AndroidVDA by using Android's MediaCodec API.

content/common/gpu/media/gles2_external_texture_copier.cc

+// Copyright (c) 2013 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 "content/common/gpu/media/gles2_external_texture_copier.h"
+
+#include "base/logging.h"
+
+namespace content {
+
+static void checkGlError(const char* op) {
+  for (GLint error = glGetError(); error; error = glGetError()) {
+    LOG(ERROR) << "after " << op <<" glError (0x" << std::hex << error << ")";
+    NOTREACHED();
+  }
+}
+
+static const char g_vertex_shader[] =
+    "uniform mat4 uMVPMatrix;\n"
+    "uniform mat4 uSTMatrix;\n"
+    "attribute vec4 aPosition;\n"
+    "attribute vec4 aTextureCoord;\n"
+    "varying vec2 vTextureCoord;\n"
+    "void main() {\n"
+    "  gl_Position = uMVPMatrix * aPosition;\n"
+    "  vTextureCoord = (uSTMatrix * aTextureCoord).xy;\n"
+    "}\n";
+
+static const char g_fragment_shader[] =
+    "#extension GL_OES_EGL_image_external : require\n"
+    "precision mediump float;\n"
+    "varying vec2 vTextureCoord;\n"
+    "uniform samplerExternalOES sTexture;\n"
+    "void main() {\n"
+    "  gl_FragColor = texture2D(sTexture, vTextureCoord);\n"
+    "}\n";
+
+enum { kVerticeStride = 5 * sizeof(float) };
+
+static const GLfloat g_vertices[] = {
+    -1.0f, -1.0f, 0, 0.f, 0.f,
+    1.0f, -1.0f, 0, 1.f, 0.f,
+    -1.0f, 1.0f, 0, 0.f, 1.f,
+    1.0f, 1.0f, 0, 1.f, 1.f,
+};
+
+// Due to the absence of matrix functions in NDK, a pre-calculated matrix
+// is used. g_mvp_matrix = P * L * I
+// Matrix.setLookAtM(L, 0, 0, 0, 2, 0, 0, 0, 0, -1, 0);
+// Matrix.orthoM(P, 0, -1, 1, -1, 1, 1, 3);
+// Matrix.setIdentityM(I, 0);
+// TODO(dwkang): currently, (0, -1, 0) is used for the up vector.
+//               figure out why up vector (0, 1, 0) generates flipped screen.
+static const GLfloat g_mvp_matrix[] = {
+    1.f, 0.f, 0.f, 0.f,
+    0.f, -1.f, 0.f, 0.f,
+    0.f, 0.f, -1.f, 0.f,
+    0.f, 0.f, 0.f, 1.f,
+};
+
+static GLuint LoadShader(GLenum shaderType, const char* pSource) {
+  GLuint shader = glCreateShader(shaderType);
+  if (shader) {
+    glShaderSource(shader, 1, &pSource, NULL);
+    glCompileShader(shader);
+    GLint compiled = 0;
+    glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+    if (!compiled) {
+      GLint infoLen = 0;
+      glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infoLen);
+      if (infoLen) {
+        char* buf = (char*) malloc(infoLen);
+        if (buf) {
+          glGetShaderInfoLog(shader, infoLen, NULL, buf);
+          LOG(ERROR) << "Could not compile shader : " << buf;
+          free(buf);
+        }
+        glDeleteShader(shader);
+        shader = 0;
+      }
+    }
+  }
+  return shader;
+}
+
+static GLuint CreateProgram(
+    const char* pVertexSource, const char* pFragmentSource) {
+  GLuint vertexShader = LoadShader(GL_VERTEX_SHADER, pVertexSource);
+  if (!vertexShader) {
+    return 0;
+  }
+
+  GLuint pixelShader = LoadShader(GL_FRAGMENT_SHADER, pFragmentSource);
+  if (!pixelShader) {
+    return 0;
+  }
+
+  GLuint program = glCreateProgram();
+  if (program) {
+    glAttachShader(program, vertexShader);
+    checkGlError("glAttachShader");
+    glAttachShader(program, pixelShader);
+    checkGlError("glAttachShader");
+    glLinkProgram(program);
+    GLint linkStatus = GL_FALSE;
+    glGetProgramiv(program, GL_LINK_STATUS, &linkStatus);
+    if (linkStatus != GL_TRUE) {
+      GLint bufLength = 0;
+      glGetProgramiv(program, GL_INFO_LOG_LENGTH, &bufLength);
+      if (bufLength) {
+        char* buf = (char*) malloc(bufLength);
+        if (buf) {
+          glGetProgramInfoLog(program, bufLength, NULL, buf);
+          LOG(ERROR) << "Could not link program: "<< buf;
+          free(buf);
+        }
+      }
+      glDeleteProgram(program);
+      program = 0;
+    }
+  }
+  return program;
+}
+
+Gles2ExternalTextureCopier::Gles2ExternalTextureCopier()
+  : initialized_(false),
+    width_(0),
+    height_(0),
+    framebuffer_id_(0),
+    renderbuffer_id_(0),
+    program_(0),
+    position_handle_(0),
+    st_matrix_handle_(0),
+    mvp_matrix_handle_(0),
+    texture_handle_(0) {
+  memset(st_matrix_, 0, sizeof(st_matrix_));
+}
+
+Gles2ExternalTextureCopier::~Gles2ExternalTextureCopier() {
+  if (initialized_) {
+    glDeleteFramebuffers(1, &framebuffer_id_);
+    glDeleteRenderbuffers(1, &renderbuffer_id_);
+  }
+}
+
+bool Gles2ExternalTextureCopier::SetupGraphics() {
+  program_ = CreateProgram(g_vertex_shader, g_fragment_shader);
+  if (!program_) {
+    LOG(ERROR) << "Could not create program.";
+    return false;
+  }
+  position_handle_ = glGetAttribLocation(program_, "aPosition");
+  checkGlError("glGetAttribLocation");
+
+  texture_handle_ = glGetAttribLocation(program_, "aTextureCoord");
+  checkGlError("glGetAttribLocation aTextureCoord");
+
+  mvp_matrix_handle_ = glGetUniformLocation(program_, "uMVPMatrix");
+  checkGlError("glGetUniformLocation uMVPMatrix");
+
+  st_matrix_handle_ = glGetUniformLocation(program_, "uSTMatrix");
+  checkGlError("glGetUniformLocation uSTMatrix");
+
+  return true;
+}
+
+void Gles2ExternalTextureCopier::RenderFrame(int w, int h, GLuint texture_id) {
+  glViewport(0, 0, w, h);
+  checkGlError("glViewport");
+
+  glClear( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);

