基于FFMPEG水印添加---avfilter庫

??avfilter，是ffmpeg為圖像和語音處理提供的濾鏡子框架，代碼位于libavfilter目錄。

??libavfilter提供了一個通用框架來實現audio和video的原始數據filter處理，如對視頻添加疊加Logo圖片或者時間文字等信息、對視頻進行裁剪和翻轉。

1.硬件平臺

操作系統：Ubuntu18.04
ffmpeg版本：ffmpeg4.2.5

2.FFMPEG編譯

??在使用avfilter庫添加漢字水印時，ffmepg默認模式時不支持矢量字庫的，要實現漢字水印添加就需要進行configure配置。

2.1 freetype庫編譯

?? freetype下載地址：https://download.savannah.gnu.org/releases/freetype/

2.2 FriBidi庫編譯

?? FriBidi下載地址：https://www.linuxfromscratch.org/blfs/view/svn/general/fribidi.html

#解壓源碼
tar xvf /mnt/hgfs/ubuntu/software_pack/fribidi-1.0.11.tar.xz
#配置生成Makefile
./configure --prefix=$PWD/_install
#編譯安裝
make && make install 
#編譯安裝
#將生成的文件拷貝到/usr/lib目錄下
cp ./_install/lib/pkgconfig/ /usr/lib -rf

2.3 ffmpeg庫編譯

#解壓源碼
tar xvf /mnt/hgfs/ubuntu/software_pack/ffmpeg-4.2.5.tar.bz2 
#配置生成Makefile
./configure --enable-static
 --enable-shared --prefix=$PWD/_install
 --extra-cflags=-I/home/wbyq/src_pack/x264-master/_install/include
 --extra-ldflags=-L/home/wbyq/src_pack/x264-master/_install/lib
 --extra-cflags=-I/home/wbyq/src_pack/freetype-2.10.0/_install/include
 --extra-ldflags=-L/home/wbyq/src_pack/freetype-2.10.0/_install/lib
 --extra-cflags=-I/home/wbyq/src_pack/fribidi-1.0.11/_install/include
 --extra-ldflags=-L/home/wbyq/src_pack/fribidi-1.0.11/_install/lib
 --enable-ffmpeg --enable-libx264 --enable-gpl --enable-libfreetype --enable-libfontconfig --enable-libfribidi --enable-avfilter
#編譯安裝
make && make install 
#將生成的文件拷貝到/usr/lib目錄下
cp ./_install/lib/pkgconfig/ /usr/lib -rf

2.4 ffmpeg命令行添加時間水印

2.4.1 以實時時間動態添加時間水印

ffmpeg -i 最后一滴水.mp4 -vf drawtext=“fontfile=msyhbd.ttc:x=100:y=10:fontcolor=white:fontsize=30:expansion=strftime:basetime=$(date +%s )000000:text=‘%Y-%m-%d %H:%M: %S’” output.mp4
drawtext 字符串水印
fontfile=msyhbd.ttc矢量字庫，可在windows下C:WindowsFonts拷貝到當期目錄下
x=100:y=10顯示位置，距離左上腳
fontcolor=white:fontsize=30字體顏色和大小
expansion=strftime:basetime=$(date +%s )000000以當前實時時間添加動態水印
text=‘%Y-%m-%d %H:%M: %S’ 時間顯示格式

2.4.1 以指定時間動態添加時間水印

ffmpeg -i 最后一滴水.mp4 -vf drawtext="fontfile=msyhbd.ttc:x=100:y=10:fontcolor=white:fontsize=30:expansion=strftime:basetime=$(date +%s -d '2020-8-8 14:10:50')000000:text='%Y-%m-%d  %H:%M: %S'  IT_阿水" output.mp4

3.代碼實現水印添加

??參考雷霄驊博客處理示例：https://blog.csdn.net/leixiaohua1020/article/details/50618190
??致敬雷神！致敬雷神！致敬雷神！

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#define FILE_SRC "sintel_480x272_yuv420p.yuv" //源文件
int waterMark(AVFrame *frame_in,AVFrame *frame_out,int w,int h,const char *str);
int main(int argc,char *argv[])
{
	int ret;
	/*打開輸入yuv文件*/
	FILE *fp_in=fopen(FILE_SRC,"rb+");
	if(fp_in==NULL)
	{
		printf("文件打開失敗n");
		return 0;
	}
	int in_width=480;
	int in_height=272;
	/*處理后的文件*/
	FILE *fp_out=fopen("new.yuv","wb+");
	if(fp_out==NULL)
	{
		printf("文件創建失敗n");
		return 0;
	}
	char buff[50];

