Fungsi WICConvertBitmapSource (wincodec.h)

Mendapatkan IWICBitmapSource dalam format piksel yang diinginkan dari IWICBitmapSource tertentu.

Sintaks

HRESULT WICConvertBitmapSource(
  [in]  REFWICPixelFormatGUID dstFormat,
  [in]  IWICBitmapSource      *pISrc,
  [out] IWICBitmapSource      **ppIDst
);

Parameter

[in] dstFormat

Jenis: REFWICPixelFormatGUID

Format piksel yang akan dikonversi.

[in] pISrc

Jenis: IWICBitmapSource*

Bitmap sumber.

[out] ppIDst

Jenis: IWICBitmapSource**

Penunjuk ke penunjuk bitmap tujuan yang diinisialisasi null.

Nilai kembali

Jenis: HRESULT

Jika fungsi ini berhasil, fungsi akan mengembalikan S_OK. Jika tidak, kode kesalahan HRESULT akan dikembalikan.

Keterangan

Jika bitmap pISrc sudah dalam format yang diinginkan, maka pISrc disalin ke penunjuk bitmap tujuan dan referensi ditambahkan. Namun, jika tidak dalam format yang diinginkan, WICConvertBitmapSource akan membuat instans pengonversi format dstFormat dan menginisialisasinya dengan pISrc.

Contoh

Contoh berikut mengonversi IWICBitmapSource menjadi format piksel GUID_WICPixelFormat128bppPRGBAFloat .

   IWICImagingFactory *pFactory = NULL;
   IWICBitmapDecoder *pDecoder = NULL;
   IWICBitmapFrameDecode *pBitmapFrameDecode = NULL;
   IWICBitmapSource *pConverter = NULL;

   UINT uiFrameCount = 0;
   UINT uiWidth = 0, uiHeight = 0;
   WICPixelFormatGUID pixelFormat;    

   // Create the image factory.
   HRESULT hr = CoCreateInstance(CLSID_WICImagingFactory,
                    NULL,
                    CLSCTX_INPROC_SERVER,
                    IID_IWICImagingFactory,
                    (LPVOID*) &pFactory);

   // Create a decoder from the file.
   if (SUCCEEDED(hr))
   {
      hr = pFactory->CreateDecoderFromFilename(L"test.jpg",
                         NULL,
                         GENERIC_READ,
                         WICDecodeMetadataCacheOnDemand,
                         &pDecoder);
   }

   // Get the frame count.
   if (SUCCEEDED(hr))
   {
      hr = pDecoder->GetFrameCount(&uiFrameCount);
   }

   if (SUCCEEDED(hr) && (uiFrameCount > 0))
   {
      IWICBitmapSource *pSource = NULL;

      hr = pDecoder->GetFrame(0, &pBitmapFrameDecode);

      if (SUCCEEDED(hr))
      {
         pSource = pBitmapFrameDecode;
         pSource->AddRef();

         hr = pSource->GetSize(&uiWidth, &uiHeight);
      }

      if (SUCCEEDED(hr))
      {
         hr = pSource->GetPixelFormat(&pixelFormat);
      }

      if (SUCCEEDED(hr))
      {
         if (!IsEqualGUID(pixelFormat, GUID_WICPixelFormat128bppPRGBAFloat))
         {

            hr = WICConvertBitmapSource(GUID_WICPixelFormat128bppPRGBAFloat, pSource, &pConverter);

            if (SUCCEEDED(hr))
            {
               pSource->Release();     // the converter has a reference to the source
               pSource = NULL;         // so we don't need it anymore.
               pSource = pConverter;   // let's treat the 128bppPABGR converter as the source
            }
         }

         if (piConverter)
         {
            UINT cbStride = uiWidth * sizeof(float) * 4;
            UINT cbBufferSize = cbStride;

            float *pixels = new float[cbBufferSize / sizeof(float)];

            if (pixels)
            {                    
               WICRect rc;
               rc.X = 0;
               rc.Y = 0;
               rc.Width = uiWidth;
               rc.Height = 1;

               for (UINT i = 0; SUCCEEDED(hr) && i < uiHeight; i++)
               {
                  hr = pSource->CopyPixels(&rc,
                                    cbStride,
                                    cbBufferSize,
                                    reinterpret_cast<BYTE*>(pixels));

                  // Do something with the scanline here...

                  rc.Y++;
               }

               delete[] pixels;
            }
            else
            {
               hr = E_OUTOFMEMORY;
            }

            pConverter->Release();
         }
      }
   }

   if (pBitmapFrameDecode)
   {
      pBitmapFrameDecode->Release();
   }

   if (pDecoder)
   {
      pDecoder->Release();
   }

   if (pFactory)
   {
      pFactory->Release();
   }

   return hr;

Persyaratan

Persyaratan	Nilai
Klien minimum yang didukung	Windows XP dengan SP2, Windows Vista [aplikasi desktop | Aplikasi UWP]
Server minimum yang didukung	Windows Server 2008 [aplikasi desktop | Aplikasi UWP]
Target Platform	Windows
Header	wincodec.h
Pustaka	Windowscodecs.lib
DLL	Windowscodecs.dll