Implement Pepper PPB_VideoDecoder interface.

ppapi/proxy/video_decoder_resource.cc

+// Copyright (c) 2012 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 "ppapi/proxy/video_decoder_resource.h"
+
+#include "base/bind.h"
+#include "gpu/command_buffer/client/gles2_cmd_helper.h"
+#include "gpu/command_buffer/client/gles2_implementation.h"
+#include "ipc/ipc_message.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/c/ppb_opengles2.h"
+#include "ppapi/proxy/plugin_dispatcher.h"
+#include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/proxy/ppb_graphics_3d_proxy.h"
+#include "ppapi/proxy/serialized_handle.h"
+#include "ppapi/proxy/video_decoder_constants.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/ppb_graphics_3d_shared.h"
+#include "ppapi/shared_impl/proxy_lock.h"
+#include "ppapi/shared_impl/resource_tracker.h"
+#include "ppapi/thunk/enter.h"
+
+using ppapi::thunk::EnterResourceNoLock;
+using ppapi::thunk::PPB_Graphics3D_API;
+using ppapi::thunk::PPB_VideoDecoder_API;
+
+namespace ppapi {
+namespace proxy {
+
+VideoDecoderResource::ShmBuffer::ShmBuffer(
+    scoped_ptr<base::SharedMemory> shm_ptr,
+    uint32_t size,
+    uint32_t shm_id)
+    : shm(shm_ptr.Pass()), addr(NULL), shm_id(shm_id) {
+  if (shm->Map(size))
+    addr = shm->memory();
+  DCHECK(addr);
+}
+
+VideoDecoderResource::ShmBuffer::~ShmBuffer() {
+}
+
+VideoDecoderResource::Texture::Texture(uint32_t texture_target,
+                                       const PP_Size& size)
+    : texture_target(texture_target), size(size) {
+}
+
+VideoDecoderResource::Texture::~Texture() {
+}
+
+VideoDecoderResource::Picture::Picture(int32_t decode_id, uint32_t texture_id)
+    : decode_id(decode_id), texture_id(texture_id) {
+}
+
+VideoDecoderResource::Picture::~Picture() {
+}
+
+VideoDecoderResource::VideoDecoderResource(Connection connection,
+                                           PP_Instance instance)
+    : PluginResource(connection, instance),
+      num_decodes_(0),
+      get_picture_(NULL),
+      gles2_impl_(NULL),
+      initialized_(false),
+      testing_(false),
+      // Set |decoder_last_error_| to PP_OK after successful initialization.
+      // This makes error checking a little more concise, since we can check
+      // that the decoder has been initialized and hasn't returned an error by
+      // just testing |decoder_last_error_|.
+      decoder_last_error_(PP_ERROR_FAILED) {
+  // Clear the decode_ids_ array.
+  memset(decode_ids_, 0, arraysize(decode_ids_));
+  SendCreate(RENDERER, PpapiHostMsg_VideoDecoder_Create());
+}
+
+VideoDecoderResource::~VideoDecoderResource() {
+  // Destroy any textures which haven't been dismissed.
+  TextureMap::iterator it = textures_.begin();
+  for (; it != textures_.end(); ++it)
+    DeleteGLTexture(it->first);
+}
+
+PPB_VideoDecoder_API* VideoDecoderResource::AsPPB_VideoDecoder_API() {
+  return this;
+}
+
+int32_t VideoDecoderResource::Initialize(
+    PP_Resource graphics_context,
+    PP_VideoProfile profile,
+    PP_Bool allow_software_fallback,
+    scoped_refptr<TrackedCallback> callback) {
+  if (initialized_)
+    return PP_ERROR_FAILED;
+  if (profile < 0 || profile > PP_VIDEOPROFILE_MAX)
+    return PP_ERROR_BADARGUMENT;
+  if (initialize_callback_)
+    return PP_ERROR_INPROGRESS;
+  if (!graphics_context)
+    return PP_ERROR_BADRESOURCE;
+
+  // Create a new Graphics3D resource that can create texture resources to share
+  // with the plugin. We can't use the plugin's Graphics3D, since we create
+  // textures on a proxy thread, and would interfere with the plugin.
+  thunk::EnterResourceCreationNoLock enter_create(pp_instance());
+  if (enter_create.failed())
+    return PP_ERROR_FAILED;
+  int32_t attrib_list[] = {PP_GRAPHICS3DATTRIB_NONE};
+  HostResource host_resource;
+  if (!testing_) {
+    graphics3d_ =
+        ScopedPPResource(ScopedPPResource::PassRef(),
+                         enter_create.functions()->CreateGraphics3D(
+                             pp_instance(), graphics_context, attrib_list));
+    EnterResourceNoLock<PPB_Graphics3D_API> enter_graphics(graphics3d_.get(),
+                                                           true);
+    if (enter_graphics.failed())
+      return PP_ERROR_BADRESOURCE;
+
+    PPB_Graphics3D_Shared* ppb_graphics3d_shared =
+        static_cast<PPB_Graphics3D_Shared*>(enter_graphics.object());
+    gles2_impl_ = ppb_graphics3d_shared->gles2_impl();
+    host_resource = ppb_graphics3d_shared->host_resource();
+  }
+
+  initialize_callback_ = callback;
+
+  Call<PpapiPluginMsg_VideoDecoder_InitializeReply>(
+      RENDERER,
+      PpapiHostMsg_VideoDecoder_Initialize(
+          host_resource, profile, PP_ToBool(allow_software_fallback)),
+      base::Bind(&VideoDecoderResource::OnPluginMsgInitializeComplete, this));
+
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t VideoDecoderResource::Decode(uint32_t decode_id,
+                                     uint32_t size,
+                                     const void* buffer,
+                                     scoped_refptr<TrackedCallback> callback) {
+  if (decoder_last_error_)
+    return decoder_last_error_;
+  if (flush_callback_ || reset_callback_)
+    return PP_ERROR_FAILED;
+  if (decode_callback_)
+    return PP_ERROR_INPROGRESS;
+  if (size > kMaximumBitstreamBufferSize)
+    return PP_ERROR_NOMEMORY;
+

