Experimental patch for MediaCodec APIs.

content/renderer/pepper/pepper_video_decoder_host.cc

Index: content/renderer/pepper/pepper_video_decoder_host.cc
diff --git a/content/renderer/pepper/pepper_video_decoder_host.cc b/content/renderer/pepper/pepper_video_decoder_host.cc
index 16019f720b29e4e6be4a8e1d236043dfecd3802e..cc18887a0084b319c5409162b2c1b010a5b6bc65 100644
--- a/content/renderer/pepper/pepper_video_decoder_host.cc
+++ b/content/renderer/pepper/pepper_video_decoder_host.cc
@@ -2,9 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+#include <GLES2/gl2extchromium.h>
+
 #include "content/renderer/pepper/pepper_video_decoder_host.h"
 
 #include "base/bind.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/shared_memory.h"
 #include "content/common/gpu/client/gpu_channel_host.h"
 #include "content/public/renderer/render_thread.h"
@@ -12,6 +17,9 @@
 #include "content/renderer/pepper/ppb_graphics_3d_impl.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/render_view_impl.h"
+#include "gpu/command_buffer/client/gles2_implementation.h"
+#include "media/base/decoder_buffer.h"
+#include "media/filters/ffmpeg_video_decoder.h"
 #include "media/video/picture.h"
 #include "media/video/video_decode_accelerator.h"
 #include "ppapi/c/pp_completion_callback.h"
@@ -22,6 +30,8 @@
 #include "ppapi/proxy/video_decoder_constants.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_graphics_3d_api.h"
+#include "third_party/libyuv/include/libyuv.h"
+#include "webkit/common/gpu/context_provider_web_context.h"
 
 using ppapi::proxy::SerializedHandle;
 using ppapi::thunk::EnterResourceNoLock;
@@ -57,14 +67,503 @@ media::VideoCodecProfile PepperToMediaVideoProfile(PP_VideoProfile profile) {
       return media::H264PROFILE_MULTIVIEWHIGH;
     case PP_VIDEOPROFILE_VP8MAIN:
       return media::VP8PROFILE_MAIN;
-    // No default case, to catch unhandled PP_VideoProfile values.
+      // No default case, to catch unhandled PP_VideoProfile values.
   }
 
   return media::VIDEO_CODEC_PROFILE_UNKNOWN;
 }
 
+int32_t MediaPipelineStatusToPepper(media::PipelineStatus status) {
+  switch (status) {
+    case media::PIPELINE_OK:
+      return PP_OK;
+    case media::DECODER_ERROR_NOT_SUPPORTED:
+      return PP_ERROR_NOTSUPPORTED;
+    default:
+      return PP_ERROR_FAILED;
+  }
+}
+
 }  // namespace
 
