X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=resample_effect.cpp;h=3ccb2fdc4054894ad49e15f2f7035033ddb6adbd;hp=50b7c6bc5c4730fc6bb25cd18c96a446c8f02986;hb=42f0fd5ccbb3560a76d55f3e725416a5e0f93523;hpb=daca930fb2f404e8800c35715f1fc5c4897d19fb diff --git a/resample_effect.cpp b/resample_effect.cpp index 50b7c6b..3ccb2fd 100644 --- a/resample_effect.cpp +++ b/resample_effect.cpp @@ -20,6 +20,12 @@ namespace movit { namespace { +template +struct Tap { + T weight; + T pos; +}; + float sinc(float x) { if (fabs(x) < 1e-6) { @@ -49,14 +55,13 @@ unsigned gcd(unsigned a, unsigned b) return a; } -unsigned combine_samples(float *src, float *dst, unsigned num_src_samples, unsigned max_samples_saved) +unsigned combine_samples(Tap *src, Tap *dst, unsigned src_size, unsigned num_src_samples, unsigned max_samples_saved) { unsigned num_samples_saved = 0; for (unsigned i = 0, j = 0; i < num_src_samples; ++i, ++j) { // Copy the sample directly; it will be overwritten later if we can combine. if (dst != NULL) { - dst[j * 2 + 0] = src[i * 2 + 0]; - dst[j * 2 + 1] = src[i * 2 + 1]; + dst[j] = src[i]; } if (i == num_src_samples - 1) { @@ -69,19 +74,19 @@ unsigned combine_samples(float *src, float *dst, unsigned num_src_samples, unsig continue; } - float w1 = src[i * 2 + 0]; - float w2 = src[(i + 1) * 2 + 0]; + float w1 = src[i].weight; + float w2 = src[i + 1].weight; if (w1 * w2 < 0.0f) { // Differing signs; cannot combine. continue; } - float pos1 = src[i * 2 + 1]; - float pos2 = src[(i + 1) * 2 + 1]; + float pos1 = src[i].pos; + float pos2 = src[i + 1].pos; assert(pos2 > pos1); - float offset, total_weight, sum_sq_error; - combine_two_samples(w1, w2, &offset, &total_weight, &sum_sq_error); + float pos, total_weight, sum_sq_error; + combine_two_samples(w1, w2, pos1, pos2, src_size, COMBINE_ROUND_TO_FP16, &pos, &total_weight, &sum_sq_error); // If the interpolation error is larger than that of about sqrt(2) of // a level at 8-bit precision, don't combine. (You'd think 1.0 was enough, @@ -94,8 +99,8 @@ unsigned combine_samples(float *src, float *dst, unsigned num_src_samples, unsig // OK, we can combine this and the next sample. if (dst != NULL) { - dst[j * 2 + 0] = total_weight; - dst[j * 2 + 1] = pos1 + offset * (pos2 - pos1); + dst[j].weight = total_weight; + dst[j].pos = pos; } ++i; // Skip the next sample. @@ -108,7 +113,10 @@ unsigned combine_samples(float *src, float *dst, unsigned num_src_samples, unsig ResampleEffect::ResampleEffect() : input_width(1280), - input_height(720) + input_height(720), + offset_x(0.0f), offset_y(0.0f), + zoom_x(1.0f), zoom_y(1.0f), + zoom_center_x(0.5f), zoom_center_y(0.5f) { register_int("width", &output_width); register_int("height", &output_height); @@ -158,6 +166,26 @@ void ResampleEffect::update_size() ok |= vpass->set_int("output_height", output_height); assert(ok); + + // The offset added due to zoom may have changed with the size. + update_offset_and_zoom(); +} + +void ResampleEffect::update_offset_and_zoom() +{ + bool ok = true; + + // Zoom from the right origin. (zoom_center is given in normalized coordinates, + // i.e. 0..1.) + float extra_offset_x = zoom_center_x * (1.0f - 1.0f / zoom_x) * input_width; + float extra_offset_y = (1.0f - zoom_center_y) * (1.0f - 1.0f / zoom_y) * input_height; + + ok |= hpass->set_float("offset", extra_offset_x + offset_x); + ok |= vpass->set_float("offset", extra_offset_y - offset_y); // Compensate for the bottom-left origin. + ok |= hpass->set_float("zoom", zoom_x); + ok |= vpass->set_float("zoom", zoom_y); + + assert(ok); } bool ResampleEffect::set_float(const string &key, float value) { @@ -171,6 +199,42 @@ bool ResampleEffect::set_float(const string &key, float value) { update_size(); return true; } + if (key == "top") { + offset_y = value; + update_offset_and_zoom(); + return true; + } + if (key == "left") { + offset_x = value; + update_offset_and_zoom(); + return true; + } + if (key == "zoom_x") { + if (value <= 