[piman, 2014/05/23 20:07:27]

nit: it would be useful here, for documentation purpose, to have a
DCHECK(!available_shm_buffers_.empty() || shm_buffers_.size() <
kMaximumPendingDecodes);

That condition is true at the beginning, and a post-condition of the previous
Decode if we didn't store a callback.

[bbudge, 2014/05/23 20:57:05]

Done.

+  // Save decode_id in a ring buffer. The ring buffer is sized to store
+  // decode_id for the maximum picture delay.
+  decode_ids_[num_decodes_ % kMaximumPictureDelay] = decode_id;
+  num_decodes_++;
+
+  if (available_shm_buffers_.empty() ||
+      available_shm_buffers_.back()->shm->mapped_size() < size) {
+    uint32_t shm_id;
+    if (shm_buffers_.size() < kMaximumPendingDecodes) {
+      // Signal the host to create a new shm buffer by passing an index outside
+      // the legal range.
+      shm_id = static_cast<uint32_t>(shm_buffers_.size());
+    } else {
+      // Signal the host to grow a buffer by passing a legal index. Choose the
+      // last available shm buffer for simplicity.
+      shm_id = available_shm_buffers_.back()->shm_id;
+      available_shm_buffers_.pop_back();
+    }
+
+    // Synchronously get shared memory. Use GenericSyncCall so we can get the
+    // reply params, which contain the handle.
+    uint32_t shm_size = 0;
+    IPC::Message reply;
+    ResourceMessageReplyParams reply_params;
+    int32_t result =
+        GenericSyncCall(RENDERER,
+                        PpapiHostMsg_VideoDecoder_GetShm(shm_id, size),
+                        &reply,
+                        &reply_params);
+    if (result != PP_OK)
+      return PP_ERROR_FAILED;
+    if (!UnpackMessage<PpapiPluginMsg_VideoDecoder_GetShmReply>(reply,
+                                                                &shm_size))
+      return PP_ERROR_FAILED;
+    base::SharedMemoryHandle shm_handle = base::SharedMemory::NULLHandle();
+    if (!reply_params.TakeSharedMemoryHandleAtIndex(0, &shm_handle))
+      return PP_ERROR_NOMEMORY;
+    scoped_ptr<base::SharedMemory> shm(
+        new base::SharedMemory(shm_handle, false /* read_only */));
+    scoped_ptr<ShmBuffer> shm_buffer(
+        new ShmBuffer(shm.Pass(), shm_size, shm_id));
+    if (!shm_buffer->addr)

[piman, 2014/05/23 20:07:27]

This test is too late, there's a DCHECK in the ShmBuffer constructor.