+// TODO
+// - variable # of shm buffers, depending on software or hardware.
+
+// This wrapper class calls methods on a media::VideoDecoder on the media thread
+// and relays results back to the host on the main thread. It should be created,
+// used, and destroyed on the main (render) thread.
+class SoftwareDecoder {
+ public:
+  explicit SoftwareDecoder(PepperVideoDecoderHost* host);
+  ~SoftwareDecoder();
+
+  void Initialize(media::VideoCodecProfile profile);
+  void Decode(uint32_t decode_id,
+              const scoped_refptr<media::DecoderBuffer>& buffer);
+  void AssignTextures(const std::vector<uint32_t>& plugin_texture_ids);
+  void RecycleTexture(uint32_t plugin_texture_id);
+  void Flush();
+  void Reset();
+  void Destroy();
+
+ private:
+  struct PendingDecode {
+    PendingDecode(uint32_t decode_id,
+                  const scoped_refptr<media::DecoderBuffer>& buffer);
+    ~PendingDecode();
+
+    uint32_t decode_id;
+    scoped_refptr<media::DecoderBuffer> buffer;
+  };
+
+  struct PendingFrame {
+    PendingFrame(uint32_t decode_id, const gfx::Size& size);
+    ~PendingFrame();
+
+    uint32_t decode_id;
+    gfx::Size size;
+    std::vector<uint8_t> pixels;
+  };
+
+  void InitializeOnMediaThread(media::VideoDecoderConfig config);
+  void PipelineStatusOnMediaThread(media::PipelineStatus status);
+  void PipelineStatusOnMainThread(media::PipelineStatus status);
+
+  void ReceiveBufferOnMediaThread(uint32_t decode_id,
+                                  scoped_refptr<media::DecoderBuffer> buffer);
+  void DecodeOnMediaThread();
+  void ConvertFrameOnMediaThread(uint32_t decode_id,
+                                 media::VideoDecoder::Status status,
+                                 const scoped_refptr<media::VideoFrame>& frame);
+  void ReceiveFrameOnMainThread(media::VideoDecoder::Status status,
+                                scoped_ptr<PendingFrame> frame);
+  void SendPicturesOnMainThread();
+
+  void DoResetOnMediaThread();
+  void ResetCompleteOnMediaThread();
+  void ResetCompleteOnMainThread();
+
+  void DestroyOnMediaThread();
+  void DestroyOnMainThread();
+
+  void DeleteTextures();
+  void FlushCommandBuffer();
+
+  // These members are accessed only on the main thread.
+
+  PepperVideoDecoderHost* host_;
+  scoped_refptr<base::MessageLoopProxy> media_message_loop_;
+  scoped_refptr<webkit::gpu::ContextProviderWebContext> context_provider_;
+  // The current decoded frame size.
+  gfx::Size texture_size_;
+  // Map that takes the plugin's GL texture id to the renderer's GL texture id.
+  typedef std::map<uint32_t, uint32_t> SharedTextureMap;
+  SharedTextureMap shared_textures_;
+  // Track available textures using the plugin's ids.
+  std::vector<uint32_t> plugin_texture_ids_;
+  // Mailboxes for pending texture requests, to write to plugin's textures.
+  std::vector<gpu::Mailbox> pending_texture_mailboxes_;
+  // Queue of pending decoded frames. These have been converted to RGB, and
+  // await upload to a GL texture.
+  typedef std::queue<PendingFrame*> PendingFrameQueue;
+  PendingFrameQueue pending_frames_;
+  uint32_t num_pending_decodes_;
+  bool flushing_;
+  bool resetting_;
+
+  // These members are accessed only on the media thread.
+
+  scoped_ptr<media::VideoDecoder> decoder_;
+  scoped_refptr<base::MessageLoopProxy> main_message_loop_;
+  // Queue of pending decodes. The front element is the buffer currently in
+  // use by the software decoder.
+  typedef std::queue<PendingDecode> PendingDecodeQueue;
+  PendingDecodeQueue pending_decodes_;
+};
+
+SoftwareDecoder::PendingDecode::PendingDecode(
+    uint32_t decode_id,
+    const scoped_refptr<media::DecoderBuffer>& buffer)
+    : decode_id(decode_id), buffer(buffer) {
+}
+
+SoftwareDecoder::PendingDecode::~PendingDecode() {
+}
+
+SoftwareDecoder::PendingFrame::PendingFrame(uint32_t decode_id,
+                                            const gfx::Size& size)
+    : decode_id(decode_id),
+      size(size),
+      pixels(size.width() * size.height() * 4) {
+}
+
+SoftwareDecoder::PendingFrame::~PendingFrame() {
+}
+
+SoftwareDecoder::SoftwareDecoder(PepperVideoDecoderHost* host)
+    : host_(host),
