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IWICJpegFrameEncode interface (wincodec.h)

  • Article

Exposes methods for writing compressed JPEG scan data directly to the WIC encoder's output stream. Also provides access to the Huffman and quantization tables.

Inheritance

The IWICJpegFrameEncode interface inherits from the IUnknown interface. IWICJpegFrameEncode also has these types of members:

Methods

The IWICJpegFrameEncode interface has these methods.

 
IWICJpegFrameEncode::GetAcHuffmanTable

Retrieves a copy of the AC Huffman table for the specified scan and table. (IWICJpegFrameEncode.GetAcHuffmanTable)
IWICJpegFrameEncode::GetDcHuffmanTable

Retrieves a copy of the DC Huffman table for the specified scan and table. (IWICJpegFrameEncode.GetDcHuffmanTable)
IWICJpegFrameEncode::GetQuantizationTable

Retrieves a copy of the quantization table. (IWICJpegFrameEncode.GetQuantizationTable)
IWICJpegFrameEncode::WriteScan

Writes scan data to a JPEG frame.

Remarks

Obtain this interface by calling IUnknown::QueryInterface on the Windows-provided IWICBitmapFrameEncoder interface for the JPEG encoder.

The WIC JPEG encoder supports a smaller subset of JPEG features than the decoder does.

  • The encoder is limited to a single scan. It does not support encoding images that are multi-scan, either for progressive encoding or planar component data.
  • The encoder supports two quantization tables, two AC Huffman tables, and two DC Huffman tables. The luma tables are used for the Y channel and, in the case of YCCK, the black channel. The chroma tables are used for the CbCr channels.
  • The encoder supports encoding gray, YCbCr (RGB), and YCCK (CMYK).
  • The encoder supports 4 fixed component subsampling, 4:2:0, 4:2:2, 4:4:0, and 4:4:4. This subsamples chroma only.
  • The encoder does not support restart markers.

Requirements

Requirement Value
Minimum supported client Windows 10 [desktop apps only]
Minimum supported server Windows Server 2016 [desktop apps only]
Target Platform Windows
Header wincodec.h