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1757 lines
73 KiB
1757 lines
73 KiB
/*
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* Copyright (C)2009-2015, 2017, 2020-2021 D. R. Commander.
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* All Rights Reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* - Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* - Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* - Neither the name of the libjpeg-turbo Project nor the names of its
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* contributors may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS",
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef __TURBOJPEG_H__
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#define __TURBOJPEG_H__
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#if defined(_WIN32) && defined(DLLDEFINE)
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#define DLLEXPORT __declspec(dllexport)
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#else
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#define DLLEXPORT
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#endif
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#define DLLCALL
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/**
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* @addtogroup TurboJPEG
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* TurboJPEG API. This API provides an interface for generating, decoding, and
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* transforming planar YUV and JPEG images in memory.
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*
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* @anchor YUVnotes
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* YUV Image Format Notes
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* ----------------------
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* Technically, the JPEG format uses the YCbCr colorspace (which is technically
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* not a colorspace but a color transform), but per the convention of the
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* digital video community, the TurboJPEG API uses "YUV" to refer to an image
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* format consisting of Y, Cb, and Cr image planes.
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*
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* Each plane is simply a 2D array of bytes, each byte representing the value
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* of one of the components (Y, Cb, or Cr) at a particular location in the
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* image. The width and height of each plane are determined by the image
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* width, height, and level of chrominance subsampling. The luminance plane
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* width is the image width padded to the nearest multiple of the horizontal
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* subsampling factor (2 in the case of 4:2:0 and 4:2:2, 4 in the case of
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* 4:1:1, 1 in the case of 4:4:4 or grayscale.) Similarly, the luminance plane
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* height is the image height padded to the nearest multiple of the vertical
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* subsampling factor (2 in the case of 4:2:0 or 4:4:0, 1 in the case of 4:4:4
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* or grayscale.) This is irrespective of any additional padding that may be
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* specified as an argument to the various YUV functions. The chrominance
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* plane width is equal to the luminance plane width divided by the horizontal
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* subsampling factor, and the chrominance plane height is equal to the
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* luminance plane height divided by the vertical subsampling factor.
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*
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* For example, if the source image is 35 x 35 pixels and 4:2:2 subsampling is
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* used, then the luminance plane would be 36 x 35 bytes, and each of the
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* chrominance planes would be 18 x 35 bytes. If you specify a line padding of
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* 4 bytes on top of this, then the luminance plane would be 36 x 35 bytes, and
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* each of the chrominance planes would be 20 x 35 bytes.
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*
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* @{
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*/
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/**
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* The number of chrominance subsampling options
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*/
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#define TJ_NUMSAMP 6
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/**
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* Chrominance subsampling options.
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* When pixels are converted from RGB to YCbCr (see #TJCS_YCbCr) or from CMYK
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* to YCCK (see #TJCS_YCCK) as part of the JPEG compression process, some of
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* the Cb and Cr (chrominance) components can be discarded or averaged together
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* to produce a smaller image with little perceptible loss of image clarity
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* (the human eye is more sensitive to small changes in brightness than to
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* small changes in color.) This is called "chrominance subsampling".
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*/
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enum TJSAMP {
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/**
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* 4:4:4 chrominance subsampling (no chrominance subsampling). The JPEG or
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* YUV image will contain one chrominance component for every pixel in the
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* source image.
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*/
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TJSAMP_444 = 0,
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/**
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* 4:2:2 chrominance subsampling. The JPEG or YUV image will contain one
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* chrominance component for every 2x1 block of pixels in the source image.
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*/
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TJSAMP_422,
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/**
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* 4:2:0 chrominance subsampling. The JPEG or YUV image will contain one
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* chrominance component for every 2x2 block of pixels in the source image.
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*/
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TJSAMP_420,
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/**
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* Grayscale. The JPEG or YUV image will contain no chrominance components.
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*/
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TJSAMP_GRAY,
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/**
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* 4:4:0 chrominance subsampling. The JPEG or YUV image will contain one
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* chrominance component for every 1x2 block of pixels in the source image.
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*
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* @note 4:4:0 subsampling is not fully accelerated in libjpeg-turbo.
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*/
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TJSAMP_440,
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/**
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* 4:1:1 chrominance subsampling. The JPEG or YUV image will contain one
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* chrominance component for every 4x1 block of pixels in the source image.
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* JPEG images compressed with 4:1:1 subsampling will be almost exactly the
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* same size as those compressed with 4:2:0 subsampling, and in the
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* aggregate, both subsampling methods produce approximately the same
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* perceptual quality. However, 4:1:1 is better able to reproduce sharp
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* horizontal features.
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*
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* @note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo.
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*/
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TJSAMP_411
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};
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/**
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* MCU block width (in pixels) for a given level of chrominance subsampling.
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* MCU block sizes:
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* - 8x8 for no subsampling or grayscale
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* - 16x8 for 4:2:2
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* - 8x16 for 4:4:0
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* - 16x16 for 4:2:0
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* - 32x8 for 4:1:1
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*/
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static const int tjMCUWidth[TJ_NUMSAMP] = { 8, 16, 16, 8, 8, 32 };
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/**
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* MCU block height (in pixels) for a given level of chrominance subsampling.
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* MCU block sizes:
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* - 8x8 for no subsampling or grayscale
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* - 16x8 for 4:2:2
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* - 8x16 for 4:4:0
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* - 16x16 for 4:2:0
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* - 32x8 for 4:1:1
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*/
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static const int tjMCUHeight[TJ_NUMSAMP] = { 8, 8, 16, 8, 16, 8 };
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/**
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* The number of pixel formats
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*/
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#define TJ_NUMPF 12
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/**
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* Pixel formats
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*/
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enum TJPF {
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/**
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* RGB pixel format. The red, green, and blue components in the image are
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* stored in 3-byte pixels in the order R, G, B from lowest to highest byte
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* address within each pixel.
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*/
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TJPF_RGB = 0,
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/**
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* BGR pixel format. The red, green, and blue components in the image are
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* stored in 3-byte pixels in the order B, G, R from lowest to highest byte
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* address within each pixel.
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*/
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TJPF_BGR,
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/**
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* RGBX pixel format. The red, green, and blue components in the image are
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* stored in 4-byte pixels in the order R, G, B from lowest to highest byte
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* address within each pixel. The X component is ignored when compressing
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* and undefined when decompressing.
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*/
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TJPF_RGBX,
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/**
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* BGRX pixel format. The red, green, and blue components in the image are
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* stored in 4-byte pixels in the order B, G, R from lowest to highest byte
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* address within each pixel. The X component is ignored when compressing
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* and undefined when decompressing.
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*/
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TJPF_BGRX,
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/**
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* XBGR pixel format. The red, green, and blue components in the image are
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* stored in 4-byte pixels in the order R, G, B from highest to lowest byte
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* address within each pixel. The X component is ignored when compressing
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* and undefined when decompressing.
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*/
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TJPF_XBGR,
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/**
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* XRGB pixel format. The red, green, and blue components in the image are
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* stored in 4-byte pixels in the order B, G, R from highest to lowest byte
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* address within each pixel. The X component is ignored when compressing
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* and undefined when decompressing.
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*/
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TJPF_XRGB,
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/**
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* Grayscale pixel format. Each 1-byte pixel represents a luminance
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* (brightness) level from 0 to 255.
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*/
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TJPF_GRAY,
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/**
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* RGBA pixel format. This is the same as @ref TJPF_RGBX, except that when
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* decompressing, the X component is guaranteed to be 0xFF, which can be
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* interpreted as an opaque alpha channel.
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*/
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TJPF_RGBA,
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/**
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* BGRA pixel format. This is the same as @ref TJPF_BGRX, except that when
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* decompressing, the X component is guaranteed to be 0xFF, which can be
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* interpreted as an opaque alpha channel.
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*/
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TJPF_BGRA,
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/**
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* ABGR pixel format. This is the same as @ref TJPF_XBGR, except that when
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* decompressing, the X component is guaranteed to be 0xFF, which can be
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* interpreted as an opaque alpha channel.
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*/
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TJPF_ABGR,
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/**
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* ARGB pixel format. This is the same as @ref TJPF_XRGB, except that when
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* decompressing, the X component is guaranteed to be 0xFF, which can be
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* interpreted as an opaque alpha channel.
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*/
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TJPF_ARGB,
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/**
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* CMYK pixel format. Unlike RGB, which is an additive color model used
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* primarily for display, CMYK (Cyan/Magenta/Yellow/Key) is a subtractive
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* color model used primarily for printing. In the CMYK color model, the
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* value of each color component typically corresponds to an amount of cyan,
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* magenta, yellow, or black ink that is applied to a white background. In
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* order to convert between CMYK and RGB, it is necessary to use a color
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* management system (CMS.) A CMS will attempt to map colors within the
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* printer's gamut to perceptually similar colors in the display's gamut and
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* vice versa, but the mapping is typically not 1:1 or reversible, nor can it
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* be defined with a simple formula. Thus, such a conversion is out of scope
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* for a codec library. However, the TurboJPEG API allows for compressing
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* CMYK pixels into a YCCK JPEG image (see #TJCS_YCCK) and decompressing YCCK
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* JPEG images into CMYK pixels.
