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/*
* BEWARE OF KLUDGE: This subroutine is a hack for decoding illegal JPEG-in-
* TIFF encapsulations produced by Microsoft's Wang Imaging
* for Windows application with the public-domain TIFF Library. Based upon an
* examination of selected output files, this program apparently divides a JPEG
* bit-stream into consecutive horizontal TIFF "strips", such that the JPEG
* encoder's/decoder's DC coefficients for each image component are reset before
* each "strip". Moreover, a "strip" is not necessarily encoded in a multiple
* of 8 bits, so one must sometimes discard 1-7 bits at the end of each "strip"
* for alignment to the next input-Byte storage boundary. IJG JPEG Library
* decoder state is not normally exposed to client applications, so this sub-
* routine provides the TIFF Library with a "hook" to make these corrections.
* It should be called after "jpeg_start_decompress()" and before
* "jpeg_finish_decompress()", just before decoding each "strip" using
* "jpeg_read_raw_data()" or "jpeg_read_scanlines()".
*
* This kludge is not sanctioned or supported by the Independent JPEG Group, and
* future changes to the IJG JPEG Library might invalidate it. Do not send bug
* reports about this code to IJG developers. Instead, contact the author for
* advice: Scott B. Marovich <marovich@hpl.hp.com>, Hewlett-Packard Labs, 6/01.
*/
GLOBAL(void)
jpeg_reset_huff_decode (register j_decompress_ptr cinfo,register float *refbw)
{ register huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
register int ci = 0;
/* Re-initialize DC predictions */
do entropy->saved.last_dc_val[ci] = -refbw[ci << 1];
while (++ci < cinfo->comps_in_scan);
/* Discard encoded input bits, up to the next Byte boundary */
entropy->bitstate.bits_left &= ~7;
}
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