MYC-YT113i核心板及开发板
国产T113-i处理器配备2*Cortex-A7@1.2GHz ，RISC-V
外置DDR3接口、支持视频编解码器、HiFi4 DSP
接口丰富：视频采集接口、显示器接口、USB2.0 接口、CAN 接口、千兆以太网接口
工业级：-40℃~+85℃、尺寸37mm*39mm
Supports layer size up to 2048 x 2048 pixels
Supports pre-multiply alpha image data
Supports color key
Supports two pipes Porter-Duff alpha blending
Supports multiple video formats 4:2:0, 4:2:2, 4:1:1 and multiple pixel formats (8/16/24/32 bits graphics
layer)
Supports memory scan order option
Supports any format convert function
Supports 1/16× to 32× resize ratio
Supports 32-phase 8-tap horizontal anti-alias filter and 32-phase 4-tap vertical anti-alias filter
Supports window clip
Supports FillRectangle, BitBlit, StretchBlit and MaskBlit
Supports horizontal and vertical flip, clockwise 0/90/180/270 degree rotate for normal buffer
Supports horizontal flip, clockwise 0/90/270 degree rotate for LBC buffer
可以看到 g2d 硬件支持相当多的2D图像处理，包括颜色空间转换，分辨率缩放，图层叠加，旋转等
void yuv420sp2rgb(const unsigned char* yuv420sp, int w, int h, unsigned char* rgb){const unsigned char* yptr = yuv420sp;const unsigned char* vuptr = yuv420sp + w * h;for (int y = 0; y < h; y += 2){const unsigned char* yptr0 = yptr;const unsigned char* yptr1 = yptr + w;unsigned char* rgb0 = rgb;unsigned char* rgb1 = rgb + w * 3;int remain = w;for (; remain > 0; remain -= 2){// R = 1.164 * yy + 1.596 * vv// G = 1.164 * yy - 0.813 * vv - 0.391 * uu// B = 1.164 * yy + 2.018 * uu// R = Y + (1.370705 * (V-128))// G = Y - (0.698001 * (V-128)) - (0.337633 * (U-128))// B = Y + (1.732446 * (U-128))// R = ((Y << 6) + 87.72512 * (V-128)) >> 6// G = ((Y << 6) - 44.672064 * (V-128) - 21.608512 * (U-128)) >> 6// B = ((Y << 6) + 110.876544 * (U-128)) >> 6// R = ((Y << 6) + 90 * (V-128)) >> 6// G = ((Y << 6) - 46 * (V-128) - 22 * (U-128)) >> 6// B = ((Y << 6) + 113 * (U-128)) >> 6// R = (yy + 90 * vv) >> 6// G = (yy - 46 * vv - 22 * uu) >> 6// B = (yy + 113 * uu) >> 6int v = vuptr[0] - 128;int u = vuptr[1] - 128;int ruv = 90 * v;int guv = -46 * v + -22 * u;int buv = 113 * u;int y00 = yptr0[0] << 6;rgb0[0] = SATURATE_CAST_UCHAR((y00 + ruv) >> 6);rgb0[1] = SATURATE_CAST_UCHAR((y00 + guv) >> 6);rgb0[2] = SATURATE_CAST_UCHAR((y00 + buv) >> 6);int y01 = yptr0[1] << 6;rgb0[3] = SATURATE_CAST_UCHAR((y01 + ruv) >> 6);rgb0[4] = SATURATE_CAST_UCHAR((y01 + guv) >> 6);rgb0[5] = SATURATE_CAST_UCHAR((y01 + buv) >> 6);int y10 = yptr1[0] << 6;rgb1[0] = SATURATE_CAST_UCHAR((y10 + ruv) >> 6);rgb1[1] = SATURATE_CAST_UCHAR((y10 + guv) >> 6);rgb1[2] = SATURATE_CAST_UCHAR((y10 + buv) >> 6);int y11 = yptr1[1] << 6;rgb1[3] = SATURATE_CAST_UCHAR((y11 + ruv) >> 6);rgb1[4] = SATURATE_CAST_UCHAR((y11 + guv) >> 6);rgb1[5] = SATURATE_CAST_UCHAR((y11 + buv) >> 6);yptr0 += 2;yptr1 += 2;vuptr += 2;rgb0 += 6;rgb1 += 6;}yptr += 2 * w;rgb += 2 * 3 * w;}}
