#include <movit/image_format.h>
#include <movit/init.h>
#include <movit/resource_pool.h>
-#include <movit/util.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "alsa_output.h"
#include "bmusb/bmusb.h"
#include "bmusb/fake_capture.h"
+#include "chroma_subsampler.h"
#include "context.h"
#include "decklink_capture.h"
#include "defs.h"
cards[card_index].queue_length_policy.reset(card_index);
}
- // Set up stuff for NV12 conversion.
- //
- // Note: Due to the horizontally co-sited chroma/luma samples in H.264
- // (chrome position is left for horizontal and center for vertical),
- // we need to be a bit careful in our subsampling. A diagram will make
- // this clearer, showing some luma and chroma samples:
- //
- // a b c d
- // +---+---+---+---+
- // | | | | |
- // | Y | Y | Y | Y |
- // | | | | |
- // +---+---+---+---+
- //
- // +-------+-------+
- // | | |
- // | C | C |
- // | | |
- // +-------+-------+
- //
- // Clearly, the rightmost chroma sample here needs to be equivalent to
- // b/4 + c/2 + d/4. (We could also implement more sophisticated filters,
- // of course, but as long as the upsampling is not going to be equally
- // sophisticated, it's probably not worth it.) If we sample once with
- // no mipmapping, we get just c, ie., no actual filtering in the
- // horizontal direction. (For the vertical direction, we can just
- // sample in the middle to get the right filtering.) One could imagine
- // we could use mipmapping (assuming we can create mipmaps cheaply),
- // but then, what we'd get is this:
- //
- // (a+b)/2 (c+d)/2
- // +-------+-------+
- // | | |
- // | Y | Y |
- // | | |
- // +-------+-------+
- //
- // +-------+-------+
- // | | |
- // | C | C |
- // | | |
- // +-------+-------+
- //
- // which ends up sampling equally from a and b, which clearly isn't right. Instead,
- // we need to do two (non-mipmapped) chroma samples, both hitting exactly in-between
- // source pixels.
- //
- // Sampling in-between b and c gives us the sample (b+c)/2, and similarly for c and d.
- // Taking the average of these gives of (b+c)/4 + (c+d)/4 = b/4 + c/2 + d/4, which is
- // exactly what we want.
- //
- // See also http://www.poynton.com/PDFs/Merging_RGB_and_422.pdf, pages 6–7.
-
- // Cb/Cr shader.
- string cbcr_vert_shader =
- "#version 130 \n"
- " \n"
- "in vec2 position; \n"
- "in vec2 texcoord; \n"
- "out vec2 tc0, tc1; \n"
- "uniform vec2 foo_chroma_offset_0; \n"
- "uniform vec2 foo_chroma_offset_1; \n"
- " \n"
- "void main() \n"
- "{ \n"
- " // The result of glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0) is: \n"
- " // \n"
- " // 2.000 0.000 0.000 -1.000 \n"
- " // 0.000 2.000 0.000 -1.000 \n"
- " // 0.000 0.000 -2.000 -1.000 \n"
- " // 0.000 0.000 0.000 1.000 \n"
- " gl_Position = vec4(2.0 * position.x - 1.0, 2.0 * position.y - 1.0, -1.0, 1.0); \n"
- " vec2 flipped_tc = texcoord; \n"
- " tc0 = flipped_tc + foo_chroma_offset_0; \n"
- " tc1 = flipped_tc + foo_chroma_offset_1; \n"
- "} \n";
- string cbcr_frag_shader =
- "#version 130 \n"
- "in vec2 tc0, tc1; \n"
- "uniform sampler2D cbcr_tex; \n"
- "out vec4 FragColor; \n"
- "void main() { \n"
- " FragColor = 0.5 * (texture(cbcr_tex, tc0) + texture(cbcr_tex, tc1)); \n"
- "} \n";
- vector<string> frag_shader_outputs;
- cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader, frag_shader_outputs);
-
- float vertices[] = {
- 0.0f, 2.0f,
- 0.0f, 0.0f,
- 2.0f, 0.0f
- };
- cbcr_vbo = generate_vbo(2, GL_FLOAT, sizeof(vertices), vertices);
- cbcr_texture_sampler_uniform = glGetUniformLocation(cbcr_program_num, "cbcr_tex");
- cbcr_position_attribute_index = glGetAttribLocation(cbcr_program_num, "position");
- cbcr_texcoord_attribute_index = glGetAttribLocation(cbcr_program_num, "texcoord");
+ chroma_subsampler.reset(new ChromaSubsampler(resource_pool.get()));
if (global_flags.enable_alsa_output) {
alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
Mixer::~Mixer()
{
- resource_pool->release_glsl_program(cbcr_program_num);
- glDeleteBuffers(1, &cbcr_vbo);
BMUSBCapture::stop_bm_thread();
for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
chain->render_to_fbo(fbo, global_flags.width, global_flags.height);
resource_pool->release_fbo(fbo);
- subsample_chroma(cbcr_full_tex, cbcr_tex);
+ chroma_subsampler->subsample_chroma(cbcr_full_tex, global_flags.width, global_flags.height, cbcr_tex);
resource_pool->release_2d_texture(cbcr_full_tex);
// Set the right state for rgba_tex.
if (alsa) {
alsa->write(samples_out);
}
+ decklink_output->send_audio(task.pts_int, samples_out);
video_encoder->add_audio(task.pts_int, move(samples_out));
}
}
-void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
-{
- GLuint vao;
- glGenVertexArrays(1, &vao);
- check_error();
-
- glBindVertexArray(vao);
- check_error();
-
- // Extract Cb/Cr.
- GLuint fbo = resource_pool->create_fbo(dst_tex);
- glBindFramebuffer(GL_FRAMEBUFFER, fbo);
- glViewport(0, 0, global_flags.width/2, global_flags.height/2);
- check_error();
-
- glUseProgram(cbcr_program_num);
- check_error();
-
- glActiveTexture(GL_TEXTURE0);
- check_error();
- glBindTexture(GL_TEXTURE_2D, src_tex);
- check_error();
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
- check_error();
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
- check_error();
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
- check_error();
-
- float chroma_offset_0[] = { -1.0f / global_flags.width, 0.0f };
- float chroma_offset_1[] = { -0.0f / global_flags.width, 0.0f };
- set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
- set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_1", chroma_offset_1);
-
- glUniform1i(cbcr_texture_sampler_uniform, 0);
-
- glBindBuffer(GL_ARRAY_BUFFER, cbcr_vbo);
- check_error();
-
- for (GLint attr_index : { cbcr_position_attribute_index, cbcr_texcoord_attribute_index }) {
- glEnableVertexAttribArray(attr_index);
- check_error();
- glVertexAttribPointer(attr_index, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
- check_error();
- }
-
- glDrawArrays(GL_TRIANGLES, 0, 3);
- check_error();
-
- for (GLint attr_index : { cbcr_position_attribute_index, cbcr_texcoord_attribute_index }) {
- glDisableVertexAttribArray(attr_index);
- check_error();
- }
-
- glUseProgram(0);
- check_error();
- glBindFramebuffer(GL_FRAMEBUFFER, 0);
- check_error();
-
- resource_pool->release_fbo(fbo);
- glDeleteVertexArrays(1, &vao);
-}
-
void Mixer::release_display_frame(DisplayFrame *frame)
{
for (GLuint texnum : frame->temp_textures) {
projects / nageru / blobdiff