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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "media/tools/shader_bench/gpu_color_painter.h"
      6 #include "ui/gl/gl_context.h"
      7 
      8 enum { kNumYUVPlanes = 3 };
      9 
     10 // Matrix used for the YUV to RGB conversion.
     11 static const float kYUV2RGB[9] = {
     12   1.f, 0.f, 1.403f,
     13   1.f, -.344f, -.714f,
     14   1.f, 1.772f, 0.f,
     15 };
     16 
     17 static const float kYUV2RGB_TRANS[9] = {
     18   1.f, 1.f, 1.f,
     19   0.f, -.344f, 1.772f,
     20   1.403f, -.714f, 0.f,
     21 };
     22 
     23 // Pass-through vertex shader.
     24 static const char kVertexShader[] =
     25     "precision highp float;\n"
     26     "precision highp int;\n"
     27     "varying vec2 interp_tc;\n"
     28     "\n"
     29     "attribute vec4 in_pos;\n"
     30     "attribute vec2 in_tc;\n"
     31     "\n"
     32     "void main() {\n"
     33     "  interp_tc = in_tc;\n"
     34     "  gl_Position = in_pos;\n"
     35     "}\n";
     36 
     37 // YUV to RGB pixel shader. Loads a pixel from each plane and pass through the
     38 // matrix.
     39 static const char kFragmentShader[] =
     40     "precision mediump float;\n"
     41     "precision mediump int;\n"
     42     "varying vec2 interp_tc;\n"
     43     "\n"
     44     "uniform sampler2D y_tex;\n"
     45     "uniform sampler2D u_tex;\n"
     46     "uniform sampler2D v_tex;\n"
     47     "uniform mat3 yuv2rgb;\n"
     48     "\n"
     49     "void main() {\n"
     50     "  float y = texture2D(y_tex, interp_tc).x;\n"
     51     "  float u = texture2D(u_tex, interp_tc).r - .5;\n"
     52     "  float v = texture2D(v_tex, interp_tc).r - .5;\n"
     53     "  vec3 rgb = yuv2rgb * vec3(y, u, v);\n"
     54     "  gl_FragColor = vec4(rgb, 1);\n"
     55     "}\n";
     56 
     57 GPUColorWithLuminancePainter::GPUColorWithLuminancePainter()
     58     : program_id_(-1) {
     59 }
     60 
     61 GPUColorWithLuminancePainter::~GPUColorWithLuminancePainter() {
     62   if (program_id_) {
     63     glDeleteProgram(program_id_);
     64     glDeleteTextures(kNumYUVPlanes, textures_);
     65   }
     66 }
     67 
     68 void GPUColorWithLuminancePainter::Initialize(int width, int height) {
     69   // Create 3 textures, one for each plane, and bind them to different
     70   // texture units.
     71   glGenTextures(kNumYUVPlanes, textures_);
     72 
     73   for (unsigned int i = 0; i < kNumYUVPlanes; ++i) {
     74     unsigned int texture_width = (i == media::VideoFrame::kYPlane) ?
     75         width : width / 2;
     76     unsigned int texture_height = (i == media::VideoFrame::kYPlane) ?
     77         height : height / 2;
     78     glActiveTexture(GL_TEXTURE0 + i);
     79     glBindTexture(GL_TEXTURE_2D, textures_[i]);
     80     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
     81     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     82     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     83     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     84     glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, texture_width, texture_height,
     85                  0, GL_LUMINANCE, GL_UNSIGNED_BYTE, 0);
     86   }
     87 
     88   GLuint program = CreateShaderProgram(kVertexShader, kFragmentShader);
     89 
     90   // Bind parameters.
     91   glUniform1i(glGetUniformLocation(program, "y_tex"), 0);
     92   glUniform1i(glGetUniformLocation(program, "u_tex"), 1);
     93   glUniform1i(glGetUniformLocation(program, "v_tex"), 2);
     94   int yuv2rgb_location = glGetUniformLocation(program, "yuv2rgb");
     95 
     96   // DesktopGL supports transpose matrices.
     97   if (gfx::GetGLImplementation() == gfx::kGLImplementationDesktopGL)
     98     glUniformMatrix3fv(yuv2rgb_location, 1, GL_TRUE, kYUV2RGB);
     99   else
    100     glUniformMatrix3fv(yuv2rgb_location, 1, GL_FALSE, kYUV2RGB_TRANS);
    101 
    102   program_id_ = program;
    103 }
    104 
    105 void GPUColorWithLuminancePainter::Paint(
    106     scoped_refptr<media::VideoFrame> video_frame) {
    107   // Not accounting for x/y offset presently.
    108   int width = video_frame->visible_rect().width();
    109   int height = video_frame->visible_rect().height();
    110   for (unsigned int i = 0; i < kNumYUVPlanes; ++i) {
    111     unsigned int plane_width =
    112         (i == media::VideoFrame::kYPlane) ? width : width / 2;
    113     unsigned int plane_height =
    114         (i == media::VideoFrame::kYPlane) ? height : height / 2;
    115     glBindTexture(GL_TEXTURE_2D, textures_[i]);
    116     glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, plane_width, plane_height,
    117                     GL_LUMINANCE, GL_UNSIGNED_BYTE, video_frame->data(i));
    118   }
    119 
    120   glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
    121   surface()->SwapBuffers();
    122 }
    123