X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=qscale.c;h=6da1b390ab5ca46616c1dea74a10d96082a4c455;hb=07342f6e7cf83fbf6707ec370c22431e98b62fd7;hp=c847a12122cc38e1deb80fe3e4c75a60c6d27428;hpb=82b2da83a6924b542e0cc399437ad848315ed8c5;p=qscale

diff --git a/qscale.c b/qscale.c
index c847a12..6da1b39 100644
--- a/qscale.c
+++ b/qscale.c
@@ -1,390 +1,40 @@
+/*
+ * qscale: Quick, high-quality JPEG-to-JPEG scaler.
+ * Copyright (C) 2008 Steinar H. Gunderson <sgunderson@bigfoot.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
 #include <stdio.h>
-#include <math.h>
-#include <string.h>
 #include <stdlib.h>
-#include "jpeglib.h"
-
-#define CACHE_LINE_FACTOR 8
-
-double sinc(double x)
-{
-	// This is bad for very small x, should use power series instead.
-	if (x == 0.0)
-		return 1.0;
-	else
-		return sin(x) / x;
-}
-
-double lanczos_tap(double x)
-{
-	if (x < -3.0 || x > 3.0)
-		return 0.0;
-	if (x < 0.0)
-		return sinc(-x*M_PI) * sinc(-x*M_PI / 3.0);
-	else
-		return sinc(x*M_PI) * sinc(x*M_PI / 3.0);
-}
-
-struct filter {
-	struct pix_desc *pd;
-	float *coeffs;
-};
-struct pix_desc {
-	unsigned start, end;
-	unsigned startcoeff;
-};
-
-void hscale_calc_filter(struct filter *filter, unsigned w, unsigned h, unsigned nw)
-{
-	struct pix_desc *pd = (struct pix_desc *)malloc(nw * sizeof(struct pix_desc));
-	int size_coeffs = 8;
-	float *coeffs = (float *)malloc(size_coeffs * sizeof(float));
-	int num_coeffs = 0;
-	int x, sx;
-	double sf = (double)w / (double)nw;
-	double support = (w > nw) ? (3.0 * sf) : (3.0 / sf);
-	
-	/* calculate the filter */
-	for (x = 0; x < nw; ++x) {
-		int start = ceil(x * sf - support);
-		int end = floor(x * sf + support);
-		double sum = 0.0;
-
-		if (start < 0) {
-			start = 0;
-		}
-		if (end > w - 1) {
-			end = w - 1;
-		}
-
-		pd[x].start = start;
-		pd[x].end = end;
-		pd[x].startcoeff = num_coeffs;
-
-		for (sx = start; sx <= end; ++sx) {
-			double nd = (w > nw) ? (sx/sf - x) : (sx - x*sf);
-			double f = lanczos_tap(nd);
-			if (num_coeffs == size_coeffs) {
-				size_coeffs <<= 1;
-				coeffs = (float *)realloc(coeffs, size_coeffs * sizeof(float));
-			}
-		
-			coeffs[num_coeffs++] = f;
-			sum += f;
-		}
-
-		for (sx = start; sx <= end; ++sx) {
-			coeffs[pd[x].startcoeff + sx - start] /= sum;
-		}
-	}
-
-	filter->pd = pd;
-	filter->coeffs = coeffs;
-}
-
-void hscale(struct filter *filter, unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nw, unsigned sstride, unsigned dstride)
-{
-	struct pix_desc *pd = filter->pd;
-	float *coeffs = filter->coeffs;
-	int y;
-
-	for (y = 0; y < h; ++y) {
-		unsigned char *sptr = pix + y*sstride;
-		float *dptr = npix + y*dstride;
-		float acc = 0.0;
-		int x;
-		for (x = 0; x < nw; ++x) {
-			float *cf = &coeffs[pd[x].startcoeff];
-			unsigned sx;
-			acc = 0.0;
-			
-			for (sx = pd[x].start; sx <= pd[x].end; ++sx) {
-				acc += sptr[sx] * *cf++;
-			}
-			*dptr++ = acc;
-		}
-		for ( ; x < dstride; ++x) {
-			*dptr++ = acc;
-		}
-	}
-}
-
-void vscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nh, unsigned dstride)
-{
-	struct pix_desc *pd = (struct pix_desc *)malloc(nh * sizeof(struct pix_desc));
-	int size_coeffs = 8;
-	float *coeffs = (float *)malloc(size_coeffs * sizeof(float));
-	int num_coeffs = 0;
-	int x, y, sy;
-	double sf = (double)h / (double)nh;
