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Merge "Added downsample()"

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This commit is contained in:
Nipun Kwatra
2010-08-20 11:35:38 -07:00
committed by Android (Google) Code Review
parent 437e6c49f1 96624731c3
commit 727f658e81
2 changed files with 41 additions and 1 deletions
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12
include/media/stagefright/YUVCanvas.h
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@@ -55,6 +55,18 @@ public:
int32_t destStartX, int32_t destStartY,
const YUVImage &srcImage);
// Downsamples the srcImage into the canvas' target image (mYUVImage)
// The downsampling copies pixels from the source image starting at
// (srcOffsetX, srcOffsetY) to the target image, starting at (0, 0).
// For each X increment in the target image, skipX pixels are skipped
// in the source image.
// Similarly for each Y increment in the target image, skipY pixels
// are skipped in the source image.
void downsample(
int32_t srcOffsetX, int32_t srcOffsetY,
int32_t skipX, int32_t skipY,
const YUVImage &srcImage);
private:
YUVImage& mYUVImage;

30
media/libstagefright/yuv/YUVCanvas.cpp
View File

@@ -17,6 +17,7 @@
#define LOG_NDEBUG 0
#define LOG_TAG "YUVCanvas"
#include <media/stagefright/MediaDebug.h>
#include <media/stagefright/YUVCanvas.h>
#include <media/stagefright/YUVImage.h>
#include <ui/Rect.h>
@@ -74,10 +75,37 @@ void YUVCanvas::CopyImageRect(
uint8_t uValue;
uint8_t vValue;
srcImage.getPixelValue(srcX, srcY, &yValue, &uValue, & vValue);
srcImage.getPixelValue(srcX, srcY, &yValue, &uValue, &vValue);
mYUVImage.setPixelValue(destX, destY, yValue, uValue, vValue);
}
}
}
void YUVCanvas::downsample(
int32_t srcOffsetX, int32_t srcOffsetY,
int32_t skipX, int32_t skipY,
const YUVImage &srcImage) {
// TODO: Add a low pass filter for downsampling.
// Check that srcImage is big enough to fill mYUVImage.
CHECK((srcOffsetX + (mYUVImage.width() - 1) * skipX) < srcImage.width());
CHECK((srcOffsetY + (mYUVImage.height() - 1) * skipY) < srcImage.height());
uint8_t yValue;
uint8_t uValue;
uint8_t vValue;
int32_t srcY = srcOffsetY;
for (int32_t y = 0; y < mYUVImage.height(); ++y) {
int32_t srcX = srcOffsetX;
for (int32_t x = 0; x < mYUVImage.width(); ++x) {
srcImage.getPixelValue(srcX, srcY, &yValue, &uValue, &vValue);
mYUVImage.setPixelValue(x, y, yValue, uValue, vValue);
srcX += skipX;
}
srcY += skipY;
}
}
} // namespace android