From: sgunderson@bigfoot.com <>
Date: Sun, 3 Feb 2008 17:13:18 +0000 (+0100)
Subject: Fix behavior for input images not aligned on a DCT block.
X-Git-Url: https://git.sesse.net/?p=qscale;a=commitdiff_plain;h=a4cf4da6be7ca6f7929a1c26d2d7968956871334

Fix behavior for input images not aligned on a DCT block.
---

diff --git a/qscale.c b/qscale.c
index 54985cc..8ceb53e 100644
--- a/qscale.c
+++ b/qscale.c
@@ -38,7 +38,7 @@ struct pix_desc {
 	unsigned startcoeff;
 };
 
-void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw, unsigned dstride)
+void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw, unsigned sstride, unsigned dstride)
 {
 	struct pix_desc *pd = (struct pix_desc *)malloc(nw * sizeof(struct pix_desc));
 	int size_coeffs = 8;
@@ -97,7 +97,7 @@ void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw
 	}
 	
 	for (y = 0; y < h; ++y) {
-		float *sptr = pix + y*w;
+		float *sptr = pix + y*sstride;
 		unsigned char *dptr = npix + y*dstride;
 		unsigned char ch;
 		for (x = 0; x < nw; ++x) {
@@ -352,6 +352,10 @@ int main(int argc, char **argv)
 	dinfo.raw_data_out = TRUE;
 	jpeg_start_decompress(&dinfo);
 
+	unsigned w0 = dinfo.image_width * samp_h0 / max_samp_h, h0 = dinfo.image_height * samp_v0 / max_samp_v;
+	unsigned w1 = dinfo.image_width * samp_h1 / max_samp_h, h1 = dinfo.image_height * samp_v1 / max_samp_v;
+	unsigned w2 = dinfo.image_width * samp_h2 / max_samp_h, h2 = dinfo.image_height * samp_v2 / max_samp_v;
+
 	fprintf(stderr, "Scaling using Lanczos filter:\n");
 	fprintf(stderr, "  Y component: %ux%u -> %ux%u\n", dinfo.comp_info[0].width_in_blocks * DCTSIZE, dinfo.comp_info[0].height_in_blocks * DCTSIZE, nw0, nh0);
 	fprintf(stderr, "  Cb component: %ux%u -> %ux%u\n", dinfo.comp_info[1].width_in_blocks * DCTSIZE, dinfo.comp_info[1].height_in_blocks * DCTSIZE, nw1, nh1);
@@ -387,23 +391,23 @@ int main(int argc, char **argv)
 
 	{
 		float *npix = (float*)memalign(16, dinfo.comp_info[0].width_in_blocks * DCTSIZE * nh0 * sizeof(float));	
-		vscale(data_y, npix, dinfo.comp_info[0].width_in_blocks * DCTSIZE, dinfo.comp_info[0].height_in_blocks * DCTSIZE, nh0, dinfo.comp_info[0].width_in_blocks * DCTSIZE);
+		vscale(data_y, npix, dinfo.comp_info[0].width_in_blocks * DCTSIZE, h0, nh0, dinfo.comp_info[0].width_in_blocks * DCTSIZE);
 		data_ny = (unsigned char *)malloc(nw0 * stride0);
-		hscale(npix, data_ny, dinfo.comp_info[0].width_in_blocks * DCTSIZE, nh0, nw0, stride0);
+		hscale(npix, data_ny, w0, nh0, nw0, dinfo.comp_info[0].width_in_blocks * DCTSIZE, stride0);
 		free(npix);
 	}
 	{
 		float *npix = (float*)memalign(16, dinfo.comp_info[1].width_in_blocks * DCTSIZE * nh1 * sizeof(float));	
-		vscale(data_cr, npix, dinfo.comp_info[1].width_in_blocks * DCTSIZE, dinfo.comp_info[1].height_in_blocks * DCTSIZE, nh1, dinfo.comp_info[1].width_in_blocks * DCTSIZE);
+		vscale(data_cr, npix, dinfo.comp_info[1].width_in_blocks * DCTSIZE, h1, nh1, dinfo.comp_info[1].width_in_blocks * DCTSIZE);
 		data_ncr = (unsigned char *)malloc(nw1 * stride1);
-		hscale(npix, data_ncr, dinfo.comp_info[1].width_in_blocks * DCTSIZE, nh1, nw1, stride1);
+		hscale(npix, data_ncr, w1, nh1, nw1, dinfo.comp_info[1].width_in_blocks * DCTSIZE, stride1);
 		free(npix);
 	}
 	{
 		float *npix = (float*)memalign(16, dinfo.comp_info[2].width_in_blocks * DCTSIZE * nh2 * sizeof(float));	
-		vscale(data_cb, npix, dinfo.comp_info[2].width_in_blocks * DCTSIZE, dinfo.comp_info[2].height_in_blocks * DCTSIZE, nh2, dinfo.comp_info[2].width_in_blocks * DCTSIZE);
+		vscale(data_cb, npix, dinfo.comp_info[2].width_in_blocks * DCTSIZE, h2, nh2, dinfo.comp_info[2].width_in_blocks * DCTSIZE);
 		data_ncb = (unsigned char *)malloc(nw2 * stride2);
-		hscale(npix, data_ncb, dinfo.comp_info[2].width_in_blocks * DCTSIZE, nh2, nw2, stride2);
+		hscale(npix, data_ncb, w2, nh2, nw2, dinfo.comp_info[2].width_in_blocks * DCTSIZE, stride2);
 		free(npix);
 	}
 	jpeg_destroy_decompress(&dinfo);