+      media_message_loop_(
+          RenderThreadImpl::current()->GetMediaThreadMessageLoopProxy()),
+      context_provider_(
+          RenderThreadImpl::current()->SharedMainThreadContextProvider()),
+      num_pending_decodes_(0),
+      flushing_(false),
+      resetting_(false),
+      main_message_loop_(base::MessageLoopProxy::current()) {
+  DCHECK(host_);
+  DCHECK(main_message_loop_);
+  DCHECK(media_message_loop_);
+  DCHECK(context_provider_);
+}
+
+SoftwareDecoder::~SoftwareDecoder() {
+  DCHECK(RenderThreadImpl::current());
+  while (!pending_frames_.empty()) {
+    delete pending_frames_.front();
+    pending_frames_.pop();
+  }
+  DeleteTextures();
+  FlushCommandBuffer();
+}
+
+void SoftwareDecoder::Initialize(media::VideoCodecProfile profile) {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(!decoder_);
+  media::VideoCodec codec = media::kUnknownVideoCodec;
+  if (profile <= media::H264PROFILE_MAX)
+    codec = media::kCodecH264;
+  else if (profile <= media::VP8PROFILE_MAX)
+    codec = media::kCodecVP8;
+  DCHECK_NE(codec, media::kUnknownVideoCodec);
+
+  media::VideoDecoderConfig config(
+      codec,
+      profile,
+      media::VideoFrame::YV12,
+      gfx::Size(32, 24),  // Small sizes that won't fail.
+      gfx::Rect(32, 24),
+      gfx::Size(32, 24),
+      NULL /* extra_data */,
+      0 /* extra_data_size */,
+      false /* decryption */);
+
+  decoder_.reset(new media::FFmpegVideoDecoder(media_message_loop_));
+
+  media_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&SoftwareDecoder::InitializeOnMediaThread,
+                 base::Unretained(this),
+                 config));
+}
+
+void SoftwareDecoder::Decode(
+    uint32_t decode_id,
+    const scoped_refptr<media::DecoderBuffer>& buffer) {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(decoder_);
+  DCHECK(!resetting_ && !flushing_);
+
+  num_pending_decodes_++;
+
+  media_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&SoftwareDecoder::ReceiveBufferOnMediaThread,
+                 base::Unretained(this),
+                 decode_id,
+                 buffer));
+}
+
+void SoftwareDecoder::AssignTextures(
+    const std::vector<uint32_t>& plugin_texture_ids) {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(decoder_);
+  DCHECK(plugin_texture_ids.size());
+  DCHECK_EQ(plugin_texture_ids.size(), pending_texture_mailboxes_.size());
+  uint32_t num_textures = static_cast<GLuint>(plugin_texture_ids.size());
+  std::vector<uint32_t> local_ids(num_textures);
+  gpu::gles2::GLES2Interface* gles2 = context_provider_->ContextGL();
+  gles2->GenTextures(num_textures, &local_ids.front());
+  for (uint32_t i = 0; i < num_textures; i++) {
+    gles2->ActiveTexture(GL_TEXTURE0);
+    gles2->BindTexture(GL_TEXTURE_2D, local_ids[i]);
+    gles2->ConsumeTextureCHROMIUM(GL_TEXTURE_2D,
+                                  pending_texture_mailboxes_[i].name);
+    // Map the plugin texture id to the local texture id.
+    shared_textures_.insert(
+        std::make_pair(plugin_texture_ids[i], local_ids[i]));
+  }
+  pending_texture_mailboxes_.clear();
+  plugin_texture_ids_ = plugin_texture_ids;
+  SendPicturesOnMainThread();
+}
+
+void SoftwareDecoder::RecycleTexture(uint32_t plugin_texture_id) {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(decoder_);
+  // Make sure it is still a valid texture.
+  SharedTextureMap::iterator it = shared_textures_.find(plugin_texture_id);
+  if (it != shared_textures_.end()) {
+    plugin_texture_ids_.push_back(plugin_texture_id);
+  }
+  SendPicturesOnMainThread();
+}
+
+void SoftwareDecoder::Flush() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(decoder_);
+  DCHECK(!resetting_ && !flushing_);
+  flushing_ = true;
+}
+
+void SoftwareDecoder::Reset() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(decoder_);
+  DCHECK(!resetting_ && !flushing_);
+printf("SoftwareDecoder::Reset\n");
+  resetting_ = true;
+  media_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&SoftwareDecoder::DoResetOnMediaThread,
+                 base::Unretained(this)));
+}
+
+void SoftwareDecoder::Destroy() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(decoder_);
