ffmpeg 視頻教程 添加水印附源碼

時間  2019-12-13
標籤 ffmpeg 視頻 教程 添加 水印 源碼 简体版
原文   原文鏈接

    本文主要講述如何利用Ffmpeg向視頻文件 添加水印這一功能，文中最後會給出源代碼下載地址以及視頻ide

下載地址，視頻除了講述添加水印的基本原理以及代碼實現，還提到了要注意的一些地方，由於直接運行this

demo源碼可能會有問題。利用Ffmpeg向視頻文件添加水印的基本原理是將視頻文件的視頻包解碼成一幀幀編碼

「Frame」，經過ffmpeg  Filter（overlay）實現待添加水印與「Frame」的疊加，最後將疊加後的視頻幀進行編碼spa

並將編碼後的數據寫到輸出文件裏。基本的流程以下圖所示：code

                                                   圖1 ffmpeg 添加水印基本流程orm

瞭解了添加水印的基本原理及流程之後，下面給出代碼部分：視頻

一  打開輸入源：blog

與以往的打開輸入源的方法不一樣，這裏的多了一個入參，根據輸入的參數不一樣既可打開視頻文件，能夠打開水印圖片。教程

int OpenInput(char *fileName,int inputIndex)
{
	context[inputIndex] = avformat_alloc_context();
	context[inputIndex]->interrupt_callback.callback = interrupt_cb;
	AVDictionary *format_opts =  nullptr;

	int ret = avformat_open_input(&context[inputIndex], fileName, nullptr, &format_opts);
	if(ret < 0)
	{
		return  ret;
	}
	ret = avformat_find_stream_info(context[inputIndex],nullptr);
	av_dump_format(context[inputIndex], 0, fileName, 0);
	if(ret >= 0) 
	{
		std::cout <<"open input stream successfully" << endl;
	}
	return ret;
}

　二．　讀取視頻包（圖片幀）圖片

shared_ptr<AVPacket> ReadPacketFromSource(int inputIndex)
{
	 std::shared_ptr<AVPacket> packet(static_cast<AVPacket*>(av_malloc(sizeof(AVPacket))), [&](AVPacket *p) { av_packet_free(&p); av_freep(&p); });
	av_init_packet(packet.get());
	int ret = av_read_frame(context[inputIndex], packet.get());
	if(ret >= 0)
	{
		return packet;
	}
	else
	{
		return nullptr;
	}
}

　　三．　建立輸出上下文

int OpenOutput(char *fileName,int inputIndex)
{
	int ret = 0;
	ret  = avformat_alloc_output_context2(&outputContext, nullptr, "mpegts", fileName);
	if(ret < 0)
	{
		goto Error;
	}
	ret = avio_open2(&outputContext->pb, fileName, AVIO_FLAG_READ_WRITE,nullptr, nullptr);	
	if(ret < 0)
	{
		goto Error;
	}

	for(int i = 0; i < context[inputIndex]->nb_streams; i++)
	{
		AVStream * stream = avformat_new_stream(outputContext, outPutEncContext->codec);
		stream->codec = outPutEncContext;
		if(ret < 0)
		{
			goto Error;
		}
	}
	av_dump_format(outputContext, 0, fileName, 1);
	ret = avformat_write_header(outputContext, nullptr);
	if(ret < 0)
	{
		goto Error;
	}
	if(ret >= 0)
		cout <<"open output stream successfully" << endl;
	return ret ;
Error:
	if(outputContext)
	{
		avformat_close_input(&outputContext);
	}
	return ret ;
}

