root/third_party/qcms/src/iccread.c

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DEFINITIONS

This source file includes following definitions.
  1. cpu_to_be32
  2. be32_to_cpu
  3. be16_to_cpu
  4. invalid_source
  5. read_u32
  6. read_u16
  7. read_u8
  8. read_s15Fixed16Number
  9. read_uInt8Number
  10. read_uInt16Number
  11. check_CMM_type_signature
  12. check_profile_version
  13. read_class_signature
  14. read_color_space
  15. read_pcs
  16. read_tag_table
  17. qcms_profile_is_bogus
  18. find_tag
  19. read_tag_s15Fixed16ArrayType
  20. read_tag_XYZType
  21. read_curveType
  22. read_tag_curveType
  23. read_nested_curveType
  24. mAB_release
  25. read_tag_lutmABType
  26. read_tag_lutType
  27. read_rendering_intent
  28. qcms_profile_create
  29. build_sRGB_gamma_table
  30. curve_from_table
  31. float_to_u8Fixed8Number
  32. curve_from_gamma
  33. qcms_profile_create_rgb_with_gamma
  34. qcms_profile_create_rgb_with_table
  35. white_point_from_temp
  36. qcms_profile_sRGB
  37. qcms_profile_from_memory
  38. qcms_profile_get_rendering_intent
  39. qcms_profile_get_color_space
  40. lut_release
  41. qcms_profile_release
  42. qcms_profile_from_file
  43. qcms_profile_from_path
  44. qcms_profile_from_unicode_path

/* vim: set ts=8 sw=8 noexpandtab: */
//  qcms
//  Copyright (C) 2009 Mozilla Foundation
//  Copyright (C) 1998-2007 Marti Maria
//
// Permission is hereby granted, free of charge, to any person obtaining 
// a copy of this software and associated documentation files (the "Software"), 
// to deal in the Software without restriction, including without limitation 
// the rights to use, copy, modify, merge, publish, distribute, sublicense, 
// and/or sell copies of the Software, and to permit persons to whom the Software 
// is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in 
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO 
// THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

#include <math.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h> //memset
#include "qcmsint.h"

/* It might be worth having a unified limit on content controlled
 * allocation per profile. This would remove the need for many
 * of the arbitrary limits that we used */

typedef uint32_t be32;
typedef uint16_t be16;

#if 0
not used yet
/* __builtin_bswap isn't available in older gccs
 * so open code it for now */
static be32 cpu_to_be32(int32_t v)
{
#ifdef IS_LITTLE_ENDIAN
        return ((v & 0xff) << 24) | ((v & 0xff00) << 8) | ((v & 0xff0000) >> 8) | ((v & 0xff000000) >> 24);
        //return __builtin_bswap32(v);
        return v;
#endif
}
#endif

static uint32_t be32_to_cpu(be32 v)
{
#ifdef IS_LITTLE_ENDIAN
        return ((v & 0xff) << 24) | ((v & 0xff00) << 8) | ((v & 0xff0000) >> 8) | ((v & 0xff000000) >> 24);
        //return __builtin_bswap32(v);
#else
        return v;
#endif
}

static uint16_t be16_to_cpu(be16 v)
{
#ifdef IS_LITTLE_ENDIAN
        return ((v & 0xff) << 8) | ((v & 0xff00) >> 8);
#else
        return v;
#endif
}

/* a wrapper around the memory that we are going to parse
 * into a qcms_profile */
struct mem_source
{
        const unsigned char *buf;
        size_t size;
        qcms_bool valid;
        const char *invalid_reason;
};

static void invalid_source(struct mem_source *mem, const char *reason)
{
        mem->valid = false;
        mem->invalid_reason = reason;
}

static uint32_t read_u32(struct mem_source *mem, size_t offset)
{
        /* Subtract from mem->size instead of the more intuitive adding to offset.
         * This avoids overflowing offset. The subtraction is safe because
         * mem->size is guaranteed to be > 4 */
        if (offset > mem->size - 4) {
                invalid_source(mem, "Invalid offset");
                return 0;
        } else {
                be32 k;
                memcpy(&k, mem->buf + offset, sizeof(k));
                return be32_to_cpu(k);
        }
}

static uint16_t read_u16(struct mem_source *mem, size_t offset)
{
        if (offset > mem->size - 2) {
                invalid_source(mem, "Invalid offset");
                return 0;
        } else {
                be16 k;
                memcpy(&k, mem->buf + offset, sizeof(k));
                return be16_to_cpu(k);
        }
}

static uint8_t read_u8(struct mem_source *mem, size_t offset)
{
        if (offset > mem->size - 1) {
                invalid_source(mem, "Invalid offset");
                return 0;
        } else {
                return *(uint8_t*)(mem->buf + offset);
        }
}

static s15Fixed16Number read_s15Fixed16Number(struct mem_source *mem, size_t offset)
{
        return read_u32(mem, offset);
}

static uInt8Number read_uInt8Number(struct mem_source *mem, size_t offset)
{
        return read_u8(mem, offset);
}

static uInt16Number read_uInt16Number(struct mem_source *mem, size_t offset)
{
        return read_u16(mem, offset);
}

#define BAD_VALUE_PROFILE NULL
#define INVALID_PROFILE NULL
#define NO_MEM_PROFILE NULL

/* An arbitrary 4MB limit on profile size */
#define MAX_PROFILE_SIZE 1024*1024*4
#define MAX_TAG_COUNT 1024

static void check_CMM_type_signature(struct mem_source *src)
{
        //uint32_t CMM_type_signature = read_u32(src, 4);
        //TODO: do the check?