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*/
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TJPF_CMYK,
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/**
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* Unknown pixel format. Currently this is only used by #tjLoadImage().
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*/
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TJPF_UNKNOWN = -1
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};
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/**
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* Red offset (in bytes) for a given pixel format. This specifies the number
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* of bytes that the red component is offset from the start of the pixel. For
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* instance, if a pixel of format TJ_BGRX is stored in <tt>char pixel[]</tt>,
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* then the red component will be <tt>pixel[tjRedOffset[TJ_BGRX]]</tt>. This
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* will be -1 if the pixel format does not have a red component.
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*/
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static const int tjRedOffset[TJ_NUMPF] = {
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0, 2, 0, 2, 3, 1, -1, 0, 2, 3, 1, -1
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};
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/**
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* Green offset (in bytes) for a given pixel format. This specifies the number
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* of bytes that the green component is offset from the start of the pixel.
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* For instance, if a pixel of format TJ_BGRX is stored in
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* <tt>char pixel[]</tt>, then the green component will be
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* <tt>pixel[tjGreenOffset[TJ_BGRX]]</tt>. This will be -1 if the pixel format
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* does not have a green component.
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*/
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static const int tjGreenOffset[TJ_NUMPF] = {
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1, 1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1
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};
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/**
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* Blue offset (in bytes) for a given pixel format. This specifies the number
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* of bytes that the Blue component is offset from the start of the pixel. For
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* instance, if a pixel of format TJ_BGRX is stored in <tt>char pixel[]</tt>,
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* then the blue component will be <tt>pixel[tjBlueOffset[TJ_BGRX]]</tt>. This
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* will be -1 if the pixel format does not have a blue component.
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*/
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static const int tjBlueOffset[TJ_NUMPF] = {
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2, 0, 2, 0, 1, 3, -1, 2, 0, 1, 3, -1
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};
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/**
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* Alpha offset (in bytes) for a given pixel format. This specifies the number
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* of bytes that the Alpha component is offset from the start of the pixel.
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* For instance, if a pixel of format TJ_BGRA is stored in
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* <tt>char pixel[]</tt>, then the alpha component will be
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* <tt>pixel[tjAlphaOffset[TJ_BGRA]]</tt>. This will be -1 if the pixel format
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* does not have an alpha component.
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*/
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static const int tjAlphaOffset[TJ_NUMPF] = {
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-1, -1, -1, -1, -1, -1, -1, 3, 3, 0, 0, -1
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};
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/**
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* Pixel size (in bytes) for a given pixel format
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*/
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static const int tjPixelSize[TJ_NUMPF] = {
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3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4
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};
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/**
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* The number of JPEG colorspaces
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*/
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#define TJ_NUMCS 5
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/**
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* JPEG colorspaces
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*/
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enum TJCS {
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/**
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* RGB colorspace. When compressing the JPEG image, the R, G, and B
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* components in the source image are reordered into image planes, but no
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* colorspace conversion or subsampling is performed. RGB JPEG images can be
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* decompressed to any of the extended RGB pixel formats or grayscale, but
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* they cannot be decompressed to YUV images.
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*/
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TJCS_RGB = 0,
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/**
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* YCbCr colorspace. YCbCr is not an absolute colorspace but rather a
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* mathematical transformation of RGB designed solely for storage and
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* transmission. YCbCr images must be converted to RGB before they can
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* actually be displayed. In the YCbCr colorspace, the Y (luminance)
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* component represents the black & white portion of the original image, and
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* the Cb and Cr (chrominance) components represent the color portion of the
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* original image. Originally, the analog equivalent of this transformation
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* allowed the same signal to drive both black & white and color televisions,
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* but JPEG images use YCbCr primarily because it allows the color data to be
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* optionally subsampled for the purposes of reducing bandwidth or disk
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* space. YCbCr is the most common JPEG colorspace, and YCbCr JPEG images
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* can be compressed from and decompressed to any of the extended RGB pixel
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* formats or grayscale, or they can be decompressed to YUV planar images.
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*/
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TJCS_YCbCr,
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/**
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* Grayscale colorspace. The JPEG image retains only the luminance data (Y
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* component), and any color data from the source image is discarded.
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* Grayscale JPEG images can be compressed from and decompressed to any of
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* the extended RGB pixel formats or grayscale, or they can be decompressed
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* to YUV planar images.
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*/
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TJCS_GRAY,
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/**
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* CMYK colorspace. When compressing the JPEG image, the C, M, Y, and K
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* components in the source image are reordered into image planes, but no
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* colorspace conversion or subsampling is performed. CMYK JPEG images can
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* only be decompressed to CMYK pixels.
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*/
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TJCS_CMYK,
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/**
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* YCCK colorspace. YCCK (AKA "YCbCrK") is not an absolute colorspace but
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* rather a mathematical transformation of CMYK designed solely for storage
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* and transmission. It is to CMYK as YCbCr is to RGB. CMYK pixels can be
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* reversibly transformed into YCCK, and as with YCbCr, the chrominance
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* components in the YCCK pixels can be subsampled without incurring major
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* perceptual loss. YCCK JPEG images can only be compressed from and
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* decompressed to CMYK pixels.
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*/
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TJCS_YCCK
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};
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/**
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* The uncompressed source/destination image is stored in bottom-up (Windows,
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* OpenGL) order, not top-down (X11) order.
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*/
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#define TJFLAG_BOTTOMUP 2
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/**
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* When decompressing an image that was compressed using chrominance
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* subsampling, use the fastest chrominance upsampling algorithm available in
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* the underlying codec. The default is to use smooth upsampling, which
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* creates a smooth transition between neighboring chrominance components in
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* order to reduce upsampling artifacts in the decompressed image.
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*/
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#define TJFLAG_FASTUPSAMPLE 256
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/**
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* Disable buffer (re)allocation. If passed to one of the JPEG compression or
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* transform functions, this flag will cause those functions to generate an
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* error if the JPEG image buffer is invalid or too small rather than
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* attempting to allocate or reallocate that buffer. This reproduces the
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* behavior of earlier versions of TurboJPEG.
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*/
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#define TJFLAG_NOREALLOC 1024
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/**
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* Use the fastest DCT/IDCT algorithm available in the underlying codec. The
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* default if this flag is not specified is implementation-specific. For
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* example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast
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* algorithm by default when compressing, because this has been shown to have
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* only a very slight effect on accuracy, but it uses the accurate algorithm
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* when decompressing, because this has been shown to have a larger effect.
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*/
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#define TJFLAG_FASTDCT 2048
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/**
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* Use the most accurate DCT/IDCT algorithm available in the underlying codec.
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* The default if this flag is not specified is implementation-specific. For
|
|
* example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast
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* algorithm by default when compressing, because this has been shown to have
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* only a very slight effect on accuracy, but it uses the accurate algorithm
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* when decompressing, because this has been shown to have a larger effect.
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*/
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#define TJFLAG_ACCURATEDCT 4096
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/**
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* Immediately discontinue the current compression/decompression/transform
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* operation if the underlying codec throws a warning (non-fatal error). The
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* default behavior is to allow the operation to complete unless a fatal error
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* is encountered.
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*/
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#define TJFLAG_STOPONWARNING 8192
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/**
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* Use progressive entropy coding in JPEG images generated by the compression
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* and transform functions. Progressive entropy coding will generally improve
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* compression relative to baseline entropy coding (the default), but it will
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* reduce compression and decompression performance considerably.
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*/
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#define TJFLAG_PROGRESSIVE 16384
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/**
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* Limit the number of progressive JPEG scans that the decompression and
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* transform functions will process. If a progressive JPEG image contains an
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* unreasonably large number of scans, then this flag will cause the
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* decompression and transform functions to return an error. The primary
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* purpose of this is to allow security-critical applications to guard against
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* an exploit of the progressive JPEG format described in
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* <a href="https://libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf" target="_blank">this report</a>.
