cdesktopenv/cde/lib/DtHelp/il/iljpgencode.c

286 lines
12 KiB
C

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/* $XConsortium: iljpgencode.c /main/3 1995/10/23 15:55:46 rswiston $ */
/**---------------------------------------------------------------------
***
*** (c)Copyright 1992 Hewlett-Packard Co.
***
*** RESTRICTED RIGHTS LEGEND
*** Use, duplication, or disclosure by the U.S. Government is subject to
*** restrictions as set forth in sub-paragraph (c)(1)(ii) of the Rights in
*** Technical Data and Computer Software clause in DFARS 252.227-7013.
*** Hewlett-Packard Company
*** 3000 Hanover Street
*** Palo Alto, CA 94304 U.S.A.
*** Rights for non-DOD U.S. Government Departments and Agencies are as set
*** forth in FAR 52.227-19(c)(1,2).
***
***-------------------------------------------------------------------*/
#include "iljpgencodeint.h"
/* -------------------- iljpgEncodeInit -------------------------- */
/* Init for JPEG encoding and return ptr to private block.
*/
ILJPG_PUBLIC
iljpgError iljpgEncodeInit (
iljpgDataPtr pData,
iljpgPtr *pPrivate /* RETURNED */
)
{
iljpgEncodePrivPtr pPriv;
iljpgECompPtr pComp;
iljpgCompDataPtr pCompData;
int comp;
iljpgError error;
unsigned int index, i;
/* Validate *pData: valid hori/vertFactor, tables present, etc. */
if (!_iljpgValidPars (pData))
return ILJPG_ERROR_ENCODE_PARS;
/* Allocate and return private block */
pPriv = (iljpgEncodePrivPtr)ILJPG_MALLOC_ZERO (sizeof (iljpgEncodePrivRec));
if (!pPriv)
return ILJPG_ERROR_ENCODE_MALLOC;
pPriv->pData = pData;
*pPrivate = (iljpgPtr)pPriv;
/* For DCT encoding, get and store into private a
scaled version of each Q table.
*/
for (i = 0; i < 4; i++)
pPriv->DCTScaleTables[i] = (float *)NULL;
for (i = 0; i < 4; i++) {
if (pData->QTables[i]) {
if (!(pPriv->DCTScaleTables[i] = (float *)ILJPG_MALLOC(sizeof(float) * 64)))
return ILJPG_ERROR_ENCODE_MALLOC;
if (error = _iljpgEnDCTScale (pData->QTables[i], pPriv->DCTScaleTables[i]))
return error;
}
}
/* Init Huffman encoding */
if (error = _iljpgEnhuffInit (pPriv))
return error;
/* Setup static part of per-comp data; copy from other places */
for (comp = 0, pCompData = pData->comp, pComp = pPriv->compData;
comp < pData->nComps; comp++, pCompData++, pComp++) {
pComp->pScale = pPriv->DCTScaleTables[pCompData->QTableIndex];
pComp->horiFactor = pCompData->horiFactor;
pComp->vertFactor = pCompData->vertFactor;
pComp->width = pData->width * pCompData->horiFactor / pData->maxHoriFactor;
pComp->mcuXInc = 8 * pCompData->horiFactor;
pComp->mcuYInc = 8 * pCompData->vertFactor;
}
return 0;
}
/* -------------------- iljpgEncodeCleanup -------------------------- */
/* Cleanup after JPEG encoding.
*/
ILJPG_PUBLIC
iljpgError iljpgEncodeCleanup (
iljpgPtr pPrivate
)
{
int i;
iljpgEncodePrivPtr pPriv;
iljpgError error;
/* Free any scaled Q tables created by Init() */
pPriv = (iljpgEncodePrivPtr)pPrivate;
for (i = 0; i < 4; i++)
if (pPriv->DCTScaleTables[i])
ILJPG_FREE (pPriv->DCTScaleTables[i]);
/* Cleanup Huffman */
error = _iljpgEnhuffCleanup(pPriv);
/* Free the given private data. Note that pPrivate->pData is not
freed; that is done when the caller calls iljpgFreeData().
*/
ILJPG_FREE (pPrivate);
return error;
}
/* -------------------- iljpgEncodeExecute -------------------------- */
/* Encode (compress) the pixels from the per-plane buffers pointed to
by "pSrcPixels": one ptr per component (# of components = "nComps" in
the iljpgData passed to iljpgEncodeInit()). "nSrcBytesPerRow" is length
of each row in the corresponding buffers in "pSrcPixels".
"pPrivate" is the ptr returned by iljpgEncodeInit().
"nSrcLines" is the # of lines to read; encoding stops when nSrcLines
lines have been encoded.
