Decode progressive DC initial
FwStatus | fwiDecodeHuffman8x8_DCFirst_JPEG_1u16s_C1 | ( | const Fw8u * pSrc, int srcLenBytes, int * pSrcCurrPos, Fw16s * pDst, Fw16s * pLastDC, int * pMarker, int Al, const FwiDecodeHuffmanSpec * pDcTable, FwiDecodeHuffmanState * pDecHuffState ); |
Al | Progressive JPEG successive approximation parameter for actual point transform. | |
pDcTable | Pointer to the Huffman DC coefficient table. | |
pDecHuffState | Pointer to the FwiDecodeHuffmanState structure. | |
pDst | Pointer to a location in a destination buffer. | |
pLastDC | Pointer to the last DC coefficient, which is in the previous 8X8 block. | |
pMarker | Pointer to the JPEG marker position. | |
pSrc | Pointer to a location in a source buffer. | |
pSrcCurrPos | Pointer to the shift value at the current source buffer in bytes. | |
srcLenBytes | Source buffer length in bytes. |
This function performs the first scan for progressive decoding of the DC coefficient of an 8X8 data block.
The decoding process follows CCITT Rec. T.81, Annex G.2.2.
When the function detects a JPEG marker, it stops decoding and writes the marker to the location specified by pMarker.