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make alpha unfilter work in-place

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* remove a malloc
* remove the unused 'bpp' argument from filter/unfilter functions

Change-Id: I28d78baaaddc20f1d5a3bb2bd0b4e96a12a920d8
This commit is contained in:
skal
2013-03-14 20:26:39 +01:00
parent 14ef5005a2
commit 0aef3ebdea
4 changed files with 44 additions and 55 deletions
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67
src/utils/filters.c
View File

@@ -26,8 +26,7 @@ extern "C" {
assert(out != NULL); \
assert(width > 0); \
assert(height > 0); \
assert(bpp > 0); \
assert(stride >= width * bpp);
assert(stride >= width);
static WEBP_INLINE void PredictLine(const uint8_t* src, const uint8_t* pred,
uint8_t* dst, int length, int inverse) {
@@ -43,7 +42,8 @@ static WEBP_INLINE void PredictLine(const uint8_t* src, const uint8_t* pred,
// Horizontal filter.
static WEBP_INLINE void DoHorizontalFilter(const uint8_t* in,
int width, int height, int bpp, int stride, int inverse, uint8_t* out) {
int width, int height, int stride,
int inverse, uint8_t* out) {
int h;
const uint8_t* preds = (inverse ? out : in);
SANITY_CHECK(in, out);
@@ -52,11 +52,11 @@ static WEBP_INLINE void DoHorizontalFilter(const uint8_t* in,
for (h = 0; h < height; ++h) {
// Leftmost pixel is predicted from above (except for topmost scanline).
if (h == 0) {
memcpy((void*)out, (const void*)in, bpp);
out[0] = in[0];
} else {
PredictLine(in, preds - stride, out, bpp, inverse);
PredictLine(in, preds - stride, out, 1, inverse);
}
PredictLine(in + bpp, preds, out + bpp, bpp * (width - 1), inverse);
PredictLine(in + 1, preds, out + 1, width - 1, inverse);
preds += stride;
in += stride;
out += stride;
@@ -64,46 +64,46 @@ static WEBP_INLINE void DoHorizontalFilter(const uint8_t* in,
}
static void HorizontalFilter(const uint8_t* data, int width, int height,
int bpp, int stride, uint8_t* filtered_data) {
DoHorizontalFilter(data, width, height, bpp, stride, 0, filtered_data);
int stride, uint8_t* filtered_data) {
DoHorizontalFilter(data, width, height, stride, 0, filtered_data);
}
static void HorizontalUnfilter(const uint8_t* data, int width, int height,
int bpp, int stride, uint8_t* recon_data) {
DoHorizontalFilter(data, width, height, bpp, stride, 1, recon_data);
static void HorizontalUnfilter(int width, int height, int stride,
uint8_t* data) {
DoHorizontalFilter(data, width, height, stride, 1, data);
}
//------------------------------------------------------------------------------
// Vertical filter.
static WEBP_INLINE void DoVerticalFilter(const uint8_t* in,
int width, int height, int bpp, int stride, int inverse, uint8_t* out) {
int width, int height, int stride,
int inverse, uint8_t* out) {
int h;
const uint8_t* preds = (inverse ? out : in);
SANITY_CHECK(in, out);
// Very first top-left pixel is copied.
memcpy((void*)out, (const void*)in, bpp);
out[0] = in[0];
// Rest of top scan-line is left-predicted.
PredictLine(in + bpp, preds, out + bpp, bpp * (width - 1), inverse);
PredictLine(in + 1, preds, out + 1, width - 1, inverse);
// Filter line-by-line.
for (h = 1; h < height; ++h) {
in += stride;
out += stride;
PredictLine(in, preds, out, bpp * width, inverse);
PredictLine(in, preds, out, width, inverse);
preds += stride;
}
}
static void VerticalFilter(const uint8_t* data, int width, int height,
int bpp, int stride, uint8_t* filtered_data) {
DoVerticalFilter(data, width, height, bpp, stride, 0, filtered_data);
int stride, uint8_t* filtered_data) {
DoVerticalFilter(data, width, height, stride, 0, filtered_data);
}
static void VerticalUnfilter(const uint8_t* data, int width, int height,
int bpp, int stride, uint8_t* recon_data) {
