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-rw-r--r--libavcodec/imgresample.c614
1 files changed, 614 insertions, 0 deletions
diff --git a/libavcodec/imgresample.c b/libavcodec/imgresample.c
new file mode 100644
index 0000000000..99153013cf
--- /dev/null
+++ b/libavcodec/imgresample.c
@@ -0,0 +1,614 @@
+/*
+ * High quality image resampling with polyphase filters
+ * Copyright (c) 2001 Gerard Lantau.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#include "dsputil.h"
+#include "avcodec.h"
+
+#define NB_COMPONENTS 3
+
+#define PHASE_BITS 4
+#define NB_PHASES (1 << PHASE_BITS)
+#define NB_TAPS 4
+#define FCENTER 1 /* index of the center of the filter */
+
+#define POS_FRAC_BITS 16
+#define POS_FRAC (1 << POS_FRAC_BITS)
+/* 6 bits precision is needed for MMX */
+#define FILTER_BITS 8
+
+#define LINE_BUF_HEIGHT (NB_TAPS * 4)
+
+struct ImgReSampleContext {
+ int iwidth, iheight, owidth, oheight;
+ int h_incr, v_incr;
+ INT16 h_filters[NB_PHASES][NB_TAPS] __align8; /* horizontal filters */
+ INT16 v_filters[NB_PHASES][NB_TAPS] __align8; /* vertical filters */
+ UINT8 *line_buf;
+};
+
+static inline int get_phase(int pos)
+{
+ return ((pos) >> (POS_FRAC_BITS - PHASE_BITS)) & ((1 << PHASE_BITS) - 1);
+}
+
+/* This function must be optimized */
+static void h_resample_fast(UINT8 *dst, int dst_width, UINT8 *src, int src_width,
+ int src_start, int src_incr, INT16 *filters)
+{
+ int src_pos, phase, sum, i;
+ UINT8 *s;
+ INT16 *filter;
+
+ src_pos = src_start;
+ for(i=0;i<dst_width;i++) {
+#ifdef TEST
+ /* test */
+ if ((src_pos >> POS_FRAC_BITS) < 0 ||
+ (src_pos >> POS_FRAC_BITS) > (src_width - NB_TAPS))
+ abort();
+#endif
+ s = src + (src_pos >> POS_FRAC_BITS);
+ phase = get_phase(src_pos);
+ filter = filters + phase * NB_TAPS;
+#if NB_TAPS == 4
+ sum = s[0] * filter[0] +
+ s[1] * filter[1] +
+ s[2] * filter[2] +
+ s[3] * filter[3];
+#else
+ {
+ int j;
+ sum = 0;
+ for(j=0;j<NB_TAPS;j++)
+ sum += s[j] * filter[j];
+ }
+#endif
+ sum = sum >> FILTER_BITS;
+ if (sum < 0)
+ sum = 0;
+ else if (sum > 255)
+ sum = 255;
+ dst[0] = sum;
+ src_pos += src_incr;
+ dst++;
+ }
+}
+
+/* This function must be optimized */
+static void v_resample(UINT8 *dst, int dst_width, UINT8 *src, int wrap,
+ INT16 *filter)
+{
+ int sum, i;
+ UINT8 *s;
+
+ s = src;
+ for(i=0;i<dst_width;i++) {
+#if NB_TAPS == 4
+ sum = s[0 * wrap] * filter[0] +
+ s[1 * wrap] * filter[1] +
+ s[2 * wrap] * filter[2] +
+ s[3 * wrap] * filter[3];
+#else
+ {
+ int j;
+ UINT8 *s1 = s;
+
+ sum = 0;
+ for(j=0;j<NB_TAPS;j++) {
+ sum += s1[0] * filter[j];
+ s1 += wrap;
+ }
+ }
+#endif
+ sum = sum >> FILTER_BITS;
+ if (sum < 0)
+ sum = 0;
+ else if (sum > 255)
+ sum = 255;
+ dst[0] = sum;
+ dst++;