0.0f) { + return false; + } + zoom_x = value; + update_offset_and_zoom(); + return true; + } + if (key == "zoom_y") { + if (value <= 0.0f) { + return false; + } + zoom_y = value; + update_offset_and_zoom(); + return true; + } + if (key == "zoom_center_x") { + zoom_center_x = value; + update_offset_and_zoom(); + return true; + } + if (key == "zoom_center_y") { + zoom_center_y = value; + update_offset_and_zoom(); + return true; + } return false; } @@ -179,16 +243,22 @@ SingleResamplePassEffect::SingleResamplePassEffect(ResampleEffect *parent) direction(HORIZONTAL), input_width(1280), input_height(720), + offset(0.0), + zoom(1.0), last_input_width(-1), last_input_height(-1), last_output_width(-1), - last_output_height(-1) + last_output_height(-1), + last_offset(0.0 / 0.0), // NaN. + last_zoom(0.0 / 0.0) // NaN. { register_int("direction", (int *)&direction); register_int("input_width", &input_width); register_int("input_height", &input_height); register_int("output_width", &output_width); register_int("output_height", &output_height); + register_float("offset", &offset); + register_float("zoom", &zoom); glGenTextures(1, &texnum); } @@ -237,7 +307,19 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const str // 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. - num_loops = gcd(src_size, dst_size); + float scaling_factor; + if (fabs(zoom - 1.0f) < 1e-6) { + num_loops = gcd(src_size, dst_size); + scaling_factor = float(dst_size) / float(src_size); + } else { + // If zooming is enabled (ie., zoom != 1), we turn off the looping. + // We _could_ perhaps do it for rational zoom levels (especially + // things like 2:1), but it doesn't seem to be worth it, given that + // the most common use case would seem to be varying the zoom + // from frame to frame. + 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; @@ -290,24 +372,25 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const str // Anyhow, in this case we clearly need to look at more source pixels // to compute the destination pixel, and how many depend on the scaling factor. // Thus, the kernel width will vary with how much we scale. - float radius_scaling_factor = min(float(dst_size) / float(src_size), 1.0f); + 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; - float *weights = new float[dst_samples * src_samples * 2]; + Tap *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) { // Find the point around which we want to sample the source image, // compensating for differing pixel centers as the scale changes. - float center_src_y = (y + 0.5f) * float(src_size) / float(dst_size) - 0.5f; + float center_src_y = (y + 0.5f) / scaling_factor - 0.5f; int base_src_y = lrintf(center_src_y); // Now sample pixels on each side around that point. for (int i = 0; i < src_samples; ++i) { int src_y = base_src_y + i - int_radius; - float weight = lanczos_weight(radius_scaling_factor * (src_y - center_src_y), LANCZOS_RADIUS); - weights[(y * src_samples + i) * 2 + 0] = weight * radius_scaling_factor; - weights[(y * src_samples + i) * 2 + 1] = (src_y + 0.5) / float(src_size); + float weight = lanczos_weight(radius_scaling_factor * (src_y - center_src_y - subpixel_offset), LANCZOS_RADIUS); + weights[y * src_samples + i].weight = weight * radius_scaling_factor; + weights[y * src_samples + i].pos = (src_y + 0.5) / float(src_size); } - } // Now make use of the bilinear filtering in the GPU to reduce the number of samples @@ -320,27 +403,28 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const str // The greedy strategy for combining samples is optimal. src_bilinear_samples = 0; for (unsigned y = 0; y < dst_samples; ++y) { - unsigned num_samples_saved = combine_samples(weights + (y * src_samples) * 2, NULL, src_samples, UINT_MAX); + unsigned num_samples_saved = combine_samples(weights + y * src_samples, NULL, src_size, src_samples, UINT_MAX); src_bilinear_samples = max(src_bilinear_samples, src_samples - num_samples_saved); } // Now