YUVImage instance
* serves as the destination image for YUV encode and decompress-to-YUV
* operations and as the source image for compress-from-YUV and YUV decode
* operations.
* * Technically, the JPEG format uses the YCbCr colorspace (which technically is * not a "colorspace" but rather a "color transform"), but per the convention * of the digital video community, the TurboJPEG API uses "YUV" to refer to an * image format consisting of Y, Cb, and Cr image planes. *
* Each plane is simply a 2D array of bytes, each byte representing the value * of one of the components (Y, Cb, or Cr) at a particular location in the * image. The width and height of each plane are determined by the image * width, height, and level of chrominance subsampling. The luminance plane * width is the image width padded to the nearest multiple of the horizontal * subsampling factor (2 in the case of 4:2:0 and 4:2:2, 4 in the case of * 4:1:1, 1 in the case of 4:4:4 or grayscale.) Similarly, the luminance plane * height is the image height padded to the nearest multiple of the vertical * subsampling factor (2 in the case of 4:2:0 or 4:4:0, 1 in the case of 4:4:4 * or grayscale.) The chrominance plane width is equal to the luminance plane * width divided by the horizontal subsampling factor, and the chrominance * plane height is equal to the luminance plane height divided by the vertical * subsampling factor. *
* For example, if the source image is 35 x 35 pixels and 4:2:2 subsampling is
* used, then the luminance plane would be 36 x 35 bytes, and each of the
* chrominance planes would be 18 x 35 bytes. If you specify a line padding of
* 4 bytes on top of this, then the luminance plane would be 36 x 35 bytes, and
* each of the chrominance planes would be 20 x 35 bytes.
*/
public class YUVImage {
private static final String NO_ASSOC_ERROR =
"No image data is associated with this instance";
/**
* Create a new YUVImage instance backed by separate image
* planes, and allocate memory for the image planes.
*
* @param width width (in pixels) of the YUV image
*
* @param strides an array of integers, each specifying the number of bytes
* per line in the corresponding plane of the YUV image. Setting the stride
* for any plane to 0 is the same as setting it to the plane width (see
* {@link YUVImage above}.) If strides is null, then the
* strides for all planes will be set to their respective plane widths. When
* using this constructor, the stride for each plane must be equal to or
* greater than the plane width.
*
* @param height height (in pixels) of the YUV image
*
* @param subsamp the level of chrominance subsampling to be used in the YUV
* image (one of {@link TJ#SAMP_444 TJ.SAMP_*})
*/
public YUVImage(int width, int[] strides, int height, int subsamp) {
setBuf(null, null, width, strides, height, subsamp, true);
}
/**
* Create a new YUVImage instance backed by a unified image
* buffer, and allocate memory for the image buffer.
*
* @param width width (in pixels) of the YUV image
*
* @param pad Each line of each plane in the YUV image buffer will be padded
* to this number of bytes (must be a power of 2.)
*
* @param height height (in pixels) of the YUV image
*
* @param subsamp the level of chrominance subsampling to be used in the YUV
* image (one of {@link TJ#SAMP_444 TJ.SAMP_*})
*/
public YUVImage(int width, int pad, int height, int subsamp) {
setBuf(new byte[TJ.bufSizeYUV(width, pad, height, subsamp)], width, pad,
height, subsamp);
}
/**
* Create a new YUVImage instance from a set of existing image
* planes.
*
* @param planes an array of buffers representing the Y, U (Cb), and V (Cr)
* image planes (or just the Y plane, if the image is grayscale.) These
* planes can be contiguous or non-contiguous in memory. Plane
* i should be at least offsets[i] +
* {@link TJ#planeSizeYUV TJ.planeSizeYUV}(i, width, strides[i], height, subsamp)
* bytes in size.
*
* @param offsets If this YUVImage instance represents a
* subregion of a larger image, then offsets[i] specifies the
* offset (in bytes) of the subregion within plane i of the
* larger image. Setting this to null is the same as setting the offsets for
* all planes to 0.