+  DCHECK(host_);
+  host_ = NULL;
+  media_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&SoftwareDecoder::DestroyOnMediaThread,
+                 base::Unretained(this)));
+}
+
+void SoftwareDecoder::InitializeOnMediaThread(
+    media::VideoDecoderConfig config) {
+  DCHECK(decoder_);
+  decoder_->Initialize(config,
+                       true /* low_delay */,
+                       base::Bind(&SoftwareDecoder::PipelineStatusOnMediaThread,
+                                  base::Unretained(this)));
+}
+
+void SoftwareDecoder::PipelineStatusOnMediaThread(
+    media::PipelineStatus status) {
+  if (!host_)
+    return;
+  main_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&SoftwareDecoder::PipelineStatusOnMainThread,
+                 base::Unretained(this),
+                 status));
+}
+
+void SoftwareDecoder::PipelineStatusOnMainThread(media::PipelineStatus status) {
+  if (!host_)
+    return;
+  host_->OnInitializeComplete(status);
+}
+
+void SoftwareDecoder::ReceiveBufferOnMediaThread(
+    uint32_t decode_id,
+    scoped_refptr<media::DecoderBuffer> buffer) {
+  bool decoder_busy = !pending_decodes_.empty();
+  pending_decodes_.push(PendingDecode(decode_id, buffer));
+  if (!decoder_busy)
+    DecodeOnMediaThread();
+}
+
+void SoftwareDecoder::DecodeOnMediaThread() {
+  DCHECK(!pending_decodes_.empty());
+  PendingDecode& next_decode = pending_decodes_.front();
+  decoder_->Decode(next_decode.buffer,
+                   base::Bind(&SoftwareDecoder::ConvertFrameOnMediaThread,
+                              base::Unretained(this),
+                              next_decode.decode_id));
+  pending_decodes_.pop();
+}
+
+void SoftwareDecoder::ConvertFrameOnMediaThread(
+    uint32_t decode_id,
+    media::VideoDecoder::Status status,
+    const scoped_refptr<media::VideoFrame>& frame) {
+  if (!host_)
+    return;
+  scoped_ptr<PendingFrame> pending_frame(
+      new PendingFrame(decode_id, gfx::Size()));
+  if (frame) {
+    pending_frame->size = frame->coded_size();
+    pending_frame->pixels.resize(frame->coded_size().width() *
+                                 frame->coded_size().height() * 4);
+    // Convert the decoded frame to ARGB pixels.
+    libyuv::I420ToARGB(frame->data(media::VideoFrame::kYPlane),
+                       frame->stride(media::VideoFrame::kYPlane),
+                       frame->data(media::VideoFrame::kUPlane),
+                       frame->stride(media::VideoFrame::kUPlane),
+                       frame->data(media::VideoFrame::kVPlane),
+                       frame->stride(media::VideoFrame::kVPlane),
+                       &pending_frame->pixels.front(),
+                       frame->coded_size().width() * 4,
+                       frame->coded_size().width(),
+                       frame->coded_size().height());
+  }
+
+  main_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&SoftwareDecoder::ReceiveFrameOnMainThread,
+                 base::Unretained(this),
+                 status,
+                 base::Passed(&pending_frame)));
+
+  if (!pending_decodes_.empty())
+    DecodeOnMediaThread();
+}
+
+void SoftwareDecoder::ReceiveFrameOnMainThread(
+    media::VideoDecoder::Status status,
+    scoped_ptr<PendingFrame> frame) {
+  DCHECK(RenderThreadImpl::current());
+  if (!host_)
+    return;
+
+  num_pending_decodes_--;
+
+  if (frame->pixels.size()) {
+    if (texture_size_ != frame->size) {
+      // If the size has changed, dismiss all textures. TODO what if some are
+      // in use? Dismiss free ones, mark busy ones, and wait for recycle?
+      for (size_t i = 0; i < plugin_texture_ids_.size(); i++)
+        host_->DismissPictureBuffer(plugin_texture_ids_[i]);
+      plugin_texture_ids_.clear();
+
+      DeleteTextures();
+
+      DCHECK(pending_texture_mailboxes_.empty());
+      const uint32_t num_textures = 8;
+      for (uint32_t i = 0; i < num_textures; i++)
+        pending_texture_mailboxes_.push_back(gpu::Mailbox::Generate());
+
+      host_->RequestTextures(
+          num_textures, frame->size, GL_TEXTURE_2D, pending_texture_mailboxes_);
+      texture_size_ = frame->size;
+    }
+
+    pending_frames_.push(frame.release());
