Reland: [qcms] Fix build_output_lut to return correct data for parametric curves

third_party/qcms/src/tests/qcms_test_output_trc.c

Index: third_party/qcms/src/tests/qcms_test_output_trc.c
diff --git a/third_party/qcms/src/tests/qcms_test_output_trc.c b/third_party/qcms/src/tests/qcms_test_output_trc.c
new file mode 100644
index 0000000000000000000000000000000000000000..9f95a3bd2e17c202ee0996dd98c729b05acf1a6b
--- /dev/null
+++ b/third_party/qcms/src/tests/qcms_test_output_trc.c
@@ -0,0 +1,197 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the Chromium LICENSE file.
+
+#include "qcms.h"
+#include "qcms_test_util.h"
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#define PARAMETRIC_CURVE_TYPE 0x70617261 // 'para'
+
+static const float inverse65535 = (float) (1.0 / 65535.0);
+
+extern float clamp_float(float a);
+
+static int get_output_gamma_table(const char *profile_path, uint16_t **table, size_t *size)
+{
+    qcms_transform *transform;
+    qcms_profile *sRGB;
+    qcms_profile *target;
+
+    target = qcms_profile_from_path(profile_path);
+    if (!target) {
+        fprintf(stderr, "Invalid input profile\n");
+        return EXIT_FAILURE;
+    }
+
+    sRGB = qcms_profile_sRGB();
+
+    transform = qcms_transform_create(sRGB, QCMS_DATA_RGBA_8, target, QCMS_DATA_RGBA_8, QCMS_INTENT_DEFAULT);
+    if (!transform) {
+        fprintf(stderr, "Failed to create colour transform\n");
+        qcms_profile_release(sRGB);
+        qcms_profile_release(target);
+        return EXIT_FAILURE;
+    }
+
+    *size = qcms_transform_get_output_trc_rgba(transform, target, QCMS_TRC_USHORT, NULL);
+    assert(*size == 256);
+
+    *table = malloc(*size * sizeof(uint16_t) * 4);
+    qcms_transform_get_output_trc_rgba(transform, target, QCMS_TRC_USHORT, *table);
+
+    qcms_transform_release(transform);
+    qcms_profile_release(sRGB);
+    qcms_profile_release(target);
+
+    return 0;
+}
+
+static int get_input_gamma_table(const char *profile_path, uint16_t **table, size_t *size)
+{
+    qcms_transform *transform;
+    qcms_profile *source;
+    qcms_profile *sRGB;
+
+    source = qcms_profile_from_path(profile_path);
+    if (!source) {
+        fprintf(stderr, "Invalid input profile\n");
+        return EXIT_FAILURE;
+    }
+
+    sRGB = qcms_profile_sRGB();
+
+    transform = qcms_transform_create(source, QCMS_DATA_RGBA_8, sRGB, QCMS_DATA_RGBA_8, QCMS_INTENT_DEFAULT);
+    if (!transform) {
+        fprintf(stderr, "Failed to create colour transform\n");
+        qcms_profile_release(sRGB);
+        qcms_profile_release(source);
+        return EXIT_FAILURE;
+    }
+
+    *size = qcms_transform_get_input_trc_rgba(transform, source, QCMS_TRC_USHORT, NULL);
+    assert(*size == 256);
+
+    *table = calloc(*size, sizeof(uint16_t) * 4);
+    qcms_transform_get_input_trc_rgba(transform, source, QCMS_TRC_USHORT, *table);
+
+    qcms_transform_release(transform);
+    qcms_profile_release(sRGB);
+    qcms_profile_release(source);
+
+    return 0;
+}
+
+static int qcms_test_output_trc(size_t width,
+        size_t height,
+        int iterations,
+        const char *in_path,
+        const char *out_path,
+        const int force_software)
+{
+    qcms_profile *profile;
+    uint16_t *gamma_table_out;
+    size_t gamma_table_size;
+    size_t i;

[Noel Gordon, 2016/04/27 00:08:08]

LGTM based on my local windows compile testing.