*
* @param width width (in pixels) of the new YUV image (or subregion)
*
* @param strides an array of integers, each specifying the number of bytes
* per line in the corresponding plane of the YUV image. Setting the stride
* for any plane to 0 is the same as setting it to the plane width (see
* {@link YUVImage above}.) If strides is null, then the
* strides for all planes will be set to their respective plane widths. You
* can adjust the strides in order to add an arbitrary amount of line padding
* to each plane or to specify that this YUVImage instance is a
* subregion of a larger image (in which case, strides[i] should
* be set to the plane width of plane i in the larger image.)
*
* @param height height (in pixels) of the new YUV image (or subregion)
*
* @param subsamp the level of chrominance subsampling used in the YUV
* image (one of {@link TJ#SAMP_444 TJ.SAMP_*})
*/
public YUVImage(byte[][] planes, int[] offsets, int width, int[] strides,
int height, int subsamp) {
setBuf(planes, offsets, width, strides, height, subsamp, false);
}
/**
* Create a new YUVImage instance from an existing unified image
* buffer.
*
* @param yuvImage image buffer that contains or will contain YUV planar
* image data. Use {@link TJ#bufSizeYUV} to determine the minimum size for
* this buffer. The Y, U (Cb), and V (Cr) image planes are stored
* sequentially in the buffer (see {@link YUVImage above} for a description
* of the image format.)
*
* @param width width (in pixels) of the YUV image
*
* @param pad the line padding used in the YUV image buffer. For
* instance, if each line in each plane of the buffer is padded to the
* nearest multiple of 4 bytes, then pad should be set to 4.
*
* @param height height (in pixels) of the YUV image
*
* @param subsamp the level of chrominance subsampling used in the YUV
* image (one of {@link TJ#SAMP_444 TJ.SAMP_*})
*/
public YUVImage(byte[] yuvImage, int width, int pad, int height,
int subsamp) {
setBuf(yuvImage, width, pad, height, subsamp);
}
/**
* Assign a set of image planes to this YUVImage instance.
*
* @param planes an array of buffers representing the Y, U (Cb), and V (Cr)
* image planes (or just the Y plane, if the image is grayscale.) These
* planes can be contiguous or non-contiguous in memory. Plane
* i should be at least offsets[i] +
* {@link TJ#planeSizeYUV TJ.planeSizeYUV}(i, width, strides[i], height, subsamp)
* bytes in size.
*
* @param offsets If this YUVImage instance represents a
* subregion of a larger image, then offsets[i] specifies the
* offset (in bytes) of the subregion within plane i of the
* larger image. Setting this to null is the same as setting the offsets for
* all planes to 0.
*
* @param width width (in pixels) of the YUV image (or subregion)
*
* @param strides an array of integers, each specifying the number of bytes
* per line in the corresponding plane of the YUV image. Setting the stride
* for any plane to 0 is the same as setting it to the plane width (see
* {@link YUVImage above}.) If strides is null, then the
* strides for all planes will be set to their respective plane widths. You
* can adjust the strides in order to add an arbitrary amount of line padding
* to each plane or to specify that this YUVImage image is a
* subregion of a larger image (in which case, strides[i] should
* be set to the plane width of plane i in the larger image.)
