From: Steinar H. Gunderson Date: Sat, 1 Jul 2017 19:07:32 +0000 (+0200) Subject: In ResampleEffect, split the weight calculation out into its own function that does... X-Git-Tag: 1.5.2~8 X-Git-Url: https://git.sesse.net/?p=movit;a=commitdiff_plain;h=b1b5194238dd8b357148a3eee48d8d3a1ad04b35 In ResampleEffect, split the weight calculation out into its own function that does not depend on OpenGL. --- diff --git a/resample_effect.cpp b/resample_effect.cpp index 9c8caf3..9b6d5f3 100644 --- a/resample_effect.cpp +++ b/resample_effect.cpp @@ -27,12 +27,6 @@ namespace movit { namespace { -template -struct Tap { - T weight; - T pos; -}; - float sinc(float x) { if (fabs(x) < 1e-6) { @@ -212,7 +206,7 @@ void normalize_sum(Tap* vals, unsigned num) // // The greedy strategy for combining samples is optimal. template -unsigned combine_many_samples(const Tap *weights, unsigned src_size, unsigned src_samples, unsigned dst_samples, Tap **bilinear_weights) +unsigned combine_many_samples(const Tap *weights, unsigned src_size, unsigned src_samples, unsigned dst_samples, unique_ptr[]> *bilinear_weights) { float num_subtexels = src_size / movit_texel_subpixel_precision; float inv_num_subtexels = movit_texel_subpixel_precision / src_size; @@ -225,9 +219,9 @@ unsigned combine_many_samples(const Tap *weights, unsigned src_size, unsi // Now that we know the right width, actually combine the samples. unsigned src_bilinear_samples = src_samples - max_samples_saved; - *bilinear_weights = new Tap[dst_samples * src_bilinear_samples]; + bilinear_weights->reset(new Tap[dst_samples * src_bilinear_samples]); for (unsigned y = 0; y < dst_samples; ++y) { - Tap *bilinear_weights_ptr = *bilinear_weights + y * src_bilinear_samples; + Tap *bilinear_weights_ptr = bilinear_weights->get() + y * src_bilinear_samples; unsigned num_samples_saved = combine_samples( weights + y * src_samples, bilinear_weights_ptr, @@ -506,12 +500,68 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const str assert(false); } + ScalingWeights weights = calculate_scaling_weights(src_size, dst_size, zoom, offset); + src_bilinear_samples = weights.src_bilinear_samples; + num_loops = weights.num_loops; + slice_height = 1.0f / weights.num_loops; + + // Encode as a two-component texture. Note the GL_REPEAT. + glActiveTexture(GL_TEXTURE0 + *sampler_num); + check_error(); + glBindTexture(GL_TEXTURE_2D, texnum); + check_error(); + if (last_texture_width == -1) { + // Need to set this state the first time. + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); + check_error(); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); + check_error(); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); + check_error(); + } + + GLenum type, internal_format; + void *pixels; + assert((weights.bilinear_weights_fp16 == nullptr) != (weights.bilinear_weights_fp32 == nullptr)); + if (weights.bilinear_weights_fp32 != nullptr) { + type = GL_FLOAT; + internal_format = GL_RG32F; + pixels = weights.bilinear_weights_fp32.get(); + } else { + type = GL_HALF_FLOAT; + internal_format = GL_RG16F; + pixels = weights.bilinear_weights_fp16.get(); + } + + if (int(weights.src_bilinear_samples) == last_texture_width && + int(weights.dst_samples) == last_texture_height && + internal_format == last_texture_internal_format) { + // Texture dimensions and type are unchanged; it is more efficient + // to just update it rather than making an entirely new texture. + glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, weights.src_bilinear_samples, weights.dst_samples, GL_RG, type, pixels); + } else { + glTexImage2D(GL_TEXTURE_2D, 0, internal_format, weights.src_bilinear_samples, weights.dst_samples, 0, GL_RG, type, pixels); + last_texture_width = weights.src_bilinear_samples; + last_texture_height = weights.dst_samples; + last_texture_internal_format = internal_format; + } + check_error(); +} + +ScalingWeights calculate_scaling_weights(unsigned src_size, unsigned dst_size, float zoom, float offset) +{ + if (!lanczos_table_init_done) { + // Only needed if run from outside ResampleEffect. + init_lanczos_table(); + } + // For many resamplings (e.g. 640 -> 1280), we will end up with the same // set of samples over and over again in a loop. Thus, we can compute only // the first such loop, and then ask the card to repeat the texture for us. // This is both easier on the texture cache and lowers our CPU cost for // generating the kernel somewhat. float scaling_factor; + int num_loops; if (fabs(zoom - 1.0f) < 1e-6) { num_loops = gcd(src_size, dst_size); scaling_factor = float(dst_size) / float(src_size); @@ -524,7 +574,6 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const str num_loops = 1; scaling_factor = zoom * float(dst_size) / float(src_size); } - slice_height = 1.0f / num_loops; unsigned dst_samples = dst_size / num_loops; // Sample the kernel in the right place. A diagram with a triangular kernel @@ -579,7 +628,7 