ppapi: implement PPB_AudioEncoder

content/renderer/pepper/audio_encoder_shim.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/bind.h"
+#include "base/thread_task_runner_handle.h"
+#include "content/renderer/pepper/audio_encoder_shim.h"
+#include "content/renderer/render_thread_impl.h"
+#include "ppapi/c/ppb_audio_buffer.h"
+#include "ppapi/proxy/serialized_structs.h"
+#include "third_party/opus/src/include/opus.h"
+
+namespace content {
+
+class AudioEncoderShim::EncoderImpl {
+ public:
+  virtual ~EncoderImpl() {}
+
+  // Called on the media thread.
+  void Encode(const scoped_refptr<AudioData>& input,
+              const scoped_refptr<AudioData>& output,
+              BitstreamBufferReadyCB callback);
+  void Stop();
+
+  // Called on the renderer thread.
+  virtual std::vector<PP_AudioProfileDescription> GetSupportedProfiles() = 0;
+  virtual bool Initialize(
+      const ppapi::proxy::PPB_AudioEncodeParameters& parameters) = 0;
+  virtual int32_t GetNumberOfSamplesPerFrame() = 0;
+  virtual void RequestBitrateChange(uint32_t bitrate) = 0;
+
+ protected:
+  EncoderImpl(const base::WeakPtr<AudioEncoderShim>& shim);
+
+  // Called on the media thread.
+  virtual int32_t EncodeInternal(const scoped_refptr<AudioData>& input,
+                                 const scoped_refptr<AudioData>& output) = 0;
+
+ private:
+  base::WeakPtr<AudioEncoderShim> shim_;
+  scoped_refptr<base::SingleThreadTaskRunner> renderer_task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(EncoderImpl);
+};
+
+AudioEncoderShim::EncoderImpl::EncoderImpl(
+    const base::WeakPtr<AudioEncoderShim>& shim)
+    : shim_(shim), renderer_task_runner_(base::ThreadTaskRunnerHandle::Get()) {
+}
+
+void AudioEncoderShim::EncoderImpl::Encode(
+    const scoped_refptr<AudioData>& input,
+    const scoped_refptr<AudioData>& output,
+    BitstreamBufferReadyCB callback) {
+  int32_t size = EncodeInternal(input, output);
+  renderer_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&AudioEncoderShim::OnEncodeDone, shim_, output,
+                            size < 0 ? -1 : size, callback));
+}
+
+void AudioEncoderShim::EncoderImpl::Stop() {
+}
+
+class AudioEncoderShim::OpusEncoderImpl : public AudioEncoderShim::EncoderImpl {
+ public:
+  OpusEncoderImpl(const base::WeakPtr<AudioEncoderShim>& shim);
+  ~OpusEncoderImpl() override;
+
+ private:
+  // AudioEncoderShim::Impl:
+  std::vector<PP_AudioProfileDescription> GetSupportedProfiles() override;
+  bool Initialize(
+      const ppapi::proxy::PPB_AudioEncodeParameters& parameters) override;
+  int32_t GetNumberOfSamplesPerFrame() override;
+  int32_t EncodeInternal(
+      const scoped_refptr<AudioEncoderShim::AudioData>& input,
+      const scoped_refptr<AudioEncoderShim::AudioData>& output) override;
+  void RequestBitrateChange(uint32_t bitrate) override;
+
+  scoped_ptr<uint8[]> encoder_memory_;
+  OpusEncoder* opus_encoder_;
+
+  ppapi::proxy::PPB_AudioEncodeParameters parameters_;
+
+  DISALLOW_COPY_AND_ASSIGN(OpusEncoderImpl);
+};
+
+AudioEncoderShim::OpusEncoderImpl::OpusEncoderImpl(
+    const base::WeakPtr<AudioEncoderShim>& shim)
+    : EncoderImpl(shim), opus_encoder_(nullptr) {
+}
+
+AudioEncoderShim::OpusEncoderImpl::~OpusEncoderImpl() {
+}
+
+std::vector<PP_AudioProfileDescription>
+AudioEncoderShim::OpusEncoderImpl::GetSupportedProfiles() {
+  std::vector<PP_AudioProfileDescription> profiles;
+  uint32_t sampling_rates[] = {8000, 12000, 16000, 24000, 48000};

[Tom Sepez, 2015/09/17 18:11:12]

nit: probably a static const.

[llandwerlin-old, 2015/10/05 16:10:59]

Done.

+
+  for (uint32_t i = 0; i < arraysize(sampling_rates); i++) {

[Tom Sepez, 2015/09/17 18:11:12]

nit: ++i

[llandwerlin-old, 2015/10/05 16:10:59]

Done.

