src/ppapi/examples/video_decode/video_decode.cc

   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 <string.h>
   6
   7 #include <iostream>
   8 #include <sstream>
   9 #include <list>
  10 #include <map>
  11 #include <set>
  12 #include <vector>
  13
  14 #include "ppapi/c/pp_errors.h"
  15 #include "ppapi/c/ppb_console.h"
  16 #include "ppapi/c/ppb_opengles2.h"
  17 #include "ppapi/cpp/dev/video_decoder_client_dev.h"
  18 #include "ppapi/cpp/dev/video_decoder_dev.h"
  19 #include "ppapi/cpp/graphics_3d.h"
  20 #include "ppapi/cpp/graphics_3d_client.h"
  21 #include "ppapi/cpp/instance.h"
  22 #include "ppapi/cpp/module.h"
  23 #include "ppapi/cpp/rect.h"
  24 #include "ppapi/cpp/var.h"
  25 #include "ppapi/examples/video_decode/testdata.h"
  26 #include "ppapi/lib/gl/include/GLES2/gl2.h"
  27 #include "ppapi/lib/gl/include/GLES2/gl2ext.h"
  28 #include "ppapi/utility/completion_callback_factory.h"
  29
  30 // Use assert as a poor-man's CHECK, even in non-debug mode.
  31 // Since <assert.h> redefines assert on every inclusion (it doesn't use
  32 // include-guards), make sure this is the last file #include'd in this file.
  33 #undef NDEBUG
  34 #include <assert.h>
  35
  36 // Assert |context_| isn't holding any GL Errors.  Done as a macro instead of a
  37 // function to preserve line number information in the failure message.
  38 #define assertNoGLError() \
  39   assert(!gles2_if_->GetError(context_->pp_resource()));
  40
  41 namespace {
  42
  43 struct PictureBufferInfo {
  44   PP_PictureBuffer_Dev buffer;
  45   GLenum texture_target;
  46 };
  47
  48 struct Shader {
  49   Shader() : program(0),
  50              texcoord_scale_location(0) {}
  51
  52   GLuint program;
  53   GLint texcoord_scale_location;
  54 };
  55
  56 class VideoDecodeDemoInstance : public pp::Instance,
  57                                 public pp::Graphics3DClient,
  58                                 public pp::VideoDecoderClient_Dev {
  59  public:
  60   VideoDecodeDemoInstance(PP_Instance instance, pp::Module* module);
  61   virtual ~VideoDecodeDemoInstance();
  62
  63   // pp::Instance implementation (see PPP_Instance).
  64   virtual void DidChangeView(const pp::Rect& position,
  65                              const pp::Rect& clip_ignored);
  66
  67   // pp::Graphics3DClient implementation.
  68   virtual void Graphics3DContextLost() {
  69     // TODO(vrk/fischman): Properly reset after a lost graphics context.  In
  70     // particular need to delete context_ and re-create textures.
  71     // Probably have to recreate the decoder from scratch, because old textures
  72     // can still be outstanding in the decoder!
  73     assert(false && "Unexpectedly lost graphics context");
  74   }
  75
  76   // pp::VideoDecoderClient_Dev implementation.
  77   virtual void ProvidePictureBuffers(
  78       PP_Resource decoder,
  79       uint32_t req_num_of_bufs,
  80       const PP_Size& dimensions,
  81       uint32_t texture_target);
  82   virtual void DismissPictureBuffer(PP_Resource decoder,
  83                                     int32_t picture_buffer_id);
  84   virtual void PictureReady(PP_Resource decoder, const PP_Picture_Dev& picture);
  85   virtual void NotifyError(PP_Resource decoder, PP_VideoDecodeError_Dev error);
  86
  87  private:
  88   enum { kNumConcurrentDecodes = 7,
  89          kNumDecoders = 2 };  // Baked into viewport rendering.
  90
  91   // A single decoder's client interface.
  92   class DecoderClient {
  93    public:
  94     DecoderClient(VideoDecodeDemoInstance* gles2,
  95                   pp::VideoDecoder_Dev* decoder);
  96     ~DecoderClient();
  97
  98     void DecodeNextNALUs();
  99
 100     // Per-decoder implementation of part of pp::VideoDecoderClient_Dev.
