FFmpeg saves rtsp stream to local h264

Description

     Saving the rtsp stream here is actually saving the AVPacket read in the loop to the local, you need to save the video or audio or other stream types that can be judged by yourself.

     

     Note: The following code shows how to write to local H264. This method has been tested that the rtsp stream can be written normally, but if the input is a local video file instead of rtsp, a normal decoder or index cannot be found when reading the h264.

 

Code

	// 注册
    av_register_all();
    avformat_network_init();
    
	// 初始化上下文
	AVFormatContext *avFormatContext = avformat_alloc_context();
	
	// 打开rtsp
    int result = avformat_open_input(&avFormatContext,"rtsp流url",nullptr,&avDictionary);
    if(result != 0)
    {
    
    
        //ErrorStr("FFmpeg - run \"avformat_open_input\" fail。error code:"+NUM2STR(result));
    
        char buf[1024] = {
    
    0};
        av_strerror(result,buf,1024);
        qDebug() << buf;
    
        return;
    }

	// 查找流信息
	result = avformat_find_stream_info(avFormatContext,nullptr);

	// 查找视频码流
    int VideoStream = -1;
    for(int index = 0;index<avFormatContext->nb_streams;index++)
    {
    
    
        if(avFormatContext->streams[index]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
        {
    
    
            VideoStream = index;
            break;
        }
    }

	// 查找视频解码器
	avCodecContext = avFormatContext->streams[VideoStream]->codec;
	AVCodec *avCodec = avcodec_find_decoder(avCodecContext->codec_id);

	// 打开视频解码器
    result = avcodec_open2(avCodecContext,avCodec,nullptr);
    if(result < 0)
    {
    
    
        ErrorStr("FFmpeg - run \"avcodec_open2\" fail。error code:"+NUM2STR(result));
        return;
    }

	// 文件
	FILE *fpSaveVideo = nullptr;
	fpSaveVideo = fopen("xxx.h264", "wb");

	// 读帧并处理 - 这里处理1000次
	for(int index=0;index<1000;++index)
	{
    
    
		// 初始化数据包
		AVPacket *avPacket = av_packet_alloc();
       	av_init_packet(avPacket);

		// 读取一帧
       	result = av_read_frame(avFormatContext,avPacket);

		// 此包数据是否为视频码流后写入本地文件
	    if (avPacket->stream_index == VideoStream)
		{
    
    
			fwrite(avPacket->data, 1, avPacket->size, fpSaveVideo);
           	fflush(fpSaveVideo);
		}
		
		// 释放
		av_packet_free(&avPacket);
      	avPacket = nullptr;
	}

	// 关闭文件
	if(fpSaveVideo)
	{
    
    
		fclose(fpSaveVideo);
	}
	fpSaveVideo = nullptr;

 

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Author-jxd