Well, the condition could happen for several reasons (out of address space, out
of file descriptors, ...), so maybe we should just remove the DCHECK.

[bbudge, 2014/05/23 20:57:05]

Removed the DCHECK in the ShmBuffer ctor.

+      return PP_ERROR_NOMEMORY;
+
+    available_shm_buffers_.push_back(shm_buffer.get());
+    if (shm_buffers_.size() < kMaximumPendingDecodes) {
+      shm_buffers_.push_back(shm_buffer.release());
+    } else {
+      // Delete manually since ScopedVector won't delete the existing element if
+      // we just assign it.
+      delete shm_buffers_[shm_id];
+      shm_buffers_[shm_id] = shm_buffer.release();
+    }
+  }
+
+  // At this point we should have shared memory to hold the plugin's buffer.
+  DCHECK(!available_shm_buffers_.empty() &&
+         available_shm_buffers_.back()->shm->mapped_size() >= size);
+
+  ShmBuffer* shm_buffer = available_shm_buffers_.back();
+  available_shm_buffers_.pop_back();
+  memcpy(shm_buffer->addr, buffer, size);
+
+  Call<PpapiPluginMsg_VideoDecoder_DecodeReply>(
+      RENDERER,
+      PpapiHostMsg_VideoDecoder_Decode(shm_buffer->shm_id, size),
+      base::Bind(&VideoDecoderResource::OnPluginMsgDecodeComplete, this));
+
+  // If we have another free buffer, or we can still create new buffers, let
+  // the plugin call Decode again.
+  if (!available_shm_buffers_.empty() ||
+      shm_buffers_.size() < kMaximumPendingDecodes)
+    return PP_OK;
+
+  // All buffers are busy and we can't create more. Delay completion until a
+  // buffer is available.
+  decode_callback_ = callback;
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t VideoDecoderResource::GetPicture(
+    PP_VideoPicture* picture,
+    scoped_refptr<TrackedCallback> callback) {
+  if (decoder_last_error_)
+    return decoder_last_error_;
+  if (reset_callback_)
+    return PP_ERROR_FAILED;
+  if (get_picture_callback_)
+    return PP_ERROR_INPROGRESS;
+
+  // If the next picture is ready, return it synchronously.
+  if (!received_pictures_.empty()) {
+    WriteNextPicture(picture);
+    return PP_OK;
+  }
+
+  get_picture_callback_ = callback;
+  get_picture_ = picture;
+  return PP_OK_COMPLETIONPENDING;
+}
+
+void VideoDecoderResource::RecyclePicture(const PP_VideoPicture* picture) {
+  if (decoder_last_error_)
+    return;
+  if (reset_callback_)
+    return;
+
+  Post(RENDERER, PpapiHostMsg_VideoDecoder_RecyclePicture(picture->texture_id));
+}
+
+int32_t VideoDecoderResource::Flush(scoped_refptr<TrackedCallback> callback) {
+  if (decoder_last_error_)
+    return decoder_last_error_;
+  if (reset_callback_)
+    return PP_ERROR_FAILED;
+  if (flush_callback_)
+    return PP_ERROR_INPROGRESS;
+  flush_callback_ = callback;
+
+  Call<PpapiPluginMsg_VideoDecoder_FlushReply>(
+      RENDERER,
+      PpapiHostMsg_VideoDecoder_Flush(),
+      base::Bind(&VideoDecoderResource::OnPluginMsgFlushComplete, this));
+
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t VideoDecoderResource::Reset(scoped_refptr<TrackedCallback> callback) {
+  if (decoder_last_error_)
+    return decoder_last_error_;
+  if (flush_callback_)
+    return PP_ERROR_FAILED;
+  if (reset_callback_)
+    return PP_ERROR_INPROGRESS;
+  reset_callback_ = callback;
+
+  // Cause any pending Decode or GetPicture callbacks to abort after we return,
+  // to avoid reentering the plugin.
+  if (TrackedCallback::IsPending(decode_callback_))
+    decode_callback_->PostAbort();

[piman, 2014/05/23 20:07:27]

What happens to the shm buffers at this point?

[bbudge, 2014/05/23 20:57:05]

We hold on to them. Reset is used to implement seek, so they're likely to be
reusable.