}

static void check_profile_version(struct mem_source *src)
{

        /*
        uint8_t major_revision = read_u8(src, 8 + 0);
        uint8_t minor_revision = read_u8(src, 8 + 1);
        */
        uint8_t reserved1      = read_u8(src, 8 + 2);
        uint8_t reserved2      = read_u8(src, 8 + 3);
        /* Checking the version doesn't buy us anything
        if (major_revision != 0x4) {
                if (major_revision > 0x2)
                        invalid_source(src, "Unsupported major revision");
                if (minor_revision > 0x40)
                        invalid_source(src, "Unsupported minor revision");
        }
        */
        if (reserved1 != 0 || reserved2 != 0)
                invalid_source(src, "Invalid reserved bytes");
}

#define INPUT_DEVICE_PROFILE   0x73636e72 // 'scnr'
#define DISPLAY_DEVICE_PROFILE 0x6d6e7472 // 'mntr'
#define OUTPUT_DEVICE_PROFILE  0x70727472 // 'prtr'
#define DEVICE_LINK_PROFILE    0x6c696e6b // 'link'
#define COLOR_SPACE_PROFILE    0x73706163 // 'spac'
#define ABSTRACT_PROFILE       0x61627374 // 'abst'
#define NAMED_COLOR_PROFILE    0x6e6d636c // 'nmcl'

static void read_class_signature(qcms_profile *profile, struct mem_source *mem)
{
        profile->class = read_u32(mem, 12);
        switch (profile->class) {
                case DISPLAY_DEVICE_PROFILE:
                case INPUT_DEVICE_PROFILE:
                case OUTPUT_DEVICE_PROFILE:
                case COLOR_SPACE_PROFILE:
                        break;
                default:
                        invalid_source(mem, "Invalid  Profile/Device Class signature");
        }
}

static void read_color_space(qcms_profile *profile, struct mem_source *mem)
{
        profile->color_space = read_u32(mem, 16);
        switch (profile->color_space) {
                case RGB_SIGNATURE:
                case GRAY_SIGNATURE:
                        break;
                default:
                        invalid_source(mem, "Unsupported colorspace");
        }
}

static void read_pcs(qcms_profile *profile, struct mem_source *mem)
{
        profile->pcs = read_u32(mem, 20);
        switch (profile->pcs) {
                case XYZ_SIGNATURE:
                case LAB_SIGNATURE:
                        break;
                default:
                        invalid_source(mem, "Unsupported pcs");
        }
}

struct tag
{
        uint32_t signature;
        uint32_t offset;
        uint32_t size;
};

struct tag_index {
        uint32_t count;
        struct tag *tags;
};

static struct tag_index read_tag_table(qcms_profile *profile, struct mem_source *mem)
{
        struct tag_index index = {0, NULL};
        unsigned int i;

        index.count = read_u32(mem, 128);
        if (index.count > MAX_TAG_COUNT) {
                invalid_source(mem, "max number of tags exceeded");
                return index;
        }

        index.tags = malloc(sizeof(struct tag)*index.count);
        if (index.tags) {
                for (i = 0; i < index.count; i++) {
                        index.tags[i].signature = read_u32(mem, 128 + 4 + 4*i*3);
                        index.tags[i].offset    = read_u32(mem, 128 + 4 + 4*i*3 + 4);
                        index.tags[i].size      = read_u32(mem, 128 + 4 + 4*i*3 + 8);
                }
        }

        return index;
}

// Checks a profile for obvious inconsistencies and returns
// true if the profile looks bogus and should probably be
// ignored.
qcms_bool qcms_profile_is_bogus(qcms_profile *profile)
{
       float sum[3], target[3], tolerance[3];
       float rX, rY, rZ, gX, gY, gZ, bX, bY, bZ;
       bool negative;
       unsigned i;

       // We currently only check the bogosity of RGB profiles
       if (profile->color_space != RGB_SIGNATURE)
               return false;

       if (qcms_supports_iccv4 && (profile->A2B0 || profile->B2A0))
               return false;

       rX = s15Fixed16Number_to_float(profile->redColorant.X);
       rY = s15Fixed16Number_to_float(profile->redColorant.Y);
       rZ = s15Fixed16Number_to_float(profile->redColorant.Z);

       gX = s15Fixed16Number_to_float(profile->greenColorant.X);
       gY = s15Fixed16Number_to_float(profile->greenColorant.Y);
       gZ = s15Fixed16Number_to_float(profile->greenColorant.Z);

       bX = s15Fixed16Number_to_float(profile->blueColorant.X);
       bY = s15Fixed16Number_to_float(profile->blueColorant.Y);
       bZ = s15Fixed16Number_to_float(profile->blueColorant.Z);

       // Check if any of the XYZ values are negative (see mozilla bug 498245)
       // CIEXYZ tristimulus values cannot be negative according to the spec.
       negative =
               (rX < 0) || (rY < 0) || (rZ < 0) ||
               (gX < 0) || (gY < 0) || (gZ < 0) ||
               (bX < 0) || (bY < 0) || (bZ < 0);

       if (negative)
               return true;


       // Sum the values; they should add up to something close to white
       sum[0] = rX + gX + bX;
       sum[1] = rY + gY + bY;
       sum[2] = rZ + gZ + bZ;