that we know the right width, actually combine the samples. - float *bilinear_weights = new float[dst_samples * src_bilinear_samples * 2]; - fp16_int_t *bilinear_weights_fp16 = new fp16_int_t[dst_samples * src_bilinear_samples * 2]; + Tap *bilinear_weights = new Tap[dst_samples * src_bilinear_samples]; + Tap *bilinear_weights_fp16 = new Tap[dst_samples * src_bilinear_samples]; for (unsigned y = 0; y < dst_samples; ++y) { - float *bilinear_weights_ptr = bilinear_weights + (y * src_bilinear_samples) * 2; - fp16_int_t *bilinear_weights_fp16_ptr = bilinear_weights_fp16 + (y * src_bilinear_samples) * 2; + Tap *bilinear_weights_ptr = bilinear_weights + y * src_bilinear_samples; + Tap *bilinear_weights_fp16_ptr = bilinear_weights_fp16 + y * src_bilinear_samples; unsigned num_samples_saved = combine_samples( - weights + (y * src_samples) * 2, + weights + y * src_samples, bilinear_weights_ptr, + src_size, src_samples, src_samples - src_bilinear_samples); assert(int(src_samples) - int(num_samples_saved) == src_bilinear_samples); // Convert to fp16. for (int i = 0; i < src_bilinear_samples; ++i) { - bilinear_weights_fp16_ptr[i * 2 + 0] = fp64_to_fp16(bilinear_weights_ptr[i * 2 + 0]); - bilinear_weights_fp16_ptr[i * 2 + 1] = fp64_to_fp16(bilinear_weights_ptr[i * 2 + 1]); + bilinear_weights_fp16_ptr[i].weight = fp64_to_fp16(bilinear_weights_ptr[i].weight); + bilinear_weights_fp16_ptr[i].pos = fp64_to_fp16(bilinear_weights_ptr[i].pos); } // Normalize so that the sum becomes one. Note that we do it twice; @@ -348,11 +432,11 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const str for (int normalize_pass = 0; normalize_pass < 2; ++normalize_pass) { double sum = 0.0; for (int i = 0; i < src_bilinear_samples; ++i) { - sum += fp16_to_fp64(bilinear_weights_fp16_ptr[i * 2 + 0]); + sum += fp16_to_fp64(bilinear_weights_fp16_ptr[i].weight); } for (int i = 0; i < src_bilinear_samples; ++i) { - bilinear_weights_fp16_ptr[i * 2 + 0] = fp64_to_fp16( - fp16_to_fp64(bilinear_weights_fp16_ptr[i * 2 + 0]) / sum); + bilinear_weights_fp16_ptr[i].weight = fp64_to_fp16( + fp16_to_fp64(bilinear_weights_fp16_ptr[i].weight) / sum); } } } @@ -388,12 +472,16 @@ void SingleResamplePassEffect::set_gl_state(GLuint glsl_program_num, const strin if (input_width != last_input_width || input_height != last_input_height || output_width != last_output_width || - output_height != last_output_height) { + output_height != last_output_height || + offset != last_offset || + zoom != last_zoom) { update_texture(glsl_program_num, prefix, sampler_num); last_input_width = input_width; last_input_height = input_height; last_output_width = output_width; last_output_height = output_height; + last_offset = offset; + last_zoom = zoom; } glActiveTexture(GL_TEXTURE0 + *sampler_num); @@ -402,7 +490,7 @@ void SingleResamplePassEffect::set_gl_state(GLuint glsl_program_num, const strin check_error(); set_uniform_int(glsl_program_num, prefix, "sample_tex", *sampler_num); - ++sampler_num; + ++*sampler_num; set_uniform_int(glsl_program_num, prefix, "num_samples", src_bilinear_samples); set_uniform_float(glsl_program_num, prefix, "num_loops", num_loops); set_uniform_float(glsl_program_num, prefix, "slice_height", slice_height); @@ -411,6 +499,14 @@ void SingleResamplePassEffect::set_gl_state(GLuint glsl_program_num, const strin set_uniform_float(glsl_program_num, prefix, "sample_x_scale", 1.0f / src_bilinear_samples); set_uniform_float(glsl_program_num, prefix, "sample_x_offset", 0.5f / src_bilinear_samples); + float whole_pixel_offset; + if (direction == SingleResamplePassEffect::VERTICAL) { + whole_pixel_offset = lrintf(offset) / float(input_height); + } else { + whole_pixel_offset = lrintf(offset) / float(input_width); + } + set_uniform_float(glsl_program_num, prefix, "whole_pixel_offset", whole_pixel_offset); + // We specifically do not want mipmaps on the input texture; // they break minification. Node *self = chain->find_node_for_effect(this);