ppapi: implement PPB_AudioEncoder

ppapi/proxy/audio_encoder_resource.cc

 // Copyright 2015 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 "base/memory/shared_memory.h"
+#include "ppapi/c/pp_array_output.h"
+#include "ppapi/c/pp_codecs.h"
+#include "ppapi/proxy/audio_buffer_resource.h"
 #include "ppapi/proxy/audio_encoder_resource.h"
+#include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/shared_impl/array_writer.h"
+#include "ppapi/shared_impl/media_stream_buffer.h"
+#include "ppapi/thunk/enter.h"
 
 namespace ppapi {
 namespace proxy {
 
+namespace {
+
+void RunCallback(scoped_refptr<TrackedCallback>* callback, int32_t error) {
+  if (!TrackedCallback::IsPending(*callback))
+    return;
+
+  scoped_refptr<TrackedCallback> temp;
+  callback->swap(temp);
+  temp->Run(error);
+}
+
+}  // namespace
+
+class AudioEncoderResource::BitstreamBufferManager {
+ public:
+  BitstreamBufferManager() : number_of_buffers_(0), buffer_size_(0) {}
+  ~BitstreamBufferManager() {}
+
+  bool Initialize(scoped_ptr<base::SharedMemory> shm,
+                  uint32_t number_of_buffers,
+                  uint32_t buffer_size) {
+    uint32_t total_size = number_of_buffers * buffer_size;
+    shm_ = shm.Pass();
+    if (!shm_ || !shm_->Map(base::checked_cast<size_t>(total_size)))
+      return false;
+
+    for (uint32_t i = 0; i < number_of_buffers; i++)
+      buffer_map_.insert(std::make_pair(
+          static_cast<uint8_t*>(shm_->memory()) + (i * buffer_size),
+          static_cast<int32_t>(i)));
+
+    number_of_buffers_ = number_of_buffers;
+    buffer_size_ = buffer_size;
+    return true;
+  }
+  int32_t GetBufferId(void* address) {
+    BufferMap::const_iterator it = buffer_map_.find(address);
+    if (it == buffer_map_.end())
+      return -1;
+    return it->second;
+  }
+  uint8_t* GetBuffer(int32_t id) {
+    return static_cast<uint8_t*>(shm_->memory()) + (id * buffer_size_);

[Tom Sepez, 2015/09/17 18:11:13]

I'd be happier if we did the bounds checking here, returning NULL, rather than
relying on callers.  This becomes an arbitrary  memory read primitive if we
can't trust the ID.

[llandwerlin-old, 2015/10/05 16:11:00]

Done.

+  }
+  std::pair<int32_t, uint32_t> DequeueBuffer() {
+    if (enqueued_buffers_.empty())
+      return std::make_pair(-1, 0U);
+    std::pair<int32_t, uint32_t> tuple = enqueued_buffers_.front();
+    enqueued_buffers_.pop_front();
+    return tuple;
+  }
+  void EnqueueBuffer(int32_t id, uint32_t size) {
+    enqueued_buffers_.push_back(std::make_pair(id, size));
+  }
+  bool AvailableBuffers() { return !enqueued_buffers_.empty(); }
+
+ private:
+  uint32_t number_of_buffers_;
+
+  // Size of individual buffers.
+  uint32_t buffer_size_;

[Tom Sepez, 2015/09/17 18:11:13]

Should be size_t.  Comment should say "in bytes" otherwise is it samples, etc?

[llandwerlin-old, 2015/10/05 16:11:00]

Done.

+
+  // Shared memory containing all objects.

[Tom Sepez, 2015/09/17 18:11:13]

nit: can you be more specific than "all objects"?

[llandwerlin-old, 2015/10/05 16:11:00]

Done.

+  scoped_ptr<base::SharedMemory> shm_;
+
+  // Queue of bitstream buffers received from the host, waiting to be
+  // handed to the plugin.
+  std::deque<std::pair<int32_t, uint32_t>> enqueued_buffers_;
+
+  // Memory pointer to buffer id map.
+  typedef std::map<void*, int32_t> BufferMap;

[Tom Sepez, 2015/09/17 18:11:13]

nit: using

[llandwerlin-old, 2015/10/05 16:11:00]

Done.

