Hisilicon 3559 sample parsing: Venc

Preface ：

   Analysis finished vio After the routine, I was full of confidence , Confidently go to the boss and ask for assignment ,“ A simple ” Several steps , Draw a ladle according to the gourd , Adjust parameters , Analyze and modify the corresponding position , Beautiful and bright “ Main road ” Clear and bright ！

   Young people ,too young too naive Ah, if it were so simple , Use chip cannons to shoot mosquitoes ？
   But it seems very simple , Properties are configured one by one , One binding , Balabala
   What if you don't bind ？ You need to modify the algorithm yourself ? How to get images , How to output ？ If you want to do personal face recognition ？

Do you feel that the simpler the process, the less free it seems , Many are out of control , I want to modify more as required , Naturally, it is not so easy
Cover your swollen face and learn from it , Be sure to take apart the specific steps
One sample If it's not enough, let's see a little more complicated ！

sample_venc

   With previous experience , The overall process is still a little x Count , You don't have to jump around every time , Take a look at the code framework directly

main  The main function 
	SAMPLE_VENC_4K60  Video capture function 
		SAMPLE_COMM_SYS_GetPicSize  obtain w.h Parameters 
		SAMPLE_COMM_VI_GetSensorInfo
		SAMPLE_VENC_CheckSensor
			SAMPLE_COMM_VI_GetSizeBySensor  obtain sensor Related parameters of , obtain mmp Some parameters required by the system 
			SAMPLE_COMM_SYS_GetPicSize  Get the size of the picture 
		SAMPLE_VENC_VI_Init
			SAMPLE_VENC_SYS_Init  Coding system initialization 
				SAMPLE_COMM_VI_GetSizeBySensor   obtain sensor Related parameters of , obtain mmp Some parameters required by the system 
				SAMPLE_COMM_SYS_GetPicSize   Get the size of the picture 
				COMMON_GetPicBufferSize   Get the size of the cache block 
				SAMPLE_COMM_SYS_Init   MMP System initialization 
					HI_MPI_SYS_Exit(); To initialize  MPP  System .
					HI_MPI_VB_Exit(); To initialize  MPP  Video buffer pool 
					HI_MPI_VB_SetConfig Set up  MPP  Video cache pool properties 
					HI_MPI_VB_Init  initialization  MPP  Video buffer pool 
					HI_MPI_SYS_Init  initialization  MPP  System .
  			SAMPLE_COMM_VI_GetFrameRateBySensor
			HI_MPI_ISP_GetCtrlParam  obtain  ISP  Control parameter .
			HI_MPI_ISP_SetCtrlParam  Set up  ISP  Control parameter .
			SAMPLE_COMM_VI_StartVi
				SAMPLE_COMM_VI_StartMIPI  initialization mipi ：  Set up mipi The pattern of .. Can make mipi The clock .mipi Reset . Can make sensor The clock .sensor Reset . Set up mipi Properties of .mipi De reset ..sensor De reset 
				SAMPLE_COMM_VI_SetParam obtain  VI,VPSS  Working mode of . Set up  VI,VPSS  Working mode 
				SAMPLE_COMM_VI_CreateVi Set up  VI  Equipment and Physics  PIPE  Binding relationship of .  establish vi pipe.  Set up  VI  passageway ch attribute , Enable  VI  passageway ch
				SAMPLE_COMM_VI_CreateIsp   Reference resources HiISP Development reference 
		SAMPLE_VENC_VPSS_Init
			SAMPLE_COMM_VI_GetSizeBySensor   obtain sensor Related parameters of , obtain mmp Some parameters required by the system 
			SAMPLE_COMM_SYS_GetPicSize   Get the size of the picture 
			SAMPLE_COMM_VPSS_Start   establish vpss group  Configure channel properties   Enable channel   Enable vpss group
		SAMPLE_COMM_VI_Bind_VPSS   Include data sources 3 Parameter recipients 3 Parameters , Namely vi and vpss, Call the data source to data receiver binding interface 
			HI_MPI_SYS_Bind

		/     start stream venc   /
		SAMPLE_VENC_GetRcMode     obtain rc Pattern （ rate control ）
		SAMPLE_VENC_GetGopMode  gop Mode selection 
		SAMPLE_COMM_VENC_GetGopAttr  according to gop Mode configuration related properties 

		 /***encode h.265 **/
		SAMPLE_COMM_VENC_Start   Start coding  stream Pattern 
			SAMPLE_COMM_VENC_Creat   establish venc channel according to enType Choose the encoding format 
			HI_MPI_VENC_StartRecvFrame  Open the encoding channel to receive the input image . Allows you to specify the number of frames received , Automatically stop receiving images when the specified number of frames is exceeded 
		SAMPLE_COMM_VPSS_Bind_VENC   Data source to data receiver binding interface .
			HI_MPI_SYS_Bind   Data source to data receiver binding interface .
  
		/***encode h.264 **/
		SAMPLE_COMM_VENC_Start
			SAMPLE_COMM_VENC_Creat   establish venc channel according to enType Choose the encoding format 
			HI_MPI_VENC_StartRecvFrame  Open the encoding channel to receive the input image . Allows you to specify the number of frames received , Automatically stop receiving images when the specified number of frames is exceeded 
		SAMPLE_COMM_VPSS_Bind_VENC
			HI_MPI_SYS_Bind   Data source to data receiver binding interface .

		/*stream save process*/
		SAMPLE_COMM_VENC_StartGetStream   Create a thread to start the code stream 
			SAMPLE_COMM_VENC_GetVencStreamProc
				 step 1:    Check and prepare to save files and venc fd
					/*  Determine the video stream file name , And open the file to save the video stream */
					 /*  Set up  Venc Fd. */
				 step 2:   Start getting video streams for each channel 
					 step 2.1 :  Query how many packets are in each frame stream .
					 step 2.2 : It is recommended to check at the same time u32CurPacks and u32LeftStreamFramese
					 step 2.3 :  malloc The number of corresponding package nodes .
					 step 2.4 :  call mpi Get a frame stream 
					 step 2.5 :  Save the frame to a file 
					 step 2.6 :  Release video stream 
 					 step 2.7 :  Release the package node 
				 step 3 : Close save file 
		SAMPLE_COMM_VENC_StopGetStream  pthread_join Threads 

It looks much clearer , Then let's take this as the basis , Let's start building our own platform ！