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Extend the TurboJPEG Java API to support compressing JPEG images from YUV planar images

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git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1071 632fc199-4ca6-4c93-a231-07263d6284db
This commit is contained in:
DRC
2013-10-31 05:04:51 +00:00
parent faa868bbb6
commit 1e67274bd7
8 changed files with 282 additions and 44 deletions
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67
java/org/libjpegturbo/turbojpeg/TJCompressor.java
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@@ -139,6 +139,7 @@ public class TJCompressor {
srcPixelFormat = pixelFormat;
srcX = x;
srcY = y;
srcIsYUV = false;
}
/**
@@ -152,6 +153,41 @@ public class TJCompressor {
srcX = srcY = -1;
}
/**
* Associate an uncompressed YUV planar source image with this compressor
* instance.
*
* @param srcImage image buffer containing a YUV planar image to be
* compressed. The Y, U (Cb), and V (Cr) image planes should be stored
* sequentially in the buffer, and the size of each plane is determined by
* the specified width, height, and padding, as well as the level of
* chrominance subsampling (specified using {@link #setSubsamp}.) If the
* chrominance components are subsampled along the horizontal dimension, then
* the width of the luminance plane should be padded to the nearest multiple
* of 2 (same goes for the height of the luminance plane, if the chrominance
* components are subsampled along the vertical dimension.) This is
* irrespective of any additional padding specified in the <code>pad</code>
* parameter.
*
* @param width width (in pixels) of the source image
*
* @param pad the line padding used in the source image. For instance, if
* each line in each plane of the YUV image is padded to the nearest multiple
* of 4 bytes, then <code>pad</code> should be set to 4.
*
* @param height height (in pixels) of the source image
*/
public void setSourceImageYUV(byte[] srcImage, int width, int pad,
int height) throws Exception {
if (handle == 0) init();
if (srcImage == null || width < 1 || pad < 1 || height < 1)
throw new Exception("Invalid argument in setSourceImageYUV()");
srcBuf = srcImage;
srcWidth = width;
srcYUVPad = pad;
srcHeight = height;
srcIsYUV = true;
}
/**
* Set the level of chrominance subsampling for subsequent compress/encode
@@ -162,6 +198,10 @@ public class TJCompressor {
* image with little perceptible loss of image clarity (the human eye is more
* sensitive to small changes in brightness than to small changes in color.)
* This is called "chrominance subsampling".
* <p>
* NOTE: When compressing a YUV planar image into a JPEG image, this method
* also specifies the level of chrominance subsampling used in the source
* image.
*
* @param newSubsamp the new level of chrominance subsampling (one of
* {@link TJ TJ.SAMP_*})
@@ -203,14 +243,19 @@ public class TJCompressor {
throw new Exception("JPEG Quality not set");
if (subsamp < 0)
throw new Exception("Subsampling level not set");
if (srcX >= 0 && srcY >= 0)
compressedSize = compress(srcBuf, srcX, srcY, srcWidth, srcPitch,
srcHeight, srcPixelFormat, dstBuf, subsamp,
jpegQuality, flags);
else
compressedSize = compress(srcBuf, srcWidth, srcPitch, srcHeight,
srcPixelFormat, dstBuf, subsamp, jpegQuality,
flags);
if (srcIsYUV)
compressedSize = compressFromYUV(srcBuf, srcWidth, srcYUVPad, srcHeight,
subsamp, dstBuf, jpegQuality, flags);
else {
if (srcX >= 0 && srcY >= 0)
compressedSize = compress(srcBuf, srcX, srcY, srcWidth, srcPitch,
srcHeight, srcPixelFormat, dstBuf, subsamp,
jpegQuality, flags);
else
compressedSize = compress(srcBuf, srcWidth, srcPitch, srcHeight,
srcPixelFormat, dstBuf, subsamp, jpegQuality,
flags);
}
}
/**
@@ -550,6 +595,10 @@ public class TJCompressor {
int stride, int height, int pixelFormat, byte[] dstBuf, int jpegSubsamp,
int jpegQual, int flags) throws Exception;
private native int compressFromYUV(byte[] srcBuf, int width, int pad,
int height, int subsamp, byte[] dstBuf, int jpegQual, int flags)
throws Exception;
private native void encodeYUV(byte[] srcBuf, int width, int pitch,
int height, int pixelFormat, byte[] dstBuf, int subsamp, int flags)
throws Exception; // deprecated
@@ -578,6 +627,8 @@ public class TJCompressor {
private int srcY = -1;
private int srcPitch = 0;
private int srcPixelFormat = -1;
private int srcYUVPad = -1;
private boolean srcIsYUV;
private int subsamp = -1;
private int jpegQuality = -1;
private int compressedSize = 0;