另一篇博客：
基于 FFMPEG 的视频编码（libavcodec ，致敬雷霄骅）
首先是头文件：
/****************************************************************************
** file: VideoRecorder.h
** brief: 利用 ffmpeg 实现视频录制
** Copyright (C) LiYuan
** Author: LiYuan
** E-Mail: 18069211#qq(.)com
** Version 1.0.1
** Last modified: 2021.12.28
** Modified By: LiYuan
**
** Permission is hereby granted, free of charge, to any person obtaining a copy
** of this software and associated documentation files (the "Software"), to deal
** in the Software without restriction, including without limitation the rights
** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
** copies of the Software, and to permit persons to whom the Software is
** furnished to do so, subject to the following conditions:
**
** The above copyright notice and this permission notice shall be included in
** all copies or substantial portions of the Software.
**
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
** THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
** THE SOFTWARE.
****************************************************************************/
#ifndef VIDEORECORDER_H
#define VIDEORECORDER_H
#include <QObject>
#include <QTime>
#include <QTimer>
#include <QSize>
#include <QImage>
#include <QQueue>
extern "C"
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
#include <libswscale/swscale.h>
#include <libavutil/opt.h>
#include <libavutil/imgutils.h>
namespace Qly
class VideoRecorder : public QObject
Q_OBJECT
public:
explicit VideoRecorder(QObject *parent = nullptr);
~VideoRecorder();
void setMaxRecordTime(int ms) m_timeout = ms * 1000;
/**
* @brief setAVCodecID 设置编码类型。默认是 MPEG4
* @param id
*/
void setAVCodecID(AVCodecID id);
/**
* @brief setTimeBase 设置视频文件的time base, 默认是 1/1000。 也就是 1ms 为基本单位。
* @param timebase
*/
void setTimeBase(AVRational timebase) m_time_base = timebase;
/**
* @brief openFile 建立视频文件
* @param url
* @return
*/
int openFile(QString url);
int errorcode() const return m_errorcode;
public slots:
/**
* @brief close 关闭视频文件
* @return
*/
bool close();
/**
* @brief setImage 将图像插入到视频中，以当前时间自动计算 pts
* @param image
* @return
*/
bool setImage(const QImage &image);
/**
* @brief setImage 将图像插入到视频中
* @param image
* @param pts 时间戳，以 time base 为基本单位。第一张图像默认 pts 为 0。 如果 pts = -1 则根据当前时间自动计算 pts.
* @return
*/
bool setImage(const QImage &image, int pts);
private slots:
void timeout();
protected:
int writeHeader();
int writeTrailer();
bool writeFrame(const AVFrame *m_pFrame);
int initFile(AVCodecID codecID, QSize size);
void initStreamParameters(AVStream *stream);
void buildFrameFromImage(AVFrame *m_pFrame, const QImage &image, int pts);
AVFormatContext *m_pFormatCtx = nullptr;
const AVCodec *m_pCodec = nullptr;
AVCodecContext *m_pCodecCtx = nullptr;
AVFrame *m_pFrame = nullptr;
AVPacket *m_pPacket = nullptr;
AVCodecID m_codecID = AV_CODEC_ID_MPEG4;
AVPixelFormat m_format = AV_PIX_FMT_YUV420P;
AVRational m_time_base = 1, 1000;
int64_t m_bit_rate = 10000000;
int m_width = 0;
int m_height = 0;
QString m_url;
private:
int m_errorcode = 0;
bool m_recording = false;
QTime m_startTime;
QTimer m_timer;
int m_timeout = 1000 * 1800; //默认半个小时
;