[ycheo (away), 2013/01/17 08:34:44]

Remove a space after the opening parenthesis. 

[dwkang1, 2013/01/18 07:14:08]

Done.

+  checkGlError("glClear");
+
+  glUseProgram(program_);
+  checkGlError("glUseProgram");
+
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_EXTERNAL_OES, texture_id);
+  checkGlError("glBindTexture");
+
+  glVertexAttribPointer(
+      position_handle_, 3, GL_FLOAT, GL_FALSE, kVerticeStride, g_vertices);
+  checkGlError("glVertexAttribPointer vPositionHandle");
+  glEnableVertexAttribArray(position_handle_);
+  checkGlError("glEnableVertexAttribArray vPositionHandle");
+
+  glVertexAttribPointer(
+      texture_handle_, 2, GL_FLOAT, GL_FALSE, kVerticeStride, g_vertices + 3);
+  checkGlError("glVertexAttribPointer aTextureHandle");
+  glEnableVertexAttribArray(texture_handle_);
+  checkGlError("glEnableVertexAttribArray aTextureHandle");
+
+  glUniformMatrix4fv(mvp_matrix_handle_, 1, GL_FALSE, g_mvp_matrix);
+  checkGlError("glUniformMatrix4fv uMVPMatrixHandle");
+
+  glUniformMatrix4fv(st_matrix_handle_, 1, GL_FALSE, st_matrix_);
+  checkGlError("glUniformMatrix4fv uSTMatrixHandle");
+
+  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+  checkGlError("glDrawArrays");
+}
+
+bool Gles2ExternalTextureCopier::Init(int32 width, int32 height) {
+  if (initialized_) {
+    LOG(ERROR) << "Init should not be called twice.";
+    return false;
+  }
+
+  width_ = width;
+  height_ = height;
+
+  SetupGraphics();
+  if (!SetupFrameBuffer()) {
+    LOG(ERROR) << "Failed to create a framebuffer.";
+    return false;
+  }
+
+  initialized_ = true;
+  return initialized_;
+}
+
+bool Gles2ExternalTextureCopier::Copy(
+    GLuint source_texture_id, GLenum source_target,
+    float transfrom_matrix[16],
+    GLuint destination_texture_id, GLenum destination_target) {
+  if (!initialized_) {
+    return false;
+  }
+  if (source_target != GL_TEXTURE_EXTERNAL_OES
+      || destination_target != GL_TEXTURE_2D) {
+    LOG(ERROR) << "Unsupported texture targets: source("
+        << source_target << ") destination(" << destination_target << ")";
+    return false;
+  }
+
+  memcpy(st_matrix_, transfrom_matrix, sizeof(st_matrix_));

[ycheo (away), 2013/01/17 08:34:44]

What's the reason to copy transform_matrix to st_matrix_ not to handle it over
RenderFrame()?

[dwkang1, 2013/01/18 07:14:08]

Because I did this in a hurry? ;-) Fixed.

+
+  glBindFramebuffer(GL_FRAMEBUFFER, framebuffer_id_);
+  glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
+                         destination_texture_id, 0);
+  GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+  if (status != GL_FRAMEBUFFER_COMPLETE) {
+    LOG(ERROR) << "Framebuffer is not complete: " << status;
+    return false;
+  }
+  glBindFramebuffer(GL_FRAMEBUFFER, framebuffer_id_);
+  checkGlError("glBindFramebuffer framebuffer_id_");
+  RenderFrame(width_, height_, source_texture_id);
+  glBindFramebuffer(GL_FRAMEBUFFER, 0);
+  checkGlError("glBindFramebuffer 0");
+
+  return true;
+}
+
+bool Gles2ExternalTextureCopier::SetupFrameBuffer() {
+  GLuint framebuffer;
+  glGenFramebuffers(1, &framebuffer);
+  glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
+
+  GLuint depthbuffer;
+  glGenRenderbuffers(1, &depthbuffer);
+
+  glBindRenderbuffer(GL_RENDERBUFFER, depthbuffer);
+  glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, width_, height_);
+  glFramebufferRenderbuffer(
+      GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthbuffer);
+  checkGlError("glFramebufferRenderbuffer");
+
+  glBindFramebuffer(GL_FRAMEBUFFER, 0);
+  framebuffer_id_ = framebuffer;
+  renderbuffer_id_ = depthbuffer;
+  return true;
+}
+
+}  // namespace content