#if defined (_MSC_VER)
#pragma warning(push)
/* Disable double to float truncation warning 4305 */
#pragma warning(disable:4305)
#endif
       // Build our target vector (see mozilla bug 460629)
       target[0] = 0.96420;
       target[1] = 1.00000;
       target[2] = 0.82491;

       // Our tolerance vector - Recommended by Chris Murphy based on
       // conversion from the LAB space criterion of no more than 3 in any one
       // channel. This is similar to, but slightly more tolerant than Adobe's
       // criterion.
       tolerance[0] = 0.02;
       tolerance[1] = 0.02;
       tolerance[2] = 0.04;

#if defined (_MSC_VER)
/* Restore warnings */
#pragma warning(pop)
#endif
       // Compare with our tolerance
       for (i = 0; i < 3; ++i) {
           if (!(((sum[i] - tolerance[i]) <= target[i]) &&
                 ((sum[i] + tolerance[i]) >= target[i])))
               return true;
       }

       // All Good
       return false;
}

#define TAG_bXYZ 0x6258595a
#define TAG_gXYZ 0x6758595a
#define TAG_rXYZ 0x7258595a
#define TAG_rTRC 0x72545243
#define TAG_bTRC 0x62545243
#define TAG_gTRC 0x67545243
#define TAG_kTRC 0x6b545243
#define TAG_A2B0 0x41324230
#define TAG_B2A0 0x42324130
#define TAG_CHAD 0x63686164

static struct tag *find_tag(struct tag_index index, uint32_t tag_id)
{
        unsigned int i;
        struct tag *tag = NULL;
        for (i = 0; i < index.count; i++) {
                if (index.tags[i].signature == tag_id) {
                        return &index.tags[i];
                }
        }
        return tag;
}

#define XYZ_TYPE                0x58595a20 // 'XYZ '
#define CURVE_TYPE              0x63757276 // 'curv'
#define PARAMETRIC_CURVE_TYPE   0x70617261 // 'para'
#define LUT16_TYPE              0x6d667432 // 'mft2'
#define LUT8_TYPE               0x6d667431 // 'mft1'
#define LUT_MAB_TYPE            0x6d414220 // 'mAB '
#define LUT_MBA_TYPE            0x6d424120 // 'mBA '
#define CHROMATIC_TYPE          0x73663332 // 'sf32'

static struct matrix read_tag_s15Fixed16ArrayType(struct mem_source *src, struct tag_index index, uint32_t tag_id)
{
        struct tag *tag = find_tag(index, tag_id);
        struct matrix matrix;
        if (tag) {
                uint8_t i;
                uint32_t offset = tag->offset;
                uint32_t type = read_u32(src, offset);

                // Check mandatory type signature for s16Fixed16ArrayType
                if (type != CHROMATIC_TYPE) {
                        invalid_source(src, "unexpected type, expected 'sf32'");
                }

                for (i = 0; i < 9; i++) {
                        matrix.m[i/3][i%3] = s15Fixed16Number_to_float(read_s15Fixed16Number(src, offset+8+i*4));
                }
                matrix.invalid = false;
        } else {
                matrix.invalid = true;
                invalid_source(src, "missing sf32tag");
        }
        return matrix;
}

static struct XYZNumber read_tag_XYZType(struct mem_source *src, struct tag_index index, uint32_t tag_id)
{
        struct XYZNumber num = {0, 0, 0};
        struct tag *tag = find_tag(index, tag_id);
        if (tag) {
                uint32_t offset = tag->offset;

                uint32_t type = read_u32(src, offset);
                if (type != XYZ_TYPE)
                        invalid_source(src, "unexpected type, expected XYZ");
                num.X = read_s15Fixed16Number(src, offset+8);
                num.Y = read_s15Fixed16Number(src, offset+12);
                num.Z = read_s15Fixed16Number(src, offset+16);
        } else {
                invalid_source(src, "missing xyztag");
        }
        return num;
}

// Read the tag at a given offset rather then the tag_index. 
// This method is used when reading mAB tags where nested curveType are
// present that are not part of the tag_index.
static struct curveType *read_curveType(struct mem_source *src, uint32_t offset, uint32_t *len)
{
        static const uint32_t COUNT_TO_LENGTH[5] = {1, 3, 4, 5, 7};
        struct curveType *curve = NULL;
        uint32_t type = read_u32(src, offset);
        uint32_t count;
        int i;

        if (type != CURVE_TYPE && type != PARAMETRIC_CURVE_TYPE) {
                invalid_source(src, "unexpected type, expected CURV or PARA");
                return NULL;
        }

        if (type == CURVE_TYPE) {
                count = read_u32(src, offset+8);