[Tom Sepez, 2015/10/05 16:54:16]

using BufferMap = std::map<void*, int32_t>;

[llandwerlin-old, 2015/10/05 17:16:31]

Done.

+  BufferMap buffer_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(BitstreamBufferManager);
+};
+
 AudioEncoderResource::AudioEncoderResource(Connection connection,
                                            PP_Instance instance)
-    : PluginResource(connection, instance) {
+    : PluginResource(connection, instance),
+      encoder_last_error_(PP_ERROR_FAILED),
+      initialized_(false),
+      closed_(false),
+      buffer_manager_(this) {
+  SendCreate(RENDERER, PpapiHostMsg_AudioEncoder_Create());
 }
 
 AudioEncoderResource::~AudioEncoderResource() {
 }
 
 thunk::PPB_AudioEncoder_API* AudioEncoderResource::AsPPB_AudioEncoder_API() {
   return this;
 }
 
 int32_t AudioEncoderResource::GetSupportedProfiles(
     const PP_ArrayOutput& output,
     const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_NOTSUPPORTED;
+  if (TrackedCallback::IsPending(get_supported_profiles_callback_))
+    return PP_ERROR_INPROGRESS;
+
+  get_supported_profiles_callback_ = callback;
+  Call<PpapiPluginMsg_AudioEncoder_GetSupportedProfilesReply>(
+      RENDERER, PpapiHostMsg_AudioEncoder_GetSupportedProfiles(),
+      base::Bind(&AudioEncoderResource::OnPluginMsgGetSupportedProfilesReply,
+                 this, output));
+  return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t AudioEncoderResource::Initialize(
     uint32_t channels,
     PP_AudioBuffer_SampleRate input_sample_rate,
     PP_AudioBuffer_SampleSize input_sample_size,
     PP_AudioProfile output_profile,
     uint32_t initial_bitrate,
     PP_HardwareAcceleration acceleration,
     const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_NOTSUPPORTED;
+  if (initialized_)
+    return PP_ERROR_FAILED;
+  if (TrackedCallback::IsPending(initialize_callback_))
+    return PP_ERROR_INPROGRESS;
+
+  initialize_callback_ = callback;
+
+  PPB_AudioEncodeParameters parameters;
+  parameters.channels = channels;
+  parameters.input_sample_rate = input_sample_rate;
+  parameters.input_sample_size = input_sample_size;
+  parameters.output_profile = output_profile;
+  parameters.initial_bitrate = initial_bitrate;
+  parameters.acceleration = acceleration;
+
+  Call<PpapiPluginMsg_AudioEncoder_InitializeReply>(
+      RENDERER, PpapiHostMsg_AudioEncoder_Initialize(parameters),
+      base::Bind(&AudioEncoderResource::OnPluginMsgInitializeReply, this));
+  return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t AudioEncoderResource::GetNumberOfSamples() {
-  return PP_ERROR_NOTSUPPORTED;
+  if (encoder_last_error_)

[Tom Sepez, 2015/09/17 18:11:13]

nit: really dislike overloading the error return and value. It relies on some
quirk of the last_error value making it distinguishable by the caller from the
valid numbers.

[llandwerlin-old, 2015/10/05 16:11:00]

Sadly this is how the API works. It would require changing the IDL.
This is a pattern already using in the VideoEncoder (I'm responsible for that
too).

bbudge: What's your opinion on changing the API?

[bbudge, 2015/10/05 16:34:08]

Pepper is a little inconsistent in how functions like this work, but there are
precedents for this style. The most obvious one is PPB_FileIO Read, which
returns the number of bytes read. Values > 0 indicate that bytes were read, == 0
means EOF, and < 0 is an error code from pp_errors.h.

https://code.google.com/p/chromium/codesearch#chromium/src/ppapi/api/ppb_file...

Other precedents are PPB_VideoEncoder and PPB_TrueTypeFont (so I suppose I'm
responsible for a lot of the precedents either directly or indirectly).

