一、环境介绍
操作系统: win10 64位
QT版本: QT5.12.6
编译器: MinGW 32
FFMPEG版本: 4.2.2
二、功能介绍
基于ffmpeg设计的视频播放器，只解码处理了图像，没有处理音频。写这个例子方便在其他平台移植播放视频。
2.1 xxx.pro文件
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
CONFIG += c++11
# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS
# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0
SOURCES += \
ReverseDecodThread.cpp \
VideoFrameDisplay.cpp \
main.cpp \
widget.cpp
HEADERS += \
ReverseDecodThread.h \
VideoFrameDisplay.h \
widget.h
FORMS += \
widget.ui
# Default rules for deployment.
qnx: target.path = /tmp/${TARGET}/bin
else: unix:!android: target.path = /opt/${TARGET}/bin
!isEmpty(target.path): INSTALLS += target
win32
{
message('运行win32版本')
INCLUDEPATH+=C:/FFMPEG/ffmpeg_x86_4.2.2/include
LIBS+=C:/FFMPEG/ffmpeg_x86_4.2.2/bin/av*
LIBS+=C:/FFMPEG/ffmpeg_x86_4.2.2/bin/sw*
LIBS+=C:/FFMPEG/ffmpeg_x86_4.2.2/bin/pos*
}
2.2 ReverseDecodThread.cpp
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//指定文件的编码为UTF-8
#pragma execution_character_set("utf-8")
#include "ReverseDecodThread.h"
ReverseDecodThread::ReverseDecodThread()
{
//注册解码器
av_register_all();
//分配上下文
format_ctx= avformat_alloc_context();
qDebug() << "FFMPEG版本信息:" << av_version_info();
}
ReverseDecodThread::~ReverseDecodThread()
{
FreeRAM();
if(format_ctx)
{
avformat_close_input(&format_ctx);//释放解封装器的空间，以防空间被快速消耗完
avformat_free_context(format_ctx);
}
}
void ReverseDecodThread::FreeRAM()
{
if(SRC_VIDEO_pFrame) av_frame_free(&SRC_VIDEO_pFrame);
if(RGB24_pFrame) av_frame_free(&RGB24_pFrame);
if(img_convert_ctx)sws_freeContext(img_convert_ctx);
if(out_buffer_rgb)av_free(out_buffer_rgb);
SRC_VIDEO_pFrame=nullptr;
RGB24_pFrame=nullptr;
img_convert_ctx=nullptr;
out_buffer_rgb=nullptr;
}
/*
工程: FFMPE_ReversePlay
日期: 2021-04-06
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 加载媒体文件
*/
int ReverseDecodThread::LoadVideoFile(QString media)
{
//释放空间
FreeRAM();
//打开媒体文件
strncpy(m_MediaFile, media.toUtf8().data(), sizeof(m_MediaFile));
if(avformat_open_input(&format_ctx, m_MediaFile, nullptr, nullptr) != 0)
{
LogSend(tr("无法打开视频文件: %1").arg(m_MediaFile));
return -1;
}
//读取媒体文件的数据包以获取流信息
if(avformat_find_stream_info(format_ctx, nullptr) < 0)
{
LogSend(tr("无法获取流信息.\n"));
return -1;
}
LogSend(tr("视频中流的数量: %1\n").arg(format_ctx->nb_streams));
for(int i = 0; i < format_ctx->nb_streams; ++i)
{
const AVStream* stream = format_ctx->streams[i];
if(stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
{
//查找解码器
AVCodec *video_pCodec=avcodec_find_decoder(stream->codecpar->codec_id);
//打开解码器
if(avcodec_open2(stream->codec,video_pCodec,nullptr)!=0)
{
LogSend(tr("解码器打开失败.\n"));
return -1;
}
video_stream_index = i;
//得到视频帧的宽高
video_width=stream->codecpar->width;
video_height=stream->codecpar->height;
LogSend(tr("视频帧的尺寸(以像素为单位): (宽X高)%1x%2 像素格式: %3\n").arg(
stream->codecpar->width).arg(stream->codecpar->height).arg(stream->codecpar->format));
}
}
if (video_stream_index == -1)
{
LogSend("没有检测到视频流.\n");
return -1;
}
AVRational frameRate = format_ctx->streams[video_stream_index]->avg_frame_rate;
/*设置视频转码器*/
SRC_VIDEO_pFrame = av_frame_alloc();
RGB24_pFrame = av_frame_alloc();// 存放解码后YUV数据的缓冲区
//将解码后的YUV数据转换成RGB24
img_convert_ctx = sws_getContext(video_width, video_height,
format_ctx->streams[video_stream_index]->codec->pix_fmt,video_width, video_height,
AV_PIX_FMT_RGB24, SWS_BICUBIC, nullptr, nullptr, nullptr);
//计算RGB图像所占字节大小
int numBytes=avpicture_get_size(AV_PIX_FMT_RGB24,video_width,video_height);
//申请空间存放RGB图像数据
out_buffer_rgb = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
// avpicture_fill函数将ptr指向的数据填充到picture内,但并没有拷贝,只是将picture结构内的data指针指向了ptr的数据
avpicture_fill((AVPicture *) RGB24_pFrame, out_buffer_rgb, AV_PIX_FMT_RGB24,
video_width, video_height);
qDebug()<<"format_ctx->duration:"<<format_ctx->duration;
}
void ReverseDecodThread::SetSate(int run)
{
m_run = run;
}
int ReverseDecodThread::GetSate()