*
* @param height height (in pixels) of the YUV image (or subregion)
*
* @param subsamp the level of chrominance subsampling used in the YUV
* image (one of {@link TJ#SAMP_444 TJ.SAMP_*})
*/
public void setBuf(byte[][] planes, int[] offsets, int width, int[] strides,
int height, int subsamp) {
setBuf(planes, offsets, width, strides, height, subsamp, false);
}
private void setBuf(byte[][] planes, int[] offsets, int width, int[] strides,
int height, int subsamp, boolean alloc) {
if ((planes == null && !alloc) || width < 1 || height < 1 || subsamp < 0 ||
subsamp >= TJ.NUMSAMP)
throw new IllegalArgumentException("Invalid argument in YUVImage::setBuf()");
int nc = (subsamp == TJ.SAMP_GRAY ? 1 : 3);
if ((planes != null && planes.length != nc) ||
(offsets != null && offsets.length != nc) ||
(strides != null && strides.length != nc))
throw new IllegalArgumentException("YUVImage::setBuf(): planes, offsets, or strides array is the wrong size");
if (planes == null)
planes = new byte[nc][];
if (offsets == null)
offsets = new int[nc];
if (strides == null)
strides = new int[nc];
for (int i = 0; i < nc; i++) {
int pw = TJ.planeWidth(i, width, subsamp);
int ph = TJ.planeHeight(i, height, subsamp);
int planeSize = TJ.planeSizeYUV(i, width, strides[i], height, subsamp);
if (strides[i] == 0)
strides[i] = pw;
if (alloc) {
if (strides[i] < pw)
throw new IllegalArgumentException("Stride must be >= plane width when allocating a new YUV image");
planes[i] = new byte[strides[i] * ph];
}
if (planes[i] == null || offsets[i] < 0)
throw new IllegalArgumentException("Invalid argument in YUVImage::setBuf()");
if (strides[i] < 0 && offsets[i] - planeSize + pw < 0)
throw new IllegalArgumentException("Stride for plane " + i +
" would cause memory to be accessed below plane boundary");
if (planes[i].length < offsets[i] + planeSize)
throw new IllegalArgumentException("Image plane " + i +
" is not large enough");
}
yuvPlanes = planes;
yuvOffsets = offsets;
yuvWidth = width;
yuvStrides = strides;
yuvHeight = height;
yuvSubsamp = subsamp;
}
/**
* Assign a unified image buffer to this YUVImage instance.
*
* @param yuvImage image buffer that contains or will contain YUV planar
* image data. Use {@link TJ#bufSizeYUV} to determine the minimum size for
* this buffer. The Y, U (Cb), and V (Cr) image planes are stored
* sequentially in the buffer (see {@link YUVImage above} for a description
* of the image format.)
*
* @param width width (in pixels) of the YUV image
*
* @param pad the line padding used in the YUV image buffer. For
* instance, if each line in each plane of the buffer is padded to the
* nearest multiple of 4 bytes, then pad should be set to 4.
*
* @param height height (in pixels) of the YUV image
*
* @param subsamp the level of chrominance subsampling used in the YUV
* image (one of {@link TJ#SAMP_444 TJ.SAMP_*})
*/
public void setBuf(byte[] yuvImage, int width, int pad, int height,
int subsamp) {
if (yuvImage == null || width < 1 || pad < 1 || ((pad & (pad - 1)) != 0) ||
height < 1 || subsamp < 0 || subsamp >= TJ.NUMSAMP)
throw new IllegalArgumentException("Invalid argument in YUVImage::setBuf()");
if (yuvImage.length < TJ.bufSizeYUV(width, pad, height, subsamp))
throw new IllegalArgumentException("YUV image buffer is not large enough");
int nc = (subsamp == TJ.SAMP_GRAY ? 1 : 3);
byte[][] planes = new byte[nc][];
int[] strides = new int[nc];
int[] offsets = new int[nc];
planes[0] = yuvImage;
strides[0] = pad(TJ.planeWidth(0, width, subsamp), pad);
if (subsamp != TJ.SAMP_GRAY) {
strides[1] = strides[2] = pad(TJ.planeWidth(1, width, subsamp), pad);
planes[1] = planes[2] = yuvImage;
offsets[1] = offsets[0] +
strides[0] * TJ.planeHeight(0, height, subsamp);
offsets[2] = offsets[1] +
strides[1] * TJ.planeHeight(1, height, subsamp);
}
yuvPad = pad;
setBuf(planes, offsets, width, strides, height, subsamp);
}
/**
* Returns the width of the YUV image (or subregion.)
*
* @return the width of the YUV image (or subregion)
*/
public int getWidth() {
if (yuvWidth < 1)
throw new IllegalStateException(NO_ASSOC_ERROR);
return yuvWidth;
}
/**
* Returns the height of the YUV image (or subregion.)
