介绍
工作开发中需要处理的文件很多并无音频,针对这一场景,这里分享工作中自己封装使用的类库。精简的代码实现了播放、暂停、停止、快进、快退、进度更新跳转播放功能。直接放代码,方便后期复制使用。
代码
头文件
#ifndef VIDEOPLAYER_H
#define VIDEOPLAYER_H#include <QThread>
#include <QDebug>
#include <QImage>extern "C"
{
#include "libavformat/avformat.h"
#include "libavcodec/avcodec.h"
#include "libswscale/swscale.h"
#include "libavutil/imgutils.h"
#include "libavutil/time.h"
}class VideoDecoder : public QThread
{Q_OBJECT
public:explicit VideoDecoder(QObject *parent = nullptr);~VideoDecoder();void startPlay(const QString &path);void stopPlay();void pausePlay(bool pause);void seekPlay(int sec);signals:void sigDuration(int sec);void sigPlayPosition(int sec);void sigPlayFinished(int ret);void sigSendImage(const QImage &image);protected:void run();private://运行标志volatile bool m_isRun = false;//暂停状态volatile bool m_pause = false;//进度跳转状态volatile bool m_seek = false;//优化跳转速度volatile bool m_seekFilter = false;//开始时间 ms单位int64_t m_startTime;//暂停时间 ms单位int64_t m_pauseTime;//跳转时间 ms单位int64_t m_seekTime;//文件路径QString m_filePath;//时长信息 秒int m_videoDuration;
};#endif // VIDEOPLAYER_H
实现文件
#include "videoplayer.h"VideoDecoder::VideoDecoder(QObject *parent) : QThread(parent)
{}VideoDecoder::~VideoDecoder()
{quit();wait();
}void VideoDecoder::startPlay(const QString &path)
{m_filePath = path;m_isRun = true;m_pause = false;m_seek = false;this->start();
}void VideoDecoder::stopPlay()
{m_pause = false;m_seek = false;m_isRun = false;
}void VideoDecoder::pausePlay(bool pause)
{m_pause = pause;if(pause){m_pauseTime = av_gettime_relative() / 1000;}else{int offset = av_gettime_relative() / 1000 - m_pauseTime;m_startTime += offset;}
}void VideoDecoder::seekPlay(int sec)
{if(!m_isRun)return;if(m_videoDuration == sec)sec -= 2;m_seekTime = sec * 1000;m_seekFilter = true;m_seek = true;
}void VideoDecoder::run()
{qDebug() << "VideoDecoder start" << m_filePath;std::string temp = m_filePath.toStdString();AVFormatContext *inFmtCtx = avformat_alloc_context();int ret = avformat_open_input(&inFmtCtx, temp.c_str(), NULL, NULL);if (ret < 0){qDebug() << "open input error";return;}//获取流信息ret = avformat_find_stream_info(inFmtCtx, NULL);if (ret < 0){qDebug() << "find stream info error";return;}//获取视频流信息 目前只有视频流bool getVideo = false;int videoIndex = av_find_best_stream(inFmtCtx, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);AVStream *videoStream = NULL;AVCodec *videoDecoder = NULL;AVCodecContext *videoDeCodecCtx = NULL;if (videoIndex >= 0){videoStream = inFmtCtx->streams[videoIndex];//初始化解码器videoDecoder = avcodec_find_decoder(videoStream->codecpar->codec_id);videoDeCodecCtx = avcodec_alloc_context3(videoDecoder);if(videoDeCodecCtx != NULL){avcodec_parameters_to_context(videoDeCodecCtx, videoStream->codecpar);ret = avcodec_open2(videoDeCodecCtx, videoDecoder, NULL);if(ret < 0)avcodec_free_context(&videoDeCodecCtx);elsegetVideo = true;}}if(!getVideo){avformat_close_input(&inFmtCtx);return;}AVFrame *swsFrame = av_frame_alloc();SwsContext *swsCtx = nullptr;uint8_t *videoData = nullptr;//输出视频参数信息if(getVideo){int srcW = videoStream->codecpar->width;int srcH = videoStream->codecpar->height;AVPixelFormat format = videoDeCodecCtx->pix_fmt;m_videoDuration = inFmtCtx->duration / AV_TIME_BASE;emit sigDuration(m_videoDuration);int byte = av_image_get_buffer_size(AV_PIX_FMT_RGB32, srcW, srcH, 1);videoData = (uint8_t *)av_malloc(byte * sizeof(uint8_t));av_image_fill_arrays(swsFrame->data, swsFrame->linesize, videoData, (AVPixelFormat)AV_PIX_FMT_RGB32, srcW, srcH, 1);swsCtx = sws_getContext(srcW, srcH, (AVPixelFormat)format, srcW, srcH, (AVPixelFormat)AV_PIX_FMT_RGB32, SWS_FAST_BILINEAR, NULL, NULL, NULL);}//开始时刻m_startTime = av_gettime_relative() / 1000;int64_t ptsTime = 0;int curPlayPos = 0;AVPacket *packet = av_packet_alloc();AVFrame *videoFrame = av_frame_alloc();while(m_isRun){//暂停if(m_pause){QThread::msleep(200);continue;}//进度切换if(m_seek){//跳转的播放时刻 单位微秒int64_t timeStamp = m_seekTime * 1000;if (inFmtCtx->start_time != AV_NOPTS_VALUE)timeStamp += inFmtCtx->start_time;//注:seek若关键帧间隔大需避免延时timeStamp = av_rescale_q(timeStamp, AVRational{1, AV_TIME_BASE}, videoStream->time_base);ret = av_seek_frame(inFmtCtx, videoIndex, timeStamp, AVSEEK_FLAG_BACKWARD);if(ret < 0){qDebug() << "av_seek_frame fail" << m_seekTime;}else{//清空内部帧队列if(videoDeCodecCtx)avcodec_flush_buffers(videoDeCodecCtx);//调整时钟int64_t offset = m_seekTime - ptsTime;m_startTime -= offset;}m_seek = false;}//不断读取packetret = av_read_frame(inFmtCtx, packet);if (ret == AVERROR_EOF){m_isRun = false;break;}if(packet->stream_index == videoIndex){//编码数据进行解码ret = avcodec_send_packet(videoDeCodecCtx, packet);if (ret < 0){av_packet_unref(packet);continue;}ret = avcodec_receive_frame(videoDeCodecCtx, videoFrame);if (ret < 0){av_packet_unref(packet);continue;}//控制速度 ms单位ptsTime = videoFrame->pts * av_q2d(videoStream->time_base) * 1000;if(m_seekFilter){//跳转播放时间不符合的帧直接丢弃 默认阈值200msint offset = m_seekTime - ptsTime;if(0 > offset || offset < 200){m_seekFilter = false;}else{av_frame_unref(videoFrame);av_packet_unref(packet);continue;}}qint64 elapsed = av_gettime_relative() / 1000 - m_startTime;int64_t sleepMs = ptsTime - elapsed;if(sleepMs > 3){QThread::msleep(sleepMs);}//发送播放位置信息int sec = ptsTime / 1000;if(sec != curPlayPos){curPlayPos = sec;emit sigPlayPosition(curPlayPos);}//将解码后的frame数据转换为Imagesws_scale(swsCtx, (const uint8_t *const *)videoFrame->data, videoFrame->linesize, 0, videoFrame->height, swsFrame->data, swsFrame->linesize);QImage image((uchar *)videoData, videoFrame->width, videoFrame->height, QImage::Format_RGB32);QImage copy = image.copy();emit sigSendImage(copy);av_frame_unref(videoFrame);}av_packet_unref(packet);}//释放资源sws_freeContext(swsCtx);av_frame_free(&swsFrame);av_free(videoData);av_packet_free(&packet);av_frame_free(&videoFrame);avcodec_free_context(&videoDeCodecCtx);avformat_close_input(&inFmtCtx);emit sigPlayFinished(0);qDebug() << "VideoDecoder end" << m_filePath;return;
}