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Qt调用FFmpeg库实时播放UDP组播视频流

article 2025/1/29 7:57:53

基于以下参考链接，通过改进实现实时播放UDP组播视频流

https://blog.csdn.net/u012532263/article/details/102736700

源码在windows（qt-opensource-windows-x86-5.12.9.exe）、ubuntu20.04.6(x64)(qt-opensource-linux-x64-5.12.12.run)、以及针对arm64的ubuntu20.04.6(x64)交叉编译环境下编译成功(QT5.12.8, 5.15.13)，可执行程序在windows，ubuntu(x64)、arm64上均可运行。

工程代码见：

https://download.csdn.net/download/daqinzl/90315016

主要代码
videoplayer.cpp

#include "videoplayer.h"
#include <QDebug>
extern "C"
{
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libavutil/pixfmt.h"
#include "libswscale/swscale.h"
}

#include <stdio.h>
#include<iostream>
using namespace std;
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()
{
/*
AVFormatContext *pFormatCtx;
AVCodecContext *pCodecCtx;
AVCodec *pCodec;
AVFrame *pFrame;
AVFrame *pFrameRGB;
AVPacket *packet;
uint8_t *out_buffer;

static struct SwsContext *img_convert_ctx;

int videoStream, i, numBytes;
int ret, got_picture;

avformat_network_init();
av_register_all();

//Allocate an AVFormatContext.
pFormatCtx = avformat_alloc_context();

// ffmpeg取rtsp流时av_read_frame阻塞的解决办法设置参数优化
AVDictionary* avdic = NULL;
//rtsp
//av_dict_set(&avdic, "buffer_size", "102400", 0); //设置缓存大小，1080p可将值调大
//av_dict_set(&avdic, "rtsp_transport", "udp", 0); //以udp方式打开，如果以tcp方式打开将udp替换为tcp

//rtmp
//av_dict_set(&avdic, "buffer_size", "8192000", 0); //设置缓存大小，1080p可将值调大
//av_dict_set(&avdic, "rtsp_transport", "tcp", 0); //以udp方式打开，如果以tcp方式打开将udp替换为tcp

//udp
av_dict_set(&avdic, "buffer_size", "8192000", 0); //设置缓存大小，1080p可将值调大
av_dict_set(&avdic, "rtsp_transport", "udp", 0); //以udp方式打开，如果以tcp方式打开将udp替换为tcp
//av_dict_set(&avdic, "fflags", "nobuffer", 0); // 设置实时选项
//av_dict_set(&avdic, "flags", "low_delay", 0); // 设置低延迟选项
av_dict_set(&avdic, "max_interleave_delta", "40000", 0);

//av_dict_set(&avdic, "stimeout", "2000000", 0); //设置超时断开连接时间，单位微秒
//av_dict_set(&avdic, "max_delay", "500000", 0); //设置最大时延

///rtsp地址，可根据实际情况修改
//char url[]="rtsp://admin:admin@192.168.1.18:554/h264/ch1/main/av_stream";
//char url[]="rtsp://192.168.17.112/test2.264";
//char url[]="rtsp://admin:admin@192.168.43.1/stream/main";
//char url[]="rtmp://mobliestream.c3tv.com:554/live/goodtv.sdp";

char url[]="udp://224.1.1.1:5001";

//char url[]="rtmp://192.168.1.100:1935/live/desktop";

if (avformat_open_input(&pFormatCtx, url, NULL, &avdic) != 0) {
qDebug("can't open the file. \n");
return;
}

if (avformat_find_stream_info(pFormatCtx, NULL) < 0) {
qDebug("Could't find stream infomation.\n");
return;
}

videoStream = -1;

///循环查找视频中包含的流信息，直到找到视频类型的流
///便将其记录下来保存到videoStream变量中
///这里我们现在只处理视频流音频流先不管他
for (i = 0; i < pFormatCtx->nb_streams; i++) {
if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
videoStream = i;
}
}

///如果videoStream为-1 说明没有找到视频流
if (videoStream == -1) {
qDebug("Didn't find a video stream.\n");
return;
}