+    PP_AudioProfileDescription profile;
+    profile.profile = PP_AUDIOPROFILE_OPUS;
+    profile.max_channels = 2;
+    profile.sample_size = PP_AUDIOBUFFER_SAMPLESIZE_16_BITS;
+    profile.sample_rate = sampling_rates[i];
+    profile.hardware_accelerated = PP_FALSE;
+    profiles.push_back(profile);
+  }
+  return profiles;
+}
+
+bool AudioEncoderShim::OpusEncoderImpl::Initialize(
+    const ppapi::proxy::PPB_AudioEncodeParameters& parameters) {
+  DCHECK(!encoder_memory_);
+
+  int32_t encoder_size = opus_encoder_get_size(parameters.channels);
+  if (encoder_size < 1)
+    return false;
+
+  encoder_memory_.reset(new uint8[encoder_size]);
+  opus_encoder_ = reinterpret_cast<OpusEncoder*>(encoder_memory_.get());
+
+  if (opus_encoder_init(opus_encoder_, parameters.input_sample_rate,
+                        parameters.channels, OPUS_APPLICATION_AUDIO) != OPUS_OK)
+    return false;
+
+  if (opus_encoder_ctl(opus_encoder_,
+                       OPUS_SET_BITRATE(parameters.initial_bitrate <= 0
+                                            ? OPUS_AUTO
+                                            : parameters.initial_bitrate)) !=
+      OPUS_OK)
+    return false;
+
+  parameters_ = parameters;
+
+  return true;
+}
+
+int32_t AudioEncoderShim::OpusEncoderImpl::GetNumberOfSamplesPerFrame() {
+  // Opus supports 2.5, 5, 10, 20, 40 or 60ms audio frames. We take
+  // 10ms by default.
+  return parameters_.input_sample_rate / 100;
+}
+
+int32_t AudioEncoderShim::OpusEncoderImpl::EncodeInternal(
+    const scoped_refptr<AudioData>& input,
+    const scoped_refptr<AudioData>& output) {
+  return opus_encode(
+      opus_encoder_, reinterpret_cast<opus_int16*>(input->GetData()),
+      (input->GetSize() / parameters_.channels) / parameters_.input_sample_size,
+      output->GetData(), output->GetSize());
+}
+
+void AudioEncoderShim::OpusEncoderImpl::RequestBitrateChange(uint32_t bitrate) {
+  opus_encoder_ctl(opus_encoder_, OPUS_SET_BITRATE(bitrate));
+}
+
+AudioEncoderShim::AudioEncoderShim()
+    : media_task_runner_(
+          RenderThreadImpl::current()->GetMediaThreadTaskRunner()),
+      weak_ptr_factory_(this) {
+}
+
+AudioEncoderShim::~AudioEncoderShim() {
+  if (encoder_impl_)
+    media_task_runner_->PostTask(
+        FROM_HERE, base::Bind(&AudioEncoderShim::EncoderImpl::Stop,
+                              base::Owned(encoder_impl_.release())));
+}
+
+std::vector<PP_AudioProfileDescription>
+AudioEncoderShim::GetSupportedProfiles() {
+  std::vector<PP_AudioProfileDescription> profiles;
+  scoped_ptr<EncoderImpl> encoder(
+      new OpusEncoderImpl(weak_ptr_factory_.GetWeakPtr()));
+  std::vector<PP_AudioProfileDescription> codec_profiles =
+      encoder->GetSupportedProfiles();
+  for (const PP_AudioProfileDescription desc : codec_profiles)

[Tom Sepez, 2015/09/17 18:11:12]

nit: how about const auto& desc :

[llandwerlin-old, 2015/10/05 16:10:59]

Done.

+    profiles.push_back(desc);
+  return profiles;
+}
+
+bool AudioEncoderShim::Initialize(
+    const ppapi::proxy::PPB_AudioEncodeParameters& parameters) {
+  if (encoder_impl_)
+    return false;
+
+  if (parameters.output_profile == PP_AUDIOPROFILE_OPUS) {
+    encoder_impl_.reset(new OpusEncoderImpl(weak_ptr_factory_.GetWeakPtr()));

[Tom Sepez, 2015/09/17 18:11:12]

nit: prefer early return if !=, combine with line 186.

[llandwerlin-old, 2015/10/05 16:10:59]

Done.

+    return encoder_impl_->Initialize(parameters);
+  }
+  return false;
+}
+
+int32_t AudioEncoderShim::GetNumberOfSamplesPerFrame() {
+  DCHECK(encoder_impl_);

[Tom Sepez, 2015/09/17 18:11:12]

nit: pointless DCHECK, the next line will segv if the check fails, so we don't
need extra instructions in the program to catch this.

[llandwerlin-old, 2015/10/05 16:10:59]

Done.

+  return encoder_impl_->GetNumberOfSamplesPerFrame();
+}
+
+void AudioEncoderShim::Encode(const scoped_refptr<AudioData>& input,
+                              const scoped_refptr<AudioData>& output,
+                              BitstreamBufferReadyCB callback) {
+  DCHECK(encoder_impl_);
+  media_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&AudioEncoderShim::EncoderImpl::Encode,
+                            base::Unretained(encoder_impl_.get()), input,
+                            output, callback));
+}
+
+void AudioEncoderShim::RequestBitrateChange(uint32_t bitrate) {
+  DCHECK(encoder_impl_);
+  media_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&AudioEncoderShim::EncoderImpl::RequestBitrateChange,
+                 base::Unretained(encoder_impl_.get()), bitrate));
+}
+
+void AudioEncoderShim::OnEncodeDone(const scoped_refptr<AudioData>& output,
+                                    int32_t size,

[Tom Sepez, 2015/09/17 18:11:12]

nit: sizes should usually be size_t's unless you have a good reason otherwise.

[llandwerlin-old, 2015/10/05 16:10:59]

Done.

+                                    BitstreamBufferReadyCB callback) {
+  callback.Run(output, size);
+}
+
+}  // namespace content