#define MAX_CURVE_ENTRIES 40000 //arbitrary
                if (count > MAX_CURVE_ENTRIES) {
                        invalid_source(src, "curve size too large");
                        return NULL;
                }
                curve = malloc(sizeof(struct curveType) + sizeof(uInt16Number)*count);
                if (!curve)
                        return NULL;

                curve->count = count;
                curve->type = type;

                for (i=0; i<count; i++) {
                        curve->data[i] = read_u16(src, offset + 12 + i*2);
                }
                *len = 12 + count * 2;
        } else { //PARAMETRIC_CURVE_TYPE
                count = read_u16(src, offset+8);

                if (count > 4) {
                        invalid_source(src, "parametric function type not supported.");
                        return NULL;
                }

                curve = malloc(sizeof(struct curveType));
                if (!curve)
                        return NULL;

                curve->count = count;
                curve->type = type;

                for (i=0; i < COUNT_TO_LENGTH[count]; i++) {
                        curve->parameter[i] = s15Fixed16Number_to_float(read_s15Fixed16Number(src, offset + 12 + i*4)); 
                }
                *len = 12 + COUNT_TO_LENGTH[count] * 4;

                if ((count == 1 || count == 2)) {
                        /* we have a type 1 or type 2 function that has a division by 'a' */
                        float a = curve->parameter[1];
                        if (a == 0.f)
                                invalid_source(src, "parametricCurve definition causes division by zero.");
                }
        }

        return curve;
}

static struct curveType *read_tag_curveType(struct mem_source *src, struct tag_index index, uint32_t tag_id)
{
        struct tag *tag = find_tag(index, tag_id);
        struct curveType *curve = NULL;
        if (tag) {
                uint32_t len;
                return read_curveType(src, tag->offset, &len);
        } else {
                invalid_source(src, "missing curvetag");
        }

        return curve;
}

#define MAX_CLUT_SIZE 500000 // arbitrary
#define MAX_CHANNELS 10 // arbitrary
static void read_nested_curveType(struct mem_source *src, struct curveType *(*curveArray)[MAX_CHANNELS], uint8_t num_channels, uint32_t curve_offset)
{
        uint32_t channel_offset = 0;
        int i;
        for (i = 0; i < num_channels; i++) {
                uint32_t tag_len;

                (*curveArray)[i] = read_curveType(src, curve_offset + channel_offset, &tag_len);
                if (!(*curveArray)[i]) {
                        invalid_source(src, "invalid nested curveType curve");
                }

                channel_offset += tag_len;
                // 4 byte aligned
                if ((tag_len % 4) != 0)
                        channel_offset += 4 - (tag_len % 4);
        }

}

static void mAB_release(struct lutmABType *lut)
{
        uint8_t i;

        for (i = 0; i < lut->num_in_channels; i++){
                free(lut->a_curves[i]);
        }
        for (i = 0; i < lut->num_out_channels; i++){
                free(lut->b_curves[i]);
                free(lut->m_curves[i]);
        }
        free(lut);
}

/* See section 10.10 for specs */
static struct lutmABType *read_tag_lutmABType(struct mem_source *src, struct tag_index index, uint32_t tag_id)
{
        struct tag *tag = find_tag(index, tag_id);
        uint32_t offset = tag->offset;
        uint32_t a_curve_offset, b_curve_offset, m_curve_offset;
        uint32_t matrix_offset;
        uint32_t clut_offset;
        uint32_t clut_size = 1;
        uint8_t clut_precision;
        uint32_t type = read_u32(src, offset);
        uint8_t num_in_channels, num_out_channels;
        struct lutmABType *lut;
        int i;

        if (type != LUT_MAB_TYPE && type != LUT_MBA_TYPE) {
                return NULL;
        }

        num_in_channels = read_u8(src, offset + 8);
        num_out_channels = read_u8(src, offset + 8);
        if (num_in_channels > MAX_CHANNELS || num_out_channels > MAX_CHANNELS)
                return NULL;

        // We require 3in/out channels since we only support RGB->XYZ (or RGB->LAB)
        // XXX: If we remove this restriction make sure that the number of channels
        //      is less or equal to the maximum number of mAB curves in qcmsint.h
        //      also check for clut_size overflow.
        if (num_in_channels != 3 || num_out_channels != 3)
                return NULL;

        // some of this data is optional and is denoted by a zero offset
        // we also use this to track their existance
        a_curve_offset = read_u32(src, offset + 28);
        clut_offset = read_u32(src, offset + 24);
        m_curve_offset = read_u32(src, offset + 20);
        matrix_offset = read_u32(src, offset + 16);
        b_curve_offset = read_u32(src, offset + 12);

        // Convert offsets relative to the tag to relative to the profile
        // preserve zero for optional fields
        if (a_curve_offset)
                a_curve_offset += offset;
        if (clut_offset)
                clut_offset += offset;
        if (m_curve_offset)
                m_curve_offset += offset;
        if (matrix_offset)
                matrix_offset += offset;
        if (b_curve_offset)
                b_curve_offset += offset;

        if (clut_offset) {
                assert (num_in_channels == 3);
                // clut_size can not overflow since lg(256^num_in_channels) = 24 bits.
                for (i = 0; i < num_in_channels; i++) {
                        clut_size *= read_u8(src, clut_offset + i);
                }
        } else {
                clut_size = 0;
        }

        // 24bits * 3 won't overflow either
        clut_size = clut_size * num_out_channels;

        if (clut_size > MAX_CLUT_SIZE)
                return NULL;

        lut = malloc(sizeof(struct lutmABType) + (clut_size) * sizeof(float));
        if (!lut)
                return NULL;
        // we'll fill in the rest below
        memset(lut, 0, sizeof(struct lutmABType));
        lut->clut_table   = &lut->clut_table_data[0];

        for (i = 0; i < num_in_channels; i++) {
                lut->num_grid_points[i] = read_u8(src, clut_offset + i);
        }

