harmony 鸿蒙Graphics Subsystem Changelog

2025-06-12
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Graphics Subsystem Changelog

cl.graphics.1 Image APIs OH_GetImageInfo() and OH_PixelMap_GetImageInfo() Changed

Access Level

Public

Reason for Change

During hardware decoding for JPEG images, Direct Memory Access (DMA) is used, which is an aligned memory. Therefore, the method for calculating rowSize in OH_GetImageInfo() and OH_PixelMap_GetImageInfo() is changed.

Change Impact

This change is incompatible with earlier versions. The method for calculating rowSize is changed.

API Level

<11>

Change Since

OpenHarmony SDK 4.1.3.1

rowSize Component

Before change:

rowSize: number of bytes per row. Calculation formula: Image width x Number of bytes in each pixel.

After change:

rowSize: number of bytes per row. In the case of DMA, the formula is as follows: Image width x Roundup(64 x Number of bytes per pixel). (The roundup means that each row is automatically padded.) In the case of other types of memory, the formula is as follows: Image width x Number of bytes per pixel.

Adaptation Guide

Scenario: The memory address of the pixel map is obtained by calling OH_PixelMap_AccessPixels(). When you directly operate the memory, adjust rowSize.

Case 1: When OpenCV uses the pixel map data to construct cv::Mat, it must include the input parameter step.

Before change:

cv::Mat srv(rows: bitmap.height, cols: bitmap.width, type: CV_8UC4, data: imagePixels);

After change:

cv::Mat srv(rows: bitmap.height, cols: bitmap.width, type: CV_8UC4, data: imagePixels, step: rowSize);

Case 2: When you copy the pixel map data, do not include the padding.

for (int i = 0; i < imageInfo_.size.height; ++i) {
    errno_t ret = memcpy_s(dst, rowDataSize_, src_ + i * rowStride_, rowDataSize_);
    if (ret != 0) {
        Hilog::Error(LABLE, "read pixels by buffer memcpy the pixelmap data to dst fail, error:%{public}d", ret);
        return ERROR_IMAGE_READ_PIXECLMAP_FAILED;
    }
    dst += rowDataSize_;
}