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*/
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#define TJFLAG_LIMITSCANS 32768
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/**
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* The number of error codes
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*/
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#define TJ_NUMERR 2
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/**
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* Error codes
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*/
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enum TJERR {
|
|
/**
|
|
* The error was non-fatal and recoverable, but the image may still be
|
|
* corrupt.
|
|
*/
|
|
TJERR_WARNING = 0,
|
|
/**
|
|
* The error was fatal and non-recoverable.
|
|
*/
|
|
TJERR_FATAL
|
|
};
|
|
|
|
|
|
/**
|
|
* The number of transform operations
|
|
*/
|
|
#define TJ_NUMXOP 8
|
|
|
|
/**
|
|
* Transform operations for #tjTransform()
|
|
*/
|
|
enum TJXOP {
|
|
/**
|
|
* Do not transform the position of the image pixels
|
|
*/
|
|
TJXOP_NONE = 0,
|
|
/**
|
|
* Flip (mirror) image horizontally. This transform is imperfect if there
|
|
* are any partial MCU blocks on the right edge (see #TJXOPT_PERFECT.)
|
|
*/
|
|
TJXOP_HFLIP,
|
|
/**
|
|
* Flip (mirror) image vertically. This transform is imperfect if there are
|
|
* any partial MCU blocks on the bottom edge (see #TJXOPT_PERFECT.)
|
|
*/
|
|
TJXOP_VFLIP,
|
|
/**
|
|
* Transpose image (flip/mirror along upper left to lower right axis.) This
|
|
* transform is always perfect.
|
|
*/
|
|
TJXOP_TRANSPOSE,
|
|
/**
|
|
* Transverse transpose image (flip/mirror along upper right to lower left
|
|
* axis.) This transform is imperfect if there are any partial MCU blocks in
|
|
* the image (see #TJXOPT_PERFECT.)
|
|
*/
|
|
TJXOP_TRANSVERSE,
|
|
/**
|
|
* Rotate image clockwise by 90 degrees. This transform is imperfect if
|
|
* there are any partial MCU blocks on the bottom edge (see
|
|
* #TJXOPT_PERFECT.)
|
|
*/
|
|
TJXOP_ROT90,
|
|
/**
|
|
* Rotate image 180 degrees. This transform is imperfect if there are any
|
|
* partial MCU blocks in the image (see #TJXOPT_PERFECT.)
|
|
*/
|
|
TJXOP_ROT180,
|
|
/**
|
|
* Rotate image counter-clockwise by 90 degrees. This transform is imperfect
|
|
* if there are any partial MCU blocks on the right edge (see
|
|
* #TJXOPT_PERFECT.)
|
|
*/
|
|
TJXOP_ROT270
|
|
};
|
|
|
|
|
|
/**
|
|
* This option will cause #tjTransform() to return an error if the transform is
|
|
* not perfect. Lossless transforms operate on MCU blocks, whose size depends
|
|
* on the level of chrominance subsampling used (see #tjMCUWidth
|
|
* and #tjMCUHeight.) If the image's width or height is not evenly divisible
|
|
* by the MCU block size, then there will be partial MCU blocks on the right
|
|
* and/or bottom edges. It is not possible to move these partial MCU blocks to
|
|
* the top or left of the image, so any transform that would require that is
|
|
* "imperfect." If this option is not specified, then any partial MCU blocks
|
|
* that cannot be transformed will be left in place, which will create
|
|
* odd-looking strips on the right or bottom edge of the image.
|
|
*/
|
|
#define TJXOPT_PERFECT 1
|
|
/**
|
|
* This option will cause #tjTransform() to discard any partial MCU blocks that
|
|
* cannot be transformed.
|
|
*/
|
|
#define TJXOPT_TRIM 2
|
|
/**
|
|
* This option will enable lossless cropping. See #tjTransform() for more
|
|
* information.
|
|
*/
|
|
#define TJXOPT_CROP 4
|
|
/**
|
|
* This option will discard the color data in the input image and produce
|
|
* a grayscale output image.
|
|
*/
|
|
#define TJXOPT_GRAY 8
|
|
/**
|
|
* This option will prevent #tjTransform() from outputting a JPEG image for
|
|
* this particular transform (this can be used in conjunction with a custom
|
|
* filter to capture the transformed DCT coefficients without transcoding
|
|
* them.)
|
|
*/
|
|
#define TJXOPT_NOOUTPUT 16
|
|
/**
|
|
* This option will enable progressive entropy coding in the output image
|
|
* generated by this particular transform. Progressive entropy coding will
|
|
* generally improve compression relative to baseline entropy coding (the
|
|
* default), but it will reduce compression and decompression performance
|
|
* considerably.
|
|
*/
|
|
#define TJXOPT_PROGRESSIVE 32
|
|
/**
|
|
* This option will prevent #tjTransform() from copying any extra markers
|
|
* (including EXIF and ICC profile data) from the source image to the output
|
|
* image.
|
|
*/
|
|
#define TJXOPT_COPYNONE 64
|
|
|
|
|
|
/**
|
|
* Scaling factor
|
|
*/
|
|
typedef struct {
|
|
/**
|
|
* Numerator
|
|
*/
|
|
int num;
|
|
/**
|
|
* Denominator
|
|
*/
|
|
int denom;
|
|
} tjscalingfactor;
|
|
|
|
/**
|
|
* Cropping region
|
|
*/
|
|
typedef struct {
|
|
/**
|
|
* The left boundary of the cropping region. This must be evenly divisible
|
|
* by the MCU block width (see #tjMCUWidth.)
|
|
*/
|
|
int x;
|
|
/**
|
|
* The upper boundary of the cropping region. This must be evenly divisible
|
|
* by the MCU block height (see #tjMCUHeight.)
|
|
*/
|
|
int y;
|
|
/**
|
|
* The width of the cropping region. Setting this to 0 is the equivalent of
|
|
* setting it to the width of the source JPEG image - x.
|
|
*/
|
|
int w;
|
|
/**
|
|
* The height of the cropping region. Setting this to 0 is the equivalent of
|
|
* setting it to the height of the source JPEG image - y.
|
|
*/
|
|
int h;
|
|
} tjregion;
|
|
|
|
/**
|
|
* Lossless transform
|
|
*/
|
|
typedef struct tjtransform {
|
|
/**
|
|
* Cropping region
|
|
*/
|
|
tjregion r;
|
|
/**
|
|
* One of the @ref TJXOP "transform operations"
|
|
*/
|
|
int op;
|
|
/**
|
|
* The bitwise OR of one of more of the @ref TJXOPT_CROP "transform options"
|
|
*/
|
|
int options;
|
|
/**
|
|
* Arbitrary data that can be accessed within the body of the callback
|
|
* function
|
|
*/
|
|
void *data;
|
|
/**
|
|
* A callback function that can be used to modify the DCT coefficients
|
|
* after they are losslessly transformed but before they are transcoded to a
|
|
* new JPEG image. This allows for custom filters or other transformations
|
|
* to be applied in the frequency domain.
|
|
*
|
|
* @param coeffs pointer to an array of transformed DCT coefficients. (NOTE:
|
|
* this pointer is not guaranteed to be valid once the callback returns, so
|
|
* applications wishing to hand off the DCT coefficients to another function
|
|
* or library should make a copy of them within the body of the callback.)
|
|
*
|
|
* @param arrayRegion #tjregion structure containing the width and height of
|
|
* the array pointed to by <tt>coeffs</tt> as well as its offset relative to
|
|
* the component plane. TurboJPEG implementations may choose to split each
|
|
* component plane into multiple DCT coefficient arrays and call the callback
|
|
* function once for each array.
|
|
*
|
|
* @param planeRegion #tjregion structure containing the width and height of
|
|
* the component plane to which <tt>coeffs</tt> belongs
|
|
*
|
|
* @param componentID ID number of the component plane to which
|
|
* <tt>coeffs</tt> belongs (Y, Cb, and Cr have, respectively, ID's of 0, 1,
|
|
* and 2 in typical JPEG images.)
|
|
*
|
|
* @param transformID ID number of the transformed image to which
|
|
* <tt>coeffs</tt> belongs. This is the same as the index of the transform
|
|
* in the <tt>transforms</tt> array that was passed to #tjTransform().
|
|
*
|
|
* @param transform a pointer to a #tjtransform structure that specifies the
|
|
* parameters and/or cropping region for this transform
|
|
*
|
|
* @return 0 if the callback was successful, or -1 if an error occurred.
|
|
*/
|
|
int (*customFilter) (short *coeffs, tjregion arrayRegion,
|
|
tjregion planeRegion, int componentIndex,
|
|
int transformIndex, struct tjtransform *transform);
|
|
} tjtransform;
|
|
|
|
/**
|
|
* TurboJPEG instance handle
|
|
*/
|
|
typedef void *tjhandle;
|
|
|
|
|
|
/**
|
|
* Pad the given width to the nearest 32-bit boundary
|
|
*/
|
|
#define TJPAD(width) (((width) + 3) & (~3))
|
|
|
|
/**
|
|
* Compute the scaled value of <tt>dimension</tt> using the given scaling
|
|
* factor. This macro performs the integer equivalent of <tt>ceil(dimension *
|
|
* scalingFactor)</tt>.
|
|
*/
|
|
#define TJSCALED(dimension, scalingFactor) \
|
|
((dimension * scalingFactor.num + scalingFactor.denom - 1) / \
|
|
scalingFactor.denom)
|
|
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
|
|
/**
|
|
* Create a TurboJPEG compressor instance.
|
|
*
|
|
* @return a handle to the newly-created instance, or NULL if an error
|
|
* occurred (see #tjGetErrorStr2().)
|
|
*/
|
|
DLLEXPORT tjhandle tjInitCompress(void);
|
|
|
|
|
|
/**
|
|
* Compress an RGB, grayscale, or CMYK image into a JPEG image.
|
|
*
|
|
* @param handle a handle to a TurboJPEG compressor or transformer instance
|
|
*
|
|
* @param srcBuf pointer to an image buffer containing RGB, grayscale, or
|
|
* CMYK pixels to be compressed
|
|
*
|
|
* @param width width (in pixels) of the source image
|
|
*
|
|
* @param pitch bytes per line in the source image. Normally, this should be
|
|
* <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or
|
|
* <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image
|
|
* is padded to the nearest 32-bit boundary, as is the case for Windows
|
|
* bitmaps. You can also be clever and use this parameter to skip lines, etc.