        // Reverse the processing of transformation elements for mBA type.
        lut->reversed = (type == LUT_MBA_TYPE);

        lut->num_in_channels = num_in_channels;
        lut->num_out_channels = num_out_channels;

        if (matrix_offset) {
                // read the matrix if we have it
                lut->e00 = read_s15Fixed16Number(src, matrix_offset+4*0);
                lut->e01 = read_s15Fixed16Number(src, matrix_offset+4*1);
                lut->e02 = read_s15Fixed16Number(src, matrix_offset+4*2);
                lut->e10 = read_s15Fixed16Number(src, matrix_offset+4*3);
                lut->e11 = read_s15Fixed16Number(src, matrix_offset+4*4);
                lut->e12 = read_s15Fixed16Number(src, matrix_offset+4*5);
                lut->e20 = read_s15Fixed16Number(src, matrix_offset+4*6);
                lut->e21 = read_s15Fixed16Number(src, matrix_offset+4*7);
                lut->e22 = read_s15Fixed16Number(src, matrix_offset+4*8);
                lut->e03 = read_s15Fixed16Number(src, matrix_offset+4*9);
                lut->e13 = read_s15Fixed16Number(src, matrix_offset+4*10);
                lut->e23 = read_s15Fixed16Number(src, matrix_offset+4*11);
        }

        if (a_curve_offset) {
                read_nested_curveType(src, &lut->a_curves, num_in_channels, a_curve_offset);
        }
        if (m_curve_offset) {
                read_nested_curveType(src, &lut->m_curves, num_out_channels, m_curve_offset);
        }
        if (b_curve_offset) {
                read_nested_curveType(src, &lut->b_curves, num_out_channels, b_curve_offset);
        } else {
                invalid_source(src, "B curves required");
        }

        if (clut_offset) {
                clut_precision = read_u8(src, clut_offset + 16);
                if (clut_precision == 1) {
                        for (i = 0; i < clut_size; i++) {
                                lut->clut_table[i] = uInt8Number_to_float(read_uInt8Number(src, clut_offset + 20 + i*1));
                        }
                } else if (clut_precision == 2) {
                        for (i = 0; i < clut_size; i++) {
                                lut->clut_table[i] = uInt16Number_to_float(read_uInt16Number(src, clut_offset + 20 + i*2));
                        }
                } else {
                        invalid_source(src, "Invalid clut precision");
                }
        }

        if (!src->valid) {
                mAB_release(lut);
                return NULL;
        }

        return lut;
}

static struct lutType *read_tag_lutType(struct mem_source *src, struct tag_index index, uint32_t tag_id)
{
        struct tag *tag = find_tag(index, tag_id);
        uint32_t offset = tag->offset;
        uint32_t type = read_u32(src, offset);
        uint16_t num_input_table_entries;
        uint16_t num_output_table_entries;
        uint8_t in_chan, grid_points, out_chan;
        size_t clut_offset, output_offset;
        uint32_t clut_size;
        size_t entry_size;
        struct lutType *lut;
        int i;

        /* I'm not sure why the spec specifies a fixed number of entries for LUT8 tables even though
         * they have room for the num_entries fields */
        if (type == LUT8_TYPE) {
                num_input_table_entries = 256;
                num_output_table_entries = 256;
                entry_size = 1;
        } else if (type == LUT16_TYPE) {
                num_input_table_entries  = read_u16(src, offset + 48);
                num_output_table_entries = read_u16(src, offset + 50);
                entry_size = 2;
        } else {
                assert(0); // the caller checks that this doesn't happen
                invalid_source(src, "Unexpected lut type");
                return NULL;
        }

        in_chan     = read_u8(src, offset + 8);
        out_chan    = read_u8(src, offset + 9);
        grid_points = read_u8(src, offset + 10);

        clut_size = pow(grid_points, in_chan);
        if (clut_size > MAX_CLUT_SIZE) {
                return NULL;
        }

        if (in_chan != 3 || out_chan != 3) {
                return NULL;
        }

        lut = malloc(sizeof(struct lutType) + (num_input_table_entries * in_chan + clut_size*out_chan + num_output_table_entries * out_chan)*sizeof(float));
        if (!lut) {
                return NULL;
        }

        /* compute the offsets of tables */
        lut->input_table  = &lut->table_data[0];
        lut->clut_table   = &lut->table_data[in_chan*num_input_table_entries];
        lut->output_table = &lut->table_data[in_chan*num_input_table_entries + clut_size*out_chan];

        lut->num_input_table_entries  = num_input_table_entries;
        lut->num_output_table_entries = num_output_table_entries;
        lut->num_input_channels   = read_u8(src, offset + 8);
        lut->num_output_channels  = read_u8(src, offset + 9);
        lut->num_clut_grid_points = read_u8(src, offset + 10);
        lut->e00 = read_s15Fixed16Number(src, offset+12);
        lut->e01 = read_s15Fixed16Number(src, offset+16);
        lut->e02 = read_s15Fixed16Number(src, offset+20);
        lut->e10 = read_s15Fixed16Number(src, offset+24);
        lut->e11 = read_s15Fixed16Number(src, offset+28);
        lut->e12 = read_s15Fixed16Number(src, offset+32);
        lut->e20 = read_s15Fixed16Number(src, offset+36);
        lut->e21 = read_s15Fixed16Number(src, offset+40);
        lut->e22 = read_s15Fixed16Number(src, offset+44);

        for (i = 0; i < lut->num_input_table_entries * in_chan; i++) {
                if (type == LUT8_TYPE) {
                        lut->input_table[i] = uInt8Number_to_float(read_uInt8Number(src, offset + 52 + i * entry_size));
                } else {
                        lut->input_table[i] = uInt16Number_to_float(read_uInt16Number(src, offset + 52 + i * entry_size));
                }
        }