The video decoder in the host should notify us (OnPluginMsgDecodeDone) that
bitstream buffers are no longer busy as it resets, so we can return them to the
available list before completing the Reset operation.

[piman, 2014/05/23 21:19:25]

But, so, if we have a decode callback, that means all the buffers were full.
When does the plugin know we have a free buffer again, so Decode can be called?
Is that guaranteed by the time the reset callback comes? Can we add DCHECKs
about that?

[bbudge, 2014/05/23 22:18:44]

Done in OnPluginMsgResetComplete (and OnPluginMsgFlushComplete by the same
reasoning).

+  decode_callback_ = NULL;
+  if (TrackedCallback::IsPending(get_picture_callback_))
+    get_picture_callback_->PostAbort();
+  get_picture_callback_ = NULL;
+  Call<PpapiPluginMsg_VideoDecoder_ResetReply>(
+      RENDERER,
+      PpapiHostMsg_VideoDecoder_Reset(),
+      base::Bind(&VideoDecoderResource::OnPluginMsgResetComplete, this));
+
+  return PP_OK_COMPLETIONPENDING;
+}
+
+void VideoDecoderResource::OnReplyReceived(
+    const ResourceMessageReplyParams& params,
+    const IPC::Message& msg) {
+  PPAPI_BEGIN_MESSAGE_MAP(VideoDecoderResource, msg)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+        PpapiPluginMsg_VideoDecoder_RequestTextures, OnPluginMsgRequestTextures)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+        PpapiPluginMsg_VideoDecoder_PictureReady, OnPluginMsgPictureReady)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+        PpapiPluginMsg_VideoDecoder_DismissPicture, OnPluginMsgDismissPicture)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+        PpapiPluginMsg_VideoDecoder_NotifyError, OnPluginMsgNotifyError)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL_UNHANDLED(
+        PluginResource::OnReplyReceived(params, msg))
+  PPAPI_END_MESSAGE_MAP()
+}
+
+void VideoDecoderResource::SetForTest() {
+  testing_ = true;
+}
+
+void VideoDecoderResource::OnPluginMsgRequestTextures(
+    const ResourceMessageReplyParams& params,
+    uint32_t num_textures,
+    const PP_Size& size,
+    uint32_t texture_target) {
+  DCHECK(num_textures);
+  std::vector<uint32_t> texture_ids(num_textures);
+  if (gles2_impl_) {
+    gles2_impl_->GenTextures(num_textures, &texture_ids.front());
+    for (uint32_t i = 0; i < num_textures; ++i) {
+      gles2_impl_->ActiveTexture(GL_TEXTURE0);
+      gles2_impl_->BindTexture(texture_target, texture_ids[i]);
+      gles2_impl_->TexParameteri(
+          texture_target, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+      gles2_impl_->TexParameteri(
+          texture_target, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+      gles2_impl_->TexParameterf(
+          texture_target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+      gles2_impl_->TexParameterf(
+          texture_target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+      if (texture_target == GL_TEXTURE_2D) {
+        gles2_impl_->TexImage2D(texture_target,
+                                0,
+                                GL_RGBA,
+                                size.width,
+                                size.height,
+                                0,
+                                GL_RGBA,
+                                GL_UNSIGNED_BYTE,
+                                NULL);
+      }
+
+      textures_.insert(
+          std::make_pair(texture_ids[i], Texture(texture_target, size)));
+    }
+    gles2_impl_->Flush();
+  } else if (testing_) {
+    // Create some fake texture ids so we can test picture handling.
+    for (uint32_t i = 0; i < num_textures; ++i) {
+      texture_ids[i] = i + 1;
+      textures_.insert(
+          std::make_pair(texture_ids[i], Texture(texture_target, size)));
+    }
+  }
+
+  Post(RENDERER, PpapiHostMsg_VideoDecoder_AssignTextures(size, texture_ids));
+}
+
+void VideoDecoderResource::OnPluginMsgPictureReady(
+    const ResourceMessageReplyParams& params,
+    uint32_t decode_id,
+    uint32_t texture_id) {
+  received_pictures_.push(Picture(decode_id, texture_id));
+  // Prepare to accept another call to GetPicture in the callback.
+  scoped_refptr<TrackedCallback> callback;
+  callback.swap(get_picture_callback_);
+  PP_VideoPicture* picture = get_picture_;
+  get_picture_ = NULL;
+  if (TrackedCallback::IsPending(callback)) {
+    WriteNextPicture(picture);
+    callback->Run(PP_OK);
+  }
+}
+
+void VideoDecoderResource::OnPluginMsgDismissPicture(
+    const ResourceMessageReplyParams& params,
+    uint32_t texture_id) {
+  DeleteGLTexture(texture_id);
+  textures_.erase(texture_id);
+}
+
+void VideoDecoderResource::OnPluginMsgNotifyError(
+    const ResourceMessageReplyParams& params,
+    int32_t error) {
+  decoder_last_error_ = error;
+  // Cause any pending Decode or GetPicture callbacks to run immediately.
+  // Reentrancy isn't a problem, since the resource is unusable now.
+  if (TrackedCallback::IsPending(decode_callback_))
+    decode_callback_->Run(decoder_last_error_);
+  decode_callback_ = NULL;
+  if (TrackedCallback::IsPending(get_picture_callback_))
+    get_picture_callback_->Run(decoder_last_error_);
+  get_picture_callback_ = NULL;