+ s++;
+ }
+}
+
+#ifdef CONFIG_MMX
+
+#include "i386/mmx.h"
+
+#define FILTER4(reg) \
+{\
+ s = src + (src_pos >> POS_FRAC_BITS);\
+ phase = get_phase(src_pos);\
+ filter = filters + phase * NB_TAPS;\
+ movq_m2r(*s, reg);\
+ punpcklbw_r2r(mm7, reg);\
+ movq_m2r(*filter, mm6);\
+ pmaddwd_r2r(reg, mm6);\
+ movq_r2r(mm6, reg);\
+ psrlq_i2r(32, reg);\
+ paddd_r2r(mm6, reg);\
+ psrad_i2r(FILTER_BITS, reg);\
+ src_pos += src_incr;\
+}
+
+#define DUMP(reg) movq_r2m(reg, tmp); printf(#reg "=%016Lx\n", tmp.uq);
+
+/* XXX: do four pixels at a time */
+static void h_resample_fast4_mmx(UINT8 *dst, int dst_width, UINT8 *src, int src_width,
+ int src_start, int src_incr, INT16 *filters)
+{
+ int src_pos, phase;
+ UINT8 *s;
+ INT16 *filter;
+ mmx_t tmp;
+
+ src_pos = src_start;
+ pxor_r2r(mm7, mm7);
+
+ while (dst_width >= 4) {
+
+ FILTER4(mm0);
+ FILTER4(mm1);
+ FILTER4(mm2);
+ FILTER4(mm3);
+
+ packuswb_r2r(mm7, mm0);
+ packuswb_r2r(mm7, mm1);
+ packuswb_r2r(mm7, mm3);
+ packuswb_r2r(mm7, mm2);
+ movq_r2m(mm0, tmp);
+ dst[0] = tmp.ub[0];
+ movq_r2m(mm1, tmp);
+ dst[1] = tmp.ub[0];
+ movq_r2m(mm2, tmp);
+ dst[2] = tmp.ub[0];
+ movq_r2m(mm3, tmp);
+ dst[3] = tmp.ub[0];
+ dst += 4;
+ dst_width -= 4;
+ }
+ while (dst_width > 0) {
+ FILTER4(mm0);
+ packuswb_r2r(mm7, mm0);
+ movq_r2m(mm0, tmp);
+ dst[0] = tmp.ub[0];
+ dst++;
+ dst_width--;
+ }
+ emms();
+}
+
+static void v_resample4_mmx(UINT8 *dst, int dst_width, UINT8 *src, int wrap,
+ INT16 *filter)
+{
+ int sum, i, v;
+ UINT8 *s;
+ mmx_t tmp;
+ mmx_t coefs[4];
+
+ for(i=0;i<4;i++) {
+ v = filter[i];
+ coefs[i].uw[0] = v;
+ coefs[i].uw[1] = v;
+ coefs[i].uw[2] = v;
+ coefs[i].uw[3] = v;
+ }
+
+ pxor_r2r(mm7, mm7);
+ s = src;
+ while (dst_width >= 4) {
+ movq_m2r(s[0 * wrap], mm0);
+ punpcklbw_r2r(mm7, mm0);
+ movq_m2r(s[1 * wrap], mm1);
+ punpcklbw_r2r(mm7, mm1);
+ movq_m2r(s[2 * wrap], mm2);
+ punpcklbw_r2r(mm7, mm2);
+ movq_m2r(s[3 * wrap], mm3);
+ punpcklbw_r2r(mm7, mm3);
+
+ pmullw_m2r(coefs[0], mm0);
+ pmullw_m2r(coefs[1], mm1);
+ pmullw_m2r(coefs[2], mm2);
+ pmullw_m2r(coefs[3], mm3);
+
+ paddw_r2r(mm1, mm0);
+ paddw_r2r(mm3, mm2);
+ paddw_r2r(mm2, mm0);
+ psraw_i2r(FILTER_BITS, mm0);
+
+ packuswb_r2r(mm7, mm0);
+ movq_r2m(mm0, tmp);
+
+ *(UINT32 *)dst = tmp.ud[0];
+ dst += 4;
+ s += 4;
+ dst_width -= 4;
+ }
+ while (dst_width > 0) {
+ sum = s[0 * wrap] * filter[0] +
+ s[1 * wrap] * filter[1] +
+ s[2 * wrap] * filter[2] +
+ s[3 * wrap] * filter[3];
+ sum = sum >> FILTER_BITS;
+ if (sum < 0)
+ sum = 0;
+ else if (sum > 255)
+ sum = 255;
+ dst[0] = sum;
+ dst++;
+ s++;
+ dst_width--;
+ }
+ emms();
+}
+#endif
+
+/* slow version to handle limit cases. Does not need optimisation */
