基于FFMPEG采集摄像头图像编码MP4视频+时间水印
1.硬件平台
操作系统:Ubuntu18.04
ffmpeg版本:ffmpeg4.2.5
摄像头:电脑自带或USB免驱摄像头
水印处理:avfilter
图像渲染:SDL库
摄像头图像采集+MP4视频编码参考示例:https://blog.csdn.net/weixin_44453694/article/details/123885112
水印添加处理参数示例:https://blog.csdn.net/weixin_44453694/article/details/123909568
2.功能实现
本示例采样三个线程实现:
子线程1实现ffmpeg编解码器注册,设置图像格式,摄像头图像数据采集。
子线程2实现MP4视频格式编码。
主线程完成子线程创建,SDL库初始化,窗口创建,图像数据渲染。
通过ffmpeg自带avfilter库实现时间水印添加。
3.核心代码
3.1 水印处理函数
//添加水印
int waterMark(AVFrame *frame_in,AVFrame *frame_out,int w,int h,const char *str)
{
int ret;
/*根据名字获取ffmegding定义的filter*/
const AVFilter *buffersrc=avfilter_get_by_name("buffer");//原始数据
const AVFilter *buffersink=avfilter_get_by_name("buffersink");//处理后的数据
/*动态分配AVFilterInOut空间*/
AVFilterInOut *outputs=avfilter_inout_alloc();
AVFilterInOut *inputs=avfilter_inout_alloc();
/*创建AVFilterGraph,分配空间*/
AVFilterGraph *filter_graph;//对filters系统的整体管理结构体
filter_graph = avfilter_graph_alloc();
enum AVPixelFormat pix_fmts[]={AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE};//设置格式
/*过滤器参数:解码器的解码帧将被插入这里。*/
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);//图像宽高,格式,帧率,画面横纵比
/*创建过滤器上下文,源数据AVFilterContext*/
AVFilterContext *buffersrc_ctx;
ret=avfilter_graph_create_filter(&buffersrc_ctx,buffersrc,"in",args,NULL,filter_graph);
if(ret<0)
{
printf("创建src过滤器上下文失败AVFilterContextn");
return -1;
}
/*创建过滤器上下文,处理后数据buffersink_params*/
AVBufferSinkParams *buffersink_params;
buffersink_params=av_buffersink_params_alloc();
buffersink_params->pixel_fmts=pix_fmts;//设置格式
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("创建sink过滤器上下文失败AVFilterContextn");
return -2;
}
/*过滤器链输入/输出链接列表*/
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};//要添加的水印数据
snprintf(filter_desrc,sizeof(filter_desrc),"drawtext=fontfile=msyhbd.ttc:fontcolor=red:fontsize=25:x=50:y=20:text='%snIT_阿水'",str);
if(avfilter_graph_parse_ptr(filter_graph,filter_desrc,&inputs,&outputs, NULL)<0)//设置过滤器数据内容
{
printf("添加字符串信息失败n");
return -3;
}
/*检测配置信息是否正常*/
if(avfilter_graph_config(filter_graph,NULL)<0)
{
printf("配置信息有误n");
return -4;
}
#if 0
/*
查找要在使用的过滤器,将要触处理的数据添加到过滤器
注意:时间若从外面传入(即144行数据已完整),则此处不需要查找,直接添加即可,否则需要添加下面代码
*/
AVFilterContext* filter_ctx;//上下文
int parsed_drawtext_0_index = -1;
for(int i=0;inb_filters;i++)//查找使用的过滤器
{
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__);//没有找到过滤器
}
filter_ctx=filter_graph->filters[parsed_drawtext_0_index];//保存找到的过滤器
/*获取系统时间,将时间加入到过滤器*/
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小时制
}
av_opt_set(filter_ctx->priv, "text", sys_time, 0 ); //设置text到过滤器
#endif
/*往源滤波器buffer中输入待处理数据*/
if(av_buffersrc_add_frame(buffersrc_ctx,frame_in)<0)
{
return -5;
}
/*从滤波器中输出处理数据*/
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;
}
3.2 读取一帧数据
读取一帧图像数据,进行图像解码,图像格式转换,添加时间水印。
static AVFrame *get_video_frame(OutputStream *ost,IntputDev* input, int *got_pic)
{
int ret,got_picture;
AVCodecContext *c=ost->enc;
AVFrame *ret_frame=NULL;
/*在各自的时基中比较两个时间戳。*/
if(av_compare_ts(ost->next_pts,c->time_base,STREAM_DURATION, (AVRational){1,1})>=0)
{
return (void*)-1;
}
/*确保帧数据可写,尽可能避免数据复制。*/
if(av_frame_make_writable(ost->frame)<0)
{
exit(1);
}
/*此函数返回文件中存储的内容,并且不验证是否存在解码器的有效帧。*/
if(av_read_frame(input->v_ifmtCtx,input->in_packet)>=0)
{
if(input->in_packet->stream_index == input->videoindex)
{
/*解码一帧视频数据。输入一个压缩编码的结构体AVPacket,输出一个解码后的结构体AVFrame*/
ret=avcodec_decode_video2(input->pcodecCtx, input->pFrame,&got_picture,input->in_packet);
*got_pic=got_picture;
if(ret<0)
{