DoVerticalFilter(data, width, height, bpp, stride, 1, recon_data);
static void VerticalUnfilter(int width, int height, int stride, uint8_t* data) {
DoVerticalFilter(data, width, height, stride, 1, data);
}
//------------------------------------------------------------------------------
@@ -111,19 +111,19 @@ static void VerticalUnfilter(const uint8_t* data, int width, int height,
static WEBP_INLINE int GradientPredictor(uint8_t a, uint8_t b, uint8_t c) {
const int g = a + b - c;
return (g < 0) ? 0 : (g > 255) ? 255 : g;
return ((g & ~0xff) == 0) ? g : (g < 0) ? 0 : 255; // clip to 8bit
}
static WEBP_INLINE
void DoGradientFilter(const uint8_t* in, int width, int height,
int bpp, int stride, int inverse, uint8_t* out) {
int stride, int inverse, uint8_t* out) {
const uint8_t* preds = (inverse ? out : in);
int h;
SANITY_CHECK(in, out);
// left prediction for top scan-line
memcpy((void*)out, (const void*)in, bpp);
PredictLine(in + bpp, preds, out + bpp, bpp * (width - 1), inverse);
out[0] = in[0];
PredictLine(in + 1, preds, out + 1, width - 1, inverse);
// Filter line-by-line.
for (h = 1; h < height; ++h) {
@@ -132,24 +132,23 @@ void DoGradientFilter(const uint8_t* in, int width, int height,
in += stride;
out += stride;
// leftmost pixel: predict from above.
PredictLine(in, preds - stride, out, bpp, inverse);
for (w = bpp; w < width * bpp; ++w) {
const int pred = GradientPredictor(preds[w - bpp],
PredictLine(in, preds - stride, out, 1, inverse);
for (w = 1; w < width; ++w) {
const int pred = GradientPredictor(preds[w - 1],
preds[w - stride],
preds[w - stride - bpp]);
preds[w - stride - 1]);
out[w] = in[w] + (inverse ? pred : -pred);
}
}
}
static void GradientFilter(const uint8_t* data, int width, int height,
int bpp, int stride, uint8_t* filtered_data) {
DoGradientFilter(data, width, height, bpp, stride, 0, filtered_data);
int stride, uint8_t* filtered_data) {
DoGradientFilter(data, width, height, stride, 0, filtered_data);
}
static void GradientUnfilter(const uint8_t* data, int width, int height,
int bpp, int stride, uint8_t* recon_data) {
DoGradientFilter(data, width, height, bpp, stride, 1, recon_data);
static void GradientUnfilter(int width, int height, int stride, uint8_t* data) {
DoGradientFilter(data, width, height, stride, 1, data);
}
#undef SANITY_CHECK
@@ -215,7 +214,7 @@ const WebPFilterFunc WebPFilters[WEBP_FILTER_LAST] = {
GradientFilter // WEBP_FILTER_GRADIENT
};
const WebPFilterFunc WebPUnfilters[WEBP_FILTER_LAST] = {
const WebPUnfilterFunc WebPUnfilters[WEBP_FILTER_LAST] = {
NULL, // WEBP_FILTER_NONE
HorizontalUnfilter, // WEBP_FILTER_HORIZONTAL
VerticalUnfilter, // WEBP_FILTER_VERTICAL

9
src/utils/filters.h
View File

@@ -30,18 +30,19 @@ typedef enum {
} WEBP_FILTER_TYPE;
typedef void (*WebPFilterFunc)(const uint8_t* in, int width, int height,
int bpp, int stride, uint8_t* out);
int stride, uint8_t* out);
typedef void (*WebPUnfilterFunc)(int width, int height, int stride,
uint8_t* data);
// Filter the given data using the given predictor.
// 'in' corresponds to a 2-dimensional pixel array of size (stride * height)
// in raster order.
// 'bpp' is number of bytes per pixel, and
// 'stride' is number of bytes per scan line (with possible padding).
// 'out' should be pre-allocated.
extern const WebPFilterFunc WebPFilters[WEBP_FILTER_LAST];
// Reconstruct the original data from the given filtered data.
extern const WebPFilterFunc WebPUnfilters[WEBP_FILTER_LAST];
// In-place reconstruct the original data from the given filtered data.
extern const WebPUnfilterFunc WebPUnfilters[WEBP_FILTER_LAST];
// Fast estimate of a potentially good filter.
extern WEBP_FILTER_TYPE EstimateBestFilter(const uint8_t* data,