 101     void ProvidePictureBuffers(
 102         uint32_t req_num_of_bufs,
 103         PP_Size dimensions,
 104         uint32_t texture_target);
 105     void DismissPictureBuffer(int32_t picture_buffer_id);
 106
 107     const PictureBufferInfo& GetPictureBufferInfoById(int id);
 108     pp::VideoDecoder_Dev* decoder() { return decoder_; }
 109
 110    private:
 111     void DecodeNextNALU();
 112     static void GetNextNALUBoundary(size_t start_pos, size_t* end_pos);
 113     void DecoderBitstreamDone(int32_t result, int bitstream_buffer_id);
 114     void DecoderFlushDone(int32_t result);
 115
 116     VideoDecodeDemoInstance* gles2_;
 117     pp::VideoDecoder_Dev* decoder_;
 118     pp::CompletionCallbackFactory<DecoderClient> callback_factory_;
 119     int next_picture_buffer_id_;
 120     int next_bitstream_buffer_id_;
 121     size_t encoded_data_next_pos_to_decode_;
 122     std::set<int> bitstream_ids_at_decoder_;
 123     // Map of texture buffers indexed by buffer id.
 124     typedef std::map<int, PictureBufferInfo> PictureBufferMap;
 125     PictureBufferMap picture_buffers_by_id_;
 126     // Map of bitstream buffers indexed by id.
 127     typedef std::map<int, pp::Buffer_Dev*> BitstreamBufferMap;
 128     BitstreamBufferMap bitstream_buffers_by_id_;
 129   };
 130
 131   // Initialize Video Decoders.
 132   void InitializeDecoders();
 133
 134   // GL-related functions.
 135   void InitGL();
 136   GLuint CreateTexture(int32_t width, int32_t height, GLenum texture_target);
 137   void CreateGLObjects();
 138   void Create2DProgramOnce();
 139   void CreateRectangleARBProgramOnce();
 140   Shader CreateProgram(const char* vertex_shader,
 141                        const char* fragment_shader);
 142   void CreateShader(GLuint program, GLenum type, const char* source, int size);
 143   void DeleteTexture(GLuint id);
 144   void PaintFinished(int32_t result, PP_Resource decoder,
 145                      int picture_buffer_id);
 146
 147   // Log an error to the developer console and stderr (though the latter may be
 148   // closed due to sandboxing or blackholed for other reasons) by creating a
 149   // temporary of this type and streaming to it.  Example usage:
 150   // LogError(this).s() << "Hello world: " << 42;
 151   class LogError {
 152    public:
 153     LogError(VideoDecodeDemoInstance* demo) : demo_(demo) {}
 154     ~LogError() {
 155       const std::string& msg = stream_.str();
 156       demo_->console_if_->Log(demo_->pp_instance(), PP_LOGLEVEL_ERROR,
 157                               pp::Var(msg).pp_var());
 158       std::cerr << msg << std::endl;
 159     }
 160     // Impl note: it would have been nicer to have LogError derive from
 161     // std::ostringstream so that it can be streamed to directly, but lookup
 162     // rules turn streamed string literals to hex pointers on output.
 163     std::ostringstream& s() { return stream_; }
 164    private:
 165     VideoDecodeDemoInstance* demo_;  // Unowned.
 166     std::ostringstream stream_;
 167   };
 168
 169   pp::Size plugin_size_;
 170   bool is_painting_;
 171   // When decode outpaces render, we queue up decoded pictures for later
 172   // painting.  Elements are <decoder,picture>.
 173   std::list<std::pair<PP_Resource, PP_Picture_Dev> > pictures_pending_paint_;
 174   int num_frames_rendered_;
 175   PP_TimeTicks first_frame_delivered_ticks_;
 176   PP_TimeTicks last_swap_request_ticks_;
 177   PP_TimeTicks swap_ticks_;
 178   pp::CompletionCallbackFactory<VideoDecodeDemoInstance> callback_factory_;
 179
 180   // Unowned pointers.
 181   const PPB_Console* console_if_;
 182   const PPB_Core* core_if_;
 183   const PPB_OpenGLES2* gles2_if_;
 184
 185   // Owned data.
