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Definition at line 53 of file jcmaster.c. Referenced by initial_setup(). {
#ifdef DCT_SCALING_SUPPORTED
/* Sanity check on input image dimensions to prevent overflow in
* following calculation.
* We do check jpeg_width and jpeg_height in initial_setup below,
* but image_width and image_height can come from arbitrary data,
* and we need some space for multiplication by block_size.
*/
if (((long) cinfo->image_width >> 24) || ((long) cinfo->image_height >> 24))
ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
/* Compute actual JPEG image dimensions and DCT scaling choices. */
if (cinfo->scale_num >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/1 scaling */
cinfo->jpeg_width = cinfo->image_width * cinfo->block_size;
cinfo->jpeg_height = cinfo->image_height * cinfo->block_size;
cinfo->min_DCT_h_scaled_size = 1;
cinfo->min_DCT_v_scaled_size = 1;
} else if (cinfo->scale_num * 2 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/2 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 2L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 2L);
cinfo->min_DCT_h_scaled_size = 2;
cinfo->min_DCT_v_scaled_size = 2;
} else if (cinfo->scale_num * 3 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/3 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 3L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 3L);
cinfo->min_DCT_h_scaled_size = 3;
cinfo->min_DCT_v_scaled_size = 3;
} else if (cinfo->scale_num * 4 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/4 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 4L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 4L);
cinfo->min_DCT_h_scaled_size = 4;
cinfo->min_DCT_v_scaled_size = 4;
} else if (cinfo->scale_num * 5 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/5 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 5L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 5L);
cinfo->min_DCT_h_scaled_size = 5;
cinfo->min_DCT_v_scaled_size = 5;
} else if (cinfo->scale_num * 6 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/6 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 6L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 6L);
cinfo->min_DCT_h_scaled_size = 6;
cinfo->min_DCT_v_scaled_size = 6;
} else if (cinfo->scale_num * 7 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/7 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 7L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 7L);
cinfo->min_DCT_h_scaled_size = 7;
cinfo->min_DCT_v_scaled_size = 7;
} else if (cinfo->scale_num * 8 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/8 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 8L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 8L);
cinfo->min_DCT_h_scaled_size = 8;
cinfo->min_DCT_v_scaled_size = 8;
} else if (cinfo->scale_num * 9 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/9 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 9L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 9L);
cinfo->min_DCT_h_scaled_size = 9;
cinfo->min_DCT_v_scaled_size = 9;
} else if (cinfo->scale_num * 10 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/10 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 10L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 10L);
cinfo->min_DCT_h_scaled_size = 10;
cinfo->min_DCT_v_scaled_size = 10;
} else if (cinfo->scale_num * 11 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/11 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 11L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 11L);
cinfo->min_DCT_h_scaled_size = 11;
cinfo->min_DCT_v_scaled_size = 11;
} else if (cinfo->scale_num * 12 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/12 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 12L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 12L);
cinfo->min_DCT_h_scaled_size = 12;
cinfo->min_DCT_v_scaled_size = 12;
} else if (cinfo->scale_num * 13 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/13 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 13L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 13L);
cinfo->min_DCT_h_scaled_size = 13;
cinfo->min_DCT_v_scaled_size = 13;
} else if (cinfo->scale_num * 14 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/14 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 14L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 14L);
cinfo->min_DCT_h_scaled_size = 14;
cinfo->min_DCT_v_scaled_size = 14;
} else if (cinfo->scale_num * 15 >= cinfo->scale_denom * cinfo->block_size) {
/* Provide block_size/15 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 15L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 15L);
cinfo->min_DCT_h_scaled_size = 15;
cinfo->min_DCT_v_scaled_size = 15;
} else {
/* Provide block_size/16 scaling */
cinfo->jpeg_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 16L);
cinfo->jpeg_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 16L);
cinfo->min_DCT_h_scaled_size = 16;
cinfo->min_DCT_v_scaled_size = 16;
}
#else /* !DCT_SCALING_SUPPORTED */
/* Hardwire it to "no scaling" */
cinfo->jpeg_width = cinfo->image_width;
cinfo->jpeg_height = cinfo->image_height;
cinfo->min_DCT_h_scaled_size = DCTSIZE;
cinfo->min_DCT_v_scaled_size = DCTSIZE;
#endif /* DCT_SCALING_SUPPORTED */
}
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Generated on Mon May 28 2012 04:49:20 for ReactOS by
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