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const str float radius_scaling_factor = min(scaling_factor, 1.0f); int int_radius = lrintf(LANCZOS_RADIUS / radius_scaling_factor); int src_samples = int_radius * 2 + 1; - Tap *weights = new Tap[dst_samples * src_samples]; + unique_ptr[]> weights(new Tap[dst_samples * src_samples]); float subpixel_offset = offset - lrintf(offset); // The part not covered by whole_pixel_offset. assert(subpixel_offset >= -0.5f && subpixel_offset <= 0.5f); for (unsigned y = 0; y < dst_samples; ++y) { @@ -602,15 +651,14 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const str // Our tolerance level for total error is a bit higher than the one for invididual // samples, since one would assume overall errors in the shape don't matter as much. const float max_error = 2.0f / (255.0f * 255.0f); - Tap *bilinear_weights_fp16; - src_bilinear_samples = combine_many_samples(weights, src_size, src_samples, dst_samples, &bilinear_weights_fp16); - Tap *bilinear_weights_fp32 = NULL; - bool fallback_to_fp32 = false; + unique_ptr[]> bilinear_weights_fp16; + int src_bilinear_samples = combine_many_samples(weights.get(), src_size, src_samples, dst_samples, &bilinear_weights_fp16); + unique_ptr[]> bilinear_weights_fp32 = NULL; double max_sum_sq_error_fp16 = 0.0; for (unsigned y = 0; y < dst_samples; ++y) { double sum_sq_error_fp16 = compute_sum_sq_error( - weights + y * src_samples, src_samples, - bilinear_weights_fp16 + y * src_bilinear_samples, src_bilinear_samples, + weights.get() + y * src_samples, src_samples, + bilinear_weights_fp16.get() + y * src_bilinear_samples, src_bilinear_samples, src_size); max_sum_sq_error_fp16 = std::max(max_sum_sq_error_fp16, sum_sq_error_fp16); if (max_sum_sq_error_fp16 > max_error) { @@ -619,54 +667,17 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const str } if (max_sum_sq_error_fp16 > max_error) { - fallback_to_fp32 = true; - src_bilinear_samples = combine_many_samples(weights, src_size, src_samples, dst_samples, &bilinear_weights_fp32); - } - - // Encode as a two-component texture. Note the GL_REPEAT. - glActiveTexture(GL_TEXTURE0 + *sampler_num); - check_error(); - glBindTexture(GL_TEXTURE_2D, texnum); - check_error(); - if (last_texture_width == -1) { - // Need to set this state the first time. - glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); - check_error(); - glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); - check_error(); - glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); - check_error(); - } - - GLenum type, internal_format; - void *pixels; - if (fallback_to_fp32) { - type = GL_FLOAT; - internal_format = GL_RG32F; - pixels = bilinear_weights_fp32; - } else { - type = GL_HALF_FLOAT; - internal_format = GL_RG16F; - pixels = bilinear_weights_fp16; + bilinear_weights_fp16.reset(); + src_bilinear_samples = combine_many_samples(weights.get(), src_size, src_samples, dst_samples, &bilinear_weights_fp32); } - if (int(src_bilinear_samples) == last_texture_width && - int(dst_samples) == last_texture_height && - internal_format == last_texture_internal_format) { - // Texture dimensions and type are unchanged; it is more efficient - // to just update it rather than making an entirely new texture. - glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, src_bilinear_samples, dst_samples, GL_RG, type, pixels); - } else { - glTexImage2D(GL_TEXTURE_2D, 0, internal_format, src_bilinear_samples, dst_samples, 0, GL_RG, type, pixels); - last_texture_width = src_bilinear_samples; - last_texture_height = dst_samples; - last_texture_internal_format = internal_format; - } - check_error(); - - delete[] weights; - delete[] bilinear_weights_fp16; - delete[] bilinear_weights_fp32; + ScalingWeights ret; + ret.src_bilinear_samples = src_bilinear_samples; + ret.dst_samples = dst_samples; + ret.num_loops = num_loops; + ret.bilinear_weights_fp16 = move(bilinear_weights_fp16); + ret.bilinear_weights_fp32 = move(bilinear_weights_fp32); + return ret; } void SingleResamplePassEffect::set_gl_state(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num) diff --git a/resample_effect.h b/resample_effect.h index b06b09b..1aa459c 100644 --- a/resample_effect.h +++ b/resample_effect.h @@ -18,9 +18,11 @@ #include #include #include +#include #include #include "effect.h" +#include "fp16.h" namespace movit { @@ -28,6 +30,22 @@ class EffectChain; class Node; class SingleResamplePassEffect; +// Public so that it can be benchmarked externally. +template +struct Tap { + T weight; + T pos; +}; +struct ScalingWeights { + unsigned src_bilinear_samples; + unsigned dst_samples, num_loops; + + // Exactly one of these is set. + std::unique_ptr[]> bilinear_weights_fp16; + std::unique_ptr[]> bilinear_weights_fp32; +}; +ScalingWeights calculate_scaling_weights(unsigned src_size, unsigned dst_size, float zoom, float offset); + class ResampleEffect : public Effect { public: ResampleEffect();