If we did want to change this, we should probably also change PPB_VideoEncoder
to be consistent.

[Tom Sepez, 2015/10/05 16:54:16]

So it goes.  Let's leave it.

+    return encoder_last_error_;
+  return number_of_samples_;
 }
 
 int32_t AudioEncoderResource::GetBuffer(
     PP_Resource* audio_buffer,
     const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_NOTSUPPORTED;
+  if (encoder_last_error_)
+    return encoder_last_error_;
+
+  if (TrackedCallback::IsPending(get_buffer_callback_))
+    return PP_ERROR_INPROGRESS;
+
+  get_buffer_data_ = audio_buffer;
+  get_buffer_callback_ = callback;
+
+  // Lazily ask for a shared memory buffer in which audio frames are allocated.
+  if (buffer_manager_.number_of_buffers() == 0) {
+    Call<PpapiPluginMsg_AudioEncoder_GetAudioFramesReply>(
+        RENDERER, PpapiHostMsg_AudioEncoder_GetAudioFrames(),
+        base::Bind(&AudioEncoderResource::OnPluginMsgGetAudioFramesReply,
+                   this));
+  } else {
+    TryWriteAudioBuffer();
+  }
+
+  return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t AudioEncoderResource::Encode(
     PP_Resource audio_buffer,
     const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_NOTSUPPORTED;
+  if (encoder_last_error_)
+    return encoder_last_error_;
+
+  AudioBufferMap::iterator it = audio_buffers_.find(audio_buffer);
+  if (it == audio_buffers_.end())
+    // TODO(llandwerlin): accept MediaStreamAudioTrack's audio buffers.
+    return PP_ERROR_BADRESOURCE;
+
+  scoped_refptr<AudioBufferResource> buffer_resource = it->second;
+
+  encode_callbacks_.insert(
+      std::make_pair(buffer_resource->GetBufferIndex(), callback));
+
+  Post(RENDERER,
+       PpapiHostMsg_AudioEncoder_Encode(buffer_resource->GetBufferIndex()));
+
+  // Invalidate the frame to prevent the plugin from modifying it.
+  buffer_resource->Invalidate();
+  audio_buffers_.erase(it);
+
+  return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t AudioEncoderResource::GetBitstreamBuffer(
     PP_AudioBitstreamBuffer* bitstream_buffer,
     const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_NOTSUPPORTED;
+  if (encoder_last_error_)
+    return encoder_last_error_;
+  if (TrackedCallback::IsPending(get_bitstream_buffer_callback_))
+    return PP_ERROR_INPROGRESS;
+
+  get_bitstream_buffer_callback_ = callback;
+  get_bitstream_buffer_data_ = bitstream_buffer;
+
+  TryWriteBitstreamBuffer();
+
+  return PP_OK_COMPLETIONPENDING;
 }
 
 void AudioEncoderResource::RecycleBitstreamBuffer(
     const PP_AudioBitstreamBuffer* bitstream_buffer) {
+  if (encoder_last_error_)
+    return;
+  int32_t buffer_id =
+      bitstream_buffer_manager_->GetBufferId(bitstream_buffer->buffer);
+
+  if (buffer_id >= 0)
+    Post(RENDERER, PpapiHostMsg_AudioEncoder_RecycleBitstreamBuffer(buffer_id));
 }
 
 void AudioEncoderResource::RequestBitrateChange(uint32_t bitrate) {
+  if (encoder_last_error_)
+    return;
+  Post(RENDERER, PpapiHostMsg_AudioEncoder_RequestBitrateChange(bitrate));
 }
 
