PNGD

// 1. Initialize the media data processing system.
int32_t ret = hi_mpi_sys_init();

// 2. Create a channel.
hi_pngd_chn chnId;
hi_pngd_chn_attr chnAttr; // hi_pngd_chn_attr is a reserved parameter and does not need to be set.
ret = hi_mpi_pngd_create_chn(chnId, &chnAttr);

// 3. Send streams.
// 3.1 Allocate input buffer.
uint8_t* inputAddr = nullptr;
// inputsize indicates the buffer size occupied by the input image. The following uses 1024 bytes as an example. You need to calculate the actual buffer size.
int32_t inputSize = 1024;
ret = hi_mpi_dvpp_malloc(0, &inputAddr, inputSize);
// Load the input image into the buffer. The ReadStreamFile function is defined by the user.
ReadStreamFile(fileName, inputAddr, inputSize);

// 3.2 Construct a structure for storing input image information.
hi_img_stream stStream{};
hi_img_info stImgInfo{};
stStream.pts = 0;
if (g_runMode == ACL_HOST) {
    stStream.addr  = (uint8_t *)hostInputAddr;
} else {
    stStream.addr  = (uint8_t *)inputAddr;
}
stStream.len  = inputSize;
stStream.type = HI_PT_PNG;

ret = hi_mpi_png_get_image_info(&stStream, &stImgInfo);
if (g_runMode == ACL_HOST) {
    // If the data on the host is not used, free the host buffer in a timely manner.
   aclrtFreeHost(hostInputAddr);
    hostInputAddr = nullptr;
}
stStream.addr = (uint8_t *)inputAddr;

// 3.3 Construct the structure for storing output image information and allocate output buffer.
hi_pic_info outPicInfo{};
void *outBuffer = nullptr;
outPicInfo.picture_width  = stImgInfo.width;
outPicInfo.picture_height = stImgInfo.height;
outPicInfo.picture_width_stride  = stImgInfo.width_stride;
outPicInfo.picture_height_stride = stImgInfo.height_stride;
outPicInfo.picture_buffer_size   = stImgInfo.img_buf_size;
outPicInfo.picture_format = HI_PIXEL_FORMAT_UNKNOWN;

ret = hi_mpi_dvpp_malloc(0, &outBuffer, outPicInfo.buffer_size);

outPicInfo.picture_address = (uint64_t)outBuffer;

// 3.4 Send the input image to be decoded.
ret = hi_mpi_pngd_send_stream(chnId, &stream, &outPicInfo, 0);

// 4. Receive the decoding result.
// 4.1 Obtain the decoding result.
hi_pic_info picInfo;
hi_img_stream stream;
ret = hi_mpi_pngd_get_image_data(chnId, &picInfo, &stream, 0);
if (ret == HI_SUCCESS) { // Decode success
    printf("[%s][%d] Chn %u GetFrame Success, Decode Success \n",__FUNCTION__, __LINE__, chnId);
} else if (ret == HI_ERR_PNGD_BUF_EMPTY){ // Decoding
    printf("[%s][%d] Chn %u Decoding, try again \n",__FUNCTION__, __LINE__, chnId);
} else { // Decode fail
    printf("[%s][%d] Chn %u GetFrame Success, Decode Fail \n",__FUNCTION__, __LINE__, chnId);
}

// 4.2 Obtain the PNGD output image data from the memory to which outputPic.picture_address points.
......

// 4.3 Free the input and output buffers.
ret = hi_mpi_dvpp_free(frame.v_frame.virt_addr[0]);
ret = hi_mpi_dvpp_free(stream.addr);

// 5. Destroy the channel.
ret = hi_mpi_pngd_destroy_chn(chnId);

// 6. Deinitialize the media data processing system.
ret = hi_mpi_sys_exit();

....