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media/libjpeg/jccolext.c@b8a032363ba2 (annotated)

media/libjpeg/jccolext.c

Thu, 22 Jan 2015 13:21:57 +0100

author

Michael Schloh von Bennewitz <michael@schloh.com>

date

Thu, 22 Jan 2015 13:21:57 +0100

branch

TOR_BUG_9701

changeset 15

b8a032363ba2

permissions

-rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

michael@0	1	/*
michael@0	2	* jccolext.c
michael@0	3	*
michael@0	4	* This file was part of the Independent JPEG Group's software:
michael@0	5	* Copyright (C) 1991-1996, Thomas G. Lane.
michael@0	6	* libjpeg-turbo Modifications:
michael@0	7	* Copyright (C) 2009-2012, D. R. Commander.
michael@0	8	* For conditions of distribution and use, see the accompanying README file.
michael@0	9	*
michael@0	10	* This file contains input colorspace conversion routines.
michael@0	11	*/
michael@0	12
michael@0	13
michael@0	14	/* This file is included by jccolor.c */
michael@0	15
michael@0	16
michael@0	17	/*
michael@0	18	* Convert some rows of samples to the JPEG colorspace.
michael@0	19	*
michael@0	20	* Note that we change from the application's interleaved-pixel format
michael@0	21	* to our internal noninterleaved, one-plane-per-component format.
michael@0	22	* The input buffer is therefore three times as wide as the output buffer.
michael@0	23	*
michael@0	24	* A starting row offset is provided only for the output buffer. The caller
michael@0	25	* can easily adjust the passed input_buf value to accommodate any row
michael@0	26	* offset required on that side.
michael@0	27	*/
michael@0	28
michael@0	29	INLINE
michael@0	30	LOCAL(void)
michael@0	31	rgb_ycc_convert_internal (j_compress_ptr cinfo,
michael@0	32	JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
michael@0	33	JDIMENSION output_row, int num_rows)
michael@0	34	{
michael@0	35	my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
michael@0	36	register int r, g, b;
michael@0	37	register INT32 * ctab = cconvert->rgb_ycc_tab;
michael@0	38	register JSAMPROW inptr;
michael@0	39	register JSAMPROW outptr0, outptr1, outptr2;
michael@0	40	register JDIMENSION col;
michael@0	41	JDIMENSION num_cols = cinfo->image_width;
michael@0	42
michael@0	43	while (--num_rows >= 0) {
michael@0	44	inptr = *input_buf++;
michael@0	45	outptr0 = output_buf[0][output_row];
michael@0	46	outptr1 = output_buf[1][output_row];
michael@0	47	outptr2 = output_buf[2][output_row];
michael@0	48	output_row++;
michael@0	49	for (col = 0; col < num_cols; col++) {
michael@0	50	r = GETJSAMPLE(inptr[RGB_RED]);
michael@0	51	g = GETJSAMPLE(inptr[RGB_GREEN]);
michael@0	52	b = GETJSAMPLE(inptr[RGB_BLUE]);
michael@0	53	inptr += RGB_PIXELSIZE;
michael@0	54	/* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
michael@0	55	* must be too; we do not need an explicit range-limiting operation.
michael@0	56	* Hence the value being shifted is never negative, and we don't
michael@0	57	* need the general RIGHT_SHIFT macro.
michael@0	58	*/
michael@0	59	/* Y */
michael@0	60	outptr0[col] = (JSAMPLE)
michael@0	61	((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
michael@0	62	>> SCALEBITS);
michael@0	63	/* Cb */
michael@0	64	outptr1[col] = (JSAMPLE)
michael@0	65	((ctab[r+R_CB_OFF] + ctab[g+G_CB_OFF] + ctab[b+B_CB_OFF])
michael@0	66	>> SCALEBITS);
michael@0	67	/* Cr */
michael@0	68	outptr2[col] = (JSAMPLE)
michael@0	69	((ctab[r+R_CR_OFF] + ctab[g+G_CR_OFF] + ctab[b+B_CR_OFF])
michael@0	70	>> SCALEBITS);
michael@0	71	}
michael@0	72	}
michael@0	73	}
michael@0	74
michael@0	75
michael@0	76	/**************** Cases other than RGB -> YCbCr **************/
michael@0	77
michael@0	78
michael@0	79	/*
michael@0	80	* Convert some rows of samples to the JPEG colorspace.
michael@0	81	* This version handles RGB->grayscale conversion, which is the same
michael@0	82	* as the RGB->Y portion of RGB->YCbCr.
michael@0	83	* We assume rgb_ycc_start has been called (we only use the Y tables).
michael@0	84	*/
michael@0	85
michael@0	86	INLINE
michael@0	87	LOCAL(void)
michael@0	88	rgb_gray_convert_internal (j_compress_ptr cinfo,
michael@0	89	JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
michael@0	90	JDIMENSION output_row, int num_rows)
michael@0	91	{
michael@0	92	my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
michael@0	93	register int r, g, b;
michael@0	94	register INT32 * ctab = cconvert->rgb_ycc_tab;
michael@0	95	register JSAMPROW inptr;
michael@0	96	register JSAMPROW outptr;
michael@0	97	register JDIMENSION col;
michael@0	98	JDIMENSION num_cols = cinfo->image_width;
michael@0	99
michael@0	100	while (--num_rows >= 0) {
michael@0	101	inptr = *input_buf++;
michael@0	102	outptr = output_buf[0][output_row];
michael@0	103	output_row++;
michael@0	104	for (col = 0; col < num_cols; col++) {
michael@0	105	r = GETJSAMPLE(inptr[RGB_RED]);
michael@0	106	g = GETJSAMPLE(inptr[RGB_GREEN]);
michael@0	107	b = GETJSAMPLE(inptr[RGB_BLUE]);
michael@0	108	inptr += RGB_PIXELSIZE;
michael@0	109	/* Y */
michael@0	110	outptr[col] = (JSAMPLE)
michael@0	111	((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
michael@0	112	>> SCALEBITS);
michael@0	113	}
michael@0	114	}
michael@0	115	}
michael@0	116
michael@0	117
michael@0	118	/*
michael@0	119	* Convert some rows of samples to the JPEG colorspace.
michael@0	120	* This version handles extended RGB->plain RGB conversion
michael@0	121	*/
michael@0	122
michael@0	123	INLINE
michael@0	124	LOCAL(void)
michael@0	125	rgb_rgb_convert_internal (j_compress_ptr cinfo,
michael@0	126	JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
michael@0	127	JDIMENSION output_row, int num_rows)
michael@0	128	{
michael@0	129	register JSAMPROW inptr;
michael@0	130	register JSAMPROW outptr0, outptr1, outptr2;
michael@0	131	register JDIMENSION col;
michael@0	132	JDIMENSION num_cols = cinfo->image_width;
michael@0	133
michael@0	134	while (--num_rows >= 0) {
michael@0	135	inptr = *input_buf++;
michael@0	136	outptr0 = output_buf[0][output_row];
michael@0	137	outptr1 = output_buf[1][output_row];
michael@0	138	outptr2 = output_buf[2][output_row];
michael@0	139	output_row++;
michael@0	140	for (col = 0; col < num_cols; col++) {
michael@0	141	outptr0[col] = GETJSAMPLE(inptr[RGB_RED]);
michael@0	142	outptr1[col] = GETJSAMPLE(inptr[RGB_GREEN]);
michael@0	143	outptr2[col] = GETJSAMPLE(inptr[RGB_BLUE]);
michael@0	144	inptr += RGB_PIXELSIZE;
michael@0	145	}
michael@0	146	}
michael@0	147	}