+static void h_resample_slow(UINT8 *dst, int dst_width, UINT8 *src, int src_width,
+ int src_start, int src_incr, INT16 *filters)
+{
+ int src_pos, phase, sum, j, v, i;
+ UINT8 *s, *src_end;
+ INT16 *filter;
+
+ src_end = src + src_width;
+ src_pos = src_start;
+ for(i=0;i<dst_width;i++) {
+ s = src + (src_pos >> POS_FRAC_BITS);
+ phase = get_phase(src_pos);
+ filter = filters + phase * NB_TAPS;
+ sum = 0;
+ for(j=0;j<NB_TAPS;j++) {
+ if (s < src)
+ v = src[0];
+ else if (s >= src_end)
+ v = src_end[-1];
+ else
+ v = s[0];
+ sum += v * filter[j];
+ s++;
+ }
+ sum = sum >> FILTER_BITS;
+ if (sum < 0)
+ sum = 0;
+ else if (sum > 255)
+ sum = 255;
+ dst[0] = sum;
+ src_pos += src_incr;
+ dst++;
+ }
+}
+
+static void h_resample(UINT8 *dst, int dst_width, UINT8 *src, int src_width,
+ int src_start, int src_incr, INT16 *filters)
+{
+ int n, src_end;
+
+ if (src_start < 0) {
+ n = (0 - src_start + src_incr - 1) / src_incr;
+ h_resample_slow(dst, n, src, src_width, src_start, src_incr, filters);
+ dst += n;
+ dst_width -= n;
+ src_start += n * src_incr;
+ }
+ src_end = src_start + dst_width * src_incr;
+ if (src_end > ((src_width - NB_TAPS) << POS_FRAC_BITS)) {
+ n = (((src_width - NB_TAPS + 1) << POS_FRAC_BITS) - 1 - src_start) /
+ src_incr;
+ } else {
+ n = dst_width;
+ }
+#ifdef CONFIG_MMX
+ if ((mm_flags & MM_MMX) && NB_TAPS == 4)
+ h_resample_fast4_mmx(dst, n,
+ src, src_width, src_start, src_incr, filters);
+ else
+#endif
+ h_resample_fast(dst, n,
+ src, src_width, src_start, src_incr, filters);
+ if (n < dst_width) {
+ dst += n;
+ dst_width -= n;
+ src_start += n * src_incr;
+ h_resample_slow(dst, dst_width,
+ src, src_width, src_start, src_incr, filters);
+ }
+}
+
+static void component_resample(ImgReSampleContext *s,
+ UINT8 *output, int owrap, int owidth, int oheight,
+ UINT8 *input, int iwrap, int iwidth, int iheight)
+{
+ int src_y, src_y1, last_src_y, ring_y, phase_y, y1, y;
+ UINT8 *new_line, *src_line;
+
+ last_src_y = - FCENTER - 1;
+ /* position of the bottom of the filter in the source image */
+ src_y = (last_src_y + NB_TAPS) * POS_FRAC;
+ ring_y = NB_TAPS; /* position in ring buffer */
+ for(y=0;y<oheight;y++) {
+ /* apply horizontal filter on new lines from input if needed */
+ src_y1 = src_y >> POS_FRAC_BITS;
+ while (last_src_y < src_y1) {
+ if (++ring_y >= LINE_BUF_HEIGHT + NB_TAPS)
+ ring_y = NB_TAPS;
+ last_src_y++;
+ /* handle limit conditions : replicate line (slighly
+ inefficient because we filter multiple times */
+ y1 = last_src_y;
+ if (y1 < 0) {
+ y1 = 0;
+ } else if (y1 >= iheight) {
+ y1 = iheight - 1;
+ }
+ src_line = input + y1 * iwrap;
+ new_line = s->line_buf + ring_y * owidth;
+ /* apply filter and handle limit cases correctly */
+ h_resample(new_line, owidth,