#endif // VIDEORECORDER_H
实现代码如下：
/****************************************************************************
** file: VideoRecorder.cpp
** brief: 利用 ffmpeg 实现视频录制
** Copyright (C) LiYuan
** Author: LiYuan
** E-Mail: 18069211#qq(.)com
** Version 1.0.1
** Last modified: 2021.12.28
** Modified By: LiYuan
**
** Permission is hereby granted, free of charge, to any person obtaining a copy
** of this software and associated documentation files (the "Software"), to deal
** in the Software without restriction, including without limitation the rights
** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
** copies of the Software, and to permit persons to whom the Software is
** furnished to do so, subject to the following conditions:
**
** The above copyright notice and this permission notice shall be included in
** all copies or substantial portions of the Software.
**
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
** THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
** THE SOFTWARE.
****************************************************************************/
#include <QDebug>
#include "VideoRecorder.h"
namespace Qly
static enum AVPixelFormat toAVPixelFormat(QImage::Format format)
switch (format)
case QImage::Format_Invalid:
return AV_PIX_FMT_NONE;
case QImage::Format_Mono:
return AV_PIX_FMT_MONOBLACK;
case QImage::Format_MonoLSB:
return AV_PIX_FMT_NONE;
case QImage::Format_Indexed8:
return AV_PIX_FMT_PAL8;
case QImage::Format_Alpha8:
case QImage::Format_Grayscale8:
return AV_PIX_FMT_GRAY8;
case QImage::Format_Grayscale16:
return AV_PIX_FMT_GRAY16LE;
case QImage::Format_RGB32:
case QImage::Format_ARGB32:
case QImage::Format_ARGB32_Premultiplied:
//return AV_PIX_FMT_BGRA;
return AV_PIX_FMT_BGR0;
case QImage::Format_RGB16:
case QImage::Format_ARGB8565_Premultiplied:
return AV_PIX_FMT_RGB565LE;
case QImage::Format_RGB666:
case QImage::Format_ARGB6666_Premultiplied:
return AV_PIX_FMT_NONE;
case QImage::Format_RGB555:
case QImage::Format_ARGB8555_Premultiplied:
return AV_PIX_FMT_BGR555LE;
case QImage::Format_RGB888:
return AV_PIX_FMT_RGB24;
case QImage::Format_RGB444:
case QImage::Format_ARGB4444_Premultiplied:
return AV_PIX_FMT_RGB444LE;
case QImage::Format_RGBX8888:
case QImage::Format_RGBA8888:
case QImage::Format_RGBA8888_Premultiplied:
return AV_PIX_FMT_RGBA;
case QImage::Format_BGR30:
case QImage::Format_A2BGR30_Premultiplied:
case QImage::Format_RGB30:
case QImage::Format_A2RGB30_Premultiplied:
return AV_PIX_FMT_NONE;
case QImage::Format_RGBX64:
case QImage::Format_RGBA64:
case QImage::Format_RGBA64_Premultiplied:
return AV_PIX_FMT_RGBA64LE;
case QImage::Format_BGR888:
return AV_PIX_FMT_BGR24;
default:
return AV_PIX_FMT_NONE;
return AV_PIX_FMT_NONE;
VideoRecorder::VideoRecorder(QObject *parent) : QObject(parent)
m_pFormatCtx = nullptr;
m_pPacket = av_packet_alloc();
if(!m_pPacket)
qWarning() << "VideoRecorder::VideoRecorder av_packet_alloc failed.";
m_pFrame = av_frame_alloc();
if (!m_pFrame)
qWarning() << "VideoRecorder::VideoRecorder av_frame_alloc failed.";
VideoRecorder::~VideoRecorder()
avcodec_free_context(&m_pCodecCtx);
av_frame_free(&m_pFrame);
av_packet_free(&m_pPacket);
if(m_pFormatCtx)
avformat_free_context(m_pFormatCtx);
int VideoRecorder::openFile(QString url)
m_startTime = QTime(); //将 m_startTime 复原到原始状态
if(url.isNull() || url.isEmpty())
qWarning() << "VideoRecorder::openFile failed, url is Invalid(empty)";
return -1;
m_url = url;
if(m_pFormatCtx)
avformat_free_context(m_pFormatCtx);
m_errorcode = avformat_alloc_output_context2(&m_pFormatCtx, nullptr,
nullptr,
url.toLocal8Bit().constData());
if(m_errorcode < 0)
qWarning() << "In VideoRecorder::openFile avformat_alloc_output_context2 failed";
return -2;
qDebug() << "avformat_alloc_output_context2 success";
if (!(m_pFormatCtx->flags & AVFMT_NOFILE))
m_errorcode = avio_open(&m_pFormatCtx->pb, m_url.toLocal8Bit().constData(), AVIO_FLAG_READ_WRITE);
if(m_errorcode < 0)
qWarning() << "in VideoRecorder::openFile avio_open failed";
return -3;
qDebug() << "avio_open success";
m_recording = true;
return 0;
void VideoRecorder::initStreamParameters(AVStream * stream)
stream->time_base.den = m_time_base.den;
stream->time_base.num = m_time_base.num;
stream->id = m_pFormatCtx->nb_streams -1;
stream->index = m_pFormatCtx->nb_streams -1;
stream->codecpar->codec_tag = 0;
stream->codecpar->codec_type = m_pCodec->type;