{
return m_run;
}
//跳转视频帧
void ReverseDecodThread::SetSeekPos(qint64 pos)
{
is_CurrentSeekPos = 1;
m_n64CurrentSeekPos = pos;
m_run=1; //运行状态
//获取系统本地时间
play_base_time=QDateTime::currentMSecsSinceEpoch();
}
void ReverseDecodThread::PausePlay()
{
m_run = 2;
}
void ReverseDecodThread::StopPlay()
{
m_run = 0;
}
void ReverseDecodThread::LogSend(QString text)
{
qDebug() << text;
}
//线程执行起点
void ReverseDecodThread::run()
{
LogSend("开始播放视频.\n");
StartPlay();
}
//播放视频
int ReverseDecodThread::StartPlay()
{
//获取系统本地时间
play_base_time=QDateTime::currentMSecsSinceEpoch();
//表示视频加载成功
while(m_run)
{
if(m_run == 2)
{
msleep(100); //暂停播放
continue;
}
if (is_CurrentSeekPos)
{
is_CurrentSeekPos = 0;
//偏移到指定位置再开始解码 AVSEEK_FLAG_BACKWARD 向后找最近的关键帧
av_seek_frame(format_ctx, -1, m_n64CurrentSeekPos* AV_TIME_BASE, AVSEEK_FLAG_BACKWARD);
qDebug()<<"跳转的位置:"<<m_n64CurrentSeekPos;
}
double video_clock;
AVPacket pkt;
//读取一帧数据
if(av_read_frame(format_ctx, &pkt) < 0)
{
m_run=2; //设置为暂停状态
qDebug()<<"数据读取完毕.";
continue;
}
if(pkt.stream_index == video_stream_index)
{
//当前时间
video_clock = av_q2d(format_ctx->streams[video_stream_index]->time_base) * pkt.pts;
qDebug()<<"pkt.pts:"<<pkt.pts<<"video_clock:"<<video_clock;
//解码视频 frame
//发送视频帧
if ( avcodec_send_packet(format_ctx->streams[video_stream_index]->codec,&pkt) != 0)
{
av_packet_unref(&pkt);//不成功就释放这个pkt
continue;
}
//接受后对视频帧进行解码
if (avcodec_receive_frame(format_ctx->streams[video_stream_index]->codec, SRC_VIDEO_pFrame) != 0)
{
av_packet_unref(&pkt);//不成功就释放这个pkt
continue;
}
//转格式
sws_scale(img_convert_ctx,
(uint8_t const **) SRC_VIDEO_pFrame->data,
SRC_VIDEO_pFrame->linesize, 0, video_height, RGB24_pFrame->data,
RGB24_pFrame->linesize);
//释放包
av_packet_unref(&pkt);
//加载图片数据
QImage image(out_buffer_rgb,video_width,video_height,QImage::Format_RGB888);
//通过pts同步视频帧--显示视频帧
while (true)
{
qint64 t1=QDateTime::currentMSecsSinceEpoch();
qint64 t2=t1-play_base_time;
qDebug()<<"t1:"<<t1;
qDebug()<<"t2:"<<t2;
qDebug()<<"video_clock:"<<video_clock*1000;
if(t2>=video_clock*1000)
{
break;
}
else
{
QThread::msleep(1);
}
}
//通知界面更新
VideoDataOutput(image.copy());
//时间信号
sig_getCurrentTime(video_clock, format_ctx->duration *1.0 / AV_TIME_BASE);
// QThread::msleep(40);
}
}
LogSend("视频音频解码播放器的线程退出成功.\n");
return 0;
}
2.3 ReverseDecodThread
#ifndef VIDEO_PLAY_H
#define VIDEO_PLAY_H
#include <QThread>
#include <qdebug.h>
#include <QImage>
#include <QDateTime>
extern "C" {
#include <libavutil/opt.h>
#include <libavutil/mem.h>
#include <libavutil/fifo.h>
#include <libavutil/pixfmt.h>
#include <libavutil/log.h>
#include <libavutil/opt.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>
#include <libswresample/swresample.h>
#include <libavfilter/avfilter.h>
#include <libavfilter/buffersrc.h>
#include <libavfilter/buffersink.h>
}
//视频音频解码线程
class ReverseDecodThread: public QThread
{
Q_OBJECT
public:
//构造函数
ReverseDecodThread();
~ReverseDecodThread();
char m_MediaFile[1024];
int m_run; //1表示运行 0表示停止 2表示暂停
double m_n64CurrentSeekPos = 0; //当前seek位置
bool is_CurrentSeekPos = 0; //1需要跳转 0不需要
void SetSate(int run);
int GetSate();
void SetSeekPos(qint64 pos);
void PausePlay();
void StopPlay();
void LogSend(QString text);
//加载视频文件
int LoadVideoFile(QString media);
//释放内存
void FreeRAM();
protected:
void run();
int StartPlay();
signals:
void sig_getCurrentTime(double Sec, double total_Sec);
void VideoDataOutput(QImage); //输出信号
private:
int video_width=0;
int video_height=0;
AVFormatContext *format_ctx=nullptr;
int video_stream_index = -1;
AVFrame *RGB24_pFrame = nullptr;
AVFrame *SRC_VIDEO_pFrame= nullptr;
uint8_t *out_buffer_rgb= nullptr;
struct SwsContext *img_convert_ctx=nullptr; //用于解码后的视频格式转换
double video_clock_tmp;
qint64 play_base_time=0;
};
#endif // VIDEO_PLAY_H
2.3 效果
![用Visual Studio 2019生成FFmpeg解决方案（五）[图]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)