 186   pp::Graphics3D* context_;
 187   typedef std::map<int, DecoderClient*> Decoders;
 188   Decoders video_decoders_;
 189
 190   // Shader program to draw GL_TEXTURE_2D target.
 191   Shader shader_2d_;
 192   // Shader program to draw GL_TEXTURE_RECTANGLE_ARB target.
 193   Shader shader_rectangle_arb_;
 194 };
 195
 196 VideoDecodeDemoInstance::DecoderClient::DecoderClient(
 197       VideoDecodeDemoInstance* gles2, pp::VideoDecoder_Dev* decoder)
 198     : gles2_(gles2), decoder_(decoder), callback_factory_(this),
 199       next_picture_buffer_id_(0),
 200       next_bitstream_buffer_id_(0), encoded_data_next_pos_to_decode_(0) {
 201 }
 202
 203 VideoDecodeDemoInstance::DecoderClient::~DecoderClient() {
 204   delete decoder_;
 205   decoder_ = NULL;
 206
 207   for (BitstreamBufferMap::iterator it = bitstream_buffers_by_id_.begin();
 208        it != bitstream_buffers_by_id_.end(); ++it) {
 209     delete it->second;
 210   }
 211   bitstream_buffers_by_id_.clear();
 212
 213   for (PictureBufferMap::iterator it = picture_buffers_by_id_.begin();
 214        it != picture_buffers_by_id_.end(); ++it) {
 215     gles2_->DeleteTexture(it->second.buffer.texture_id);
 216   }
 217   picture_buffers_by_id_.clear();
 218 }
 219
 220 VideoDecodeDemoInstance::VideoDecodeDemoInstance(PP_Instance instance,
 221                                                  pp::Module* module)
 222     : pp::Instance(instance), pp::Graphics3DClient(this),
 223       pp::VideoDecoderClient_Dev(this),
 224       is_painting_(false),
 225       num_frames_rendered_(0),
 226       first_frame_delivered_ticks_(-1),
 227       swap_ticks_(0),
 228       callback_factory_(this),
 229       context_(NULL) {
 230   assert((console_if_ = static_cast<const PPB_Console*>(
 231       module->GetBrowserInterface(PPB_CONSOLE_INTERFACE))));
 232   assert((core_if_ = static_cast<const PPB_Core*>(
 233       module->GetBrowserInterface(PPB_CORE_INTERFACE))));
 234   assert((gles2_if_ = static_cast<const PPB_OpenGLES2*>(
 235       module->GetBrowserInterface(PPB_OPENGLES2_INTERFACE))));
 236 }
 237
 238 VideoDecodeDemoInstance::~VideoDecodeDemoInstance() {
 239   if (shader_2d_.program)
 240     gles2_if_->DeleteProgram(context_->pp_resource(), shader_2d_.program);
 241   if (shader_rectangle_arb_.program) {
 242     gles2_if_->DeleteProgram(
 243         context_->pp_resource(), shader_rectangle_arb_.program);
 244   }
 245
 246   for (Decoders::iterator it = video_decoders_.begin();
 247        it != video_decoders_.end(); ++it) {
 248     delete it->second;
 249   }
 250   video_decoders_.clear();
 251   delete context_;
 252 }
 253
 254 void VideoDecodeDemoInstance::DidChangeView(
 255     const pp::Rect& position, const pp::Rect& clip_ignored) {
 256   if (position.width() == 0 || position.height() == 0)
 257     return;
 258   if (plugin_size_.width()) {
 259     assert(position.size() == plugin_size_);
 260     return;
 261   }
 262   plugin_size_ = position.size();
 263
 264   // Initialize graphics.