        clut_offset = offset + 52 + lut->num_input_table_entries * in_chan * entry_size;
        for (i = 0; i < clut_size * out_chan; i+=3) {
                if (type == LUT8_TYPE) {
                        lut->clut_table[i+0] = uInt8Number_to_float(read_uInt8Number(src, clut_offset + i*entry_size + 0));
                        lut->clut_table[i+1] = uInt8Number_to_float(read_uInt8Number(src, clut_offset + i*entry_size + 1));
                        lut->clut_table[i+2] = uInt8Number_to_float(read_uInt8Number(src, clut_offset + i*entry_size + 2));
                } else {
                        lut->clut_table[i+0] = uInt16Number_to_float(read_uInt16Number(src, clut_offset + i*entry_size + 0));
                        lut->clut_table[i+1] = uInt16Number_to_float(read_uInt16Number(src, clut_offset + i*entry_size + 2));
                        lut->clut_table[i+2] = uInt16Number_to_float(read_uInt16Number(src, clut_offset + i*entry_size + 4));
                }
        }

        output_offset = clut_offset + clut_size * out_chan * entry_size;
        for (i = 0; i < lut->num_output_table_entries * out_chan; i++) {
                if (type == LUT8_TYPE) {
                        lut->output_table[i] = uInt8Number_to_float(read_uInt8Number(src, output_offset + i*entry_size));
                } else {
                        lut->output_table[i] = uInt16Number_to_float(read_uInt16Number(src, output_offset + i*entry_size));
                }
        }

        return lut;
}

static void read_rendering_intent(qcms_profile *profile, struct mem_source *src)
{
        profile->rendering_intent = read_u32(src, 64);
        switch (profile->rendering_intent) {
                case QCMS_INTENT_PERCEPTUAL:
                case QCMS_INTENT_SATURATION:
                case QCMS_INTENT_RELATIVE_COLORIMETRIC:
                case QCMS_INTENT_ABSOLUTE_COLORIMETRIC:
                        break;
                default:
                        invalid_source(src, "unknown rendering intent");
        }
}

qcms_profile *qcms_profile_create(void)
{
        return calloc(sizeof(qcms_profile), 1);
}



/* build sRGB gamma table */
/* based on cmsBuildParametricGamma() */
static uint16_t *build_sRGB_gamma_table(int num_entries)
{
        int i;
        /* taken from lcms: Build_sRGBGamma() */
        double gamma = 2.4;
        double a = 1./1.055;
        double b = 0.055/1.055;
        double c = 1./12.92;
        double d = 0.04045;

        uint16_t *table = malloc(sizeof(uint16_t) * num_entries);
        if (!table)
                return NULL;

        for (i=0; i<num_entries; i++) {
                double x = (double)i / (num_entries-1);
                double y, output;
                // IEC 61966-2.1 (sRGB)
                // Y = (aX + b)^Gamma | X >= d
                // Y = cX             | X < d
                if (x >= d) {
                        double e = (a*x + b);
                        if (e > 0)
                                y = pow(e, gamma);
                        else
                                y = 0;
                } else {
                        y = c*x;
                }

                // Saturate -- this could likely move to a separate function
                output = y * 65535. + .5;
                if (output > 65535.)
                        output = 65535;
                if (output < 0)
                        output = 0;
                table[i] = (uint16_t)floor(output);
        }
        return table;
}

static struct curveType *curve_from_table(uint16_t *table, int num_entries)
{
        struct curveType *curve;
        int i;
        curve = malloc(sizeof(struct curveType) + sizeof(uInt16Number)*num_entries);
        if (!curve)
                return NULL;
        curve->type = CURVE_TYPE;
        curve->count = num_entries;
        for (i = 0; i < num_entries; i++) {
                curve->data[i] = table[i];
        }
        return curve;
}

static uint16_t float_to_u8Fixed8Number(float a)
{
        if (a > (255.f + 255.f/256))
                return 0xffff;
        else if (a < 0.f)
                return 0;
        else
                return floor(a*256.f + .5f);
}

static struct curveType *curve_from_gamma(float gamma)
{
        struct curveType *curve;
        int num_entries = 1;
        curve = malloc(sizeof(struct curveType) + sizeof(uInt16Number)*num_entries);
        if (!curve)
                return NULL;
        curve->count = num_entries;
        curve->data[0] = float_to_u8Fixed8Number(gamma);
        return curve;
}


//XXX: it would be nice if we had a way of ensuring
// everything in a profile was initialized regardless of how it was created

//XXX: should this also be taking a black_point?
/* similar to CGColorSpaceCreateCalibratedRGB */
qcms_profile* qcms_profile_create_rgb_with_gamma(
                qcms_CIE_xyY white_point,
                qcms_CIE_xyYTRIPLE primaries,
                float gamma)
{
        qcms_profile* profile = qcms_profile_create();
        if (!profile)
                return NO_MEM_PROFILE;