|
|
* Setting this parameter to 0 is the equivalent of setting it to
|
|
* <tt>width * #tjPixelSize[pixelFormat]</tt>.
|
|
*
|
|
* @param height height (in pixels) of the source image
|
|
*
|
|
* @param pixelFormat pixel format of the source image (see @ref TJPF
|
|
* "Pixel formats".)
|
|
*
|
|
* @param jpegBuf address of a pointer to an image buffer that will receive the
|
|
* JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer
|
|
* to accommodate the size of the JPEG image. Thus, you can choose to:
|
|
* -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
|
|
* let TurboJPEG grow the buffer as needed,
|
|
* -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer
|
|
* for you, or
|
|
* -# pre-allocate the buffer to a "worst case" size determined by calling
|
|
* #tjBufSize(). This should ensure that the buffer never has to be
|
|
* re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.)
|
|
* .
|
|
* If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your
|
|
* pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC,
|
|
* you should always check <tt>*jpegBuf</tt> upon return from this function, as
|
|
* it may have changed.
|
|
*
|
|
* @param jpegSize pointer to an unsigned long variable that holds the size of
|
|
* the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated
|
|
* buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer.
|
|
* Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in
|
|
* bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being
|
|
* reused from a previous call to one of the JPEG compression functions, then
|
|
* <tt>*jpegSize</tt> is ignored.
|
|
*
|
|
* @param jpegSubsamp the level of chrominance subsampling to be used when
|
|
* generating the JPEG image (see @ref TJSAMP
|
|
* "Chrominance subsampling options".)
|
|
*
|
|
* @param jpegQual the image quality of the generated JPEG image (1 = worst,
|
|
* 100 = best)
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjCompress2(tjhandle handle, const unsigned char *srcBuf,
|
|
int width, int pitch, int height, int pixelFormat,
|
|
unsigned char **jpegBuf, unsigned long *jpegSize,
|
|
int jpegSubsamp, int jpegQual, int flags);
|
|
|
|
|
|
/**
|
|
* Compress a YUV planar image into a JPEG image.
|
|
*
|
|
* @param handle a handle to a TurboJPEG compressor or transformer instance
|
|
*
|
|
* @param srcBuf pointer to an image buffer containing a YUV planar image to be
|
|
* compressed. The size of this buffer should match the value returned by
|
|
* #tjBufSizeYUV2() for the given image width, height, padding, and level of
|
|
* chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be
|
|
* stored sequentially in the source buffer (refer to @ref YUVnotes
|
|
* "YUV Image Format Notes".)
|
|
*
|
|
* @param width width (in pixels) of the source image. If the width is not an
|
|
* even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
|
|
* buffer copy will be performed within TurboJPEG.
|
|
*
|
|
* @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 <tt>pad</tt> should be set to 4.
|
|
*
|
|
* @param height height (in pixels) of the source image. If the height is not
|
|
* an even multiple of the MCU block height (see #tjMCUHeight), then an
|
|
* intermediate buffer copy will be performed within TurboJPEG.
|
|
*
|
|
* @param subsamp the level of chrominance subsampling used in the source
|
|
* image (see @ref TJSAMP "Chrominance subsampling options".)
|
|
*
|
|
* @param jpegBuf address of a pointer to an image buffer that will receive the
|
|
* JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to
|
|
* accommodate the size of the JPEG image. Thus, you can choose to:
|
|
* -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
|
|
* let TurboJPEG grow the buffer as needed,
|
|
* -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer
|
|
* for you, or
|
|
* -# pre-allocate the buffer to a "worst case" size determined by calling
|
|
* #tjBufSize(). This should ensure that the buffer never has to be
|
|
* re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.)
|
|
* .
|
|
* If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your
|
|
* pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC,
|
|
* you should always check <tt>*jpegBuf</tt> upon return from this function, as
|
|
* it may have changed.
|
|
*
|
|
* @param jpegSize pointer to an unsigned long variable that holds the size of
|
|
* the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated
|
|
* buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer.
|
|
* Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in
|
|
* bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being
|
|
* reused from a previous call to one of the JPEG compression functions, then
|
|
* <tt>*jpegSize</tt> is ignored.
|
|
*
|
|
* @param jpegQual the image quality of the generated JPEG image (1 = worst,
|
|
* 100 = best)
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjCompressFromYUV(tjhandle handle, const unsigned char *srcBuf,
|
|
int width, int pad, int height, int subsamp,
|
|
unsigned char **jpegBuf,
|
|
unsigned long *jpegSize, int jpegQual,
|
|
int flags);
|
|
|
|
|
|
/**
|
|
* Compress a set of Y, U (Cb), and V (Cr) image planes into a JPEG image.
|
|
*
|
|
* @param handle a handle to a TurboJPEG compressor or transformer instance
|
|
*
|
|
* @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
|
|
* (or just a Y plane, if compressing a grayscale image) that contain a YUV
|
|
* image to be compressed. These planes can be contiguous or non-contiguous in
|
|
* memory. The size of each plane should match the value returned by
|
|
* #tjPlaneSizeYUV() for the given image width, height, strides, and level of
|
|
* chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes"
|
|
* for more details.
|
|
*
|
|
* @param width width (in pixels) of the source image. If the width is not an
|
|
* even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
|
|
* buffer copy will be performed within TurboJPEG.
|
|
*
|
|
* @param strides an array of integers, each specifying the number of bytes per
|
|
* line in the corresponding plane of the YUV source image. Setting the stride
|
|
* for any plane to 0 is the same as setting it to the plane width (see
|
|
* @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then
|
|
* the strides for all planes will be set to their respective plane widths.
|
|
* You can adjust the strides in order to specify an arbitrary amount of line
|
|
* padding in each plane or to create a JPEG image from a subregion of a larger
|
|
* YUV planar image.
|
|
*
|
|
* @param height height (in pixels) of the source image. If the height is not
|
|
* an even multiple of the MCU block height (see #tjMCUHeight), then an
|
|
* intermediate buffer copy will be performed within TurboJPEG.
|
|
*
|
|
* @param subsamp the level of chrominance subsampling used in the source
|
|
* image (see @ref TJSAMP "Chrominance subsampling options".)
|
|
*
|
|
* @param jpegBuf address of a pointer to an image buffer that will receive the
|
|
* JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to
|
|
* accommodate the size of the JPEG image. Thus, you can choose to:
|
|
* -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
|
|
* let TurboJPEG grow the buffer as needed,
|
|
* -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer
|
|
* for you, or
|
|
* -# pre-allocate the buffer to a "worst case" size determined by calling
|
|
* #tjBufSize(). This should ensure that the buffer never has to be
|
|
* re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.)
|
|
* .
|
|
* If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your
|
|
* pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC,
|
|
* you should always check <tt>*jpegBuf</tt> upon return from this function, as
|
|
* it may have changed.
|
|
*
|
|
* @param jpegSize pointer to an unsigned long variable that holds the size of
|
|
* the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated
|
|
* buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer.
|
|
* Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in
|
|
* bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being
|
|
* reused from a previous call to one of the JPEG compression functions, then
|
|
* <tt>*jpegSize</tt> is ignored.
|
|
*
|
|
* @param jpegQual the image quality of the generated JPEG image (1 = worst,
|
|
* 100 = best)
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjCompressFromYUVPlanes(tjhandle handle,
|
|
const unsigned char **srcPlanes,
|
|
int width, const int *strides,
|
|
int height, int subsamp,
|
|
unsigned char **jpegBuf,
|
|
unsigned long *jpegSize, int jpegQual,
|
|
int flags);
|
|
|
|
|
|
/**
|
|
* The maximum size of the buffer (in bytes) required to hold a JPEG image with
|
|
* the given parameters. The number of bytes returned by this function is
|
|
* larger than the size of the uncompressed source image. The reason for this
|
|
* is that the JPEG format uses 16-bit coefficients, and it is thus possible
|
|
* for a very high-quality JPEG image with very high-frequency content to
|
|
* expand rather than compress when converted to the JPEG format. Such images
|
|
* represent a very rare corner case, but since there is no way to predict the
|
|
* size of a JPEG image prior to compression, the corner case has to be
|
|
* handled.
|
|
*
|
|
* @param width width (in pixels) of the image
|
|
*
|
|
* @param height height (in pixels) of the image
|
|
*
|
|
* @param jpegSubsamp the level of chrominance subsampling to be used when
|
|
* generating the JPEG image (see @ref TJSAMP
|
|
* "Chrominance subsampling options".)
|
|
*
|
|
* @return the maximum size of the buffer (in bytes) required to hold the
|
|
* image, or -1 if the arguments are out of bounds.
|
|
*/
|
|
DLLEXPORT unsigned long tjBufSize(int width, int height, int jpegSubsamp);
|
|
|
|
|
|
/**
|
|
* The size of the buffer (in bytes) required to hold a YUV planar image with
|
|
* the given parameters.
|
|
*
|
|
* @param width width (in pixels) of the image
|
|
*
|
|
* @param pad the width of each line in each plane of the image is padded to
|
|
* the nearest multiple of this number of bytes (must be a power of 2.)