+    SendPicturesOnMainThread();
+  } else {
+    host_->NotifyEndOfBitstreamBuffer(frame->decode_id);
+  }
+}
+
+void SoftwareDecoder::SendPicturesOnMainThread() {
+  DCHECK(RenderThreadImpl::current());
+  if (!host_)
+    return;
+  while (!pending_frames_.empty() && !plugin_texture_ids_.empty()) {
+    scoped_ptr<PendingFrame> frame(pending_frames_.front());
+    pending_frames_.pop();
+
+    uint32_t plugin_texture_id = plugin_texture_ids_.back();
+    plugin_texture_ids_.pop_back();
+
+    uint32_t local_id = shared_textures_[plugin_texture_id];
+    gpu::gles2::GLES2Interface* gles2 = context_provider_->ContextGL();
+    gles2->ActiveTexture(GL_TEXTURE0);
+    gles2->BindTexture(GL_TEXTURE_2D, local_id);
+    gles2->TexImage2D(GL_TEXTURE_2D,
+                      0,
+                      GL_RGBA,
+                      texture_size_.width(),
+                      texture_size_.height(),
+                      0,
+                      GL_RGBA,
+                      GL_UNSIGNED_BYTE,
+                      &frame->pixels.front());
+
+    host_->NotifyEndOfBitstreamBuffer(frame->decode_id);
+    host_->PictureReady(media::Picture(plugin_texture_id, frame->decode_id));
+  }
+
+  FlushCommandBuffer();
+
+  if (flushing_ && !num_pending_decodes_ && pending_frames_.empty()) {
+    flushing_ = false;
+    host_->NotifyFlushDone();
+  }
+}
+
+void SoftwareDecoder::DoResetOnMediaThread() {
+printf("SoftwareDecoder::DoResetOnMediaThread\n");
+  decoder_->Reset(base::Bind(&SoftwareDecoder::ResetCompleteOnMediaThread,
+                             base::Unretained(this)));
+}
+
+void SoftwareDecoder::ResetCompleteOnMediaThread() {
+printf("SoftwareDecoder::ResetCompleteOnMediaThread\n");
+  // Cancel all remaining decodes, and notify the host so it can free the shm
+  // buffers. We'll clear pending frames on the main thread.
+  while (!pending_decodes_.empty()) {
+    PendingDecode& next_decode = pending_decodes_.front();
+    scoped_ptr<PendingFrame> pending_frame(
+        new PendingFrame(next_decode.decode_id, gfx::Size()));
+    main_message_loop_->PostTask(
+        FROM_HERE,
+        base::Bind(&SoftwareDecoder::ReceiveFrameOnMainThread,
+                   base::Unretained(this),
+                   media::VideoDecoder::kAborted,
+                   base::Passed(&pending_frame)));
+    pending_decodes_.pop();
+  }
+  main_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&SoftwareDecoder::ResetCompleteOnMainThread,
+                 base::Unretained(this)));
+}
+
+void SoftwareDecoder::ResetCompleteOnMainThread() {
+  if (!host_)
+    return;
+printf("SoftwareDecoder::ResetCompleteOnMainThread\n");
+
+  while (!pending_frames_.empty()) {
+    scoped_ptr<PendingFrame> frame(pending_frames_.front());
+    host_->NotifyEndOfBitstreamBuffer(frame->decode_id);
+    pending_frames_.pop();
+  }
+
+  resetting_ = false;
+  host_->NotifyResetDone();
+}
+
+void SoftwareDecoder::DestroyOnMediaThread() {
+  DCHECK(decoder_);
+  decoder_->Stop();
+  // All callbacks have been called on the media thread, and thus all tasks
+  // posted for the main thread. This is our last task for the main thread.
+  main_message_loop_->PostTask(FROM_HERE,
+                               base::Bind(&SoftwareDecoder::DestroyOnMainThread,
+                                          base::Unretained(this)));
+}
+
+void SoftwareDecoder::DestroyOnMainThread() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(!host_);
+  delete this;
+}
+
+void SoftwareDecoder::DeleteTextures() {
+  gpu::gles2::GLES2Interface* gles2 = context_provider_->ContextGL();
+  SharedTextureMap::iterator it = shared_textures_.begin();
+  for (; it != shared_textures_.end(); ++it)
+    gles2->DeleteTextures(1, &it->second);
+  shared_textures_.clear();
+}
+
+void SoftwareDecoder::FlushCommandBuffer() {
+  DCHECK(RenderThreadImpl::current());
+  context_provider_->ContextGL()->Flush();
+}
+
 PepperVideoDecoderHost::PendingDecode::PendingDecode(
     uint32_t shm_id,
     const ppapi::host::ReplyMessageContext& reply_context)
@@ -83,26 +582,29 @@ PepperVideoDecoderHost::PepperVideoDecoderHost(RendererPpapiHost* host,
 }
 