+ src_line, iwidth, - FCENTER * POS_FRAC, s->h_incr,
+ &s->h_filters[0][0]);
+ /* handle ring buffer wraping */
+ if (ring_y >= LINE_BUF_HEIGHT) {
+ memcpy(s->line_buf + (ring_y - LINE_BUF_HEIGHT) * owidth,
+ new_line, owidth);
+ }
+ }
+ /* apply vertical filter */
+ phase_y = get_phase(src_y);
+#ifdef CONFIG_MMX
+ /* desactivated MMX because loss of precision */
+ if ((mm_flags & MM_MMX) && NB_TAPS == 4 && 0)
+ v_resample4_mmx(output, owidth,
+ s->line_buf + (ring_y - NB_TAPS + 1) * owidth, owidth,
+ &s->v_filters[phase_y][0]);
+ else
+#endif
+ v_resample(output, owidth,
+ s->line_buf + (ring_y - NB_TAPS + 1) * owidth, owidth,
+ &s->v_filters[phase_y][0]);
+
+ src_y += s->v_incr;
+ output += owrap;
+ }
+}
+
+/* XXX: the following filter is quite naive, but it seems to suffice
+ for 4 taps */
+static void build_filter(INT16 *filter, float factor)
+{
+ int ph, i, v;
+ float x, y, tab[NB_TAPS], norm, mult;
+
+ /* if upsampling, only need to interpolate, no filter */
+ if (factor > 1.0)
+ factor = 1.0;
+
+ for(ph=0;ph<NB_PHASES;ph++) {
+ norm = 0;
+ for(i=0;i<NB_TAPS;i++) {
+
+ x = M_PI * ((float)(i - FCENTER) - (float)ph / NB_PHASES) * factor;
+ if (x == 0)
+ y = 1.0;
+ else
+ y = sin(x) / x;
+ tab[i] = y;
+ norm += y;
+ }
+
+ /* normalize so that an uniform color remains the same */
+ mult = (float)(1 << FILTER_BITS) / norm;
+ for(i=0;i<NB_TAPS;i++) {
+ v = (int)(tab[i] * mult);
+ filter[ph * NB_TAPS + i] = v;
+ }
+ }
+}
+
+ImgReSampleContext *img_resample_init(int owidth, int oheight,
+ int iwidth, int iheight)
+{
+ ImgReSampleContext *s;
+
+ s = av_mallocz(sizeof(ImgReSampleContext));
+ if (!s)
+ return NULL;
+ s->line_buf = av_mallocz(owidth * (LINE_BUF_HEIGHT + NB_TAPS));
+ if (!s->line_buf)
+ goto fail;
+
+ s->owidth = owidth;
+ s->oheight = oheight;
+ s->iwidth = iwidth;
+ s->iheight = iheight;
+
+ s->h_incr = (iwidth * POS_FRAC) / owidth;
+ s->v_incr = (iheight * POS_FRAC) / oheight;
+
+ build_filter(&s->h_filters[0][0], (float)owidth / (float)iwidth);
+ build_filter(&s->v_filters[0][0], (float)oheight / (float)iheight);
+
+ return s;
+ fail:
+ free(s);
+ return NULL;
+}
+
+void img_resample(ImgReSampleContext *s,
+ AVPicture *output, AVPicture *input)
+{
+ int i, shift;
+
+ for(i=0;i<3;i++) {
+ shift = (i == 0) ? 0 : 1;
+ component_resample(s, output->data[i], output->linesize[i],
+ s->owidth >> shift, s->oheight >> shift,
+ input->data[i], input->linesize[i],
+ s->iwidth >> shift, s->iheight >> shift);
+ }
+}
+
+void img_resample_close(ImgReSampleContext *s)
+{
+ free(s->line_buf);
+ free(s);
+}
+
+#ifdef TEST
+
+void *av_mallocz(int size)
+{
+ void *ptr;
+ ptr = malloc(size);
+ memset(ptr, 0, size);
+ return ptr;
+}
+
+/* input */
