From: Steinar H. Gunderson Date: Mon, 22 Dec 2014 15:34:55 +0000 (+0100) Subject: Make number of BlurEffect taps configurable. X-Git-Tag: 1.1.3~18 X-Git-Url: https://git.sesse.net/?p=movit;a=commitdiff_plain;h=8b58b0d92cbf62e173bd8a903774ba0d2c91c81f Make number of BlurEffect taps configurable. This can be useful if you are using blur as part of a larger effect chain, where artifacts get masked by further processing. Request and initial patch by Christophe Thommeret, although the patch was redone from scratch. --- diff --git a/blur_effect.cpp b/blur_effect.cpp index 903737a..027d25b 100644 --- a/blur_effect.cpp +++ b/blur_effect.cpp @@ -8,15 +8,13 @@ #include "effect_util.h" #include "util.h" -// Must match blur_effect.frag. -#define NUM_TAPS 16 - using namespace std; namespace movit { BlurEffect::BlurEffect() - : radius(3.0f), + : num_taps(16), + radius(3.0f), input_width(1280), input_height(720) { @@ -58,7 +56,7 @@ void BlurEffect::update_radius() // box blurs) until we have what we need. unsigned mipmap_width = input_width, mipmap_height = input_height; float adjusted_radius = radius; - while ((mipmap_width > 1 || mipmap_height > 1) && adjusted_radius * 1.5f > NUM_TAPS / 2) { + while ((mipmap_width > 1 || mipmap_height > 1) && adjusted_radius * 1.5f > num_taps / 2) { // Find the next mipmap size (round down, minimum 1 pixel). mipmap_width = max(mipmap_width / 2, 1u); mipmap_height = max(mipmap_height / 2, 1u); @@ -72,12 +70,14 @@ void BlurEffect::update_radius() ok |= hpass->set_int("height", mipmap_height); ok |= hpass->set_int("virtual_width", mipmap_width); ok |= hpass->set_int("virtual_height", mipmap_height); + ok |= hpass->set_int("num_taps", num_taps); ok |= vpass->set_float("radius", adjusted_radius); ok |= vpass->set_int("width", mipmap_width); ok |= vpass->set_int("height", mipmap_height); ok |= vpass->set_int("virtual_width", input_width); ok |= vpass->set_int("virtual_height", input_height); + ok |= vpass->set_int("num_taps", num_taps); assert(ok); } @@ -91,8 +91,21 @@ bool BlurEffect::set_float(const string &key, float value) { return false; } +bool BlurEffect::set_int(const string &key, int value) { + if (key == "num_taps") { + if (value < 2 || value % 2 != 0) { + return false; + } + num_taps = value; + update_radius(); + return true; + } + return false; +} + SingleBlurPassEffect::SingleBlurPassEffect(BlurEffect *parent) : parent(parent), + num_taps(16), radius(3.0f), direction(HORIZONTAL), width(1280), @@ -104,12 +117,14 @@ SingleBlurPassEffect::SingleBlurPassEffect(BlurEffect *parent) register_int("height", &height); register_int("virtual_width", &virtual_width); register_int("virtual_height", &virtual_height); + register_int("num_taps", &num_taps); } string SingleBlurPassEffect::output_fragment_shader() { char buf[256]; - sprintf(buf, "#define DIRECTION_VERTICAL %d\n", (direction == VERTICAL)); + sprintf(buf, "#define DIRECTION_VERTICAL %d\n#define NUM_TAPS %d\n", + (direction == VERTICAL), num_taps); return buf + read_file("blur_effect.frag"); } @@ -119,15 +134,15 @@ void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const string &p // Compute the weights; they will be symmetrical, so we only compute // the right side. - float weight[NUM_TAPS + 1]; + float* weight = new float[num_taps + 1]; if (radius < 1e-3) { weight[0] = 1.0f; - for (unsigned i = 1; i < NUM_TAPS + 1; ++i) { + for (int i = 1; i < num_taps + 1; ++i) { weight[i] = 0.0f; } } else { float sum = 0.0f; - for (unsigned i = 0; i < NUM_TAPS + 1; ++i) { + for (int i = 0; i < num_taps + 1; ++i) { // Gaussian blur is a common, but maybe not the prettiest choice; // it can feel a bit too blurry in the fine detail and too little // long-tail. This is a simple logistic distribution, which has @@ -146,7 +161,7 @@ void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const string &p sum += 2.0f * weight[i]; } } - for (unsigned i = 0; i < NUM_TAPS + 1; ++i) { + for (int i = 0; i < num_taps + 1; ++i) { weight[i] /= sum; } } @@ -161,14 +176,14 @@ void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const string &p // // We pack the parameters into a float4: The relative sample coordinates // in (x,y), and the weight in z. w is unused. - float samples[2 * (NUM_TAPS / 2 + 1)]; + float* samples = new