        //XXX: should store the whitepoint
        if (!set_rgb_colorants(profile, white_point, primaries)) {
                qcms_profile_release(profile);
                return INVALID_PROFILE;
        }

        profile->redTRC = curve_from_gamma(gamma);
        profile->blueTRC = curve_from_gamma(gamma);
        profile->greenTRC = curve_from_gamma(gamma);

        if (!profile->redTRC || !profile->blueTRC || !profile->greenTRC) {
                qcms_profile_release(profile);
                return NO_MEM_PROFILE;
        }
        profile->class = DISPLAY_DEVICE_PROFILE;
        profile->rendering_intent = QCMS_INTENT_PERCEPTUAL;
        profile->color_space = RGB_SIGNATURE;
        return profile;
}

qcms_profile* qcms_profile_create_rgb_with_table(
                qcms_CIE_xyY white_point,
                qcms_CIE_xyYTRIPLE primaries,
                uint16_t *table, int num_entries)
{
        qcms_profile* profile = qcms_profile_create();
        if (!profile)
                return NO_MEM_PROFILE;

        //XXX: should store the whitepoint
        if (!set_rgb_colorants(profile, white_point, primaries)) {
                qcms_profile_release(profile);
                return INVALID_PROFILE;
        }

        profile->redTRC = curve_from_table(table, num_entries);
        profile->blueTRC = curve_from_table(table, num_entries);
        profile->greenTRC = curve_from_table(table, num_entries);

        if (!profile->redTRC || !profile->blueTRC || !profile->greenTRC) {
                qcms_profile_release(profile);
                return NO_MEM_PROFILE;
        }
        profile->class = DISPLAY_DEVICE_PROFILE;
        profile->rendering_intent = QCMS_INTENT_PERCEPTUAL;
        profile->color_space = RGB_SIGNATURE;
        return profile;
}

/* from lcms: cmsWhitePointFromTemp */
/* tempK must be >= 4000. and <= 25000.
 * similar to argyll: icx_DTEMP2XYZ() */
static qcms_CIE_xyY white_point_from_temp(int temp_K)
{
        qcms_CIE_xyY white_point;
        double x, y;
        double T, T2, T3;
        // double M1, M2;

        // No optimization provided.
        T = temp_K;
        T2 = T*T;            // Square
        T3 = T2*T;           // Cube

        // For correlated color temperature (T) between 4000K and 7000K:
        if (T >= 4000. && T <= 7000.) {
                x = -4.6070*(1E9/T3) + 2.9678*(1E6/T2) + 0.09911*(1E3/T) + 0.244063;
        } else {
                // or for correlated color temperature (T) between 7000K and 25000K:
                if (T > 7000.0 && T <= 25000.0) {
                        x = -2.0064*(1E9/T3) + 1.9018*(1E6/T2) + 0.24748*(1E3/T) + 0.237040;
                } else {
                        assert(0 && "invalid temp");
                }
        }

        // Obtain y(x)

        y = -3.000*(x*x) + 2.870*x - 0.275;

        // wave factors (not used, but here for futures extensions)

        // M1 = (-1.3515 - 1.7703*x + 5.9114 *y)/(0.0241 + 0.2562*x - 0.7341*y);
        // M2 = (0.0300 - 31.4424*x + 30.0717*y)/(0.0241 + 0.2562*x - 0.7341*y);

        // Fill white_point struct
        white_point.x = x;
        white_point.y = y;
        white_point.Y = 1.0;

        return white_point;
}

qcms_profile* qcms_profile_sRGB(void)
{
        qcms_profile *profile;
        uint16_t *table;

        qcms_CIE_xyYTRIPLE Rec709Primaries = {
                {0.6400, 0.3300, 1.0},
                {0.3000, 0.6000, 1.0},
                {0.1500, 0.0600, 1.0}
        };
        qcms_CIE_xyY D65;

        D65 = white_point_from_temp(6504);

        table = build_sRGB_gamma_table(1024);

        if (!table)
                return NO_MEM_PROFILE;

        profile = qcms_profile_create_rgb_with_table(D65, Rec709Primaries, table, 1024);
        free(table);
        return profile;
}


/* qcms_profile_from_memory does not hold a reference to the memory passed in */
qcms_profile* qcms_profile_from_memory(const void *mem, size_t size)
{
        uint32_t length;
        struct mem_source source;
        struct mem_source *src = &source;
        struct tag_index index;
        qcms_profile *profile;

        source.buf = mem;
        source.size = size;
        source.valid = true;

        length = read_u32(src, 0);
        if (length <= size) {
                // shrink the area that we can read if appropriate
                source.size = length;
        } else {
                return INVALID_PROFILE;
        }

        /* ensure that the profile size is sane so it's easier to reason about */
        if (source.size <= 64 || source.size >= MAX_PROFILE_SIZE)
                return INVALID_PROFILE;

        profile = qcms_profile_create();
        if (!profile)
                return NO_MEM_PROFILE;

        check_CMM_type_signature(src);
        check_profile_version(src);
        read_class_signature(profile, src);
        read_rendering_intent(profile, src);
        read_color_space(profile, src);
        read_pcs(profile, src);
        //TODO read rest of profile stuff

        if (!src->valid)
                goto invalid_profile;

        index = read_tag_table(profile, src);
        if (!src->valid || !index.tags)
                goto invalid_tag_table;

        if (find_tag(index, TAG_CHAD)) {
                profile->chromaticAdaption = read_tag_s15Fixed16ArrayType(src, index, TAG_CHAD);
        } else {
                profile->chromaticAdaption.invalid = true; //Signal the data is not present
        }