 265   InitGL();
 266   InitializeDecoders();
 267 }
 268
 269 void VideoDecodeDemoInstance::InitializeDecoders() {
 270   assert(video_decoders_.empty());
 271   for (int i = 0; i < kNumDecoders; ++i) {
 272     DecoderClient* client = new DecoderClient(
 273         this, new pp::VideoDecoder_Dev(
 274             this, *context_, PP_VIDEODECODER_H264PROFILE_MAIN));
 275     assert(!client->decoder()->is_null());
 276     assert(video_decoders_.insert(std::make_pair(
 277         client->decoder()->pp_resource(), client)).second);
 278     client->DecodeNextNALUs();
 279   }
 280 }
 281
 282 void VideoDecodeDemoInstance::DecoderClient::DecoderBitstreamDone(
 283     int32_t result, int bitstream_buffer_id) {
 284   assert(bitstream_ids_at_decoder_.erase(bitstream_buffer_id) == 1);
 285   BitstreamBufferMap::iterator it =
 286       bitstream_buffers_by_id_.find(bitstream_buffer_id);
 287   assert(it != bitstream_buffers_by_id_.end());
 288   delete it->second;
 289   bitstream_buffers_by_id_.erase(it);
 290   DecodeNextNALUs();
 291 }
 292
 293 void VideoDecodeDemoInstance::DecoderClient::DecoderFlushDone(int32_t result) {
 294   assert(result == PP_OK);
 295   // Check that each bitstream buffer ID we handed to the decoder got handed
 296   // back to us.
 297   assert(bitstream_ids_at_decoder_.empty());
 298   delete decoder_;
 299   decoder_ = NULL;
 300 }
 301
 302 static bool LookingAtNAL(const unsigned char* encoded, size_t pos) {
 303   return pos + 3 < kDataLen &&
 304       encoded[pos] == 0 && encoded[pos + 1] == 0 &&
 305       encoded[pos + 2] == 0 && encoded[pos + 3] == 1;
 306 }
 307
 308 void VideoDecodeDemoInstance::DecoderClient::GetNextNALUBoundary(
 309     size_t start_pos, size_t* end_pos) {
 310   assert(LookingAtNAL(kData, start_pos));
 311   *end_pos = start_pos;
 312   *end_pos += 4;
 313   while (*end_pos + 3 < kDataLen &&
 314          !LookingAtNAL(kData, *end_pos)) {
 315     ++*end_pos;
 316   }
 317   if (*end_pos + 3 >= kDataLen) {
 318     *end_pos = kDataLen;
 319     return;
 320   }
 321 }
 322
 323 void VideoDecodeDemoInstance::DecoderClient::DecodeNextNALUs() {
 324   while (encoded_data_next_pos_to_decode_ <= kDataLen &&
 325          bitstream_ids_at_decoder_.size() < kNumConcurrentDecodes) {
 326     DecodeNextNALU();
 327   }
 328 }
 329
 330 void VideoDecodeDemoInstance::DecoderClient::DecodeNextNALU() {
 331   if (encoded_data_next_pos_to_decode_ == kDataLen) {
 332     ++encoded_data_next_pos_to_decode_;
 333     pp::CompletionCallback cb = callback_factory_.NewCallback(
 334         &VideoDecodeDemoInstance::DecoderClient::DecoderFlushDone);
 335     decoder_->Flush(cb);
 336     return;
 337   }
 338   size_t start_pos = encoded_data_next_pos_to_decode_;
 339   size_t end_pos;
 340   GetNextNALUBoundary(start_pos, &end_pos);
 341   pp::Buffer_Dev* buffer = new pp::Buffer_Dev(gles2_, end_pos - start_pos);
 342   PP_VideoBitstreamBuffer_Dev bitstream_buffer;
 343   int id = ++next_bitstream_buffer_id_;
 344   bitstream_buffer.id = id;
 345   bitstream_buffer.size = end_pos - start_pos;
 346   bitstream_buffer.data = buffer->pp_resource();
 347   memcpy(buffer->data(), kData + start_pos, end_pos - start_pos);
 348   assert(bitstream_buffers_by_id_.insert(std::make_pair(id, buffer)).second);