///查找解码器
pCodecCtx = pFormatCtx->streams[videoStream]->codec;
pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
///2017.8.9---lizhen
//pCodecCtx->bit_rate = 0; //初始化为0
//pCodecCtx->time_base.num = 1; //下面两行：一秒钟25帧
//pCodecCtx->time_base.den = 10;
//pCodecCtx->frame_number = 1; //每包一个视频帧

if (pCodec == NULL) {
qDebug("Codec not found.\n");
return;
}

///打开解码器
if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) {
qDebug("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_FAST_BILINEAR, NULL, NULL, NULL);

numBytes = avpicture_get_size(AV_PIX_FMT_RGB32, pCodecCtx->width,pCodecCtx->height);

out_buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
avpicture_fill((AVPicture *) pFrameRGB, out_buffer, AV_PIX_FMT_RGB32,
pCodecCtx->width, pCodecCtx->height);

int y_size = pCodecCtx->width * pCodecCtx->height;

packet = (AVPacket *) malloc(sizeof(AVPacket)); //分配一个packet
av_new_packet(packet, y_size); //分配packet的数据
//*/

//bool CanRun = true;

//ffmpeg 初始化
// 初始化注册ffmpeg相关的编码器
av_register_all();
avcodec_register_all();
avformat_network_init();

//qDebug()<<"1 FFmpeg version info: { av_version_info() }";
qDebug()<<"2 FFmpeg version info: { " << av_version_info() << "}";
qDebug()<<"3 FFmpeg version info:";
qDebug()<< av_version_info() ;

char url[]="udp://224.1.1.1:5001";

// ffmpeg 转码
// 分配音视频格式上下文
AVFormatContext *pFormatCtx = avformat_alloc_context();

AVDictionary* avdic = NULL;
av_dict_set(&avdic, "buffer_size", "8192000", 0);
av_dict_set(&avdic, "max_interleave_delta", "40000", 0);

av_dict_set(&avdic, "analyzeduration", "100000000", 0);
av_dict_set(&avdic, "probesize", "100000000", 0);

int ret;
//打开流
ret = avformat_open_input(&pFormatCtx, url, NULL, &avdic);
if (ret != 0){ qDebug("can't open the url. \n"); return; }

// 读取媒体流信息
ret = avformat_find_stream_info(pFormatCtx, NULL);
if (ret != 0) { qDebug("Could't find stream infomation.\n"); return; }

// 这里只是为了打印些视频参数
AVDictionaryEntry* tag = NULL;
while ((tag = av_dict_get(pFormatCtx->metadata, "", tag, AV_DICT_IGNORE_SUFFIX)) != NULL)
{
char * key = tag->key;
char * value = tag->value;
qDebug()<< *key << *value << "\n";
}

// 从格式化上下文获取流索引
AVStream* pStream = NULL;
//AVStream* aStream = NULL;
int videoStream = -1;
for (int i = 0; i < pFormatCtx->nb_streams; i++)
{
if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
{
pStream = pFormatCtx->streams[i];
videoStream = i;
}
//else if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO)
//{
// aStream = pFormatCtx->streams[i];
//}
}
if (pStream == NULL) { qDebug("Didn't find a video stream.\n"); return; }

// 获取流的编码器上下文
AVCodecContext codecContext = *pStream->codec;

qDebug() << "codec name: {" << avcodec_get_name(codecContext.codec_id) << "}\n";
// 获取图像的宽、高及像素格式
int width = codecContext.width;
int height = codecContext.height;
AVPixelFormat sourcePixFmt = codecContext.pix_fmt;

// 得到编码器ID
AVCodecID codecId = codecContext.codec_id;
// 目标像素格式
AVPixelFormat destinationPixFmt = AV_PIX_FMT_RGB32;

// 某些264格式codecContext.pix_fmt获取到的格式是AV_PIX_FMT_NONE 统一都认为是YUV420P
if (sourcePixFmt == AV_PIX_FMT_NONE && codecId == AV_CODEC_ID_MPEG2TS)
{
sourcePixFmt = AV_PIX_FMT_YUV420P;
}

static struct SwsContext *img_convert_ctx;

// 得到SwsContext对象：用于图像的缩放和转换操作
img_convert_ctx = sws_getContext(width, height, sourcePixFmt,
width, height, destinationPixFmt,
SWS_FAST_BILINEAR, NULL, NULL, NULL);
if (img_convert_ctx == NULL) { qDebug() << "Could not initialize the conversion context.\n" ; return; }