-	double support = (h > nh) ? (3.0 * sf) : (3.0 / sf);
-
-	/* calculate the filter */
-	for (y = 0; y < nh; ++y) {
-		int start = ceil(y * sf - support);
-		int end = floor(y * sf + support);
-		double sum = 0.0;
-
-		if (start < 0) {
-			start = 0;
-		}
-		if (end > h - 1) {
-			end = h - 1;
-		}
-
-		pd[y].start = start;
-		pd[y].end = end;
-		pd[y].startcoeff = num_coeffs;
-
-		for (sy = start; sy <= end; ++sy) {
-			double nd = (h > nh) ? (sy/sf - y) : (sy - y*sf);
-			double f = lanczos_tap(nd);
-			if (num_coeffs == size_coeffs) {
-				size_coeffs <<= 1;
-				coeffs = (float *)realloc(coeffs, size_coeffs * sizeof(float));
-			}
-			
-			coeffs[num_coeffs++] = f;
-			sum += f;
-		}
-
-		for (sy = start; sy <= end; ++sy) {
-			coeffs[pd[y].startcoeff + sy - start] /= sum;
-		}
-	}
-
-#if CACHE_LINE_FACTOR > 1
-	for (x = 0; x < w; x += CACHE_LINE_FACTOR) {
-		float *sptr = pix + x;
-		unsigned char *dptr = npix + x;
-		for (y = 0; y < nh; ++y) {
-			int i;
-			float acc[CACHE_LINE_FACTOR];
-			for (i = 0; i < CACHE_LINE_FACTOR; ++i)
-				acc[i] = 0.0;
-			float *cf = &coeffs[pd[y].startcoeff];
-			unsigned sy;
-			
-			for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
-				for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
-					acc[i] += sptr[sy * w + i] * *cf;
-				}
-				++cf;
-			}
-
-			for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
-				unsigned char ch;
-				if (acc[i] < 0.0)
-					ch = 0;
-				else if (acc[i] > 255.0)
-					ch = 255;
-				else
-					ch = (unsigned char)acc[i];
-				dptr[i] = ch;
-			}
-			dptr += dstride;
-		}
-	}
-	for (x = (x/CACHE_LINE_FACTOR)*CACHE_LINE_FACTOR; x < w; ++x) {
-#else
-	for (x = 0; x < w; ++x) {
-#endif
-		float *sptr = pix + x;
-		unsigned char *dptr = npix + x;
-		for (y = 0; y < nh; ++y) {
-			float acc = 0.0;
-			float *cf = &coeffs[pd[y].startcoeff];
-			unsigned sy;
-			
-			for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
-				acc += sptr[sy * w] * *cf++;
-			}
-
-			unsigned char ch;
-			if (acc < 0.0)
-				ch = 0;
-			else if (acc > 255.0)
-				ch = 255;
-			else
-				ch = (unsigned char)acc;
-			*dptr = ch;
-			dptr += dstride;
-		}
-	}
-}
+#include "libqscale.h"
 
 int main(int argc, char **argv)
 {
+	/* user-settable parameters */
 	unsigned nominal_w = atoi(argv[1]);
 	unsigned nominal_h = atoi(argv[2]);
-
 	unsigned samp_h0 = 2, samp_v0 = 2;
 	unsigned samp_h1 = 1, samp_v1 = 1;
 	unsigned samp_h2 = 1, samp_v2 = 1;
-	unsigned max_samp_h = 2, max_samp_v = 2;
-
-	unsigned nw0 = nominal_w * samp_h0 / max_samp_h, nh0 = nominal_h * samp_v0 / max_samp_v;
-	unsigned nw1 = nominal_w * samp_h1 / max_samp_h, nh1 = nominal_h * samp_v1 / max_samp_v;
-	unsigned nw2 = nominal_w * samp_h2 / max_samp_h, nh2 = nominal_h * samp_v2 / max_samp_v;
-
-	unsigned stride0 = (nw0 + DCTSIZE-1) & ~(DCTSIZE-1);
-	unsigned stride1 = (nw1 + DCTSIZE-1) & ~(DCTSIZE-1);
-	unsigned stride2 = (nw2 + DCTSIZE-1) & ~(DCTSIZE-1);
-
-	struct jpeg_decompress_struct dinfo;
-	struct jpeg_error_mgr jerr;
-	dinfo.err = jpeg_std_error(&jerr);
-	jpeg_create_decompress(&dinfo);
-	jpeg_stdio_src(&dinfo, stdin);
-	jpeg_read_header(&dinfo, TRUE);
-	dinfo.raw_data_out = TRUE;
-	jpeg_start_decompress(&dinfo);
-
-	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);