　　四. 初始化編解碼code

int InitEncoderCodec( int iWidth, int iHeight,int inputIndex)
{
	AVCodec *  pH264Codec = avcodec_find_encoder(AV_CODEC_ID_H264);
	if(NULL == pH264Codec)
	{
		printf("%s", "avcodec_find_encoder failed");
		return  -1;
	}
	outPutEncContext = avcodec_alloc_context3(pH264Codec);
	outPutEncContext->gop_size = 30;
	outPutEncContext->has_b_frames = 0;
	outPutEncContext->max_b_frames = 0;
	outPutEncContext->codec_id = pH264Codec->id;
	outPutEncContext->time_base.num =context[inputIndex]->streams[0]->codec->time_base.num;
	outPutEncContext->time_base.den = context[inputIndex]->streams[0]->codec->time_base.den;
	outPutEncContext->pix_fmt            = *pH264Codec->pix_fmts;
	outPutEncContext->width              =  iWidth;
	outPutEncContext->height             = iHeight;

	outPutEncContext->me_subpel_quality = 0;
	outPutEncContext->refs = 1;
	outPutEncContext->scenechange_threshold = 0;
	outPutEncContext->trellis = 0;
	AVDictionary *options = nullptr;
	outPutEncContext->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

	int ret = avcodec_open2(outPutEncContext, pH264Codec, &options);
	if (ret < 0)
	{
		printf("%s", "open codec failed");
		return  ret;
	}
	return 1;
}

int InitDecodeCodec(AVCodecID codecId,int inputIndex)
{
	auto codec = avcodec_find_decoder(codecId);
	if(!codec)
	{
		return -1;
	}
	decoderContext[inputIndex] = context[inputIndex]->streams[0]->codec;
	if (!decoderContext) {
		fprintf(stderr, "Could not allocate video codec context\n");
		exit(1);
	}

	int ret = avcodec_open2(decoderContext[inputIndex], codec, NULL);
	return ret;

}

    五. 初始化Filter

int InitInputFilter(AVFilterInOut *input,const char *filterName,  int inputIndex)
{
	char args[512];
	memset(args,0, sizeof(args));
	AVFilterContext *padFilterContext = input->filter_ctx;
	
	 auto filter = avfilter_get_by_name("buffer");
	auto codecContext = context[inputIndex]->streams[0]->codec;

	sprintf_s(args, sizeof(args),
		"video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
		codecContext->width, codecContext->height, codecContext->pix_fmt,
		codecContext->time_base.num, codecContext->time_base.den /codecContext->ticks_per_frame,
		codecContext->sample_aspect_ratio.num, codecContext->sample_aspect_ratio.den);

	int ret = avfilter_graph_create_filter(&inputFilterContext[inputIndex],filter,filterName, args,
		NULL, filter_graph);
	 if(ret < 0)  return ret;
	 ret = avfilter_link(inputFilterContext[inputIndex],0,padFilterContext,input->pad_idx);
	 return ret;
}

int InitOutputFilter(AVFilterInOut *output,const char *filterName)
{
	AVFilterContext *padFilterContext = output->filter_ctx;	
	 auto filter = avfilter_get_by_name("buffersink");


	int ret = avfilter_graph_create_filter(&outputFilterContext,filter,filterName, NULL,
		NULL, filter_graph);
	 if(ret < 0)  return ret;
	 ret = avfilter_link(padFilterContext,output->pad_idx,outputFilterContext,0);
	 
	 return ret;
}

　六. Demo

int _tmain(int argc, _TCHAR* argv[])
{
	//string fileInput = "D:\\test11.ts";
	string fileInput[2];
	fileInput[0]= "F:\\test.ts";
	fileInput[1]= "F:\\test1.jpg";
	string fileOutput = "F:\\codeoutput.ts";
	std::thread decodeTask;
	Init();
	int ret = 0;
	for(int i = 0; i < 2;i++)
	{
		if(OpenInput((char *)fileInput[i].c_str(),i) < 0)
		{
			cout << "Open file Input 0 failed!" << endl;
			this_thread::sleep_for(chrono::seconds(10));
			return 0;
		}

		ret = InitDecodeCodec(context[i]->streams[0]->codec->codec_id,i);
		if(ret <0)
		{
			cout << "InitDecodeCodec failed!" << endl;
			this_thread::sleep_for(chrono::seconds(10));
			return 0;
		}
	}

	ret = InitEncoderCodec(decoderContext[0]->width,decoderContext[0]->height,0);
	if(ret < 0)
	{
		cout << "open eccoder failed ret is " << ret<<endl;
		cout << "InitEncoderCodec failed!" << endl;
		this_thread::sleep_for(chrono::seconds(10));
		return 0;
	}