//分配一个默认的帧对象:AVFrame
//AVFrame* pConvertedFrame = av_frame_alloc();
// 目标媒体格式需要的字节长度
//numBytes = avpicture_get_size(AV_PIX_FMT_RGB32, pCodecCtx->width,pCodecCtx->height);
int numBytes = avpicture_get_size(destinationPixFmt, width, height);
// 分配目标媒体格式内存使用
//out_buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
uint8_t * out_buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
//var dstData = new byte_ptrArray4();
//var dstLinesize = new int_array4();
AVFrame *pFrameRGB = av_frame_alloc();
// 设置图像填充参数
//av_image_fill_arrays(pFrameRGB->data, pFrameRGB->linesize, convertedFrameBufferPtr, destinationPixFmt, width, height, 1);
avpicture_fill((AVPicture *) pFrameRGB, out_buffer, destinationPixFmt,width, height);

// ffmpeg 解码
// 根据编码器ID获取对应的解码器
AVCodec* pCodec = avcodec_find_decoder(codecId);
if (pCodec == NULL) { qDebug() << "Unsupported codec.\n"; }

AVCodecContext* pCodecCtx = &codecContext;

if ((pCodec->capabilities & AV_CODEC_CAP_TRUNCATED) == AV_CODEC_CAP_TRUNCATED)
pCodecCtx->flags |= AV_CODEC_FLAG_TRUNCATED;

// 通过解码器打开解码器上下文:AVCodecContext pCodecContext
ret = avcodec_open2(pCodecCtx, pCodec, NULL);
if (ret < 0) { qDebug() << ret << "\n"; return; }

// 分配解码帧对象：AVFrame pDecodedFrame
AVFrame* pFrame = av_frame_alloc();

// 初始化媒体数据包
AVPacket* packet = new AVPacket();
AVPacket** pPacket = &packet;
av_init_packet(packet);

while (1)
{
/*
if (av_read_frame(pFormatCtx, packet) < 0)
{
qDebug() << "av_read_frame < 0";
break; //这里认为视频读取完了
}

if (packet->stream_index == videoStream) {
ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture,packet);

if (ret < 0) {
qDebug("decode error.\n");
return;
}

if (got_picture) {
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
//emit sig_GetOneFrame(tmpImg);

//提取出图像中的R数据
//for(int i=0;i<pCodecCtx->width;i++)
//{
// for(int j=0;j<pCodecCtx->height;j++)
// {
// QRgb rgb=image.pixel(i,j);
// int r=qRed(rgb);
// image.setPixel(i,j,qRgb(r,0,0));
// }
//}
//emit sig_GetRFrame(image);

}else qDebug() << "got_picture < 0";
}else qDebug() << "packet->stream_index not video stream";
av_free_packet(packet); //释放资源,否则内存会一直上升
//msleep(0.02); //停一停不然放的太快了
//*/

//*
try
{
do
{
// 读取一帧未解码数据
ret = av_read_frame(pFormatCtx, packet);
// Console.WriteLine(pPacket->dts);
if (ret == AVERROR_EOF) break;
if (ret < 0) { qDebug() << "got error "; return; }

if (packet->stream_index != videoStream) continue;

// 解码
ret = avcodec_send_packet(pCodecCtx, packet);
if (ret < 0) { qDebug() << "got error 2 "; return; }
// 解码输出解码数据
ret = avcodec_receive_frame(pCodecCtx, pFrame);
} while (ret == AVERROR(EAGAIN) && 1);
if (ret == AVERROR_EOF) break;
if (ret < 0) { qDebug() << "got error 3 "; return; }

if (packet->stream_index != videoStream) continue;

//Console.WriteLine($@"frame: {frameNumber}");
// YUV->RGB
sws_scale(img_convert_ctx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);

} catch (exception e) {

}
{
av_packet_unref(packet);//释放数据包对象引用
av_frame_unref(pFrame);//释放解码帧对象引用
}
//*/
}
av_free(out_buffer);
av_free(pFrameRGB);
avcodec_close(pCodecCtx);
avformat_close_input(&pFormatCtx);
}

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