-	fprintf(stderr, "  Cr component: %ux%u -> %ux%u\n", dinfo.comp_info[2].width_in_blocks * DCTSIZE, dinfo.comp_info[2].height_in_blocks * DCTSIZE, nw2, nh2);
-		
-	float *npix_y  = (float *)malloc((dinfo.comp_info[0].height_in_blocks + dinfo.comp_info[0].v_samp_factor - 1) * DCTSIZE * stride0 * sizeof(float));
-	float *npix_cb = (float *)malloc((dinfo.comp_info[1].height_in_blocks + dinfo.comp_info[1].v_samp_factor - 1) * DCTSIZE * stride1 * sizeof(float));
-	float *npix_cr = (float *)malloc((dinfo.comp_info[2].height_in_blocks + dinfo.comp_info[2].v_samp_factor - 1) * DCTSIZE * stride2 * sizeof(float));
-	JSAMPLE *data_y  = (unsigned char *)malloc(nh0 * stride0);
-	JSAMPLE *data_cb = (unsigned char *)malloc(nh1 * stride1);
-	JSAMPLE *data_cr = (unsigned char *)malloc(nh2 * stride2);
-
-	struct filter filt0, filt1, filt2;
-
-	hscale_calc_filter(&filt0,
-		/* w=       */ dinfo.image_width * dinfo.comp_info[0].h_samp_factor / dinfo.max_h_samp_factor,
-		/* h=       */ dinfo.comp_info[0].v_samp_factor * DCTSIZE,
-		/* nw=      */ nw0
-	);
-	hscale_calc_filter(&filt1,
-		/* w=       */ dinfo.image_width * dinfo.comp_info[1].h_samp_factor / dinfo.max_h_samp_factor,
-		/* h=       */ dinfo.comp_info[1].v_samp_factor * DCTSIZE,
-		/* nw=      */ nw1
-	);
-	hscale_calc_filter(&filt2,
-		/* w=       */ dinfo.image_width * dinfo.comp_info[2].h_samp_factor / dinfo.max_h_samp_factor,
-		/* h=       */ dinfo.comp_info[2].v_samp_factor * DCTSIZE,
-		/* nw=      */ nw2
-	);
-
-	int total_lines = 0, blocks = 0;
-	while (total_lines < dinfo.comp_info[0].height_in_blocks * DCTSIZE) {
-		unsigned max_lines = dinfo.max_v_samp_factor * DCTSIZE;
-		JSAMPLE tmp_y [(dinfo.comp_info[0].width_in_blocks * DCTSIZE) * (DCTSIZE * dinfo.comp_info[0].v_samp_factor)];
-		JSAMPLE tmp_cb[(dinfo.comp_info[1].width_in_blocks * DCTSIZE) * (DCTSIZE * dinfo.comp_info[1].v_samp_factor)];
-		JSAMPLE tmp_cr[(dinfo.comp_info[2].width_in_blocks * DCTSIZE) * (DCTSIZE * dinfo.comp_info[2].v_samp_factor)];
-
-		JSAMPROW y_row_ptrs[max_lines];
-		JSAMPROW cb_row_ptrs[max_lines];
-		JSAMPROW cr_row_ptrs[max_lines];
-		JSAMPROW* ptrs[] = { y_row_ptrs, cb_row_ptrs, cr_row_ptrs };
-		int i;
-
-		for (i = 0; i < max_lines; ++i) {
-			y_row_ptrs[i]  = tmp_y  + i * dinfo.comp_info[0].width_in_blocks * DCTSIZE;
-			cb_row_ptrs[i] = tmp_cb + i * dinfo.comp_info[1].width_in_blocks * DCTSIZE;
-			cr_row_ptrs[i] = tmp_cr + i * dinfo.comp_info[2].width_in_blocks * DCTSIZE;
-		}
-		
-		int lines = jpeg_read_raw_data(&dinfo, ptrs, max_lines);
-		if (lines == 0)
-			break;
-
-		hscale(/* filter=  */ &filt0,
-		       /* from=    */ tmp_y, 
-		       /* to=      */ npix_y + blocks * DCTSIZE * dinfo.comp_info[0].v_samp_factor * stride0,
-		       /* w=       */ dinfo.image_width * dinfo.comp_info[0].h_samp_factor / dinfo.max_h_samp_factor,
-		       /* h=       */ dinfo.comp_info[0].v_samp_factor * DCTSIZE,
-		       /* nw=      */ nw0,
-		       /* sstride= */ dinfo.comp_info[0].width_in_blocks * DCTSIZE,
-		       /* dstride= */ stride0);
-
-		hscale(/* filter=  */ &filt1,
-		       /* from=    */ tmp_cb, 
-		       /* to=      */ npix_cb + blocks * DCTSIZE * dinfo.comp_info[1].v_samp_factor * stride1,
-		       /* w=       */ dinfo.image_width * dinfo.comp_info[1].h_samp_factor / dinfo.max_h_samp_factor,