+#define XSIZE 256
+#define YSIZE 256
+UINT8 img[XSIZE * YSIZE];
+
+/* output */
+#define XSIZE1 512
+#define YSIZE1 512
+UINT8 img1[XSIZE1 * YSIZE1];
+UINT8 img2[XSIZE1 * YSIZE1];
+
+void save_pgm(const char *filename, UINT8 *img, int xsize, int ysize)
+{
+ FILE *f;
+ f=fopen(filename,"w");
+ fprintf(f,"P5\n%d %d\n%d\n", xsize, ysize, 255);
+ fwrite(img,1, xsize * ysize,f);
+ fclose(f);
+}
+
+static void dump_filter(INT16 *filter)
+{
+ int i, ph;
+
+ for(ph=0;ph<NB_PHASES;ph++) {
+ printf("%2d: ", ph);
+ for(i=0;i<NB_TAPS;i++) {
+ printf(" %5.2f", filter[ph * NB_TAPS + i] / 256.0);
+ }
+ printf("\n");
+ }
+}
+
+#ifdef CONFIG_MMX
+int mm_flags;
+#endif
+
+int main(int argc, char **argv)
+{
+ int x, y, v, i, xsize, ysize;
+ ImgReSampleContext *s;
+ float fact, factors[] = { 1/2.0, 3.0/4.0, 1.0, 4.0/3.0, 16.0/9.0, 2.0 };
+ char buf[256];
+
+ /* build test image */
+ for(y=0;y<YSIZE;y++) {
+ for(x=0;x<XSIZE;x++) {
+ if (x < XSIZE/2 && y < YSIZE/2) {
+ if (x < XSIZE/4 && y < YSIZE/4) {
+ if ((x % 10) <= 6 &&
+ (y % 10) <= 6)
+ v = 0xff;
+ else
+ v = 0x00;
+ } else if (x < XSIZE/4) {
+ if (x & 1)
+ v = 0xff;
+ else
+ v = 0;
+ } else if (y < XSIZE/4) {
+ if (y & 1)
+ v = 0xff;
+ else
+ v = 0;
+ } else {
+ if (y < YSIZE*3/8) {
+ if ((y+x) & 1)
+ v = 0xff;
+ else
+ v = 0;
+ } else {
+ if (((x+3) % 4) <= 1 &&
+ ((y+3) % 4) <= 1)
+ v = 0xff;
+ else
+ v = 0x00;
+ }
+ }
+ } else if (x < XSIZE/2) {
+ v = ((x - (XSIZE/2)) * 255) / (XSIZE/2);
+ } else if (y < XSIZE/2) {
+ v = ((y - (XSIZE/2)) * 255) / (XSIZE/2);
+ } else {
+ v = ((x + y - XSIZE) * 255) / XSIZE;
+ }
+ img[y * XSIZE + x] = v;
+ }
+ }
+ save_pgm("/tmp/in.pgm", img, XSIZE, YSIZE);
+ for(i=0;i<sizeof(factors)/sizeof(float);i++) {
+ fact = factors[i];
+ xsize = (int)(XSIZE * fact);
+ ysize = (int)(YSIZE * fact);
+ s = img_resample_init(xsize, ysize, XSIZE, YSIZE);
+ printf("Factor=%0.2f\n", fact);
+ dump_filter(&s->h_filters[0][0]);
+ component_resample(s, img1, xsize, xsize, ysize,
+ img, XSIZE, XSIZE, YSIZE);
+ img_resample_close(s);
+
+ sprintf(buf, "/tmp/out%d.pgm", i);
+ save_pgm(buf, img1, xsize, ysize);
+ }
+
+ /* mmx test */
+#ifdef CONFIG_MMX
+ printf("MMX test\n");
+ fact = 0.72;
+ xsize = (int)(XSIZE * fact);
+ ysize = (int)(YSIZE * fact);
+ mm_flags = MM_MMX;
+ s = img_resample_init(xsize, ysize, XSIZE, YSIZE);
+ component_resample(s, img1, xsize, xsize, ysize,
+ img, XSIZE, XSIZE, YSIZE);
+
+ mm_flags = 0;
+ s = img_resample_init(xsize, ysize, XSIZE, YSIZE);
+ component_resample(s, img2, xsize, xsize, ysize,
+ img, XSIZE, XSIZE, YSIZE);
+ if (memcmp(img1, img2, xsize * ysize) != 0) {
+ fprintf(stderr, "mmx error\n");
+ exit(1);
+ }
+ printf("MMX OK\n");
+#endif
+ return 0;
+}
+
+#endif