[piman, 2014/05/23 20:07:27]

What about the other callbacks?

[bbudge, 2014/05/23 20:57:05]

I should add checks for them too. Done.

+}
+
+void VideoDecoderResource::OnPluginMsgInitializeComplete(
+    const ResourceMessageReplyParams& params) {
+  decoder_last_error_ = params.result();
+  if (decoder_last_error_ == PP_OK)
+    initialized_ = true;
+
+  // Let the plugin call Initialize again from its callback in case of failure.
+  scoped_refptr<TrackedCallback> callback;
+  callback.swap(initialize_callback_);
+  callback->Run(decoder_last_error_);
+}
+
+void VideoDecoderResource::OnPluginMsgDecodeComplete(
+    const ResourceMessageReplyParams& params,
+    uint32_t shm_id) {
+  if (shm_id >= shm_buffers_.size()) {
+    NOTREACHED();
+    return;
+  }
+  // Make the shm buffer available.
+  available_shm_buffers_.push_back(shm_buffers_[shm_id]);
+  // If the plugin is waiting, let it call Decode again.
+  if (decode_callback_)
+    RunDecodeCallback(PP_OK);
+}
+
+void VideoDecoderResource::OnPluginMsgFlushComplete(
+    const ResourceMessageReplyParams& params) {
+  if (get_picture_callback_) {
+    scoped_refptr<TrackedCallback> callback;
+    callback.swap(get_picture_callback_);
+    callback->Abort();
+  }
+
+  scoped_refptr<TrackedCallback> callback;
+  callback.swap(flush_callback_);
+  callback->Run(params.result());
+}
+
+void VideoDecoderResource::OnPluginMsgResetComplete(
+    const ResourceMessageReplyParams& params) {
+  scoped_refptr<TrackedCallback> callback;
+  callback.swap(reset_callback_);
+  callback->Run(params.result());
+}
+
+void VideoDecoderResource::RunDecodeCallback(int32_t result) {
+  DCHECK(decode_callback_);
+  scoped_refptr<TrackedCallback> callback;
+  callback.swap(decode_callback_);
+  callback->Run(result);
+}
+
+void VideoDecoderResource::DeleteGLTexture(uint32_t id) {
+  if (gles2_impl_) {
+    gles2_impl_->DeleteTextures(1, &id);
+    gles2_impl_->Flush();
+  }
+}
+
+void VideoDecoderResource::WriteNextPicture(PP_VideoPicture* pp_picture) {
+  DCHECK(!received_pictures_.empty());
+  Picture& picture = received_pictures_.front();
+  uint32_t texture_id = picture.texture_id;
+  TextureMap::iterator it = textures_.find(texture_id);
+  DCHECK(it != textures_.end());
+  // The resource and host identify decodes by a unique id, |num_decodes_|. Use
+  // this to get the plugin's decode_id value, which we stored in |decode_ids_|.
+  uint32_t decode_id = picture.decode_id % kMaximumPictureDelay;
+  pp_picture->decode_id = decode_ids_[decode_id];
+  pp_picture->texture_id = texture_id;
+  pp_picture->texture_target = it->second.texture_target;
+  pp_picture->texture_size = it->second.size;
+  received_pictures_.pop();
+}
+
+}  // namespace proxy
+}  // namespace ppapi