 PepperVideoDecoderHost::~PepperVideoDecoderHost() {
+  // TODO DefaultDeleter.
+  if (software_decoder_)
+    software_decoder_.release()->Destroy();
 }
 
 int32_t PepperVideoDecoderHost::OnResourceMessageReceived(
     const IPC::Message& msg,
     ppapi::host::HostMessageContext* context) {
   PPAPI_BEGIN_MESSAGE_MAP(PepperVideoDecoderHost, msg)
-    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_Initialize,
-                                      OnHostMsgInitialize)
-    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_GetShm,
-                                      OnHostMsgGetShm)
-    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_Decode,
-                                      OnHostMsgDecode)
-    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_AssignTextures,
-                                      OnHostMsgAssignTextures)
-    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_RecyclePicture,
-                                      OnHostMsgRecyclePicture)
-    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(PpapiHostMsg_VideoDecoder_Flush,
-                                        OnHostMsgFlush)
-    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(PpapiHostMsg_VideoDecoder_Reset,
-                                        OnHostMsgReset)
+  PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_Initialize,
+                                    OnHostMsgInitialize)
+  PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_GetShm,
+                                    OnHostMsgGetShm)
+  PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_Decode,
+                                    OnHostMsgDecode)
+  PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_AssignTextures,
+                                    OnHostMsgAssignTextures)
+  PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_VideoDecoder_RecyclePicture,
+                                    OnHostMsgRecyclePicture)
+  PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(PpapiHostMsg_VideoDecoder_Flush,
+                                      OnHostMsgFlush)
+  PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(PpapiHostMsg_VideoDecoder_Reset,
+                                      OnHostMsgReset)
   PPAPI_END_MESSAGE_MAP()
   return PP_ERROR_FAILED;
 }
@@ -119,9 +621,10 @@ int32_t PepperVideoDecoderHost::OnHostMsgInitialize(
       graphics_context.host_resource(), true);
   if (enter_graphics.failed())
     return PP_ERROR_FAILED;
-  graphics3d_ = static_cast<PPB_Graphics3D_Impl*>(enter_graphics.object());
+  PPB_Graphics3D_Impl* graphics3d =
+      static_cast<PPB_Graphics3D_Impl*>(enter_graphics.object());
 