-		       /* h=       */ dinfo.comp_info[1].v_samp_factor * DCTSIZE,
-		       /* nw=      */ nw1,
-		       /* sstride= */ dinfo.comp_info[1].width_in_blocks * DCTSIZE,
-		       /* dstride= */ stride1);
-
-		hscale(/* filter=  */ &filt2,
-		       /* from=    */ tmp_cr, 
-		       /* to=      */ npix_cr + blocks * DCTSIZE * dinfo.comp_info[2].v_samp_factor * stride2,
-		       /* w=       */ dinfo.image_width * dinfo.comp_info[2].h_samp_factor / dinfo.max_h_samp_factor,
-		       /* h=       */ dinfo.comp_info[2].v_samp_factor * DCTSIZE,
-		       /* nw=      */ nw2,
-		       /* sstride= */ dinfo.comp_info[2].width_in_blocks * DCTSIZE,
-		       /* dstride= */ stride2);
-		
-		total_lines += max_lines;
-		++blocks;
-	}
-
-	vscale(npix_y,  data_y,  stride0, dinfo.image_height * dinfo.comp_info[0].v_samp_factor / dinfo.max_v_samp_factor, nh0, stride0);
-	vscale(npix_cb, data_cb, stride1, dinfo.image_height * dinfo.comp_info[1].v_samp_factor / dinfo.max_v_samp_factor, nh1, stride1);
-	vscale(npix_cr, data_cr, stride2, dinfo.image_height * dinfo.comp_info[2].v_samp_factor / dinfo.max_v_samp_factor, nh2, stride2);
-	jpeg_destroy_decompress(&dinfo);
-	
-	struct jpeg_compress_struct cinfo;
-	cinfo.err = jpeg_std_error(&jerr);
-	jpeg_create_compress(&cinfo);
-	jpeg_stdio_dest(&cinfo, stdout);
-	cinfo.input_components = 3;
-	jpeg_set_defaults(&cinfo);
-	jpeg_set_quality(&cinfo, 85, FALSE);
-	cinfo.image_width = nominal_w;
-	cinfo.image_height = nominal_h;
-	cinfo.raw_data_in = TRUE;
-	jpeg_set_colorspace(&cinfo, JCS_YCbCr);
-	cinfo.comp_info[0].h_samp_factor = samp_h0;
-	cinfo.comp_info[0].v_samp_factor = samp_v0;
-	cinfo.comp_info[1].h_samp_factor = samp_h1;
-	cinfo.comp_info[1].v_samp_factor = samp_v1;
-	cinfo.comp_info[2].h_samp_factor = samp_h2;
-	cinfo.comp_info[2].v_samp_factor = samp_v2;
-	jpeg_start_compress(&cinfo, TRUE);
-
-	total_lines = 0;
-	blocks = 0;
-	while (total_lines < cinfo.comp_info[0].height_in_blocks * DCTSIZE) {
-		unsigned max_lines = cinfo.max_v_samp_factor * DCTSIZE;
-
-		JSAMPROW y_row_ptrs[max_lines];
-		JSAMPROW cb_row_ptrs[max_lines];
-		JSAMPROW cr_row_ptrs[max_lines];
-		JSAMPROW* ptrs[] = { y_row_ptrs, cb_row_ptrs, cr_row_ptrs };
-		int i;
-
-		for (i = 0; i < max_lines; ++i) {
-			// simple edge extension
-			int yline = i + blocks*DCTSIZE*cinfo.comp_info[0].v_samp_factor;
-			if (yline > nh0 - 1)
-				yline = nh0 - 1;
-
-			int cbline = i + blocks*DCTSIZE*cinfo.comp_info[1].v_samp_factor;
-			if (cbline > nh1 - 1)
-				cbline = nh1 - 1;
-
-			int crline = i + blocks*DCTSIZE*cinfo.comp_info[2].v_samp_factor;
-			if (crline > nh2 - 1)
-				crline = nh2 - 1;
-
-			y_row_ptrs[i]  = data_y  + yline * stride0;
-			cb_row_ptrs[i] = data_cb + cbline * stride1;
-			cr_row_ptrs[i] = data_cr + crline * stride2;
-		}
-		
-		total_lines += max_lines;
-		++blocks;
+	unsigned jpeg_quality = 85;
+	/* end */
 
-		jpeg_write_raw_data(&cinfo, ptrs, max_lines);
-	}
-	jpeg_finish_compress(&cinfo);
-	jpeg_destroy_compress(&cinfo);
+	qscale_img *img = qscale_load_jpeg_from_stdio(stdin);
+	qscale_img *scaled = qscale_scale(img, nominal_w, nominal_h, samp_h0, samp_v0, samp_h1, samp_v1, samp_h2, samp_v2, LANCZOS);
+	qscale_destroy(img);
+	qscale_save_jpeg_to_stdio(scaled, stdout, jpeg_quality, SEQUENTIAL);
 
 	return 0;
 }