	AVFrame *frame_in=av_frame_alloc();
	unsigned char *frame_buffer_in;
	frame_buffer_in=(unsigned char *)av_malloc(av_image_get_buffer_size(AV_PIX_FMT_YUV420P,in_width,in_height,4));
	/*根據圖像設置圖像指針和內存對齊方式*/
	av_image_fill_arrays(frame_in->data,frame_in->linesize,frame_buffer_in,AV_PIX_FMT_YUV420P,in_width,in_height,4);

	AVFrame *frame_out=av_frame_alloc();
	unsigned char *frame_buffer_out;
	frame_buffer_out=(unsigned char *)av_malloc(av_image_get_buffer_size(AV_PIX_FMT_YUV420P,in_width,in_height,4));
	av_image_fill_arrays(frame_out->data,frame_out->linesize,frame_buffer_out,AV_PIX_FMT_YUV420P,in_width,in_height,4);
	
	frame_in->width=in_width;
	frame_in->height=in_height;
	frame_in->format=AV_PIX_FMT_YUV420P;
	char sys_time[64];
	time_t sec,sec2;
	while(1)
	{

		if(fread(frame_buffer_in,1,in_width*in_height*3/2,fp_in)!=in_width*in_height*3/2)
		{
			break;
		}
		frame_in->data[0]=frame_buffer_in;
		frame_in->data[1]=frame_buffer_in+in_width*in_height;
		frame_in->data[2]=frame_buffer_in+in_width*in_height*5/4;
		
		sec=time(NULL);
		if(sec!=sec2)
		{
			sec2=sec;
			struct tm* today = localtime(&sec2);	
			strftime(sys_time, sizeof(sys_time), "%Y/%m/%d %H:%M:%S", today);    
		}
		
		waterMark(frame_in,frame_out,in_width,in_height,sys_time);//添加水印
	
		/*添加水印后的數據寫入到過濾器*/
		if(frame_out->format==AV_PIX_FMT_YUV420P)
		{
			for(int i=0;iheight;i++)
			{
				fwrite(frame_out->data[0]+frame_out->linesize[0]*i,1,frame_out->width,fp_out);
			}
			for(int i=0;iheight/2;i++)
			{
				fwrite(frame_out->data[1]+frame_out->linesize[1]*i,1,frame_out->width/2,fp_out);
			}
			for(int i=0;iheight/2;i++)
			{
				fwrite(frame_out->data[2]+frame_out->linesize[2]*i,1,frame_out->width/2,fp_out);
			}
			printf("一幀數據處理完成n");
		}
		av_frame_unref(frame_out);
	}
	fclose(fp_in);
	fclose(fp_out);
	av_frame_free(&frame_in);
	av_frame_free(&frame_out);
    return 0;	
	
}
int waterMark(AVFrame *frame_in,AVFrame *frame_out,int w,int h,const char *str)
{
	int ret;
	/*根據名字獲取ffmegding定義的filter*/
	const AVFilter *buffersrc=avfilter_get_by_name("buffer");//原始數據
	const AVFilter *buffersink=avfilter_get_by_name("buffersink");//處理后的數據
	/*動態分配AVFilterInOut空間*/
	AVFilterInOut *outputs=avfilter_inout_alloc();
	AVFilterInOut *inputs=avfilter_inout_alloc();	
	/*創建AVFilterGraph,分配空間*/
	AVFilterGraph *filter_graph;//對filters系統的整體管理結構體
	filter_graph = avfilter_graph_alloc();
	enum AVPixelFormat pix_fmts[]={AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE};//設置格式
	/*過濾器參數：解碼器的解碼幀將被插入這里。*/
	char args[256];
	snprintf(args, sizeof(args),
		"video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
		w,h,AV_PIX_FMT_YUV420P,1,25,1,1);//圖像寬高，格式，幀率，畫面橫縱比
	/*創建過濾器上下文,源數據AVFilterContext*/
	AVFilterContext *buffersrc_ctx;
	ret=avfilter_graph_create_filter(&buffersrc_ctx,buffersrc,"in",args,NULL,filter_graph);
	if(ret<0)
	{
		printf("創建src過濾器上下文失敗AVFilterContextn");
		return -1;
	}		
	/*創建過濾器上下文，處理后數據buffersink_params*/
	AVBufferSinkParams *buffersink_params;
	buffersink_params=av_buffersink_params_alloc();
	buffersink_params->pixel_fmts=pix_fmts;//設置格式
	AVFilterContext *buffersink_ctx;
	ret=avfilter_graph_create_filter(&buffersink_ctx,buffersink,"out",NULL,buffersink_params,filter_graph);
	av_free(buffersink_params);
	if(ret<0)
	{
		printf("創建sink過濾器上下文失敗AVFilterContextn");
		return -2;
	}	
	/*過濾器鏈輸入/輸出鏈接列表*/
	outputs->name       =av_strdup("in");
	outputs->filter_ctx =buffersrc_ctx;
	outputs->pad_idx    =0;
	outputs->next		=NULL;