        if (profile->class == DISPLAY_DEVICE_PROFILE || profile->class == INPUT_DEVICE_PROFILE ||
            profile->class == OUTPUT_DEVICE_PROFILE  || profile->class == COLOR_SPACE_PROFILE) {
                if (profile->color_space == RGB_SIGNATURE) {
                        if (find_tag(index, TAG_A2B0)) {
                                if (read_u32(src, find_tag(index, TAG_A2B0)->offset) == LUT8_TYPE ||
                                    read_u32(src, find_tag(index, TAG_A2B0)->offset) == LUT16_TYPE) {
                                        profile->A2B0 = read_tag_lutType(src, index, TAG_A2B0);
                                } else if (read_u32(src, find_tag(index, TAG_A2B0)->offset) == LUT_MAB_TYPE) {
                                        profile->mAB = read_tag_lutmABType(src, index, TAG_A2B0);
                                }
                        }
                        if (find_tag(index, TAG_B2A0)) {
                                if (read_u32(src, find_tag(index, TAG_B2A0)->offset) == LUT8_TYPE ||
                                    read_u32(src, find_tag(index, TAG_B2A0)->offset) == LUT16_TYPE) {
                                        profile->B2A0 = read_tag_lutType(src, index, TAG_B2A0);
                                } else if (read_u32(src, find_tag(index, TAG_B2A0)->offset) == LUT_MBA_TYPE) {
                                        profile->mBA = read_tag_lutmABType(src, index, TAG_B2A0);
                                }
                        }
                        if (find_tag(index, TAG_rXYZ) || !qcms_supports_iccv4) {
                                profile->redColorant = read_tag_XYZType(src, index, TAG_rXYZ);
                                profile->greenColorant = read_tag_XYZType(src, index, TAG_gXYZ);
                                profile->blueColorant = read_tag_XYZType(src, index, TAG_bXYZ);
                        }

                        if (!src->valid)
                                goto invalid_tag_table;

                        if (find_tag(index, TAG_rTRC) || !qcms_supports_iccv4) {
                                profile->redTRC = read_tag_curveType(src, index, TAG_rTRC);
                                profile->greenTRC = read_tag_curveType(src, index, TAG_gTRC);
                                profile->blueTRC = read_tag_curveType(src, index, TAG_bTRC);

                                if (!profile->redTRC || !profile->blueTRC || !profile->greenTRC)
                                        goto invalid_tag_table;
                        }
                } else if (profile->color_space == GRAY_SIGNATURE) {

                        profile->grayTRC = read_tag_curveType(src, index, TAG_kTRC);
                        if (!profile->grayTRC)
                                goto invalid_tag_table;

                } else {
                        assert(0 && "read_color_space protects against entering here");
                        goto invalid_tag_table;
                }
        } else {
                goto invalid_tag_table;
        }

        if (!src->valid)
                goto invalid_tag_table;

        free(index.tags);

        return profile;

invalid_tag_table:
        free(index.tags);
invalid_profile:
        qcms_profile_release(profile);
        return INVALID_PROFILE;
}

qcms_intent qcms_profile_get_rendering_intent(qcms_profile *profile)
{
        return profile->rendering_intent;
}

icColorSpaceSignature
qcms_profile_get_color_space(qcms_profile *profile)
{
        return profile->color_space;
}

static void lut_release(struct lutType *lut)
{
        free(lut);
}

void qcms_profile_release(qcms_profile *profile)
{
        if (profile->output_table_r)
                precache_release(profile->output_table_r);
        if (profile->output_table_g)
                precache_release(profile->output_table_g);
        if (profile->output_table_b)
                precache_release(profile->output_table_b);

        if (profile->A2B0)
                lut_release(profile->A2B0);
        if (profile->B2A0)
                lut_release(profile->B2A0);

        if (profile->mAB)
                mAB_release(profile->mAB);
        if (profile->mBA)
                mAB_release(profile->mBA);

        free(profile->redTRC);
        free(profile->blueTRC);
        free(profile->greenTRC);
        free(profile->grayTRC);
        free(profile);
}


#include <stdio.h>
qcms_profile* qcms_profile_from_file(FILE *file)
{
        uint32_t length, remaining_length;
        qcms_profile *profile;
        size_t read_length;
        be32 length_be;
        void *data;

        if (fread(&length_be, 1, sizeof(length_be), file) != sizeof(length_be))
                return BAD_VALUE_PROFILE;

        length = be32_to_cpu(length_be);
        if (length > MAX_PROFILE_SIZE || length < sizeof(length_be))
                return BAD_VALUE_PROFILE;

        /* allocate room for the entire profile */
        data = malloc(length);
        if (!data)
                return NO_MEM_PROFILE;

        /* copy in length to the front so that the buffer will contain the entire profile */
        *((be32*)data) = length_be;
        remaining_length = length - sizeof(length_be);

        /* read the rest profile */
        read_length = fread((unsigned char*)data + sizeof(length_be), 1, remaining_length, file);
        if (read_length != remaining_length) {
                free(data);
                return INVALID_PROFILE;
        }

        profile = qcms_profile_from_memory(data, length);
        free(data);
        return profile;
}

qcms_profile* qcms_profile_from_path(const char *path)
{
        qcms_profile *profile = NULL;
        FILE *file = fopen(path, "rb");
        if (file) {
                profile = qcms_profile_from_file(file);
                fclose(file);
        }
        return profile;
}

#ifdef _WIN32
/* Unicode path version */
qcms_profile* qcms_profile_from_unicode_path(const wchar_t *path)
{
        qcms_profile *profile = NULL;
        FILE *file = _wfopen(path, L"rb");
        if (file) {
                profile = qcms_profile_from_file(file);
                fclose(file);
        }
        return profile;
}
#endif

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