|
|
*
|
|
* @param height height (in pixels) of the image
|
|
*
|
|
* @param subsamp level of chrominance subsampling in the image (see
|
|
* @ref TJSAMP "Chrominance subsampling options".)
|
|
*
|
|
* @return the size of the buffer (in bytes) required to hold the image, or
|
|
* -1 if the arguments are out of bounds.
|
|
*/
|
|
DLLEXPORT unsigned long tjBufSizeYUV2(int width, int pad, int height,
|
|
int subsamp);
|
|
|
|
|
|
/**
|
|
* The size of the buffer (in bytes) required to hold a YUV image plane with
|
|
* the given parameters.
|
|
*
|
|
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
|
|
*
|
|
* @param width width (in pixels) of the YUV image. NOTE: this is the width of
|
|
* the whole image, not the plane width.
|
|
*
|
|
* @param stride bytes per line in the image plane. Setting this to 0 is the
|
|
* equivalent of setting it to the plane width.
|
|
*
|
|
* @param height height (in pixels) of the YUV image. NOTE: this is the height
|
|
* of the whole image, not the plane height.
|
|
*
|
|
* @param subsamp level of chrominance subsampling in the image (see
|
|
* @ref TJSAMP "Chrominance subsampling options".)
|
|
*
|
|
* @return the size of the buffer (in bytes) required to hold the YUV image
|
|
* plane, or -1 if the arguments are out of bounds.
|
|
*/
|
|
DLLEXPORT unsigned long tjPlaneSizeYUV(int componentID, int width, int stride,
|
|
int height, int subsamp);
|
|
|
|
|
|
/**
|
|
* The plane width of a YUV image plane with the given parameters. Refer to
|
|
* @ref YUVnotes "YUV Image Format Notes" for a description of plane width.
|
|
*
|
|
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
|
|
*
|
|
* @param width width (in pixels) of the YUV image
|
|
*
|
|
* @param subsamp level of chrominance subsampling in the image (see
|
|
* @ref TJSAMP "Chrominance subsampling options".)
|
|
*
|
|
* @return the plane width of a YUV image plane with the given parameters, or
|
|
* -1 if the arguments are out of bounds.
|
|
*/
|
|
DLLEXPORT int tjPlaneWidth(int componentID, int width, int subsamp);
|
|
|
|
|
|
/**
|
|
* The plane height of a YUV image plane with the given parameters. Refer to
|
|
* @ref YUVnotes "YUV Image Format Notes" for a description of plane height.
|
|
*
|
|
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
|
|
*
|
|
* @param height height (in pixels) of the YUV image
|
|
*
|
|
* @param subsamp level of chrominance subsampling in the image (see
|
|
* @ref TJSAMP "Chrominance subsampling options".)
|
|
*
|
|
* @return the plane height of a YUV image plane with the given parameters, or
|
|
* -1 if the arguments are out of bounds.
|
|
*/
|
|
DLLEXPORT int tjPlaneHeight(int componentID, int height, int subsamp);
|
|
|
|
|
|
/**
|
|
* Encode an RGB or grayscale image into a YUV planar image. This function
|
|
* uses the accelerated color conversion routines in the underlying
|
|
* codec but does not execute any of the other steps in the JPEG compression
|
|
* process.
|
|
*
|
|
* @param handle a handle to a TurboJPEG compressor or transformer instance
|
|
*
|
|
* @param srcBuf pointer to an image buffer containing RGB or grayscale pixels
|
|
* to be encoded
|
|
*
|
|
* @param width width (in pixels) of the source image
|
|
*
|
|
* @param pitch bytes per line in the source image. Normally, this should be
|
|
* <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or
|
|
* <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image
|
|
* is padded to the nearest 32-bit boundary, as is the case for Windows
|
|
* bitmaps. You can also be clever and use this parameter to skip lines, etc.
|
|
* Setting this parameter to 0 is the equivalent of setting it to
|
|
* <tt>width * #tjPixelSize[pixelFormat]</tt>.
|
|
*
|
|
* @param height height (in pixels) of the source image
|
|
*
|
|
* @param pixelFormat pixel format of the source image (see @ref TJPF
|
|
* "Pixel formats".)
|
|
*
|
|
* @param dstBuf pointer to an image buffer that will receive the YUV image.
|
|
* Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based
|
|
* on the image width, height, padding, and level of chrominance subsampling.
|
|
* The Y, U (Cb), and V (Cr) image planes will be stored sequentially in the
|
|
* buffer (refer to @ref YUVnotes "YUV Image Format Notes".)
|
|
*
|
|
* @param pad the width of each line in each plane of the YUV image will be
|
|
* padded to the nearest multiple of this number of bytes (must be a power of
|
|
* 2.) To generate images suitable for X Video, <tt>pad</tt> should be set to
|
|
* 4.
|
|
*
|
|
* @param subsamp the level of chrominance subsampling to be used when
|
|
* generating the YUV image (see @ref TJSAMP
|
|
* "Chrominance subsampling options".) To generate images suitable for X
|
|
* Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420. This produces an
|
|
* image compatible with the I420 (AKA "YUV420P") format.
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjEncodeYUV3(tjhandle handle, const unsigned char *srcBuf,
|
|
int width, int pitch, int height, int pixelFormat,
|
|
unsigned char *dstBuf, int pad, int subsamp,
|
|
int flags);
|
|
|
|
|
|
/**
|
|
* Encode an RGB or grayscale image into separate Y, U (Cb), and V (Cr) image
|
|
* planes. This function uses the accelerated color conversion routines in the
|
|
* underlying codec but does not execute any of the other steps in the JPEG
|
|
* compression process.
|
|
*
|
|
* @param handle a handle to a TurboJPEG compressor or transformer instance
|
|
*
|
|
* @param srcBuf pointer to an image buffer containing RGB or grayscale pixels
|
|
* to be encoded
|
|
*
|
|
* @param width width (in pixels) of the source image
|
|
*
|
|
* @param pitch bytes per line in the source image. Normally, this should be
|
|
* <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or
|
|
* <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image
|
|
* is padded to the nearest 32-bit boundary, as is the case for Windows
|
|
* bitmaps. You can also be clever and use this parameter to skip lines, etc.
|
|
* Setting this parameter to 0 is the equivalent of setting it to
|
|
* <tt>width * #tjPixelSize[pixelFormat]</tt>.
|
|
*
|
|
* @param height height (in pixels) of the source image
|
|
*
|
|
* @param pixelFormat pixel format of the source image (see @ref TJPF
|
|
* "Pixel formats".)
|
|
*
|
|
* @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
|
|
* (or just a Y plane, if generating a grayscale image) that will receive the
|
|
* encoded image. These planes can be contiguous or non-contiguous in memory.
|
|
* Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
|
|
* on the image width, height, strides, and level of chrominance subsampling.
|
|
* Refer to @ref YUVnotes "YUV Image Format Notes" for more details.
|
|
*
|
|
* @param strides an array of integers, each specifying the number of bytes per
|
|
* line in the corresponding plane of the output image. Setting the stride for
|
|
* any plane to 0 is the same as setting it to the plane width (see
|
|
* @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> 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 encode an RGB or grayscale image into a
|
|
* subregion of a larger YUV planar image.
|
|
*
|
|
* @param subsamp the level of chrominance subsampling to be used when
|
|
* generating the YUV image (see @ref TJSAMP
|
|
* "Chrominance subsampling options".) To generate images suitable for X
|
|
* Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420. This produces an
|
|
* image compatible with the I420 (AKA "YUV420P") format.
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjEncodeYUVPlanes(tjhandle handle, const unsigned char *srcBuf,
|
|
int width, int pitch, int height,
|
|
int pixelFormat, unsigned char **dstPlanes,
|
|
int *strides, int subsamp, int flags);
|
|
|
|
|
|
/**
|
|
* Create a TurboJPEG decompressor instance.
|
|
*
|
|
* @return a handle to the newly-created instance, or NULL if an error
|
|
* occurred (see #tjGetErrorStr2().)
|
|
*/
|
|
DLLEXPORT tjhandle tjInitDecompress(void);
|
|
|
|
|
|
/**
|
|
* Retrieve information about a JPEG image without decompressing it.
|
|
*
|
|
* @param handle a handle to a TurboJPEG decompressor or transformer instance
|
|
*
|
|
* @param jpegBuf pointer to a buffer containing a JPEG image
|
|
*
|
|
* @param jpegSize size of the JPEG image (in bytes)
|
|
*
|
|
* @param width pointer to an integer variable that will receive the width (in
|
|
* pixels) of the JPEG image
|
|
*
|
|
* @param height pointer to an integer variable that will receive the height
|
|
* (in pixels) of the JPEG image
|
|
*
|
|
* @param jpegSubsamp pointer to an integer variable that will receive the
|
|
* level of chrominance subsampling used when the JPEG image was compressed
|
|
* (see @ref TJSAMP "Chrominance subsampling options".)
|
|
*
|
|
* @param jpegColorspace pointer to an integer variable that will receive one
|
|
* of the JPEG colorspace constants, indicating the colorspace of the JPEG
|
|
* image (see @ref TJCS "JPEG colorspaces".)