 void AudioEncoderResource::Close() {
+  if (encoder_last_error_)
+    return;
+  Post(RENDERER, PpapiHostMsg_AudioEncoder_Close());
+  closed_ = true;
+  if (!encoder_last_error_ || !initialized_)
+    NotifyError(PP_ERROR_ABORTED);
+  ReleaseBuffers();
+}
+
+void AudioEncoderResource::OnReplyReceived(
+    const ResourceMessageReplyParams& params,
+    const IPC::Message& msg) {
+  PPAPI_BEGIN_MESSAGE_MAP(AudioEncoderResource, msg)
+  PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+      PpapiPluginMsg_AudioEncoder_BitstreamBufferReady,
+      OnPluginMsgBitstreamBufferReady)
+  PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(PpapiPluginMsg_AudioEncoder_EncodeReply,
+                                      OnPluginMsgEncodeReply)
+  PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(PpapiPluginMsg_AudioEncoder_NotifyError,
+                                      OnPluginMsgNotifyError)
+  PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL_UNHANDLED(
+      PluginResource::OnReplyReceived(params, msg))
+  PPAPI_END_MESSAGE_MAP()
+}
+
+void AudioEncoderResource::OnPluginMsgGetSupportedProfilesReply(
+    const PP_ArrayOutput& output,
+    const ResourceMessageReplyParams& params,
+    const std::vector<PP_AudioProfileDescription>& profiles) {
+  int32_t error = params.result();
+  if (error) {
+    NotifyError(error);
+    return;
+  }
+
+  ArrayWriter writer(output);
+  if (!writer.is_valid()) {
+    RunCallback(&get_supported_profiles_callback_, PP_ERROR_BADARGUMENT);
+    return;
+  }
+
+  bool write_result = writer.StoreVector(profiles);
+
+  if (!write_result) {
+    RunCallback(&get_supported_profiles_callback_, PP_ERROR_FAILED);
+    return;
+  }
+
+  RunCallback(&get_supported_profiles_callback_,
+              base::checked_cast<int32_t>(profiles.size()));
+}
+
+void AudioEncoderResource::OnPluginMsgInitializeReply(
+    const ResourceMessageReplyParams& params,
+    uint32_t number_of_samples,
+    uint32_t buffer_count,
+    uint32_t buffer_size) {
+  DCHECK(!initialized_);
+
+  int32_t error = params.result();
+  if (error) {
+    NotifyError(error);
+    return;
+  }
+
+  base::SharedMemoryHandle buffer_handle;
+  if (!params.TakeSharedMemoryHandleAtIndex(0, &buffer_handle)) {
+    NotifyError(PP_ERROR_FAILED);
+    return;
+  }
+
+  bitstream_buffer_manager_.reset(new BitstreamBufferManager());
+  if (!bitstream_buffer_manager_->Initialize(
+          make_scoped_ptr(new base::SharedMemory(buffer_handle, false)),
+          buffer_count, buffer_size)) {
+    NotifyError(PP_ERROR_FAILED);
+    return;
+  }
+
+  encoder_last_error_ = PP_OK;
+  number_of_samples_ = number_of_samples;
+  initialized_ = true;
+
+  RunCallback(&initialize_callback_, encoder_last_error_);
+}
+
+void AudioEncoderResource::OnPluginMsgGetAudioFramesReply(
+    const ResourceMessageReplyParams& params,
+    uint32_t frame_count,
+    uint32_t frame_length) {
+  int32_t error = params.result();
+  if (error) {
+    NotifyError(error);
+    return;
+  }
+
+  base::SharedMemoryHandle buffer_handle;
+  if (!params.TakeSharedMemoryHandleAtIndex(0, &buffer_handle)) {
+    NotifyError(PP_ERROR_FAILED);
+    return;
+  }
+
+  if (!buffer_manager_.SetBuffers(
+          frame_count, frame_length + sizeof(ppapi::MediaStreamBuffer::Audio),
+          make_scoped_ptr(new base::SharedMemory(buffer_handle, false)),
+          true)) {
+    NotifyError(PP_ERROR_FAILED);
+    return;
+  }
+
+  if (TrackedCallback::IsPending(get_buffer_callback_))
+    TryWriteAudioBuffer();
