QT+ffmpeg播放视频

#include "videoplayer.h" extern "C" { #include "libavcodec/avcodec.h" #include "libavformat/avformat.h" #include "libavutil/pixfmt.h" #include "libswscale/swscale.h" #include "libavutil/imgutils.h" } #include <stdio.h> VideoPlayer::VideoPlayer() { } VideoPlayer::~VideoPlayer() { } void VideoPlayer::startPlay() { ///调用 QThread 的start函数 将会自动执行下面的run函数 run函数是一个新的线程 this->start(); } void VideoPlayer::run() { char *file_path = mFileName.toUtf8().data(); AVFormatContext *pFormatCtx; AVCodecContext *pCodecCtx; AVCodec *pCodec; AVFrame *pFrame, *pFrameRGB; AVPacket *packet; uint8_t *out_buffer; static struct SwsContext *img_convert_ctx; int videoStream, numBytes; int ret; av_register_all(); //初始化FFMPEG 调用了这个才能正常适用编码器和解码器 pFormatCtx = avformat_alloc_context(); if (avformat_open_input(&pFormatCtx, file_path, NULL, NULL) != 0) { printf("can't open the file. \n"); return; } if (avformat_find_stream_info(pFormatCtx, NULL) < 0) { printf("Could't find stream infomation.\n"); return; } videoStream = -1; for (unsigned int i = 0; i < pFormatCtx->nb_streams; i++) { if (pFormatCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) { videoStream = i; } } ///如果videoStream为-1 说明没有找到视频流 if (videoStream == -1) { printf("Didn't find a video stream.\n"); return; } ///查找解码器 AVCodecParameters *codec_para = pFormatCtx->streams[videoStream]->codecpar; pCodec = avcodec_find_decoder(codec_para->codec_id); if (pCodec == 0) { printf("Codec not found.\n"); return; } pCodecCtx = avcodec_alloc_context3(pCodec); avcodec_parameters_to_context(pCodecCtx, codec_para); ///打开解码器 if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) { printf("Could not open codec.\n"); return; } pFrame = av_frame_alloc(); pFrameRGB = av_frame_alloc(); ///这里我们改成了 将解码后的YUV数据转换成RGB32 img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_RGB32, SWS_BICUBIC, NULL, NULL, NULL); numBytes = av_image_get_buffer_size(AV_PIX_FMT_RGB32, pCodecCtx->width,pCodecCtx->height, 1); out_buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t)); av_image_fill_arrays(pFrameRGB->data, pFrameRGB->linesize, out_buffer, AV_PIX_FMT_RGB32, pCodecCtx->width, pCodecCtx->height, 1); packet = av_packet_alloc(); while (1) { if (av_read_frame(pFormatCtx, packet) < 0) { break; //这里认为视频读取完了 } if (packet->stream_index == videoStream) { ret = avcodec_send_packet(pCodecCtx, packet); if (ret < 0) { continue; } while (avcodec_receive_frame(pCodecCtx, pFrame)>=0) { // printf("pkt pts = %lld\n", packet->pts); // printf("frame pts = %lld\n", pFrame->pts); // uint64_t pts = av_frame_get_best_effort_timestamp(pFrame); sws_scale(img_convert_ctx, (uint8_t const * const *) pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize); //把这个RGB数据 用QImage加载 QImage tmpImg((uchar *)out_buffer, pCodecCtx->width, pCodecCtx->height, QImage::Format_RGB32); QImage image = tmpImg.copy(); //把图像复制一份 传递给界面显示 emit sig_GetOneFrame(image); //发送信号 } } av_packet_unref(packet); msleep(5); //停一停 不然放的太快了 } av_packet_free(&packet); av_free(out_buffer); av_free(pFrameRGB); avcodec_close(pCodecCtx); avformat_close_input(&pFormatCtx); }