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjDecompressHeader3(tjhandle handle,
|
|
const unsigned char *jpegBuf,
|
|
unsigned long jpegSize, int *width,
|
|
int *height, int *jpegSubsamp,
|
|
int *jpegColorspace);
|
|
|
|
|
|
/**
|
|
* Returns a list of fractional scaling factors that the JPEG decompressor in
|
|
* this implementation of TurboJPEG supports.
|
|
*
|
|
* @param numscalingfactors pointer to an integer variable that will receive
|
|
* the number of elements in the list
|
|
*
|
|
* @return a pointer to a list of fractional scaling factors, or NULL if an
|
|
* error is encountered (see #tjGetErrorStr2().)
|
|
*/
|
|
DLLEXPORT tjscalingfactor *tjGetScalingFactors(int *numscalingfactors);
|
|
|
|
|
|
/**
|
|
* Decompress a JPEG image to an RGB, grayscale, or CMYK image.
|
|
*
|
|
* @param handle a handle to a TurboJPEG decompressor or transformer instance
|
|
*
|
|
* @param jpegBuf pointer to a buffer containing the JPEG image to decompress
|
|
*
|
|
* @param jpegSize size of the JPEG image (in bytes)
|
|
*
|
|
* @param dstBuf pointer to an image buffer that will receive the decompressed
|
|
* image. This buffer should normally be <tt>pitch * scaledHeight</tt> bytes
|
|
* in size, where <tt>scaledHeight</tt> can be determined by calling
|
|
* #TJSCALED() with the JPEG image height and one of the scaling factors
|
|
* returned by #tjGetScalingFactors(). The <tt>dstBuf</tt> pointer may also be
|
|
* used to decompress into a specific region of a larger buffer.
|
|
*
|
|
* @param width desired width (in pixels) of the destination image. If this is
|
|
* different than the width of the JPEG image being decompressed, then
|
|
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
|
|
* possible image that will fit within the desired width. If <tt>width</tt> is
|
|
* set to 0, then only the height will be considered when determining the
|
|
* scaled image size.
|
|
*
|
|
* @param pitch bytes per line in the destination image. Normally, this is
|
|
* <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt> if the decompressed image
|
|
* is unpadded, else <tt>#TJPAD(scaledWidth * #tjPixelSize[pixelFormat])</tt>
|
|
* if each line of the decompressed image is padded to the nearest 32-bit
|
|
* boundary, as is the case for Windows bitmaps. (NOTE: <tt>scaledWidth</tt>
|
|
* can be determined by calling #TJSCALED() with the JPEG image width and one
|
|
* of the scaling factors returned by #tjGetScalingFactors().) You can also be
|
|
* clever and use the pitch parameter to skip lines, etc. Setting this
|
|
* parameter to 0 is the equivalent of setting it to
|
|
* <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt>.
|
|
*
|
|
* @param height desired height (in pixels) of the destination image. If this
|
|
* is different than the height of the JPEG image being decompressed, then
|
|
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
|
|
* possible image that will fit within the desired height. If <tt>height</tt>
|
|
* is set to 0, then only the width will be considered when determining the
|
|
* scaled image size.
|
|
*
|
|
* @param pixelFormat pixel format of the destination image (see @ref
|
|
* TJPF "Pixel formats".)
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjDecompress2(tjhandle handle, const unsigned char *jpegBuf,
|
|
unsigned long jpegSize, unsigned char *dstBuf,
|
|
int width, int pitch, int height, int pixelFormat,
|
|
int flags);
|
|
|
|
|
|
/**
|
|
* Decompress a JPEG image to a YUV planar image. This function performs JPEG
|
|
* decompression but leaves out the color conversion step, so a planar YUV
|
|
* image is generated instead of an RGB image.
|
|
*
|
|
* @param handle a handle to a TurboJPEG decompressor or transformer instance
|
|
*
|
|
* @param jpegBuf pointer to a buffer containing the JPEG image to decompress
|
|
*
|
|
* @param jpegSize size of the JPEG image (in bytes)
|
|
*
|
|
* @param dstBuf pointer to an image buffer that will receive the YUV image.
|
|
* Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based
|
|
* on the image width, height, padding, and level of subsampling. The Y,
|
|
* U (Cb), and V (Cr) image planes will be stored sequentially in the buffer
|
|
* (refer to @ref YUVnotes "YUV Image Format Notes".)
|
|
*
|
|
* @param width desired width (in pixels) of the YUV image. If this is
|
|
* different than the width of the JPEG image being decompressed, then
|
|
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
|
|
* possible image that will fit within the desired width. If <tt>width</tt> is
|
|
* set to 0, then only the height will be considered when determining the
|
|
* scaled image size. If the scaled width is not an even multiple of the MCU
|
|
* block width (see #tjMCUWidth), then an intermediate buffer copy will be
|
|
* performed within TurboJPEG.
|
|
*
|
|
* @param pad the width of each line in each plane of the YUV image will be
|
|
* padded to the nearest multiple of this number of bytes (must be a power of
|
|
* 2.) To generate images suitable for X Video, <tt>pad</tt> should be set to
|
|
* 4.
|
|
*
|
|
* @param height desired height (in pixels) of the YUV image. If this is
|
|
* different than the height of the JPEG image being decompressed, then
|
|
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
|
|
* possible image that will fit within the desired height. If <tt>height</tt>
|
|
* is set to 0, then only the width will be considered when determining the
|
|
* scaled image size. If the scaled height is not an even multiple of the MCU
|
|
* block height (see #tjMCUHeight), then an intermediate buffer copy will be
|
|
* performed within TurboJPEG.
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjDecompressToYUV2(tjhandle handle, const unsigned char *jpegBuf,
|
|
unsigned long jpegSize, unsigned char *dstBuf,
|
|
int width, int pad, int height, int flags);
|
|
|
|
|
|
/**
|
|
* Decompress a JPEG image into separate Y, U (Cb), and V (Cr) image
|
|
* planes. This function performs JPEG decompression but leaves out the color
|
|
* conversion step, so a planar YUV image is generated instead of an RGB image.
|
|
*
|
|
* @param handle a handle to a TurboJPEG decompressor or transformer instance
|
|
*
|
|
* @param jpegBuf pointer to a buffer containing the JPEG image to decompress
|
|
*
|
|
* @param jpegSize size of the JPEG image (in bytes)
|
|
*
|
|
* @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
|
|
* (or just a Y plane, if decompressing a grayscale image) that will receive
|
|
* the YUV image. These planes can be contiguous or non-contiguous in memory.
|
|
* Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
|
|
* on the scaled image width, scaled image height, strides, and level of
|
|
* chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes"
|
|
* for more details.
|
|
*
|
|
* @param width desired width (in pixels) of the YUV image. If this is
|
|
* different than the width of the JPEG image being decompressed, then
|
|
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
|
|
* possible image that will fit within the desired width. If <tt>width</tt> is
|
|
* set to 0, then only the height will be considered when determining the
|
|
* scaled image size. If the scaled width is not an even multiple of the MCU
|
|
* block width (see #tjMCUWidth), then an intermediate buffer copy will be
|
|
* performed within TurboJPEG.
|
|
*
|
|
* @param strides an array of integers, each specifying the number of bytes per
|
|
* line in the corresponding plane of the output image. Setting the stride for
|
|
* any plane to 0 is the same as setting it to the scaled plane width (see
|
|
* @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then
|
|
* the strides for all planes will be set to their respective scaled plane
|
|
* widths. You can adjust the strides in order to add an arbitrary amount of
|
|
* line padding to each plane or to decompress the JPEG image into a subregion
|
|
* of a larger YUV planar image.
|
|
*
|
|
* @param height desired height (in pixels) of the YUV image. If this is
|
|
* different than the height of the JPEG image being decompressed, then
|
|
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
|
|
* possible image that will fit within the desired height. If <tt>height</tt>
|
|
* is set to 0, then only the width will be considered when determining the
|
|
* scaled image size. If the scaled height is not an even multiple of the MCU
|
|
* block height (see #tjMCUHeight), then an intermediate buffer copy will be
|
|
* performed within TurboJPEG.
