Move chroma subsampling into its own function.

diff --git a/mixer.cpp b/mixer.cpp
index db5f3a322d479a39ea63b53a188d2268807ece4e..83f0b1540a9bfb84f2d8825fe0fd5157eaca9f79 100644 (file)
--- a/mixer.cpp
+++ b/mixer.cpp
@@ -281,10 +281,6 @@ void Mixer::thread_func()
        struct timespec start, now;
        clock_gettime(CLOCK_MONOTONIC, &start);
 
-       GLuint vao;
-       glGenVertexArrays(1, &vao);
-       check_error();
-
        while (!should_quit) {
                ++frame;
 
@@ -406,65 +402,18 @@ void Mixer::thread_func()
                bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
                assert(got_frame);
 
-               GLuint chroma_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
-
                // Render chain.
+               GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
                GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGBA8, WIDTH, HEIGHT);
-               GLuint ycbcr_fbo = resource_pool->create_fbo(y_tex, chroma_tex, rgba_tex);
-               chain->render_to_fbo(ycbcr_fbo, WIDTH, HEIGHT);
-               resource_pool->release_fbo(ycbcr_fbo);
-
-               // Set up for extraction.
-               float vertices[] = {
-                       0.0f, 2.0f,
-                       0.0f, 0.0f,
-                       2.0f, 0.0f
-               };
-
-               glBindVertexArray(vao);
-               check_error();
-
-               // Extract Cb/Cr.
-               GLuint cbcr_fbo = resource_pool->create_fbo(cbcr_tex);
-               glBindFramebuffer(GL_FRAMEBUFFER, cbcr_fbo);
-               glViewport(0, 0, WIDTH/2, HEIGHT/2);
-               check_error();
-
-               glUseProgram(cbcr_program_num);
-               check_error();
-
-               glActiveTexture(GL_TEXTURE0);
-               check_error();
-               glBindTexture(GL_TEXTURE_2D, chroma_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[] = { -0.5f / WIDTH, 0.0f };
-               set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
+               GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
+               chain->render_to_fbo(fbo, WIDTH, HEIGHT);
+               resource_pool->release_fbo(fbo);
 
-               GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
-               GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
-
-               glDrawArrays(GL_TRIANGLES, 0, 3);
-               check_error();
+               subsample_chroma(cbcr_full_tex, cbcr_tex);
+               resource_pool->release_2d_texture(cbcr_full_tex);
 
                RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
                check_error();
-
-               cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
-               cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
-
-               glUseProgram(0);
-               check_error();
-
-               resource_pool->release_fbo(cbcr_fbo);
-               resource_pool->release_2d_texture(chroma_tex);
-
                h264_encoder->end_frame(fence, input_frames_to_release);
 
                // Store this frame for display. Remove the ready frame if any
@@ -504,6 +453,59 @@ void Mixer::thread_func()
                }
                check_error();
        }
+}
+
+void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
+{
+       GLuint vao;
+       glGenVertexArrays(1, &vao);
+       check_error();
+
+       float vertices[] = {
+               0.0f, 2.0f,
+               0.0f, 0.0f,
+               2.0f, 0.0f
+       };
+
+       glBindVertexArray(vao);
+       check_error();
+
+       // Extract Cb/Cr.
+       GLuint fbo = resource_pool->create_fbo(dst_tex);
+       glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+       glViewport(0, 0, WIDTH/2, 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[] = { -0.5f / WIDTH, 0.0f };
+       set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
+
+       GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
+       GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
+
+       glDrawArrays(GL_TRIANGLES, 0, 3);
+       check_error();
+
+       cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
+       cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
+
+       glUseProgram(0);
+       check_error();
+
+       resource_pool->release_fbo(fbo);
        glDeleteVertexArrays(1, &vao);
 }
 

diff --git a/mixer.h b/mixer.h
index 9a9ee585752754c180c79caa0fc907bf7e622892..901b269cf6a5a47f4b46192df049d559545dcb23 100644 (file)
--- a/mixer.h
+++ b/mixer.h
@@ -53,6 +53,7 @@ private:
                FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format);
        void place_rectangle(movit::Effect *resample_effect, movit::Effect *padding_effect, float x0, float y0, float x1, float y1);
        void thread_func();
+       void subsample_chroma(GLuint src_tex, GLuint dst_dst);
 
        QSurface *surface1, *surface2, *surface3, *surface4;
        std::unique_ptr<movit::EffectChain> chain;