ryan/mozjpeg
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Calculate jpeg_simple_progression nscans correctly with respect to dc_scan_opt_mode

Browse Source
This commit is contained in:
Daniel Hugenroth
2017-04-21 17:23:50 +01:00
parent 41dd774c1f
commit 31d957d25a
1 changed files with 13 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
jcparam.c
View File

@@ -868,7 +868,13 @@ jpeg_simple_progression (j_compress_ptr cinfo)
ncomps = cinfo->num_components;
if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) {
/* Custom script for YCbCr color images. */
nscans = 10;
if (cinfo->master->dc_scan_opt_mode == 0) {
nscans = 8; /* 1 DC scan for all components */
} else if (cinfo->master->dc_scan_opt_mode == 1) {
nscans = 10; /* 1 DC scan for each component */
} else {
nscans = 9; /* 1 DC scan for luminance and 1 DC scan for chroma */
}
} else {
/* All-purpose script for other color spaces. */
if (cinfo->master->compress_profile == JCP_MAX_COMPRESSION) {
@@ -906,14 +912,16 @@ jpeg_simple_progression (j_compress_ptr cinfo)
if (cinfo->master->compress_profile == JCP_MAX_COMPRESSION) {
/* scan defined in jpeg_scan_rgb.txt in jpgcrush */
/* Initial DC scan */
if (cinfo->master->dc_scan_opt_mode == 0)
if (cinfo->master->dc_scan_opt_mode == 0) {
/* 1 DC scan for all components */
scanptr = fill_dc_scans(scanptr, ncomps, 0, 0);
else if (cinfo->master->dc_scan_opt_mode == 1) {
} else if (cinfo->master->dc_scan_opt_mode == 1) {
/* 1 DC scan for each component */
scanptr = fill_a_scan(scanptr, 0, 0, 0, 0, 0);
scanptr = fill_a_scan(scanptr, 1, 0, 0, 0, 0);
scanptr = fill_a_scan(scanptr, 2, 0, 0, 0, 0);
}
else {
} else {
/* 1 DC scan for luminance and 1 DC scan for chroma */
scanptr = fill_dc_scans(scanptr, 1, 0, 0);
scanptr = fill_a_scan_pair(scanptr, 1, 0, 0, 0, 0);
}