-Added ability to convert xml and tscn scenes to binary on export, makes loading of larger scenes faster
229 lines
7.6 KiB
C
229 lines
7.6 KiB
C
// Copyright 2011 Google Inc. All Rights Reserved.
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//
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// This code is licensed under the same terms as WebM:
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// Software License Agreement: http://www.webmproject.org/license/software/
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// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
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// -----------------------------------------------------------------------------
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//
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// Spatial prediction using various filters
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//
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// Author: Urvang (urvang@google.com)
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#include "./filters.h"
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#include <assert.h>
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#include <stdlib.h>
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#include <string.h>
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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//------------------------------------------------------------------------------
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// Helpful macro.
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# define SANITY_CHECK(in, out) \
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assert(in != NULL); \
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assert(out != NULL); \
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assert(width > 0); \
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assert(height > 0); \
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assert(bpp > 0); \
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assert(stride >= width * bpp);
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static WEBP_INLINE void PredictLine(const uint8_t* src, const uint8_t* pred,
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uint8_t* dst, int length, int inverse) {
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int i;
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if (inverse) {
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for (i = 0; i < length; ++i) dst[i] = src[i] + pred[i];
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} else {
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for (i = 0; i < length; ++i) dst[i] = src[i] - pred[i];
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}
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}
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//------------------------------------------------------------------------------
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// Horizontal filter.
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static WEBP_INLINE void DoHorizontalFilter(const uint8_t* in,
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int width, int height, int bpp, int stride, int inverse, uint8_t* out) {
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int h;
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const uint8_t* preds = (inverse ? out : in);
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SANITY_CHECK(in, out);
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// Filter line-by-line.
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for (h = 0; h < height; ++h) {
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// Leftmost pixel is predicted from above (except for topmost scanline).
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if (h == 0) {
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memcpy((void*)out, (const void*)in, bpp);
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} else {
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PredictLine(in, preds - stride, out, bpp, inverse);
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}
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PredictLine(in + bpp, preds, out + bpp, bpp * (width - 1), inverse);
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preds += stride;
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in += stride;
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out += stride;
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}
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}
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static void HorizontalFilter(const uint8_t* data, int width, int height,
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int bpp, int stride, uint8_t* filtered_data) {
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DoHorizontalFilter(data, width, height, bpp, stride, 0, filtered_data);
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}
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static void HorizontalUnfilter(const uint8_t* data, int width, int height,
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int bpp, int stride, uint8_t* recon_data) {
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DoHorizontalFilter(data, width, height, bpp, stride, 1, recon_data);
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}
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//------------------------------------------------------------------------------
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// Vertical filter.
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static WEBP_INLINE void DoVerticalFilter(const uint8_t* in,
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int width, int height, int bpp, int stride, int inverse, uint8_t* out) {
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int h;
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const uint8_t* preds = (inverse ? out : in);
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SANITY_CHECK(in, out);
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// Very first top-left pixel is copied.
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memcpy((void*)out, (const void*)in, bpp);
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// Rest of top scan-line is left-predicted.
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PredictLine(in + bpp, preds, out + bpp, bpp * (width - 1), inverse);
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// Filter line-by-line.
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for (h = 1; h < height; ++h) {
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in += stride;
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out += stride;
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PredictLine(in, preds, out, bpp * width, inverse);
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preds += stride;
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}
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}
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static void VerticalFilter(const uint8_t* data, int width, int height,
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int bpp, int stride, uint8_t* filtered_data) {
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DoVerticalFilter(data, width, height, bpp, stride, 0, filtered_data);
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}
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static void VerticalUnfilter(const uint8_t* data, int width, int height,
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int bpp, int stride, uint8_t* recon_data) {
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DoVerticalFilter(data, width, height, bpp, stride, 1, recon_data);
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}
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//------------------------------------------------------------------------------
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// Gradient filter.
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static WEBP_INLINE int GradientPredictor(uint8_t a, uint8_t b, uint8_t c) {
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const int g = a + b - c;
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return (g < 0) ? 0 : (g > 255) ? 255 : g;
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}
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static WEBP_INLINE
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void DoGradientFilter(const uint8_t* in, int width, int height,
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int bpp, int stride, int inverse, uint8_t* out) {
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const uint8_t* preds = (inverse ? out : in);
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int h;
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SANITY_CHECK(in, out);
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// left prediction for top scan-line
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memcpy((void*)out, (const void*)in, bpp);
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PredictLine(in + bpp, preds, out + bpp, bpp * (width - 1), inverse);
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// Filter line-by-line.
