海思mpp学习（3）：视频缓存池-vb
1.说明
视频缓存池主要向媒体业务提供大块物理内存管理功能，必须在系统初始化之前配置公共视频缓存池。
2.示例代码
VB_CONFIG_S config;
memset(&config, 0, sizeof(VB_CONFIG_S));
config.u32MaxPoolCnt = 1;
HI_U64 blk_size = COMMON_GetPicBufferSize(1920,1080, PIXEL_FORMAT_YVU_SEMIPLANAR_420,
DATA_BITWIDTH_8,COMPRESS_MODE_NONE, DEFAULT_ALIGN);
config.astCommPool[0].u64BlkSize = blk_size;
printf("blk size: %llu\n", config.astCommPool[0].u64BlkSize);
config.astCommPool[0].u32BlkCnt = 3;
// 设置公共视频缓存池属性
HI_S32 ret = HI_MPI_VB_SetConfig(&config);
if(ret != HI_SUCCESS)
{
printf("HI_MPI_VB_SetConfig falied: %#x\n", ret);
return;
}
// 初始化缓存池
ret = HI_MPI_VB_Init();
if(ret != HI_SUCCESS)
{
printf("HI_MPI_VB_Init falied: %#x\n", ret);
return;
}
// mpp系统初始化
ret = HI_MPI_SYS_Init();
if(ret != HI_SUCCESS)
{
printf("HI_MPI_SYS_Init falied: %#x\n", ret);
return;
}
// 从公共视频缓存池获取一个缓存块
VB_BLK blk = HI_MPI_VB_GetBlock(VB_INVALID_POOLID, blk_size, NULL);
if(blk == VB_INVALID_HANDLE)
printf("HI_MPI_VB_GetBlock failed\n");
else
printf("blk id: %u\n", blk);
HI_U64 phy_addr = HI_MPI_VB_Handle2PhysAddr(blk);
if(phy_addr == 0)
printf("HI_MPI_VB_Handle2PhysAddr failed\n");
else
printf("phy addr: %llx\n", phy_addr);
// 通过mmap获取虚拟地址
HI_VOID* tmp_addr = HI_MPI_SYS_Mmap(phy_addr, blk_size);
if(!tmp_addr)
printf("HI_MPI_SYS_Mmap falied\n");
else
printf("tmp addr: %#x\n", tmp_addr);
// 使用VB提供的接口获取虚拟地址
// 需要先把缓存池映射出虚拟地址，才能获取其中缓存块的虚拟地址
// 公共缓存池的pool id是0
ret = HI_MPI_VB_MmapPool(0);
if(ret != HI_SUCCESS)
printf("HI_MPI_VB_MmapPool falied: %#x\n", ret);
HI_VOID *vir_addr = NULL;
ret = HI_MPI_VB_GetBlockVirAddr(0, phy_addr, &vir_addr);
if(ret != HI_SUCCESS)
printf("HI_MPI_VB_GetBlockVirAddr failed %#x\n", ret);
else
printf("vir addr: %#x\n", vir_addr);
// tmp_addr和vir_addr指向同一块内存
char str[] = "hello";
memset(tmp_addr, 0, blk_size);
memcpy(tmp_addr, str, strlen(str));
printf(">>>%s<<<\n", (char*)vir_addr);
getchar();
HI_MPI_SYS_Munmap(tmp_addr, blk_size);
HI_MPI_VB_ReleaseBlock(blk);
// 需要保证对应的缓存池中没有被MPI层占用
HI_MPI_VB_MunmapPool(0);
ret = HI_MPI_SYS_Exit();
if(ret != HI_SUCCESS)
{
printf("HI_MPI_SYS_Exit falied: %#x\n", ret);
return;
}
ret = HI_MPI_VB_Exit();
if(ret != HI_SUCCESS)
{
printf("HI_MPI_VB_Exit falied: %#x\n", ret);
return;
}
运行结果：
blk size: 3110400
blk id: 0
phy addr: 441f0000
tmp addr: 0xb6990000
vir addr: 0xb60a9000
>>>hello<<<
从运行结果可以看到，HI_MPI_SYS_Mmap可以直接映射出缓存块的虚拟地址，HI_MPI_VB_GetBlockVirAddr需要先映射出整个缓存池的虚拟地址，才能映射出自己的虚拟地址，HI_MPI_SYS_Mmap这个函数更常用一些。
程序运行过程中可以使用cat /proc/media-mem和cat /proc/umap/vb分别查看mmz内存和vb的使用情况。
~ # cat /proc/media-mem
+---ZONE: PHYS(0x44000000, 0x47FFFFFF), GFP=0, nBYTES=65536KB, NAME="anonymous"
|-MMB: phys(0x44000000, 0x44007FFF), kvirt=0xC4B98000, flags=0x00000001, length=32KB, name="sys_scale_coef"
|-MMB: phys(0x44008000, 0x44008FFF), kvirt=0xC56BB000, flags=0x00000001, length=4KB, name="VbPool_supNC"
|-MMB: phys(0x44009000, 0x4403DFFF), kvirt=0xC5A80000, flags=0x00000001, length=212KB, name="IVE_QUEUE"
|-MMB: phys(0x4403E000, 0x4403EFFF), kvirt=0xC58E4000, flags=0x00000003, length=4KB, name="IVE_TEMP_NODE"
|-MMB: phys(0x4405B000, 0x441EFFFF), kvirt=0x00000000, flags=0x00000000, length=1620KB, name="hifb_layer0"
|-MMB: phys(0x441F0000, 0x44AD6FFF), kvirt=0x00000000, flags=0x00000000, length=9116KB, name="VbPool"
|-MMB: phys(0x44AD7000, 0x44B29FFF), kvirt=0xC5A00000, flags=0x00000001, length=332KB, name="VGS_NodeBuf"
---MMZ_USE_INFO:
total size=65536KB(64MB),used=11320KB(11MB + 56KB),remain=54216KB(52MB + 968KB),zone_number=1,block_number=7
可以看出，视频缓存池-VbPool是在mmz内存中创建的。
~ # cat /proc/umap/vb
[VB] Version: [Hi3516EV200_MPP_V1.0.1.0 B050 Release], Build Time[May 9 2019, 22:51:50]
-----VB PUB CONFIG--------------------------------------------------------------
MaxPoolCnt
512
-----VB SUPPLEMENT ATTR---------------------------------------------------------
Config Size VbCnt
0 0 3
-----COMMON POOL CONFIG---------------------------------------------------------
PoolId 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Size 3110400 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Count 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
--------------------------------------------------------------------------------
PoolId PhysAddr VirtAddr IsComm Owner BlkSz BlkCnt Free MinFree
0 0x441f0000 0x0 1 -1 3110400 3 2 2
BLK VI VO VGS VENC VDEC H265E H264E JPEGE H264D JPEGD VPSS DIS USER PCIV AI AENC RC VFMW GDC AVS RECT MATCH MCF
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0
Sum 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0