1.写视频头

void writeVideoHeader(const char* videoFileName){int r = avformat_alloc_output_context2(&pFormatCtx, nullptr, nullptr,videoFileName);if(r < 0){qDebug()<<"Error: avformat_alloc_output_context2: "<<av_err2str(r);return;}pStream = avformat_new_stream(pFormatCtx,nullptr);qDebug()<<"创建视频流成功";pFormatCtx->streams[0]->codecpar->width = 1280;pFormatCtx->streams[0]->codecpar->height = 720;AVCodecContext *c= pStream->codec;c->codec_type = AVMEDIA_TYPE_VIDEO;c->codec_id = AV_CODEC_ID_H264;c->bit_rate = 2000000;c->width = 1080;c->height = 720;c->time_base.num = 1;c->time_base.den = 30;qDebug()<<"配置解码器选项成功";r = avio_open(&pFormatCtx->pb, videoFileName, AVIO_FLAG_WRITE);if(r < 0){qDebug()<<"Error: avio_open: "<<av_err2str(r);return;}qDebug()<<"打开视频流成功";r = avformat_write_header(pFormatCtx, nullptr);if(r < 0){qDebug()<<"Error: avformat_write_header error"<<av_err2str(r)<<r;return;}qDebug()<<"写入视频头部信息成功";
}

2.写视频帧

void writeAVFrame(AVPacket *packet){qDebug()<<"原始视频帧信息:"<<packet->pts<<packet->dts<<packet->size;int64_t video_max_pts = 0;av_packet_rescale_ts(packet, pStream->time_base, pStream->time_base);packet->stream_index = 0;video_max_pts = qMax(packet->pts, video_max_pts);qDebug("视频：PTS-> %d %d %d",packet->pts,packet->dts, &pStream->time_base);qDebug()<<"计算时间基成功";int r=av_write_frame(pFormatCtx, packet);if (r<0) {qDebug()<<"Error: av_write_frame: "<<av_err2str(r);return;}qDebug()<<"写入视频帧成功";
}

3.关闭视频流

if(pFormatCtx){av_write_trailer(pFormatCtx);avio_close(pFormatCtx->pb);avformat_free_context(pFormatCtx);}