 349
 350   pp::CompletionCallback cb =
 351       callback_factory_.NewCallback(
 352           &VideoDecodeDemoInstance::DecoderClient::DecoderBitstreamDone, id);
 353   assert(bitstream_ids_at_decoder_.insert(id).second);
 354   encoded_data_next_pos_to_decode_ = end_pos;
 355   decoder_->Decode(bitstream_buffer, cb);
 356 }
 357
 358 void VideoDecodeDemoInstance::ProvidePictureBuffers(PP_Resource decoder,
 359                                                     uint32_t req_num_of_bufs,
 360                                                     const PP_Size& dimensions,
 361                                                     uint32_t texture_target) {
 362   DecoderClient* client = video_decoders_[decoder];
 363   assert(client);
 364   client->ProvidePictureBuffers(req_num_of_bufs, dimensions, texture_target);
 365 }
 366
 367 void VideoDecodeDemoInstance::DecoderClient::ProvidePictureBuffers(
 368     uint32_t req_num_of_bufs,
 369     PP_Size dimensions,
 370     uint32_t texture_target) {
 371   std::vector<PP_PictureBuffer_Dev> buffers;
 372   for (uint32_t i = 0; i < req_num_of_bufs; ++i) {
 373     PictureBufferInfo info;
 374     info.buffer.size = dimensions;
 375     info.texture_target = texture_target;
 376     info.buffer.texture_id = gles2_->CreateTexture(
 377         dimensions.width, dimensions.height, info.texture_target);
 378     int id = ++next_picture_buffer_id_;
 379     info.buffer.id = id;
 380     buffers.push_back(info.buffer);
 381     assert(picture_buffers_by_id_.insert(std::make_pair(id, info)).second);
 382   }
 383   decoder_->AssignPictureBuffers(buffers);
 384 }
 385
 386 const PictureBufferInfo&
 387 VideoDecodeDemoInstance::DecoderClient::GetPictureBufferInfoById(
 388     int id) {
 389   PictureBufferMap::iterator it = picture_buffers_by_id_.find(id);
 390   assert(it != picture_buffers_by_id_.end());
 391   return it->second;
 392 }
 393
 394 void VideoDecodeDemoInstance::DismissPictureBuffer(PP_Resource decoder,
 395                                              int32_t picture_buffer_id) {
 396   DecoderClient* client = video_decoders_[decoder];
 397   assert(client);
 398   client->DismissPictureBuffer(picture_buffer_id);
 399 }
 400
 401 void VideoDecodeDemoInstance::DecoderClient::DismissPictureBuffer(
 402     int32_t picture_buffer_id) {
 403   gles2_->DeleteTexture(GetPictureBufferInfoById(
 404       picture_buffer_id).buffer.texture_id);
 405   picture_buffers_by_id_.erase(picture_buffer_id);
 406 }
 407
 408 void VideoDecodeDemoInstance::PictureReady(PP_Resource decoder,
 409                                      const PP_Picture_Dev& picture) {
 410   if (first_frame_delivered_ticks_ == -1)
 411     assert((first_frame_delivered_ticks_ = core_if_->GetTimeTicks()) != -1);
 412   if (is_painting_) {
 413     pictures_pending_paint_.push_back(std::make_pair(decoder, picture));
 414     return;
 415   }
 416   DecoderClient* client = video_decoders_[decoder];
 417   assert(client);
 418   const PictureBufferInfo& info =
 419       client->GetPictureBufferInfoById(picture.picture_buffer_id);
 420   assert(!is_painting_);
 421   is_painting_ = true;
 422   int x = 0;
 423   int y = 0;
 424   if (client != video_decoders_.begin()->second) {