	inputs->name		=av_strdup("out");
	inputs->filter_ctx	=buffersink_ctx;
	inputs->pad_idx    =0;
	inputs->next		=NULL;
	char filter_desrc[200]={0};//要添加的水印數據
	snprintf(filter_desrc,sizeof(filter_desrc),"drawtext=fontfile=msyhbd.ttc:fontcolor=green:fontsize=20:x=50:y=20:text='%snIT_阿水'",str);
	if(avfilter_graph_parse_ptr(filter_graph,filter_desrc,&inputs,&outputs, NULL)<0)//設置過濾器數據內容
	{
		printf("添加字符串信息失敗n");
		return -3;
	}
	/*檢測配置信息是否正常*/
	if(avfilter_graph_config(filter_graph,NULL)<0)
	{
		printf("配置信息有誤n");
		return -4;
	}	
	#if 0
	/*
		查找要在使用的過濾器，將要觸處理的數據添加到過濾器
		注意：時間若從外面傳入(即144行數據已完整)，則此處不需要查找，直接添加即可，否則需要添加下面代碼
	*/
	AVFilterContext* filter_ctx;//上下文
	int parsed_drawtext_0_index = -1;
	 for(int i=0;inb_filters;i++)//查找使用的過濾器
	 {
		 AVFilterContext *filter_ctxn=filter_graph->filters[i];
		 printf("[%s %d]:filter_ctxn_name=%sn",__FUNCTION__,__LINE__,filter_ctxn->name);
		 if(!strcmp(filter_ctxn->name,"Parsed_drawtext_0"))
		 {
			parsed_drawtext_0_index=i;
		 }
	 }
	 if(parsed_drawtext_0_index==-1)
	 {
		printf("[%s %d]:no Parsed_drawtext_0n",__FUNCTION__,__LINE__);//沒有找到過濾器
	 }
	 filter_ctx=filter_graph->filters[parsed_drawtext_0_index];//保存找到的過濾器
	 
		/*獲取系統時間，將時間加入到過濾器*/
		char sys_time[64];
		time_t sec,sec2;	 
		sec=time(NULL);
		if(sec!=sec2)
		{
			sec2=sec;
			struct tm* today = localtime(&sec2);	
			strftime(sys_time, sizeof(sys_time), "%Y/%m/%d %H:%M:%S", today);       //24小時制
		}
		av_opt_set(filter_ctx->priv, "text", sys_time, 0 );  //設置text到過濾器
	 #endif
	/*往源濾波器buffer中輸入待處理數據*/
	 if(av_buffersrc_add_frame(buffersrc_ctx,frame_in)<0)
	 {
		return -5;
	 }
	 /*從濾波器中輸出處理數據*/
	 if(av_buffersink_get_frame(buffersink_ctx, frame_out)<0)
	 {
		return -6;
	 }
	avfilter_inout_free(&outputs);
    avfilter_inout_free(&inputs);
    avfilter_graph_free(&filter_graph);
	return 0;
}

??Makefile文件：

OBJ=addwatermart.o
CFLAGS =-I/home/wbyq/src_pack/ffmpeg-4.2.5/_install/include -L/home/wbyq/src_pack/ffmpeg-4.2.5/_install/lib
CFLAGS +=-lpthread -lm -ldl -lSDL2_image -lavcodec -lavfilter -lavutil -lswresample -lavdevice -lavformat -lpostproc -lswscale -lpthread -lstdc++ -lm -lasound -lavfilter -lfreetype
app:$(OBJ)
	gcc -o app $(OBJ) $(CFLAGS) 
.PHONY=clean
clean:
	rm app -f

??本示例實現效果為動態添加時間水印。示例效果：