+
+    printf("Test qcms output gamma curve table integrity.\n");
+
+    if (!in_path) {
+        fprintf(stderr, "%s: please provide valid ICC profiles via -i option\n", __FUNCTION__);
+        return EXIT_FAILURE;
+    }
+
+    // Create profiles and transforms, get table and then free resources to make sure none
+    // of the internal tables are initialized by previous calls.
+    gamma_table_out = NULL;
+    gamma_table_size = 0;
+    if (get_output_gamma_table(in_path, &gamma_table_out, &gamma_table_size) != 0) {
+        fprintf(stderr, "Unable to extract output gamma table\n");
+        return EXIT_FAILURE;
+    }
+
+    printf("LUT size = %zu\n", gamma_table_size);
+
+    profile = qcms_profile_from_path(in_path);
+    if (!profile) {
+        fprintf(stderr, "Invalid input profile\n");
+        free(gamma_table_out);
+        return EXIT_FAILURE;
+    }
+
+    // Check only for red curve for now.
+    if (profile->redTRC->type == PARAMETRIC_CURVE_TYPE) {
+        int type = - (int)(profile->redTRC->count + 1);
+        FILE *gamma_file;
+        uint16_t *gamma_table_in = NULL;
+        uint16_t *p_table_out, *p_table_in;
+        char file_name[256] = {0,};
+        size_t input_size = 0;
+
+        printf("Detected parametric curve type = %d\n", profile->redTRC->count);
+
+        sprintf(file_name, "qcms-test-%ld-parametric-gamma-%s.csv", (long int)time(NULL), profile->description);
+        printf("Writing input and output gamma tables to %s\n", file_name);
+
+        printf("gamma = %.6f, a = %.6f, b = %.6f, c = %.6f, d = %.6f, e = %.6f, f = %.6f\n",
+                profile->redTRC->parameter[0], profile->redTRC->parameter[1], profile->redTRC->parameter[2],
+                profile->redTRC->parameter[3], profile->redTRC->parameter[4], profile->redTRC->parameter[5],
+                profile->redTRC->parameter[6]);
+
+        // Write output to stdout and tables into a csv file.
+        gamma_file = fopen(file_name, "w");
+        fprintf(gamma_file, "Parametric gamma values for %s\n", profile->description);
+        fprintf(gamma_file, "gamma, a, b, c, d, e, f\n");
+        fprintf(gamma_file, "%.6f, %.6f, %.6f, %.6f, %.6f, %.6f, %.6f\n",
+                profile->redTRC->parameter[0], profile->redTRC->parameter[1], profile->redTRC->parameter[2],
+                profile->redTRC->parameter[3], profile->redTRC->parameter[4], profile->redTRC->parameter[5],
+                profile->redTRC->parameter[6]);
+
+        get_input_gamma_table(in_path, &gamma_table_in, &input_size);
+        assert(input_size == gamma_table_size);
+        if (!gamma_table_in) {
+            fprintf(stderr, "Unable to compute input trc. Aborting\n");
+            fclose(gamma_file);
+            qcms_profile_release(profile);
+            free(gamma_table_out);
+            return EXIT_FAILURE;
+        }
+
+        fprintf(gamma_file, "\n\nInput gamma, Output gamma, LCMS Output gamma, Output gamma error\n");
+
+        p_table_out = gamma_table_out;
+        p_table_in = gamma_table_in;
+
+        for (i = 0; i < gamma_table_size; ++i) {
+            float p = i / (gamma_table_size * 1.0);
+            float reference_out = clamp_float(evaluate_parametric_curve(type, profile->redTRC->parameter, p));
+            float actual_out = *p_table_out * inverse65535;
+            float error_out = fabs(actual_out - reference_out);
+            float input = *p_table_in * inverse65535;
+
+            fprintf(gamma_file, "%.6f, %.6f, %6f, %6f\n",input, actual_out, reference_out, error_out);
+
+            p_table_out += 4; // Skip other channels.
+            p_table_in += 4; // Skip other channels.
+        }
+
+        free(gamma_table_in);
+        fclose(gamma_file);
+    }
+
+    qcms_profile_release(profile);
+    free(gamma_table_out);
+
+    return 0;
+}
+
+struct qcms_test_case qcms_test_output_trc_info = {
+        "qcms_test_output_trc",
+        qcms_test_output_trc,
+        QCMS_TEST_DISABLED
+};