 425     x = plugin_size_.width() / kNumDecoders;
 426     y = plugin_size_.height() / kNumDecoders;
 427   }
 428
 429   if (info.texture_target == GL_TEXTURE_2D) {
 430     Create2DProgramOnce();
 431     gles2_if_->UseProgram(context_->pp_resource(), shader_2d_.program);
 432     gles2_if_->Uniform2f(
 433         context_->pp_resource(), shader_2d_.texcoord_scale_location, 1.0, 1.0);
 434   } else {
 435     assert(info.texture_target == GL_TEXTURE_RECTANGLE_ARB);
 436     CreateRectangleARBProgramOnce();
 437     gles2_if_->UseProgram(
 438         context_->pp_resource(), shader_rectangle_arb_.program);
 439     gles2_if_->Uniform2f(context_->pp_resource(),
 440                          shader_rectangle_arb_.texcoord_scale_location,
 441                          info.buffer.size.width,
 442                          info.buffer.size.height);
 443   }
 444
 445   gles2_if_->Viewport(context_->pp_resource(), x, y,
 446                       plugin_size_.width() / kNumDecoders,
 447                       plugin_size_.height() / kNumDecoders);
 448   gles2_if_->ActiveTexture(context_->pp_resource(), GL_TEXTURE0);
 449   gles2_if_->BindTexture(
 450       context_->pp_resource(), info.texture_target, info.buffer.texture_id);
 451   gles2_if_->DrawArrays(context_->pp_resource(), GL_TRIANGLE_STRIP, 0, 4);
 452
 453   gles2_if_->UseProgram(context_->pp_resource(), 0);
 454
 455   pp::CompletionCallback cb =
 456       callback_factory_.NewCallback(
 457           &VideoDecodeDemoInstance::PaintFinished, decoder, info.buffer.id);
 458   last_swap_request_ticks_ = core_if_->GetTimeTicks();
 459   assert(context_->SwapBuffers(cb) == PP_OK_COMPLETIONPENDING);
 460 }
 461
 462 void VideoDecodeDemoInstance::NotifyError(PP_Resource decoder,
 463                                           PP_VideoDecodeError_Dev error) {
 464   LogError(this).s() << "Received error: " << error;
 465   assert(false && "Unexpected error; see stderr for details");
 466 }
 467
 468 // This object is the global object representing this plugin library as long
 469 // as it is loaded.
 470 class VideoDecodeDemoModule : public pp::Module {
 471  public:
 472   VideoDecodeDemoModule() : pp::Module() {}
 473   virtual ~VideoDecodeDemoModule() {}
 474
 475   virtual pp::Instance* CreateInstance(PP_Instance instance) {
 476     return new VideoDecodeDemoInstance(instance, this);
 477   }
 478 };
 479
 480 void VideoDecodeDemoInstance::InitGL() {
 481   assert(plugin_size_.width() && plugin_size_.height());
 482   is_painting_ = false;
 483
 484   assert(!context_);
 485   int32_t context_attributes[] = {
 486     PP_GRAPHICS3DATTRIB_ALPHA_SIZE, 8,
 487     PP_GRAPHICS3DATTRIB_BLUE_SIZE, 8,
 488     PP_GRAPHICS3DATTRIB_GREEN_SIZE, 8,
 489     PP_GRAPHICS3DATTRIB_RED_SIZE, 8,
 490     PP_GRAPHICS3DATTRIB_DEPTH_SIZE, 0,
 491     PP_GRAPHICS3DATTRIB_STENCIL_SIZE, 0,
 492     PP_GRAPHICS3DATTRIB_SAMPLES, 0,
 493     PP_GRAPHICS3DATTRIB_SAMPLE_BUFFERS, 0,
 494     PP_GRAPHICS3DATTRIB_WIDTH, plugin_size_.width(),
 495     PP_GRAPHICS3DATTRIB_HEIGHT, plugin_size_.height(),
 496     PP_GRAPHICS3DATTRIB_NONE,
 497   };
 498   context_ = new pp::Graphics3D(this, context_attributes);
 499   assert(!context_->is_null());
 500   assert(BindGraphics(*context_));
 501
 502   // Clear color bit.