printf("Decode Error.n");
av_packet_unref(input->in_packet);
return NULL;
}
if(got_picture)
{
sws_scale(input->img_convert_ctx, (const unsigned char * const *)input->pFrame->data,input->pFrame->linesize,0,input->pcodecCtx->height,input->pFrameYUV->data,input->pFrameYUV->linesize);
sws_scale(input->img_convert_ctx, (const unsigned char * const *)input->pFrame->data,input->pFrame->linesize,0,input->pcodecCtx->height,ost->frame->data,ost->frame->linesize);
pthread_mutex_lock(&fastmutex);//互斥锁上锁
memcpy(rgb_buff,input->pFrameYUV->data[0],size);
pthread_cond_broadcast(&cond);//广播唤醒所有线程
pthread_mutex_unlock(&fastmutex);//互斥锁解锁
//ost->frame->pts=ost->next_pts++;
//水印添加处理
//frame->frame->format=AV_PIX_FMT_YUV420P;
AVFrame *frame_out=av_frame_alloc();
unsigned char *frame_buffer_out;
frame_buffer_out=(unsigned char *)av_malloc(size);
av_image_fill_arrays(frame_out->data,frame_out->linesize,frame_buffer_out,AV_PIX_FMT_YUV420P,width,height,32);
//添加水印,调用libavfilter库实现
time_t sec;
sec=time(NULL);
struct tm* today = localtime(&sec);
char sys_time[64];
strftime(sys_time, sizeof(sys_time), "%Y/%m/%d %H:%M:%S", today);
waterMark(ost->frame,frame_out,width,height,sys_time);
//yuv420p,y表示亮度,uv表示像素颜色
ost->frame=frame_out;
ost->frame->pts=ost->next_pts++;
ret_frame=frame_out;
}
}
av_packet_unref(input->in_packet);
}
return ret_frame;
}
3.3 SDL库图像渲染
int main()
{
/*创建摄像头采集线程*/
pthread_t pthid[2];
pthread_create(&pthid[0],NULL,Video_CollectImage, NULL);
pthread_detach(pthid[0]);/*设置分离属性*/
sleep(1);
while(1)
{
if(width!=0 && height!=0 && size!=0)break;
if(video_flag==0)return 0;
}
printf("image:%d * %d,%dn",width,height,size);
unsigned char *rgb_data=malloc(size);
/*创建mp4视频编码线程*/
pthread_create(&pthid[1],NULL,Video_savemp4, NULL);
pthread_detach(pthid[1]);/*设置分离属性*/
/*创建窗口 */
SDL_Window *window=SDL_CreateWindow("SDL_VIDEO", SDL_WINDOWPOS_CENTERED,SDL_WINDOWPOS_CENTERED,800,480,SDL_WINDOW_ALLOW_HIGHDPI|SDL_WINDOW_RESIZABLE);
/*创建渲染器*/
SDL_Renderer *render=SDL_CreateRenderer(window,-1,SDL_RENDERER_ACCELERATED);
/*清空渲染器*/
SDL_RenderClear(render);
/*创建纹理*/
SDL_Texture*sdltext=SDL_CreateTexture(render,SDL_PIXELFORMAT_IYUV,SDL_TEXTUREACCESS_STREAMING,width,height);
bool quit=true;
SDL_Event event;
SDL_Rect rect;
int count=0;
while(quit)
{
while(SDL_PollEvent(&event))/*事件监测*/
{
if(event.type==SDL_QUIT)/*退出事件*/
{
quit=false;
video_flag=0;
pthread_cancel(pthid[1]);/*杀死指定线程*/
pthread_cancel(pthid[0]);/*杀死指定线程*/
continue;
}
else if(event.type == SDL_KEYDOWN)
{
if(event.key.keysym.sym==SDLK_q)//按‘q’保存视频
{
count++;
snprintf(file_name,sizeof(file_name),"%d.mp4",count);
mp4_decode_stat=1;
}
}
}
if(!video_flag)
{
quit=false;
continue;
}
pthread_mutex_lock(&fastmutex);//互斥锁上锁
pthread_cond_wait(&cond,&fastmutex);
memcpy(rgb_data,rgb_buff,size);
pthread_mutex_unlock(&fastmutex);//互斥锁解锁
SDL_UpdateTexture(sdltext,NULL,rgb_data,width);
//SDL_RenderCopy(render, sdltext, NULL,NULL); // 拷贝纹理到渲染器
SDL_RenderCopyEx(render, sdltext,NULL,NULL,0,NULL,SDL_FLIP_NONE);
SDL_RenderPresent(render); // 渲染
}
SDL_DestroyTexture(sdltext);/*销毁纹理*/
SDL_DestroyRenderer(render);/*销毁渲染器*/
SDL_DestroyWindow(window);/*销毁窗口 */
SDL_Quit();/*关闭SDL*/
pthread_mutex_destroy(&fastmutex);/*销毁互斥锁*/
pthread_cond_destroy(&cond);/*销毁条件变量*/
free(rgb_buff);
free(rgb_data);
return 0;
}
4.示例效果
摄像头采集图像实时渲染:
5.完整示例
Gitee源码链接:https://gitee.com/it-a-shui/ffmpeg
CSDN源码链接:https://download.csdn.net/download/weixin_44453694/85084851
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