float[2 * (num_taps / 2 + 1)]; // Center sample. samples[2 * 0 + 0] = 0.0f; samples[2 * 0 + 1] = weight[0]; // All other samples. - for (unsigned i = 1; i < NUM_TAPS / 2 + 1; ++i) { + for (int i = 1; i < num_taps / 2 + 1; ++i) { unsigned base_pos = i * 2 - 1; float w1 = weight[base_pos]; float w2 = weight[base_pos + 1]; @@ -187,7 +202,10 @@ void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const string &p samples[2 * i + 1] = total_weight; } - set_uniform_vec2_array(glsl_program_num, prefix, "samples", samples, NUM_TAPS / 2 + 1); + set_uniform_vec2_array(glsl_program_num, prefix, "samples", samples, num_taps / 2 + 1); + + delete[] weight; + delete[] samples; } void SingleBlurPassEffect::clear_gl_state() diff --git a/blur_effect.frag b/blur_effect.frag index df0aa46..8a7a4a6 100644 --- a/blur_effect.frag +++ b/blur_effect.frag @@ -2,8 +2,6 @@ // DIRECTION_VERTICAL will be #defined to 1 if we are doing a vertical blur, // 0 otherwise. -#define NUM_TAPS 16 - uniform vec2 PREFIX(samples)[NUM_TAPS / 2 + 1]; vec4 FUNCNAME(vec2 tc) { diff --git a/blur_effect.h b/blur_effect.h index ad269f5..f531eb6 100644 --- a/blur_effect.h +++ b/blur_effect.h @@ -8,6 +8,11 @@ // Works in two passes; first horizontal, then vertical (BlurEffect, // which is what the user is intended to use, instantiates two copies of // SingleBlurPassEffect behind the scenes). +// +// The recommended number of taps is the default (16). Fewer will be faster +// but uglier; a tradeoff that might be worth it as part of more complicated +// effects. This can be set only before finalization, and must be an +// even number. #include #include @@ -45,10 +50,12 @@ public: virtual void rewrite_graph(EffectChain *graph, Node *self); virtual bool set_float(const std::string &key, float value); + virtual bool set_int(const std::string &key, int value); private: void update_radius(); - + + int num_taps; float radius; SingleBlurPassEffect *hpass, *vpass; unsigned input_width, input_height; @@ -89,6 +96,7 @@ public: private: BlurEffect *parent; + int num_taps; float radius; Direction direction; int width, height, virtual_width, virtual_height; diff --git a/blur_effect_test.cpp b/blur_effect_test.cpp index fb4e025..1c9193d 100644 --- a/blur_effect_test.cpp +++ b/blur_effect_test.cpp @@ -22,12 +22,15 @@ TEST(BlurEffectTest, IdentityTransformDoesNothing) { }; float out_data[size * size]; - EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR); - Effect *blur_effect = tester.get_chain()->add_effect(new BlurEffect()); - ASSERT_TRUE(blur_effect->set_float("radius", 0.0f)); - tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR); - - expect_equal(data, out_data, size, size); + for (int num_taps = 2; num_taps < 20; num_taps += 2) { + EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR); + Effect *blur_effect = tester.get_chain()->add_effect(new BlurEffect()); + ASSERT_TRUE(blur_effect->set_float("radius", 0.0f)); + ASSERT_TRUE(blur_effect->set_int("num_taps", num_taps)); + tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR); + + expect_equal(data, out_data, size, size); + } } namespace { @@ -102,4 +105,32 @@ TEST(BlurEffectTest, BlurTwoDotsLargeRadius) { expect_equal(expected_data, out_data, size, size, 0.1f, 1e-3); } +TEST(BlurEffectTest, BlurTwoDotsSmallRadiusFewerTaps) { + const float sigma = 3.0f; + const int size = 32; + const int x1 = 8; + const int y1 = 8; + const int x2 = 20; + const int y2 = 10; + + float data[size * size], out_data[size * size], expected_data[size * size]; + memset(data, 0, sizeof(data)); + memset(expected_data, 0, sizeof(expected_data)); + + data[y1 * size + x1] = 1.0f; + data[y2 * size + x2] = 1.0f; + + add_blurred_point(expected_data, size, x1, y1, 1.0f, sigma); + add_blurred_point(expected_data, size, x2, y2, 1.0f, sigma); + + EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR); + Effect *blur_effect = tester.get_chain()->add_effect(new BlurEffect()); + ASSERT_TRUE(blur_effect->set_float("radius", sigma)); + ASSERT_TRUE(blur_effect->set_int("num_taps", 10)); + tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR); + + // Set the limits a bit tighter than usual, since there is so little energy in here. + expect_equal(expected_data, out_data, size, size, 1e-3, 1e-5); +} + } // namespace movit