This chapter provides an overview of the information contained in the functional descriptions.
Image Compression library functional descriptions include the following types of information.
JPEG library function definitions use the following data structures.
| FwiDecodeHuffmanSpec | Internal data structure for Huffman decoder table. | |
| FwiDecodeHuffmanState | Internal data structure for Huffman decoder state. | |
| FwiEncodeHuffmanSpec | Internal data structure for Huffman encoder table. | |
| FwiEncodeHuffmanState | Internal data structure for Huffman encoder state. |
JPEG library function definitions use the following parameters.
| Al | Progressive JPEG successive approximation parameter for actual point transform. | |
| Se | Progressive JPEG spectral selection end index. | |
| Ss | Progressive JPEG spectral selection start index. | |
| bFlushState | Indicates the last 8X8 block in a scan. | |
| dstLenBytes | Destination buffer length in bytes. | |
| dstSize | Destination image size. | |
| dstStep | Destination buffer step size (width of the buffer in bytes). | |
| pAcStatistics[256] | Pointer to Huffman symbol statistics for AC coefficient. | |
| pAcTable | Pointer to the Huffman AC coefficient table. | |
| pDcStatistics[256] | Pointer to Huffman symbol statistics for DC coefficient. | |
| pDcTable | Pointer to the Huffman DC coefficient table. | |
| pDecHuffSpec | Pointer to the FwiDecodeHuffmanSpec structure. | |
| pDecHuffState | Pointer to the FwiDecodeHuffmanState structure. | |
| pDst | Pointer to a location in a destination buffer. | |
| pDstBGR | Pointer to destination image ROI for BGR image format. | |
| pDstBitsLen | Pointer to destination buffer length in bits. | |
| pDstCMYK | Pointer to destination image ROI for CMYK image format. | |
| pDstCMYK[4] | Pointer to destination image ROI for CMYK image format (four-channel planar). | |
| pDstCurrPos | Pointer to the shift value at the current destination buffer in bytes. | |
| pDstMCU[3] | Array of pointers to destination MCU image blocks. | |
| pDstMCU[4] | Array of pointers to destination MCU image blocks. | |
| pDstRGB | Pointer to destination image ROI for RGB image format. | |
| pDstRGB[3] | Pointer to destination image ROI for RGB image format (three-channel planar). | |
| pDstY | Pointer to destination image ROI for grayscale image format. | |
| pDstYCCK[4] | Pointer to destination image ROI for YCCK image format (four-channel planar). | |
| pDstYCbCr[3] | Pointer to destination image ROI for YCbCr image format (three-channel planar). | |
| pEncHuffSpec | Pointer to the FwiEncodeHuffmanSpec structure. | |
| pEncHuffState | Pointer to the FwiEncodeHuffmanState structure. | |
| pLastDC | Pointer to the last DC coefficient, which is in the previous 8X8 block. | |
| pListBits | Pointer to the Bits list. | |
| pListVals | Pointer to the Vals list. | |
| pMarker | Pointer to the JPEG marker position. | |
| pNumValidPrefetchedBits | Pointer to the value of valid bits in the prefetched buffer. | |
| pPrefetchedBits | Pointer to the prefetched buffer, which contains decoded data from the previous block. | |
| pQuantFwdTable | Pointer to the forward quantization table (encoder). | |
| pQuantInvTable | Pointer to the inverse quantization table (decoder). | |
| pQuantRawTable | Pointer to the raw quantization table. | |
| pSize | Pointer to the size of an internal structure. | |
| pSrc | Pointer to a location in a source buffer. | |
| pSrc1 | Pointer to a location in source buffer one. | |
| pSrc2 | Pointer to a location in source buffer two. | |
| pSrcBGR | Pointer to source image ROI for BGR image format. | |
| pSrcBitsLen | Pointer to the source buffer length in bits. | |
| pSrcCMYK | Pointer to source image ROI for CMYK image format. | |
| pSrcCMYK[4] | Pointer to source image ROI for CMYK image format (four-channel planar). | |
| pSrcCurrPos | Pointer to the shift value at the current source buffer in bytes. | |
| pSrcDst | Pointer to a location in a buffer that contains both the source and destination. | |
| pSrcMCU[3] | Array of pointers to source MCU image blocks. | |
| pSrcMCU[4] | Array of pointers to source MCU image blocks. | |
| pSrcRGB | Pointer to source image ROI for RGB image format. | |
| pSrcRGB[3] | Pointer to source image ROI for RGB image format (three-channel planar). | |
| pSrcYCCK[4] | Pointer to source image ROI for YCCK image format (four-channel planar). | |
| pSrcYCbCr[3] | Pointer to source image ROI for YCbCr image format (three-channel planar). | |
| pStatistics[256] | Pointer to Huffman symbol statistics. | |
| qualityFactor | JPEG image quality factor (value between 1 and 100). | |
| roiSize | Specifies the height and width of an ROI. | |
| srcLenBytes | Source buffer length in bytes. | |
| srcSize | Source image size. | |
| srcStep | Source buffer step size (width of the buffer in bytes). | |
| srcWidth | Width of the source row in pixels. |