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for (h = 1; h < height; ++h) {
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int w;
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preds += stride;
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in += stride;
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out += stride;
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// leftmost pixel: predict from above.
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PredictLine(in, preds - stride, out, bpp, inverse);
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for (w = bpp; w < width * bpp; ++w) {
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const int pred = GradientPredictor(preds[w - bpp],
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preds[w - stride],
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preds[w - stride - bpp]);
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out[w] = in[w] + (inverse ? pred : -pred);
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}
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}
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}
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static void GradientFilter(const uint8_t* data, int width, int height,
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int bpp, int stride, uint8_t* filtered_data) {
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DoGradientFilter(data, width, height, bpp, stride, 0, filtered_data);
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}
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static void GradientUnfilter(const uint8_t* data, int width, int height,
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int bpp, int stride, uint8_t* recon_data) {
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DoGradientFilter(data, width, height, bpp, stride, 1, recon_data);
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}
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#undef SANITY_CHECK
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// -----------------------------------------------------------------------------
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// Quick estimate of a potentially interesting filter mode to try, in addition
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// to the default NONE.
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#define SMAX 16
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#define SDIFF(a, b) (abs((a) - (b)) >> 4) // Scoring diff, in [0..SMAX)
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WEBP_FILTER_TYPE EstimateBestFilter(const uint8_t* data,
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int width, int height, int stride) {
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int i, j;
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int bins[WEBP_FILTER_LAST][SMAX];
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memset(bins, 0, sizeof(bins));
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// We only sample every other pixels. That's enough.
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for (j = 2; j < height - 1; j += 2) {
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const uint8_t* const p = data + j * stride;
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int mean = p[0];
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for (i = 2; i < width - 1; i += 2) {
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const int diff0 = SDIFF(p[i], mean);
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const int diff1 = SDIFF(p[i], p[i - 1]);
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const int diff2 = SDIFF(p[i], p[i - width]);
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const int grad_pred =
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GradientPredictor(p[i - 1], p[i - width], p[i - width - 1]);
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const int diff3 = SDIFF(p[i], grad_pred);
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bins[WEBP_FILTER_NONE][diff0] = 1;
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bins[WEBP_FILTER_HORIZONTAL][diff1] = 1;
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bins[WEBP_FILTER_VERTICAL][diff2] = 1;
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bins[WEBP_FILTER_GRADIENT][diff3] = 1;
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mean = (3 * mean + p[i] + 2) >> 2;
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}
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}
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{
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WEBP_FILTER_TYPE filter, best_filter = WEBP_FILTER_NONE;
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int best_score = 0x7fffffff;
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for (filter = WEBP_FILTER_NONE; filter < WEBP_FILTER_LAST; ++filter) {
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int score = 0;
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for (i = 0; i < SMAX; ++i) {
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if (bins[filter][i] > 0) {
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score += i;
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}
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}
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if (score < best_score) {
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best_score = score;
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best_filter = filter;
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}
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}
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return best_filter;
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}
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}
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#undef SMAX
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#undef SDIFF
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//------------------------------------------------------------------------------
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const WebPFilterFunc WebPFilters[WEBP_FILTER_LAST] = {
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NULL, // WEBP_FILTER_NONE
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HorizontalFilter, // WEBP_FILTER_HORIZONTAL
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VerticalFilter, // WEBP_FILTER_VERTICAL
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GradientFilter // WEBP_FILTER_GRADIENT
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};
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const WebPFilterFunc WebPUnfilters[WEBP_FILTER_LAST] = {
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NULL, // WEBP_FILTER_NONE
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HorizontalUnfilter, // WEBP_FILTER_HORIZONTAL
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VerticalUnfilter, // WEBP_FILTER_VERTICAL
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GradientUnfilter // WEBP_FILTER_GRADIENT
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};
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//------------------------------------------------------------------------------
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#if defined(__cplusplus) || defined(c_plusplus)
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} // extern "C"
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#endif
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