 503   gles2_if_->ClearColor(context_->pp_resource(), 1, 0, 0, 1);
 504   gles2_if_->Clear(context_->pp_resource(), GL_COLOR_BUFFER_BIT);
 505
 506   assertNoGLError();
 507
 508   CreateGLObjects();
 509 }
 510
 511 void VideoDecodeDemoInstance::PaintFinished(int32_t result, PP_Resource decoder,
 512                                       int picture_buffer_id) {
 513   assert(result == PP_OK);
 514   swap_ticks_ += core_if_->GetTimeTicks() - last_swap_request_ticks_;
 515   is_painting_ = false;
 516   ++num_frames_rendered_;
 517   if (num_frames_rendered_ % 50 == 0) {
 518     double elapsed = core_if_->GetTimeTicks() - first_frame_delivered_ticks_;
 519     double fps = (elapsed > 0) ? num_frames_rendered_ / elapsed : 1000;
 520     double ms_per_swap = (swap_ticks_ * 1e3) / num_frames_rendered_;
 521     LogError(this).s() << "Rendered frames: " << num_frames_rendered_
 522                        << ", fps: " << fps << ", with average ms/swap of: "
 523                        << ms_per_swap;
 524   }
 525   DecoderClient* client = video_decoders_[decoder];
 526   if (client && client->decoder())
 527     client->decoder()->ReusePictureBuffer(picture_buffer_id);
 528   if (!pictures_pending_paint_.empty()) {
 529     std::pair<PP_Resource, PP_Picture_Dev> decoder_picture =
 530         pictures_pending_paint_.front();
 531     pictures_pending_paint_.pop_front();
 532     PictureReady(decoder_picture.first, decoder_picture.second);
 533   }
 534 }
 535
 536 GLuint VideoDecodeDemoInstance::CreateTexture(int32_t width,
 537                                               int32_t height,
 538                                               GLenum texture_target) {
 539   GLuint texture_id;
 540   gles2_if_->GenTextures(context_->pp_resource(), 1, &texture_id);
 541   assertNoGLError();
 542   // Assign parameters.
 543   gles2_if_->ActiveTexture(context_->pp_resource(), GL_TEXTURE0);
 544   gles2_if_->BindTexture(context_->pp_resource(), texture_target, texture_id);
 545   gles2_if_->TexParameteri(
 546       context_->pp_resource(), texture_target, GL_TEXTURE_MIN_FILTER,
 547       GL_NEAREST);
 548   gles2_if_->TexParameteri(
 549       context_->pp_resource(), texture_target, GL_TEXTURE_MAG_FILTER,
 550       GL_NEAREST);
 551   gles2_if_->TexParameterf(
 552       context_->pp_resource(), texture_target, GL_TEXTURE_WRAP_S,
 553       GL_CLAMP_TO_EDGE);
 554   gles2_if_->TexParameterf(
 555       context_->pp_resource(), texture_target, GL_TEXTURE_WRAP_T,
 556       GL_CLAMP_TO_EDGE);
 557
 558   if (texture_target == GL_TEXTURE_2D) {
 559     gles2_if_->TexImage2D(
 560         context_->pp_resource(), texture_target, 0, GL_RGBA, width, height, 0,
 561         GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 562   }
 563   assertNoGLError();
 564   return texture_id;
 565 }
 566
 567 void VideoDecodeDemoInstance::DeleteTexture(GLuint id) {
 568   gles2_if_->DeleteTextures(context_->pp_resource(), 1, &id);
 569 }
 570
 571 void VideoDecodeDemoInstance::CreateGLObjects() {
 572   // Assign vertex positions and texture coordinates to buffers for use in
 573   // shader program.
 574   static const float kVertices[] = {
 575     -1, 1, -1, -1, 1, 1, 1, -1,  // Position coordinates.
 576     0, 1, 0, 0, 1, 1, 1, 0,      // Texture coordinates.