+}
+
+void AudioEncoderResource::OnPluginMsgEncodeReply(
+    const ResourceMessageReplyParams& params,
+    uint32_t buffer_id) {
+  // We need to ensure there are still callbacks to be called before
+  // processing this message. We might receive a EncodeReply message
+  // after having sent a Close message to the renderer. In this case,
+  // we don't have any callback left to call.
+  if (encode_callbacks_.empty())
+    return;
+  encoder_last_error_ = params.result();
+
+  EncodeMap::iterator it = encode_callbacks_.find(buffer_id);
+  DCHECK(encode_callbacks_.end() != it);
+
+  scoped_refptr<TrackedCallback> callback = it->second;
+  encode_callbacks_.erase(it);
+  RunCallback(&callback, encoder_last_error_);
+
+  buffer_manager_.EnqueueBuffer(buffer_id);
+  // If the plugin is waiting for an audio buffer, we can give the one
+  // that just became available again.
+  if (TrackedCallback::IsPending(get_buffer_callback_))
+    TryWriteAudioBuffer();
+}
+
+void AudioEncoderResource::OnPluginMsgBitstreamBufferReady(
+    const ResourceMessageReplyParams& params,
+    uint32_t buffer_id,
+    uint32_t buffer_size) {
+  bitstream_buffer_manager_->EnqueueBuffer(
+      base::checked_cast<int32_t>(buffer_id), buffer_size);
+
+  if (TrackedCallback::IsPending(get_bitstream_buffer_callback_))
+    TryWriteBitstreamBuffer();
+}
+
+void AudioEncoderResource::OnPluginMsgNotifyError(
+    const ResourceMessageReplyParams& params,
+    int32_t error) {
+  NotifyError(error);
+}
+
+void AudioEncoderResource::NotifyError(int32_t error) {
+  encoder_last_error_ = error;
+  RunCallback(&get_supported_profiles_callback_, error);
+  RunCallback(&initialize_callback_, error);
+  RunCallback(&get_buffer_callback_, error);
+  get_buffer_data_ = nullptr;
+  RunCallback(&get_bitstream_buffer_callback_, error);
+  get_bitstream_buffer_data_ = nullptr;
+  for (EncodeMap::iterator it = encode_callbacks_.begin();
+       it != encode_callbacks_.end(); ++it) {
+    scoped_refptr<TrackedCallback> callback = it->second;
+    RunCallback(&callback, error);
+  }
+  encode_callbacks_.clear();
+}
+
+void AudioEncoderResource::TryWriteAudioBuffer() {
+  DCHECK(TrackedCallback::IsPending(get_buffer_callback_));
+
+  int32_t buffer_id = buffer_manager_.DequeueBuffer();
+  if (buffer_id < 0)
+    return;
+
+  scoped_refptr<AudioBufferResource> resource = new AudioBufferResource(
+      pp_instance(), buffer_id, buffer_manager_.GetBufferPointer(buffer_id));
+  audio_buffers_.insert(
+      AudioBufferMap::value_type(resource->pp_resource(), resource));
+
+  *get_buffer_data_ = resource->GetReference();
+  get_buffer_data_ = nullptr;
+  RunCallback(&get_buffer_callback_, PP_OK);
+}
+
+void AudioEncoderResource::TryWriteBitstreamBuffer() {
+  DCHECK(TrackedCallback::IsPending(get_bitstream_buffer_callback_));
+
+  if (!bitstream_buffer_manager_->AvailableBuffers())
+    return;
+
+  std::pair<int32_t, uint32_t> data =
+      bitstream_buffer_manager_->DequeueBuffer();
+
+  get_bitstream_buffer_data_->buffer =
+      bitstream_buffer_manager_->GetBuffer(data.first);
+  get_bitstream_buffer_data_->size = data.second;
+  get_bitstream_buffer_data_ = nullptr;
+  RunCallback(&get_bitstream_buffer_callback_, PP_OK);
+}
+
+void AudioEncoderResource::ReleaseBuffers() {
+  for (AudioBufferMap::iterator it = audio_buffers_.begin();
+       it != audio_buffers_.end(); ++it) {
+    it->second->Invalidate();
+    it->second = nullptr;
+  }
+  audio_buffers_.clear();
 }
 
 }  // namespace proxy
 }  // namespace ppapi