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjDecompressToYUVPlanes(tjhandle handle,
|
|
const unsigned char *jpegBuf,
|
|
unsigned long jpegSize,
|
|
unsigned char **dstPlanes, int width,
|
|
int *strides, int height, int flags);
|
|
|
|
|
|
/**
|
|
* Decode a YUV planar image into an RGB or grayscale image. This function
|
|
* uses the accelerated color conversion routines in the underlying
|
|
* codec but does not execute any of the other steps in the JPEG decompression
|
|
* process.
|
|
*
|
|
* @param handle a handle to a TurboJPEG decompressor or transformer instance
|
|
*
|
|
* @param srcBuf pointer to an image buffer containing a YUV planar image to be
|
|
* decoded. The size of this buffer should match the value returned by
|
|
* #tjBufSizeYUV2() for the given image width, height, padding, and level of
|
|
* chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be
|
|
* stored sequentially in the source buffer (refer to @ref YUVnotes
|
|
* "YUV Image Format Notes".)
|
|
*
|
|
* @param pad Use this parameter to specify that the width of each line in each
|
|
* plane of the YUV source image is padded to the nearest multiple of this
|
|
* number of bytes (must be a power of 2.)
|
|
*
|
|
* @param subsamp the level of chrominance subsampling used in the YUV source
|
|
* image (see @ref TJSAMP "Chrominance subsampling options".)
|
|
*
|
|
* @param dstBuf pointer to an image buffer that will receive the decoded
|
|
* image. This buffer should normally be <tt>pitch * height</tt> bytes in
|
|
* size, but the <tt>dstBuf</tt> pointer can also be used to decode into a
|
|
* specific region of a larger buffer.
|
|
*
|
|
* @param width width (in pixels) of the source and destination images
|
|
*
|
|
* @param pitch bytes per line in the destination image. Normally, this should
|
|
* be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is
|
|
* unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line
|
|
* of the destination image should be padded to the nearest 32-bit boundary, as
|
|
* is the case for Windows bitmaps. You can also be clever and use the pitch
|
|
* parameter to skip lines, etc. Setting this parameter to 0 is the equivalent
|
|
* of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
|
|
*
|
|
* @param height height (in pixels) of the source and destination images
|
|
*
|
|
* @param pixelFormat pixel format of the destination image (see @ref TJPF
|
|
* "Pixel formats".)
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjDecodeYUV(tjhandle handle, const unsigned char *srcBuf,
|
|
int pad, int subsamp, unsigned char *dstBuf,
|
|
int width, int pitch, int height, int pixelFormat,
|
|
int flags);
|
|
|
|
|
|
/**
|
|
* Decode a set of Y, U (Cb), and V (Cr) image planes into an RGB or grayscale
|
|
* image. This function uses the accelerated color conversion routines in the
|
|
* underlying codec but does not execute any of the other steps in the JPEG
|
|
* decompression process.
|
|
*
|
|
* @param handle a handle to a TurboJPEG decompressor or transformer instance
|
|
*
|
|
* @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
|
|
* (or just a Y plane, if decoding a grayscale image) that contain a YUV image
|
|
* to be decoded. These planes can be contiguous or non-contiguous in memory.
|
|
* The size of each plane should match the value returned by #tjPlaneSizeYUV()
|
|
* for the given image width, height, strides, and level of chrominance
|
|
* subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" for more
|
|
* details.
|
|
*
|
|
* @param strides an array of integers, each specifying the number of bytes per
|
|
* line in the corresponding plane of the YUV source image. Setting the stride
|
|
* for any plane to 0 is the same as setting it to the plane width (see
|
|
* @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then
|
|
* the strides for all planes will be set to their respective plane widths.
|
|
* You can adjust the strides in order to specify an arbitrary amount of line
|
|
* padding in each plane or to decode a subregion of a larger YUV planar image.
|
|
*
|
|
* @param subsamp the level of chrominance subsampling used in the YUV source
|
|
* image (see @ref TJSAMP "Chrominance subsampling options".)
|
|
*
|
|
* @param dstBuf pointer to an image buffer that will receive the decoded
|
|
* image. This buffer should normally be <tt>pitch * height</tt> bytes in
|
|
* size, but the <tt>dstBuf</tt> pointer can also be used to decode into a
|
|
* specific region of a larger buffer.
|
|
*
|
|
* @param width width (in pixels) of the source and destination images
|
|
*
|
|
* @param pitch bytes per line in the destination image. Normally, this should
|
|
* be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is
|
|
* unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line
|
|
* of the destination image should be padded to the nearest 32-bit boundary, as
|
|
* is the case for Windows bitmaps. You can also be clever and use the pitch
|
|
* parameter to skip lines, etc. Setting this parameter to 0 is the equivalent
|
|
* of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
|
|
*
|
|
* @param height height (in pixels) of the source and destination images
|
|
*
|
|
* @param pixelFormat pixel format of the destination image (see @ref TJPF
|
|
* "Pixel formats".)
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjDecodeYUVPlanes(tjhandle handle,
|
|
const unsigned char **srcPlanes,
|
|
const int *strides, int subsamp,
|
|
unsigned char *dstBuf, int width, int pitch,
|
|
int height, int pixelFormat, int flags);
|
|
|
|
|
|
/**
|
|
* Create a new TurboJPEG transformer instance.
|
|
*
|
|
* @return a handle to the newly-created instance, or NULL if an error
|
|
* occurred (see #tjGetErrorStr2().)
|
|
*/
|
|
DLLEXPORT tjhandle tjInitTransform(void);
|
|
|
|
|
|
/**
|
|
* Losslessly transform a JPEG image into another JPEG image. Lossless
|
|
* transforms work by moving the raw DCT coefficients from one JPEG image
|
|
* structure to another without altering the values of the coefficients. While
|
|
* this is typically faster than decompressing the image, transforming it, and
|
|
* re-compressing it, lossless transforms are not free. Each lossless
|
|
* transform requires reading and performing Huffman decoding on all of the
|
|
* coefficients in the source image, regardless of the size of the destination
|
|
* image. Thus, this function provides a means of generating multiple
|
|
* transformed images from the same source or applying multiple
|
|
* transformations simultaneously, in order to eliminate the need to read the
|
|
* source coefficients multiple times.
|
|
*
|
|
* @param handle a handle to a TurboJPEG transformer instance
|
|
*
|
|
* @param jpegBuf pointer to a buffer containing the JPEG source image to
|
|
* transform
|
|
*
|
|
* @param jpegSize size of the JPEG source image (in bytes)
|
|
*
|
|
* @param n the number of transformed JPEG images to generate
|
|
*
|
|
* @param dstBufs pointer to an array of n image buffers. <tt>dstBufs[i]</tt>
|
|
* will receive a JPEG image that has been transformed using the parameters in
|
|
* <tt>transforms[i]</tt>. TurboJPEG has the ability to reallocate the JPEG
|
|
* buffer to accommodate the size of the JPEG image. Thus, you can choose to:
|
|
* -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
|
|
* let TurboJPEG grow the buffer as needed,
|
|
* -# set <tt>dstBufs[i]</tt> to NULL to tell TurboJPEG to allocate the buffer
|
|
* for you, or
|
|
* -# pre-allocate the buffer to a "worst case" size determined by calling
|
|
* #tjBufSize() with the transformed or cropped width and height. Under normal
|
|
* circumstances, this should ensure that the buffer never has to be
|
|
* re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.) Note,
|
|
* however, that there are some rare cases (such as transforming images with a
|
|
* large amount of embedded EXIF or ICC profile data) in which the output image
|
|
* will be larger than the worst-case size, and #TJFLAG_NOREALLOC cannot be
|
|
* used in those cases.
|
|
* .
|
|
* If you choose option 1, <tt>dstSizes[i]</tt> should be set to the size of
|
|
* your pre-allocated buffer. In any case, unless you have set
|
|
* #TJFLAG_NOREALLOC, you should always check <tt>dstBufs[i]</tt> upon return
|
|
* from this function, as it may have changed.
|
|
*
|
|
* @param dstSizes pointer to an array of n unsigned long variables that will
|
|
* receive the actual sizes (in bytes) of each transformed JPEG image. If
|
|
* <tt>dstBufs[i]</tt> points to a pre-allocated buffer, then
|
|
* <tt>dstSizes[i]</tt> should be set to the size of the buffer. Upon return,
|
|
* <tt>dstSizes[i]</tt> will contain the size of the JPEG image (in bytes.)
|
|
*
|
|
* @param transforms pointer to an array of n #tjtransform structures, each of
|
|
* which specifies the transform parameters and/or cropping region for the
|
|
* corresponding transformed output image.
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
|
|
* "flags"
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
|
|
* and #tjGetErrorCode().)
|
|
*/
|
|
DLLEXPORT int tjTransform(tjhandle handle, const unsigned char *jpegBuf,
|
|
unsigned long jpegSize, int n,
|
|
unsigned char **dstBufs, unsigned long *dstSizes,
|
|
tjtransform *transforms, int flags);
|
|
|
|
|
|
/**
|
|
* Destroy a TurboJPEG compressor, decompressor, or transformer instance.
|
|
*
|
|
* @param handle a handle to a TurboJPEG compressor, decompressor or
|
|
* transformer instance
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2().)
|
|
*/
|
|
DLLEXPORT int tjDestroy(tjhandle handle);
|
|
|
|
|
|
/**
|
|
* Allocate an image buffer for use with TurboJPEG. You should always use
|
|
* this function to allocate the JPEG destination buffer(s) for the compression
|
|
* and transform functions unless you are disabling automatic buffer
|
|
* (re)allocation (by setting #TJFLAG_NOREALLOC.)
|
|
*
|
|
* @param bytes the number of bytes to allocate
|
|
*
|
|
* @return a pointer to a newly-allocated buffer with the specified number of
|
|
* bytes.
|
|
*
|
|
* @sa tjFree()
|
|
*/
|
|
DLLEXPORT unsigned char *tjAlloc(int bytes);
|
|
|
|
|
|
/**
|
|
* Load an uncompressed image from disk into memory.