考虑到armv7编译器的自动neon优化能力较差，这里针对性的编写 arm neon inline assembly 实现YUV2RGB内核部分，达到最优化的性能，榨干cpu性能
void yuv420sp2rgb_neon(const unsigned char* yuv420sp, int w, int h, unsigned char* rgb){const unsigned char* yptr = yuv420sp;const unsigned char* vuptr = yuv420sp + w * h;uint8x8_t _v128 = vdup_n_u8(128);int8x8_t _v90 = vdup_n_s8(90);int8x8_t _v46 = vdup_n_s8(46);int8x8_t _v22 = vdup_n_s8(22);int8x8_t _v113 = vdup_n_s8(113);for (int y = 0; y < h; y += 2){const unsigned char* yptr0 = yptr;const unsigned char* yptr1 = yptr + w;unsigned char* rgb0 = rgb;unsigned char* rgb1 = rgb + w * 3;int nn = w >> 3;int remain = w - (nn << 3);int remain = w;for (; nn > 0; nn--){int16x8_t _yy0 = vreinterpretq_s16_u16(vshll_n_u8(vld1_u8(yptr0), 6));int16x8_t _yy1 = vreinterpretq_s16_u16(vshll_n_u8(vld1_u8(yptr1), 6));int8x8_t _vvuu = vreinterpret_s8_u8(vsub_u8(vld1_u8(vuptr), _v128));int8x8x2_t _vvvvuuuu = vtrn_s8(_vvuu, _vvuu);int8x8_t _vv = _vvvvuuuu.val[0];int8x8_t _uu = _vvvvuuuu.val[1];int16x8_t _r0 = vmlal_s8(_yy0, _vv, _v90);int16x8_t _g0 = vmlsl_s8(_yy0, _vv, _v46);_g0 = vmlsl_s8(_g0, _uu, _v22);int16x8_t _b0 = vmlal_s8(_yy0, _uu, _v113);int16x8_t _r1 = vmlal_s8(_yy1, _vv, _v90);int16x8_t _g1 = vmlsl_s8(_yy1, _vv, _v46);_g1 = vmlsl_s8(_g1, _uu, _v22);int16x8_t _b1 = vmlal_s8(_yy1, _uu, _v113);uint8x8x3_t _rgb0;_rgb0.val[0] = vqshrun_n_s16(_r0, 6);_rgb0.val[1] = vqshrun_n_s16(_g0, 6);_rgb0.val[2] = vqshrun_n_s16(_b0, 6);uint8x8x3_t _rgb1;_rgb1.val[0] = vqshrun_n_s16(_r1, 6);_rgb1.val[1] = vqshrun_n_s16(_g1, 6);_rgb1.val[2] = vqshrun_n_s16(_b1, 6);vst3_u8(rgb0, _rgb0);vst3_u8(rgb1, _rgb1);yptr0 += 8;yptr1 += 8;vuptr += 8;rgb0 += 24;rgb1 += 24;}if (nn > 0){asm volatile("0: \n""pld [%3, #128] \n""vld1.u8 {d2}, [%3]! \n""vsub.s8 d2, d2, %12 \n""pld [%1, #128] \n""vld1.u8 {d0}, [%1]! \n""pld [%2, #128] \n""vld1.u8 {d1}, [%2]! \n""vshll.u8 q2, d0, #6 \n""vorr d3, d2, d2 \n""vshll.u8 q3, d1, #6 \n""vorr q9, q2, q2 \n""vtrn.s8 d2, d3 \n""vorr q11, q3, q3 \n""vmlsl.s8 q9, d2, %14 \n""vorr q8, q2, q2 \n""vmlsl.s8 q11, d2, %14 \n""vorr q10, q3, q3 \n""vmlal.s8 q8, d2, %13 \n""vmlal.s8 q2, d3, %16 \n""vmlal.s8 q10, d2, %13 \n""vmlsl.s8 q9, d3, %15 \n""vmlal.s8 q3, d3, %16 \n""vmlsl.s8 q11, d3, %15 \n""vqshrun.s16 d24, q8, #6 \n""vqshrun.s16 d26, q2, #6 \n""vqshrun.s16 d4, q10, #6 \n""vqshrun.s16 d25, q9, #6 \n""vqshrun.s16 d6, q3, #6 \n""vqshrun.s16 d5, q11, #6 \n""subs %0, #1 \n""vst3.u8 {d24-d26}, [%4]! \n""vst3.u8 {d4-d6}, [%5]! \n""bne 0b \n": "=r"(nn), // %0"=r"(yptr0), // %1"=r"(yptr1), // %2"=r"(vuptr), // %3"=r"(rgb0), // %4"=r"(rgb1) // %5: "0"(nn),"1"(yptr0),"2"(yptr1),"3"(vuptr),"4"(rgb0),"5"(rgb1),"w"(_v128), // %12"w"(_v90), // %13"w"(_v46), // %14"w"(_v22), // %15"w"(_v113) // %16: "cc", "memory", "q0", "q1", "q2", "q3", "q8", "q9", "q10", "q11", "q12", "d26");}for (; remain > 0; remain -= 2){// R = 1.164 * yy + 1.596 * vv// G = 1.164 * yy - 0.813 * vv - 0.391 * uu// B = 1.164 * yy + 2.018 * uu// R = Y + (1.370705 * (V-128))// G = Y - (0.698001 * (V-128)) - (0.337633 * (U-128))// B = Y + (1.732446 * (U-128))// R = ((Y << 6) + 87.72512 * (V-128)) >> 6// G = ((Y << 6) - 44.672064 * (V-128) - 21.608512 * (U-128)) >> 6// B = ((Y << 6) + 110.876544 * (U-128)) >> 6// R = ((Y << 6) + 90 * (V-128)) >> 6// G = ((Y << 6) - 46 * (V-128) - 22 * (U-128)) >> 6// B = ((Y << 6) + 113 * (U-128)) >> 6// R = (yy + 90 * vv) >> 6// G = (yy - 46 * vv - 22 * uu) >> 6// B = (yy + 113 * uu) >> 6int v = vuptr[0] - 128;int u = vuptr[1] - 128;int ruv = 90 * v;int guv = -46 * v + -22 * u;int buv = 113 * u;int y00 = yptr0[0] << 6;rgb0[0] = SATURATE_CAST_UCHAR((y00 + ruv) >> 6);rgb0[1] = SATURATE_CAST_UCHAR((y00 + guv) >> 6);rgb0[2] = SATURATE_CAST_UCHAR((y00 + buv) >> 6);int y01 = yptr0[1] << 6;rgb0[3] = SATURATE_CAST_UCHAR((y01 + ruv) >> 6);rgb0[4] = SATURATE_CAST_UCHAR((y01 + guv) >> 6);rgb0[5] = SATURATE_CAST_UCHAR((y01 + buv) >> 6);int y10 = yptr1[0] << 6;rgb1[0] = SATURATE_CAST_UCHAR((y10 + ruv) >> 6);rgb1[1] = SATURATE_CAST_UCHAR((y10 + guv) >> 6);rgb1[2] = SATURATE_CAST_UCHAR((y10 + buv) >> 6);int y11 = yptr1[1] << 6;rgb1[3] = SATURATE_CAST_UCHAR((y11 + ruv) >> 6);rgb1[4] = SATURATE_CAST_UCHAR((y11 + guv) >> 6);rgb1[5] = SATURATE_CAST_UCHAR((y11 + buv) >> 6);yptr0 += 2;yptr1 += 2;vuptr += 2;rgb0 += 6;rgb1 += 6;}yptr += 2 * w;rgb += 2 * 3 * w;}}
我们先实现 dmaion buffer 管理器，参考
https://github.com/MYIR-ALLWINNER/framework/blob/develop-yt113-framework/auto/sdk_lib/sdk_memory/DmaIon.cpp
这里贴的代码省略了异常错误处理的逻辑，有个坑是 linux-4.9 和 linux-5.4 用法不一样，米尔电子的这个T113-i系统是linux-5.4，所以不兼容4.9内核的ioctl用法习惯
struct ion_memory{size_t size;int fd;void* virt_addr;unsigned int phy_addr;};class ion_allocator{public:ion_allocator();~ion_allocator();int open();void close();int alloc(size_t size, struct ion_memory* mem);int free(struct ion_memory* mem);int flush(struct ion_memory* mem);public:int ion_fd;int cedar_fd;};ion_allocator::ion_allocator(){ion_fd = -1;cedar_fd = -1;}ion_allocator::~ion_allocator(){close();}int ion_allocator::open(){close();ion_fd = ::open("/dev/ion", O_RDWR);cedar_fd = ::open("/dev/cedar_dev", O_RDONLY);ioctl(cedar_fd, IOCTL_ENGINE_REQ, 0);return 0;}void ion_allocator::close(){if (cedar_fd != -1){ioctl(cedar_fd, IOCTL_ENGINE_REL, 0);::close(cedar_fd);cedar_fd = -1;}if (ion_fd != -1){::close(ion_fd);ion_fd = -1;}}int ion_allocator::alloc(size_t size, struct ion_memory* mem){struct aw_ion_new_alloc_data alloc_data;alloc_data.len = size;alloc_data.heap_id_mask = AW_ION_SYSTEM_HEAP_MASK;alloc_data.flags = AW_ION_CACHED_FLAG | AW_ION_CACHED_NEEDS_SYNC_FLAG;alloc_data.fd = 0;alloc_data.unused = 0;ioctl(ion_fd, AW_ION_IOC_NEW_ALLOC, &alloc_data);void* virt_addr = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_SHARED, alloc_data.fd, 0);struct aw_user_iommu_param iommu_param;iommu_param.fd = alloc_data.fd;iommu_param.iommu_addr = 0;ioctl(cedar_fd, IOCTL_GET_IOMMU_ADDR, &iommu_param);mem->size = size;mem->fd = alloc_data.fd;mem->virt_addr = virt_addr;mem->phy_addr = iommu_param.iommu_addr;return 0;}int ion_allocator::free(struct ion_memory* mem){if (mem->fd == -1)return 0;struct aw_user_iommu_param iommu_param;iommu_param.fd = mem->fd;ioctl(cedar_fd, IOCTL_FREE_IOMMU_ADDR, &iommu_param);munmap(mem->virt_addr, mem->size);::close(mem->fd);mem->size = 0;mem->fd = -1;mem->virt_addr = 0;mem->phy_addr = 0;return 0;}int ion_allocator::flush(struct ion_memory* mem){struct dma_buf_sync sync;sync.flags = DMA_BUF_SYNC_END | DMA_BUF_SYNC_RW;ioctl(mem->fd, DMA_BUF_IOCTL_SYNC, &sync);return 0;}
然后再实现 G2D图形硬件 YUV转RGB 的转换器
提前分配好YUV和RGB的dmaion buffer
将YUV数据拷贝到dmaion buffer，flush cache完成同步
配置转换参数，ioctl调用G2D_CMD_BITBLT_H完成转换
flush cache完成同步，从dmaion buffer拷贝出RGB数据
释放dmaion buffer
// 步骤1ion_allocator ion;ion.open();struct ion_memory yuv_ion;ion.alloc(rgb_size, &rgb_ion);struct ion_memory rgb_ion;ion.alloc(yuv_size, &yuv_ion);int g2d_fd = ::open("/dev/g2d", O_RDWR);// 步骤2memcpy((unsigned char*)yuv_ion.virt_addr, yuv420sp, yuv_size);ion.flush(&yuv_ion);// 步骤3g2d_blt_h blit;memset(&blit, 0, sizeof(blit));blit.flag_h = G2D_BLT_NONE_H;blit.src_image_h.format = G2D_FORMAT_YUV420UVC_V1U1V0U0;blit.src_image_h.width = width;blit.src_image_h.height = height;blit.src_image_h.align[0] = 0;blit.src_image_h.align[1] = 0;blit.src_image_h.clip_rect.x = 0;blit.src_image_h.clip_rect.y = 0;blit.src_image_h.clip_rect.w = width;blit.src_image_h.clip_rect.h = height;blit.src_image_h.gamut = G2D_BT601;blit.src_image_h.bpremul = 0;blit.src_image_h.mode = G2D_PIXEL_ALPHA;blit.src_image_h.use_phy_addr = 0;blit.src_image_h.fd = yuv_ion.fd;blit.dst_image_h.format = G2D_FORMAT_RGB888;blit.dst_image_h.width = width;blit.dst_image_h.height = height;blit.dst_image_h.align[0] = 0;blit.dst_image_h.clip_rect.x = 0;blit.dst_image_h.clip_rect.y = 0;blit.dst_image_h.clip_rect.w = width;blit.dst_image_h.clip_rect.h = height;blit.dst_image_h.gamut = G2D_BT601;blit.dst_image_h.bpremul = 0;blit.dst_image_h.mode = G2D_PIXEL_ALPHA;blit.dst_image_h.use_phy_addr = 0;blit.dst_image_h.fd = rgb_ion.fd;ioctl(g2d_fd, G2D_CMD_BITBLT_H, &blit);// 步骤4ion.flush(&rgb_ion);memcpy(rgb, (const unsigned char*)rgb_ion.virt_addr, rgb_size);// 步骤5ion.free(&rgb_ion);ion.free(&yuv_ion);ion.close();::close(g2d_fd);
考虑到dmaion buffer分配和释放都比较耗时，我们提前做好，循环调用步骤3的G2D转换，统计耗时，并在top工具中查看CPU占用率