-  int command_buffer_route_id = graphics3d_->GetCommandBufferRouteId();
+  int command_buffer_route_id = graphics3d->GetCommandBufferRouteId();
   if (!command_buffer_route_id)
     return PP_ERROR_FAILED;
 
@@ -129,7 +632,7 @@ int32_t PepperVideoDecoderHost::OnHostMsgInitialize(
 
   // This is not synchronous, but subsequent IPC messages will be buffered, so
   // it is okay to immediately send IPC messages through the returned channel.
-  GpuChannelHost* channel = graphics3d_->channel();
+  GpuChannelHost* channel = graphics3d->channel();
   DCHECK(channel);
   decoder_ = channel->CreateVideoDecoder(command_buffer_route_id);
   if (decoder_ && decoder_->Initialize(media_profile, this)) {
@@ -138,8 +641,14 @@ int32_t PepperVideoDecoderHost::OnHostMsgInitialize(
   }
   decoder_.reset();
 
-  // TODO(bbudge) Implement software fallback.
-  return PP_ERROR_NOTSUPPORTED;
+  if (!allow_software_fallback)
+    return PP_ERROR_NOTSUPPORTED;
+
+  software_decoder_.reset(new SoftwareDecoder(this));
+  initialize_reply_context_ = context->MakeReplyMessageContext();
+  software_decoder_->Initialize(media_profile);
+
+  return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t PepperVideoDecoderHost::OnHostMsgGetShm(
@@ -208,7 +717,7 @@ int32_t PepperVideoDecoderHost::OnHostMsgDecode(
     int32_t decode_id) {
   if (!initialized_)
     return PP_ERROR_FAILED;
-  DCHECK(decoder_);
+  DCHECK(decoder_ || software_decoder_);
   // |shm_id| is just an index into shm_buffers_. Make sure it's in range.
   if (static_cast<size_t>(shm_id) >= shm_buffers_.size())
     return PP_ERROR_FAILED;
@@ -226,8 +735,14 @@ int32_t PepperVideoDecoderHost::OnHostMsgDecode(
       decode_id, PendingDecode(shm_id, context->MakeReplyMessageContext())));
 
   shm_buffer_busy_[shm_id] = true;
-  decoder_->Decode(
-      media::BitstreamBuffer(decode_id, shm_buffers_[shm_id]->handle(), size));
+  base::SharedMemory* shm = shm_buffers_[shm_id];
+  if (decoder_) {
+    decoder_->Decode(media::BitstreamBuffer(decode_id, shm->handle(), size));
+  } else {
+    software_decoder_->Decode(decode_id,
+                              media::DecoderBuffer::CopyFrom(
+                                  static_cast<uint8_t*>(shm->memory()), size));
+  }
 
   return PP_OK_COMPLETIONPENDING;
 }
@@ -238,17 +753,21 @@ int32_t PepperVideoDecoderHost::OnHostMsgAssignTextures(
     const std::vector<uint32_t>& texture_ids) {
   if (!initialized_)
     return PP_ERROR_FAILED;
-  DCHECK(decoder_);
-
-  std::vector<media::PictureBuffer> picture_buffers;
-  for (uint32 i = 0; i < texture_ids.size(); i++) {
-    media::PictureBuffer buffer(
-        texture_ids[i],  // Use the texture_id to identify the buffer.
-        gfx::Size(size.width, size.height),
-        texture_ids[i]);
-    picture_buffers.push_back(buffer);
+  DCHECK(decoder_ || software_decoder_);
+
+  if (decoder_) {
+    std::vector<media::PictureBuffer> picture_buffers;
+    for (uint32 i = 0; i < texture_ids.size(); i++) {
+      media::PictureBuffer buffer(
+          texture_ids[i],  // Use the texture_id to identify the buffer.
+          gfx::Size(size.width, size.height),
+          texture_ids[i]);
+      picture_buffers.push_back(buffer);
+    }
+    decoder_->AssignPictureBuffers(picture_buffers);
+  } else {
+    software_decoder_->AssignTextures(texture_ids);
   }
-  decoder_->AssignPictureBuffers(picture_buffers);
   return PP_OK;
 }
 