	//ret = InitFilter(outPutEncContext);
	if(OpenOutput((char *)fileOutput.c_str(),0) < 0)
	{
		cout << "Open file Output failed!" << endl;
		this_thread::sleep_for(chrono::seconds(10));
		return 0;
	}

	AVFrame *pSrcFrame[2];
	pSrcFrame[0] = av_frame_alloc();
	pSrcFrame[1] = av_frame_alloc();

	AVFrame *inputFrame[2];
	inputFrame[0] = av_frame_alloc();
	inputFrame[1] = av_frame_alloc();
	auto  filterFrame = av_frame_alloc();
	int got_output = 0;	
	int64_t  timeRecord = 0;
	int64_t  firstPacketTime = 0;
	int64_t outLastTime = av_gettime();
	int64_t inLastTime = av_gettime();
	int64_t videoCount = 0;

	filter_graph = avfilter_graph_alloc();
	if(!filter_graph)
	{
		cout <<"graph alloc failed"<<endl;
		goto End;
	}
	avfilter_graph_parse2(filter_graph, filter_descr, &inputs, &outputs);
	InitInputFilter(inputs,"MainFrame",0);
	InitInputFilter(inputs->next,"OverlayFrame",1);
	InitOutputFilter(outputs,"output");

	FreeInout();
	
	
    ret = avfilter_graph_config(filter_graph, NULL);
	if(ret < 0)
	{
          goto End;
	}
	decodeTask.swap(thread([&]{
		bool ret = true;
		while(ret)
		{
			auto packet = ReadPacketFromSource(1);
			ret = DecodeVideo(packet.get(),pSrcFrame[1],1);
			if(ret) break;
		}
	}));
	decodeTask.join();

	while(true)
	{
		outLastTime = av_gettime();
		auto packet = ReadPacketFromSource(0);
		if(packet)
		{
			if(DecodeVideo(packet.get(),pSrcFrame[0],0))
			{
				av_frame_ref( inputFrame[0],pSrcFrame[0]);
				if (av_buffersrc_add_frame_flags(inputFilterContext[0], inputFrame[0], AV_BUFFERSRC_FLAG_PUSH) >= 0)
				{
					pSrcFrame[1]->pts = pSrcFrame[0]->pts;
					//av_frame_ref( inputFrame[1],pSrcFrame[1]);
					if(av_buffersrc_add_frame_flags(inputFilterContext[1],pSrcFrame[1], AV_BUFFERSRC_FLAG_PUSH) >= 0)
					{						
						ret = av_buffersink_get_frame_flags(outputFilterContext, filterFrame,AV_BUFFERSINK_FLAG_NO_REQUEST);
						
						//this_thread::sleep_for(chrono::milliseconds(10));
						if ( ret >= 0)
						{
							std::shared_ptr<AVPacket> pTmpPkt(static_cast<AVPacket*>(av_malloc(sizeof(AVPacket))), [&](AVPacket *p) { av_packet_free(&p); av_freep(&p); });
							av_init_packet(pTmpPkt.get());
							pTmpPkt->data = NULL;
							pTmpPkt->size = 0;
							ret = avcodec_encode_video2(outPutEncContext, pTmpPkt.get(), filterFrame, &got_output);
							if (ret >= 0 && got_output)
							{
								int ret = av_write_frame(outputContext, pTmpPkt.get());
							}
							//this_thread::sleep_for(chrono::milliseconds(10));
						}
						av_frame_unref(filterFrame);
					}
				}
			}
		}
		else break;
	}
	CloseInput(0);
	CloseOutput();
	std::cout <<"Transcode file end!" << endl;
	End:
	this_thread::sleep_for(chrono::hours(10));
	return 0;
}

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