 577   };
 578
 579   GLuint buffer;
 580   gles2_if_->GenBuffers(context_->pp_resource(), 1, &buffer);
 581   gles2_if_->BindBuffer(context_->pp_resource(), GL_ARRAY_BUFFER, buffer);
 582
 583   gles2_if_->BufferData(context_->pp_resource(), GL_ARRAY_BUFFER,
 584                         sizeof(kVertices), kVertices, GL_STATIC_DRAW);
 585   assertNoGLError();
 586 }
 587
 588 static const char kVertexShader[] =
 589     "varying vec2 v_texCoord;            \n"
 590     "attribute vec4 a_position;          \n"
 591     "attribute vec2 a_texCoord;          \n"
 592     "uniform vec2 v_scale;               \n"
 593     "void main()                         \n"
 594     "{                                   \n"
 595     "    v_texCoord = v_scale * a_texCoord; \n"
 596     "    gl_Position = a_position;       \n"
 597     "}";
 598
 599 void VideoDecodeDemoInstance::Create2DProgramOnce() {
 600   if (shader_2d_.program)
 601     return;
 602   static const char kFragmentShader2D[] =
 603       "precision mediump float;            \n"
 604       "varying vec2 v_texCoord;            \n"
 605       "uniform sampler2D s_texture;        \n"
 606       "void main()                         \n"
 607       "{"
 608       "    gl_FragColor = texture2D(s_texture, v_texCoord); \n"
 609       "}";
 610   shader_2d_ = CreateProgram(kVertexShader, kFragmentShader2D);
 611   assertNoGLError();
 612 }
 613
 614 void VideoDecodeDemoInstance::CreateRectangleARBProgramOnce() {
 615   if (shader_rectangle_arb_.program)
 616     return;
 617   static const char kFragmentShaderRectangle[] =
 618       "#extension GL_ARB_texture_rectangle : require\n"
 619       "precision mediump float;            \n"
 620       "varying vec2 v_texCoord;            \n"
 621       "uniform sampler2DRect s_texture;    \n"
 622       "void main()                         \n"
 623       "{"
 624       "    gl_FragColor = texture2DRect(s_texture, v_texCoord).rgba; \n"
 625       "}";
 626   shader_rectangle_arb_ =
 627       CreateProgram(kVertexShader, kFragmentShaderRectangle);
 628 }
 629
 630 Shader VideoDecodeDemoInstance::CreateProgram(const char* vertex_shader,
 631                                               const char* fragment_shader) {
 632   Shader shader;
 633
 634   // Create shader program.
 635   shader.program = gles2_if_->CreateProgram(context_->pp_resource());
 636   CreateShader(shader.program, GL_VERTEX_SHADER, vertex_shader,
 637                strlen(vertex_shader));
 638   CreateShader(shader.program, GL_FRAGMENT_SHADER, fragment_shader,
 639                strlen(fragment_shader));
 640   gles2_if_->LinkProgram(context_->pp_resource(), shader.program);
 641   gles2_if_->UseProgram(context_->pp_resource(), shader.program);
 642   gles2_if_->Uniform1i(
 643       context_->pp_resource(),
 644       gles2_if_->GetUniformLocation(
 645           context_->pp_resource(), shader.program, "s_texture"), 0);
 646   assertNoGLError();
 647
 648   shader.texcoord_scale_location = gles2_if_->GetUniformLocation(
 649       context_->pp_resource(), shader.program, "v_scale");
 650
 651   GLint pos_location = gles2_if_->GetAttribLocation(
 652       context_->pp_resource(), shader.program, "a_position");
 653   GLint tc_location = gles2_if_->GetAttribLocation(
 654       context_->pp_resource(), shader.program, "a_texCoord");
 655   assertNoGLError();
 656
 657   gles2_if_->EnableVertexAttribArray(context_->pp_resource(), pos_location);
 658   gles2_if_->VertexAttribPointer(context_->pp_resource(), pos_location, 2,
 659                                  GL_FLOAT, GL_FALSE, 0, 0);
 660   gles2_if_->EnableVertexAttribArray(context_->pp_resource(), tc_location);
 661   gles2_if_->VertexAttribPointer(
 662       context_->pp_resource(), tc_location, 2, GL_FLOAT, GL_FALSE, 0,
 663       static_cast<float*>(0) + 8);  // Skip position coordinates.
 664
 665   gles2_if_->UseProgram(context_->pp_resource(), 0);
 666   assertNoGLError();
 667   return shader;
 668 }
 669
 670 void VideoDecodeDemoInstance::CreateShader(
 671     GLuint program, GLenum type, const char* source, int size) {
 672   GLuint shader = gles2_if_->CreateShader(context_->pp_resource(), type);
 673   gles2_if_->ShaderSource(context_->pp_resource(), shader, 1, &source, &size);
 674   gles2_if_->CompileShader(context_->pp_resource(), shader);
 675   gles2_if_->AttachShader(context_->pp_resource(), program, shader);
 676   gles2_if_->DeleteShader(context_->pp_resource(), shader);
 677 }
 678 }  // anonymous namespace
 679
 680 namespace pp {
 681 // Factory function for your specialization of the Module object.
 682 Module* CreateModule() {
 683   return new VideoDecodeDemoModule();
 684 }
 685 }  // namespace pp