Benchmark tool for GPU-accelerated video rendering

media/tools/shader_bench/gl_painter.cc

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "app/gfx/gl/gl_context.h"
+#include "media/tools/shader_bench/gl_painter.h"
+
+// Matrix used for the YUV to RGB conversion.
+static const float kYUV2RGB[9] = {
+  1.f, 0.f, 1.403f,
+  1.f, -.344f, -.714f,
+  1.f, 1.772f, 0.f,
+};
+
+static const float kYUV2RGB_TRANS[9] = {
+  1.f, 1.f, 1.f,
+  0.f, -.344f, 1.772f,
+  1.403f, -.714f, 0.f,
+};
+
+// Pass-through vertex shader.
+static const char kVertexShader[] =
+    "precision highp float;\n"
+    "precision highp int;\n"
+    "varying vec2 interp_tc;\n"
+    "\n"
+    "attribute vec4 in_pos;\n"
+    "attribute vec2 in_tc;\n"
+    "\n"
+    "void main() {\n"
+    "  interp_tc = in_tc;\n"
+    "  gl_Position = in_pos;\n"
+    "}\n";
+
+// YUV to RGB pixel shader. Loads a pixel from each plane and pass through the
+// matrix.
+static const char kFragmentShader[] =
+    "precision mediump float;\n"
+    "precision mediump int;\n"
+    "varying vec2 interp_tc;\n"
+    "\n"
+    "uniform sampler2D y_tex;\n"
+    "uniform sampler2D u_tex;\n"
+    "uniform sampler2D v_tex;\n"
+    "uniform mat3 yuv2rgb;\n"
+    "\n"
+    "void main() {\n"
+    "  float y = texture2D(y_tex, interp_tc).x;\n"
+    "  float u = texture2D(u_tex, interp_tc).r - .5;\n"
+    "  float v = texture2D(v_tex, interp_tc).r - .5;\n"
+    "  vec3 rgb = yuv2rgb * vec3(y, u, v);\n"
+    "  gl_FragColor = vec4(rgb, 1);\n"
+    "}\n";
+
+GLPainter::GLPainter()
+  : program_id_(-1) {
+}
+
+GLPainter::~GLPainter() {
+  if (program_id_) {
+    glDeleteProgram(program_id_);
+    glDeleteTextures(media::VideoFrame::kNumYUVPlanes, textures_);
+  }
+}
+
+void GLPainter::Initialize(int width, int height) {
+  //TODO(vrk): assert context_;
+  // Create 3 textures, one for each plane, and bind them to different
+  // texture units.
+  glGenTextures(media::VideoFrame::kNumYUVPlanes, textures_);
+
+  for (unsigned int i = 0; i < media::VideoFrame::kNumYUVPlanes; ++i) {
+    unsigned int texture_width = (i == media::VideoFrame::kYPlane) ?
+        width : width / 2;
+    unsigned int texture_height = (i == media::VideoFrame::kYPlane) ?
+        height : height / 2;
+    glActiveTexture(GL_TEXTURE0 + i);
+    glBindTexture(GL_TEXTURE_2D, textures_[i]);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, texture_width, texture_height, 0,

[Alpha Left Google, 2010/11/15 20:43:51]

nit: 80 chars.

+                 GL_LUMINANCE, GL_UNSIGNED_BYTE, 0);
+  }
+
+  GLuint program = CreateShaderProgram(context_, kVertexShader, kFragmentShader);
+
+  // Bind parameters.
+  glUniform1i(glGetUniformLocation(program, "y_tex"), 0);
+  glUniform1i(glGetUniformLocation(program, "u_tex"), 1);
+  glUniform1i(glGetUniformLocation(program, "v_tex"), 2);
+  int yuv2rgb_location = glGetUniformLocation(program, "yuv2rgb");
+
+  // DesktopGL supports transpose matrices.
+  if (gfx::GetGLImplementation() == gfx::kGLImplementationDesktopGL)
+    glUniformMatrix3fv(yuv2rgb_location, 1, GL_TRUE, kYUV2RGB);
+  else
+    glUniformMatrix3fv(yuv2rgb_location, 1, GL_FALSE, kYUV2RGB_TRANS);
+
+  program_id_ = program;
+}
+
+void GLPainter::Paint(scoped_refptr<media::VideoFrame> video_frame) {
+  //TODO(vrk): assert context_;
+  for (unsigned int i = 0; i < media::VideoFrame::kNumYUVPlanes; ++i) {
+    unsigned int width = (i == media::VideoFrame::kYPlane) ?
+        video_frame->width() : video_frame->width() / 2;
+    unsigned int height = (i == media::VideoFrame::kYPlane) ?
+        video_frame->height() : video_frame->height() / 2;
+    glBindTexture(GL_TEXTURE_2D, textures_[i]);

[fbarchard, 2010/11/12 17:49:17]

glBindTexture is slow.  It will cause the glDrawArray to stall.  So you're
measuring latency, not throughput.

+    glPixelStorei(GL_UNPACK_ROW_LENGTH, video_frame->stride(i));
+    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height,
+               GL_LUMINANCE, GL_UNSIGNED_BYTE, video_frame->data(i));

[Alpha Left Google, 2010/11/15 20:43:51]

nit: indentation.

+  }
+
+  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+  context_->SwapBuffers();

[fbarchard, 2010/11/12 17:49:17]

SwapBuffers is slow.  Are you sure you want to benchmark this?

+}
+
+void GLPainter::SetGLContext(gfx::GLContext* context) {
+  context_ = context;
+}