@@ -257,11 +776,14 @@ int32_t PepperVideoDecoderHost::OnHostMsgRecyclePicture(
     uint32_t texture_id) {
   if (!initialized_)
     return PP_ERROR_FAILED;
-  DCHECK(decoder_);
+  DCHECK(decoder_ || software_decoder_);
   if (reset_reply_context_.is_valid())
     return PP_ERROR_FAILED;
-
-  decoder_->ReusePictureBuffer(texture_id);
+  if (decoder_) {
+    decoder_->ReusePictureBuffer(texture_id);
+  } else {
+    software_decoder_->RecycleTexture(texture_id);
+  }
 
   return PP_OK;
 }
@@ -270,12 +792,15 @@ int32_t PepperVideoDecoderHost::OnHostMsgFlush(
     ppapi::host::HostMessageContext* context) {
   if (!initialized_)
     return PP_ERROR_FAILED;
-  DCHECK(decoder_);
+  DCHECK(decoder_ || software_decoder_);
   if (flush_reply_context_.is_valid() || reset_reply_context_.is_valid())
     return PP_ERROR_FAILED;
 
   flush_reply_context_ = context->MakeReplyMessageContext();
-  decoder_->Flush();
+  if (decoder_)
+    decoder_->Flush();
+  else
+    software_decoder_->Flush();
 
   return PP_OK_COMPLETIONPENDING;
 }
@@ -284,12 +809,16 @@ int32_t PepperVideoDecoderHost::OnHostMsgReset(
     ppapi::host::HostMessageContext* context) {
   if (!initialized_)
     return PP_ERROR_FAILED;
-  DCHECK(decoder_);
+  DCHECK(decoder_ || software_decoder_);
   if (flush_reply_context_.is_valid() || reset_reply_context_.is_valid())
     return PP_ERROR_FAILED;
+printf("PepperVideoDecoderHost::OnHostMsgReset\n");
 
   reset_reply_context_ = context->MakeReplyMessageContext();
-  decoder_->Reset();
+  if (decoder_)
+    decoder_->Reset();
+  else
+    software_decoder_->Reset();
 
   return PP_OK_COMPLETIONPENDING;
 }
@@ -298,13 +827,10 @@ void PepperVideoDecoderHost::ProvidePictureBuffers(
     uint32 requested_num_of_buffers,
     const gfx::Size& dimensions,
     uint32 texture_target) {
-  DCHECK(RenderThreadImpl::current());
-  host()->SendUnsolicitedReply(
-      pp_resource(),
-      PpapiPluginMsg_VideoDecoder_RequestTextures(
-          requested_num_of_buffers,
-          PP_MakeSize(dimensions.width(), dimensions.height()),
-          texture_target));
+  RequestTextures(requested_num_of_buffers,
+                  dimensions,
+                  texture_target,
+                  std::vector<gpu::Mailbox>());
 }
 
 void PepperVideoDecoderHost::PictureReady(const media::Picture& picture) {
@@ -343,6 +869,7 @@ void PepperVideoDecoderHost::NotifyError(
 }
 
 void PepperVideoDecoderHost::NotifyResetDone() {
+  printf("PepperVideoDecoderHost::NotifyResetDone:pending=%i\n", (int)pending_decodes_.size());
   DCHECK(RenderThreadImpl::current());
   host()->SendReply(reset_reply_context_,
                     PpapiPluginMsg_VideoDecoder_ResetReply());
@@ -372,4 +899,30 @@ void PepperVideoDecoderHost::NotifyFlushDone() {
   flush_reply_context_ = ppapi::host::ReplyMessageContext();
 }
 
+void PepperVideoDecoderHost::OnInitializeComplete(
+    media::PipelineStatus status) {
+  if (!initialized_) {
+    initialized_ = true;
+    int32_t result = MediaPipelineStatusToPepper(status);
+    initialize_reply_context_.params.set_result(result);
+    host()->SendReply(initialize_reply_context_,
+                      PpapiPluginMsg_VideoDecoder_InitializeReply());
+  }
+}
+
+void PepperVideoDecoderHost::RequestTextures(
+    uint32 requested_num_of_buffers,
+    const gfx::Size& dimensions,
+    uint32 texture_target,
+    const std::vector<gpu::Mailbox>& mailboxes) {
+  DCHECK(RenderThreadImpl::current());
+  host()->SendUnsolicitedReply(
+      pp_resource(),
+      PpapiPluginMsg_VideoDecoder_RequestTextures(
+          requested_num_of_buffers,
+          PP_MakeSize(dimensions.width(), dimensions.height()),
+          texture_target,
+          mailboxes));
+}
+
 }  // namespace content