|
|
*
|
|
* @param filename name of a file containing an uncompressed image in Windows
|
|
* BMP or PBMPLUS (PPM/PGM) format
|
|
*
|
|
* @param width pointer to an integer variable that will receive the width (in
|
|
* pixels) of the uncompressed image
|
|
*
|
|
* @param align row alignment of the image buffer to be returned (must be a
|
|
* power of 2.) For instance, setting this parameter to 4 will cause all rows
|
|
* in the image buffer to be padded to the nearest 32-bit boundary, and setting
|
|
* this parameter to 1 will cause all rows in the image buffer to be unpadded.
|
|
*
|
|
* @param height pointer to an integer variable that will receive the height
|
|
* (in pixels) of the uncompressed image
|
|
*
|
|
* @param pixelFormat pointer to an integer variable that specifies or will
|
|
* receive the pixel format of the uncompressed image buffer. The behavior of
|
|
* #tjLoadImage() will vary depending on the value of <tt>*pixelFormat</tt>
|
|
* passed to the function:
|
|
* - @ref TJPF_UNKNOWN : The uncompressed image buffer returned by the function
|
|
* will use the most optimal pixel format for the file type, and
|
|
* <tt>*pixelFormat</tt> will contain the ID of this pixel format upon
|
|
* successful return from the function.
|
|
* - @ref TJPF_GRAY : Only PGM files and 8-bit BMP files with a grayscale
|
|
* colormap can be loaded.
|
|
* - @ref TJPF_CMYK : The RGB or grayscale pixels stored in the file will be
|
|
* converted using a quick & dirty algorithm that is suitable only for testing
|
|
* purposes (proper conversion between CMYK and other formats requires a color
|
|
* management system.)
|
|
* - Other @ref TJPF "pixel formats" : The uncompressed image buffer will use
|
|
* the specified pixel format, and pixel format conversion will be performed if
|
|
* necessary.
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
|
|
* "flags".
|
|
*
|
|
* @return a pointer to a newly-allocated buffer containing the uncompressed
|
|
* image, converted to the chosen pixel format and with the chosen row
|
|
* alignment, or NULL if an error occurred (see #tjGetErrorStr2().) This
|
|
* buffer should be freed using #tjFree().
|
|
*/
|
|
DLLEXPORT unsigned char *tjLoadImage(const char *filename, int *width,
|
|
int align, int *height, int *pixelFormat,
|
|
int flags);
|
|
|
|
|
|
/**
|
|
* Save an uncompressed image from memory to disk.
|
|
*
|
|
* @param filename name of a file to which to save the uncompressed image.
|
|
* The image will be stored in Windows BMP or PBMPLUS (PPM/PGM) format,
|
|
* depending on the file extension.
|
|
*
|
|
* @param buffer pointer to an image buffer containing RGB, grayscale, or
|
|
* CMYK pixels to be saved
|
|
*
|
|
* @param width width (in pixels) of the uncompressed image
|
|
*
|
|
* @param pitch bytes per line in the image buffer. Setting this parameter to
|
|
* 0 is the equivalent of setting it to
|
|
* <tt>width * #tjPixelSize[pixelFormat]</tt>.
|
|
*
|
|
* @param height height (in pixels) of the uncompressed image
|
|
*
|
|
* @param pixelFormat pixel format of the image buffer (see @ref TJPF
|
|
* "Pixel formats".) If this parameter is set to @ref TJPF_GRAY, then the
|
|
* image will be stored in PGM or 8-bit (indexed color) BMP format. Otherwise,
|
|
* the image will be stored in PPM or 24-bit BMP format. If this parameter
|
|
* is set to @ref TJPF_CMYK, then the CMYK pixels will be converted to RGB
|
|
* using a quick & dirty algorithm that is suitable only for testing (proper
|
|
* conversion between CMYK and other formats requires a color management
|
|
* system.)
|
|
*
|
|
* @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
|
|
* "flags".
|
|
*
|
|
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2().)
|
|
*/
|
|
DLLEXPORT int tjSaveImage(const char *filename, unsigned char *buffer,
|
|
int width, int pitch, int height, int pixelFormat,
|
|
int flags);
|
|
|
|
|
|
/**
|
|
* Free an image buffer previously allocated by TurboJPEG. You should always
|
|
* use this function to free JPEG destination buffer(s) that were automatically
|
|
* (re)allocated by the compression and transform functions or that were
|
|
* manually allocated using #tjAlloc().
|
|
*
|
|
* @param buffer address of the buffer to free. If the address is NULL, then
|
|
* this function has no effect.
|
|
*
|
|
* @sa tjAlloc()
|
|
*/
|
|
DLLEXPORT void tjFree(unsigned char *buffer);
|
|
|
|
|
|
/**
|
|
* Returns a descriptive error message explaining why the last command failed.
|
|
*
|
|
* @param handle a handle to a TurboJPEG compressor, decompressor, or
|
|
* transformer instance, or NULL if the error was generated by a global
|
|
* function (but note that retrieving the error message for a global function
|
|
* is thread-safe only on platforms that support thread-local storage.)
|
|
*
|
|
* @return a descriptive error message explaining why the last command failed.
|
|
*/
|
|
DLLEXPORT char *tjGetErrorStr2(tjhandle handle);
|
|
|
|
|
|
/**
|
|
* Returns a code indicating the severity of the last error. See
|
|
* @ref TJERR "Error codes".
|
|
*
|
|
* @param handle a handle to a TurboJPEG compressor, decompressor or
|
|
* transformer instance
|
|
*
|
|
* @return a code indicating the severity of the last error. See
|
|
* @ref TJERR "Error codes".
|
|
*/
|
|
DLLEXPORT int tjGetErrorCode(tjhandle handle);
|
|
|
|
|
|
/* Deprecated functions and macros */
|
|
#define TJFLAG_FORCEMMX 8
|
|
#define TJFLAG_FORCESSE 16
|
|
#define TJFLAG_FORCESSE2 32
|
|
#define TJFLAG_FORCESSE3 128
|
|
|
|
|
|
/* Backward compatibility functions and macros (nothing to see here) */
|
|
#define NUMSUBOPT TJ_NUMSAMP
|
|
#define TJ_444 TJSAMP_444
|
|
#define TJ_422 TJSAMP_422
|
|
#define TJ_420 TJSAMP_420
|
|
#define TJ_411 TJSAMP_420
|
|
#define TJ_GRAYSCALE TJSAMP_GRAY
|
|
|
|
#define TJ_BGR 1
|
|
#define TJ_BOTTOMUP TJFLAG_BOTTOMUP
|
|
#define TJ_FORCEMMX TJFLAG_FORCEMMX
|
|
#define TJ_FORCESSE TJFLAG_FORCESSE
|
|
#define TJ_FORCESSE2 TJFLAG_FORCESSE2
|
|
#define TJ_ALPHAFIRST 64
|
|
#define TJ_FORCESSE3 TJFLAG_FORCESSE3
|
|
#define TJ_FASTUPSAMPLE TJFLAG_FASTUPSAMPLE
|
|
#define TJ_YUV 512
|
|
|
|
DLLEXPORT unsigned long TJBUFSIZE(int width, int height);
|
|
|
|
DLLEXPORT unsigned long TJBUFSIZEYUV(int width, int height, int jpegSubsamp);
|
|
|
|
DLLEXPORT unsigned long tjBufSizeYUV(int width, int height, int subsamp);
|
|
|
|
DLLEXPORT int tjCompress(tjhandle handle, unsigned char *srcBuf, int width,
|
|
int pitch, int height, int pixelSize,
|
|
unsigned char *dstBuf, unsigned long *compressedSize,
|
|
int jpegSubsamp, int jpegQual, int flags);
|
|
|
|
DLLEXPORT int tjEncodeYUV(tjhandle handle, unsigned char *srcBuf, int width,
|
|
int pitch, int height, int pixelSize,
|
|
unsigned char *dstBuf, int subsamp, int flags);
|
|
|
|
DLLEXPORT int tjEncodeYUV2(tjhandle handle, unsigned char *srcBuf, int width,
|
|
int pitch, int height, int pixelFormat,
|
|
unsigned char *dstBuf, int subsamp, int flags);
|
|
|
|
DLLEXPORT int tjDecompressHeader(tjhandle handle, unsigned char *jpegBuf,
|
|
unsigned long jpegSize, int *width,
|
|
int *height);
|
|
|
|
DLLEXPORT int tjDecompressHeader2(tjhandle handle, unsigned char *jpegBuf,
|
|
unsigned long jpegSize, int *width,
|
|
int *height, int *jpegSubsamp);
|
|
|
|
DLLEXPORT int tjDecompress(tjhandle handle, unsigned char *jpegBuf,
|
|
unsigned long jpegSize, unsigned char *dstBuf,
|
|
int width, int pitch, int height, int pixelSize,
|
|
int flags);
|
|
|
|
DLLEXPORT int tjDecompressToYUV(tjhandle handle, unsigned char *jpegBuf,
|
|
unsigned long jpegSize, unsigned char *dstBuf,
|
|
int flags);
|
|
|
|
DLLEXPORT char *tjGetErrorStr(void);
|
|
|
|
|
|
/**
|
|
* @}
|
|
*/
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif
|