stream->codecpar->codec_id = m_pCodec->id;
stream->codecpar->format = m_format;
stream->codecpar->width = m_width;
stream->codecpar->height = m_height;
stream->codecpar->bit_rate = m_bit_rate;
int VideoRecorder::initFile(AVCodecID codecID, QSize size)
qDebug() << "IN VideoRecorder::initFile";
m_width = size.width();
m_height = size.height();
m_codecID = codecID;
m_pCodec = avcodec_find_encoder(codecID);
if (!m_pCodec)
qWarning() << "VideoRecorder::initFile avcodec_find_encoder failed.";
return -2;
qDebug() << "avcodec_find_encoder success, codecID = " << codecID ;
AVStream *pStream = avformat_new_stream(m_pFormatCtx, m_pCodec);
if(pStream == nullptr)
qWarning() << "VideoRecorder::initFile avformat_new_stream failed.";
return -3;
qDebug() << "avformat_new_stream success";
initStreamParameters(pStream);
//m_pCodecCtx = pStream->codec;
qDebug() << "initStreamParameters success";
if(m_pCodecCtx)
qDebug() << "avcodec_free_context";
avcodec_free_context(&m_pCodecCtx);
qDebug() << "m_pCodecCtx = " << m_pCodecCtx;
m_pCodecCtx = avcodec_alloc_context3(m_pCodec);
if(!m_pCodecCtx)
qWarning() << "VideoRecorder::initFile avcodec_alloc_context3 failed.";
return -4;
qDebug() << "avcodec_alloc_context3 success";
m_pCodecCtx->codec_id = m_pCodec->id;
m_pCodecCtx->time_base = pStream->time_base;
m_pCodecCtx->gop_size = 10;
m_pCodecCtx->max_b_frames = 0;
//qDebug() << "max_b_frames";
if (codecID == AV_CODEC_ID_H264)
av_opt_set(m_pCodecCtx->priv_data, "preset", "fast", 0);
//av_opt_set(pCodecCtx->priv_data, "tune", "zerolatency", 0);
//av_opt_set(pCodecCtx->priv_data, "profile", "main", 0);
else if(codecID == AV_CODEC_ID_H265)
av_opt_set(m_pCodecCtx->priv_data, "preset", "fast", 0);
//av_opt_set(pCodecCtx->priv_data, "tune", "zerolatency", 0);
//av_opt_set(pCodecCtx->priv_data, "profile", "main", 0);
qDebug() << "av_opt_set";
/* Some formats want stream headers to be separate. */
if (m_pFormatCtx->oformat->flags & AVFMT_GLOBALHEADER)
m_pFormatCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
avcodec_parameters_to_context(m_pCodecCtx, pStream->codecpar);
m_errorcode = avcodec_open2(m_pCodecCtx, m_pCodec, nullptr);
if(m_errorcode < 0)
qWarning() << "VideoRecorder::initFile avcodec_open2 failed.";
return -5;
qDebug() << "avcodec_open2 success";
m_pFrame->format = (int)m_pCodecCtx->pix_fmt;
m_pFrame->width = m_pCodecCtx->width;
m_pFrame->height = m_pCodecCtx->height;
if( av_frame_get_buffer(m_pFrame, 0) < 0 )
qWarning() << "VideoRecorder::initFile av_frame_get_buffer() failed.";
return -6;
qDebug() << "av_frame_get_buffer success";
return 0;
void VideoRecorder::buildFrameFromImage(AVFrame *pFrame, const QImage &image, int pts)
//qDebug() << "IN VideoRecorder::buildFrameFromImage";
/* make sure the frame data is writable */
if (av_frame_make_writable(pFrame) < 0)
qWarning() << "in VideoRecorder::buildFrameFromImage av_frame_make_writable(pFrame) failed";
return;
int width = image.width();
int height = image.height();
AVPixelFormat imgFmt = toAVPixelFormat(image.format());
SwsContext * pContext = sws_getContext(width, height, imgFmt,
width, height, (AVPixelFormat)pFrame->format, SWS_POINT, nullptr, nullptr, nullptr);
if(!pContext) return;
const uint8_t *in_data[1];
int in_linesize[1];
in_data[0] = image.bits();
in_linesize[0] = image.bytesPerLine();
sws_scale(pContext, in_data, in_linesize, 0, height,
pFrame->data, pFrame->linesize);
sws_freeContext(pContext);
pFrame->pts = pts;
bool VideoRecorder::setImage(const QImage &image, int pts)
//qDebug() << "IN VideoRecorder::setImage";
if(!m_recording)
qDebug() << "in VideoRecorder::setImage m_recording = false";
return false;
QTime t = QTime::currentTime();
if( pts < 0 ) // 说明这时要用真实的时间来做为 pts
if(m_startTime.isNull())
m_startTime = t; // 说明这是第一帧。需要初始化起始时间。
int oldpts = m_startTime.msecsTo(t);
pts = av_rescale_q_rnd(oldpts, AVRational(1, 1000), m_time_base, AV_ROUND_NEAR_INF);
//qDebug() << "oldpts = " << oldpts << ", pts = " << pts;
//qDebug() << "pts = " << pts;
if(m_width == 0) // 说明这是第一个帧
initFile(m_codecID, image.size());
writeHeader();
av_dump_format(m_pFormatCtx, 0, m_url.toLocal8Bit().constData(), true);
m_timer.singleShot(m_timeout, this, SLOT(timeout()));
buildFrameFromImage(m_pFrame, image, pts);
return writeFrame(m_pFrame);
void VideoRecorder::timeout()
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