*/
ILJPG_PUBLIC
iljpgError iljpgEncodeExecute (
iljpgPtr pPrivate,
ILJPG_ENCODE_STREAM stream,
long nSrcLines,
iljpgPtr pSrcPixels[],
long nSrcBytesPerRow[]
)
{
iljpgEncodePrivPtr pPriv;
iljpgDataPtr pData;
iljpgECompPtr pComp;
iljpgPtr pPixels;
iljpgError error;
long nBytesPerRow, mcuMaxX, mcuMaxY, bX, bY;
int comp, v, h, mcuWidth, mcuHeight;
int pixels[64];
pPriv = (iljpgEncodePrivPtr)pPrivate;
pData = pPriv->pData;
/* Encode "interleaved" JPEG data, where all components are grouped together
in Minimum Coded Unit (MCU) size, = 8 * max hori(width) or vert(height)
factor. The "factors" are the inverse of IL subsample factors. For
example, if component 0 is not subsampled and 1 and 2 are subsampled by 2,
then hori/vertFactor for comp 0 is 2, for comps 1..2 is 1, and max hori/vert
factor is 2 (there are 4x as many comp 0 pixels as comps 1 or 2).
So: loop over y, and over x within y, and decode one MCU (all components),
advancing x by mcuWidth and y by mcuHeight.
*/
mcuWidth = 8 * pData->maxHoriFactor;
mcuHeight = 8 * pData->maxVertFactor;
/* Reset temp vars in comp data in private; "height" is size of one strip */
for (comp = 0, pComp = pPriv->compData; comp < pData->nComps; comp++, pComp++) {
pComp->height = nSrcLines * pComp->vertFactor / pData->maxVertFactor;
pComp->x = 0;
pComp->y = 0;
pComp->lastDC = 0; /* new strip; clear as if a reset/restart */
}
/* Loop over y, and over x within y, and encode one MCU (all components),
advancing x by mcuWidth and y by mcuHeight.
*/
for (mcuMaxY = 0; mcuMaxY < nSrcLines; mcuMaxY += mcuHeight) {
for (mcuMaxX = 0; mcuMaxX < pData->width; mcuMaxX += mcuWidth) {
/* Encode one MCU, all components, to (mcuX, mcuY). For each component
there are horiFactor * vertFactor 8x8 blocks that go across then down.
*/
for (comp = 0, pComp = pPriv->compData; comp < pData->nComps; comp++, pComp++) {
nBytesPerRow = nSrcBytesPerRow[comp];
pPixels = pSrcPixels[comp];
for (v = 0, bY = pComp->y; v < pComp->vertFactor; v++, bY += 8) {
for (h = 0, bX = pComp->x; h < pComp->horiFactor; h++, bX += 8) {
/* Extract one 8x8 block from position (bX, bY). If
clipped replicate pixel or above scan line out to 8x8.
*/
{ int nBytesInit;
int nLines, nBytesM1, *pDst, *pDstLine;
iljpgPtr pSrc, pSrcLine;
nLines = pComp->height - bY;
if (nLines > 8)
nLines = 8;
nBytesInit = pComp->width - bX;
if (nBytesInit > 8)
nBytesInit = 8;
if ((nLines > 0) && (nBytesInit > 0)) {
pSrcLine = pPixels + (bY * nBytesPerRow) + bX;
pDstLine = pixels;
/* If clipped; do nLines, replicate at right edge */
if ((nLines < 8) || (nBytesInit < 8)) {
int i, j, pixel;
for (i = 0; i < nLines; i++) {
pSrc = pSrcLine;
pSrcLine += nBytesPerRow;
pDst = pDstLine;
pDstLine += 8;
for (j = 0; j < nBytesInit; j++)
*pDst++ = pixel = *pSrc++;
for (j = nBytesInit; j < 8; j++)
*pDst++ = pixel; /* replicate right */
}
/* Replicate last dst line out to 8 lines */
pDst = pDstLine;
pDstLine -= 8; /* back up one line */
for (i = nLines; i < 8; i++) {
for (j = 0; j < 8; j++)
*pDst++ = pDstLine[j];
}
} /* END clipped */
else { /* all 8x8 available; do simple case */
nLines--; /* make # lines/bytes - 1 */
nBytesInit--;
do {
nBytesM1 = nBytesInit;
pSrc = pSrcLine;
pSrcLine += nBytesPerRow;
pDst = pDstLine;
pDstLine += 8;
do {
*pDst++ = *pSrc++;
} while (--nBytesM1 >= 0);
} while (--nLines >= 0);
}
}
}
/* Do DCT encoding, from "pixels" back into "pixels" */
_iljpgEnDCT (pixels, pComp->pScale);
/* Subtract previous DC from this one, save this one for next */
{ int dc;
dc = pixels[0];
pixels[0] = dc - pComp->lastDC;
pComp->lastDC = dc;
}
/* Do Huffman encoding of block */
if (error = _iljpgEnhuffExecute (pPriv, comp, pixels, stream))
return error;
} /* END hori, one 8x8 block */
} /* END vert */
pComp->x += pComp->mcuXInc; /* move component one MCU to right */
} /* END one component */
} /* END one hori MCU */
/* Move each component one MCU down, reset to left edge */
for (comp = 0, pComp = pPriv->compData; comp < pData->nComps; comp++, pComp++) {
pComp->y += pComp->mcuYInc;
pComp->x = 0;
}
} /* END one vert MCU */
/* Flush any bits not yet output from Huffman encoding and exit */
return _iljpgEnhuffFlush (pPriv, stream);
}