*
* @return the height of the YUV image (or subregion)
*/
public int getHeight() {
if (yuvHeight < 1)
throw new IllegalStateException(NO_ASSOC_ERROR);
return yuvHeight;
}
/**
* Returns the line padding used in the YUV image buffer (if this image is
* stored in a unified buffer rather than separate image planes.)
*
* @return the line padding used in the YUV image buffer
*/
public int getPad() {
if (yuvPlanes == null)
throw new IllegalStateException(NO_ASSOC_ERROR);
if (yuvPad < 1 || ((yuvPad & (yuvPad - 1)) != 0))
throw new IllegalStateException("Image is not stored in a unified buffer");
return yuvPad;
}
/**
* Returns the number of bytes per line of each plane in the YUV image.
*
* @return the number of bytes per line of each plane in the YUV image
*/
public int[] getStrides() {
if (yuvStrides == null)
throw new IllegalStateException(NO_ASSOC_ERROR);
return yuvStrides;
}
/**
* Returns the offsets (in bytes) of each plane within the planes of a larger
* YUV image.
*
* @return the offsets (in bytes) of each plane within the planes of a larger
* YUV image
*/
public int[] getOffsets() {
if (yuvOffsets == null)
throw new IllegalStateException(NO_ASSOC_ERROR);
return yuvOffsets;
}
/**
* Returns the level of chrominance subsampling used in the YUV image. See
* {@link TJ#SAMP_444 TJ.SAMP_*}.
*
* @return the level of chrominance subsampling used in the YUV image
*/
public int getSubsamp() {
if (yuvSubsamp < 0 || yuvSubsamp >= TJ.NUMSAMP)
throw new IllegalStateException(NO_ASSOC_ERROR);
return yuvSubsamp;
}
/**
* Returns the YUV image planes. If the image is stored in a unified buffer,
* then all image planes will point to that buffer.
*
* @return the YUV image planes
*/
public byte[][] getPlanes() {
if (yuvPlanes == null)
throw new IllegalStateException(NO_ASSOC_ERROR);
return yuvPlanes;
}
/**
* Returns the YUV image buffer (if this image is stored in a unified
* buffer rather than separate image planes.)
*
* @return the YUV image buffer
*/
public byte[] getBuf() {
if (yuvPlanes == null || yuvSubsamp < 0 || yuvSubsamp >= TJ.NUMSAMP)
throw new IllegalStateException(NO_ASSOC_ERROR);
int nc = (yuvSubsamp == TJ.SAMP_GRAY ? 1 : 3);
for (int i = 1; i < nc; i++) {
if (yuvPlanes[i] != yuvPlanes[0])
throw new IllegalStateException("Image is not stored in a unified buffer");
}
return yuvPlanes[0];
}
/**
* Returns the size (in bytes) of the YUV image buffer (if this image is
* stored in a unified buffer rather than separate image planes.)
*
* @return the size (in bytes) of the YUV image buffer
*/
public int getSize() {
if (yuvPlanes == null || yuvSubsamp < 0 || yuvSubsamp >= TJ.NUMSAMP)
throw new IllegalStateException(NO_ASSOC_ERROR);
int nc = (yuvSubsamp == TJ.SAMP_GRAY ? 1 : 3);
if (yuvPad < 1)
throw new IllegalStateException("Image is not stored in a unified buffer");
for (int i = 1; i < nc; i++) {
if (yuvPlanes[i] != yuvPlanes[0])
throw new IllegalStateException("Image is not stored in a unified buffer");
}
return TJ.bufSizeYUV(yuvWidth, yuvPad, yuvHeight, yuvSubsamp);
}
private static int pad(int v, int p) {
return (v + p - 1) & (~(p - 1));
}
protected long handle = 0;
protected byte[][] yuvPlanes = null;
protected int[] yuvOffsets = null;
protected int[] yuvStrides = null;
protected int yuvPad = 0;
protected int yuvWidth = 0;
protected int yuvHeight = 0;
protected int yuvSubsamp = -1;
}