Finish plumbing MojoVideoDecoder.

media/mojo/services/mojo_video_decoder_service.cc

+// Copyright 2016 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 "media/mojo/services/mojo_video_decoder_service.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/logging.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "media/base/decoder_buffer.h"
+#include "media/base/video_decoder.h"
+#include "media/base/video_decoder_config.h"
+#include "media/base/video_frame.h"
+#include "media/mojo/common/media_type_converters.h"
+#include "media/mojo/services/mojo_media_client.h"
+#include "mojo/public/c/system/types.h"
+#include "mojo/public/cpp/system/buffer.h"
+#include "mojo/public/cpp/system/handle.h"
+
+namespace media {
+
+MojoVideoDecoderService::MojoVideoDecoderService(
+    mojo::InterfaceRequest<mojom::VideoDecoder> request,
+    MojoMediaClient* mojo_media_client)
+    : binding_(this, std::move(request)),
+      mojo_media_client_(mojo_media_client),
+      weak_factory_(this) {
+  weak_this_ = weak_factory_.GetWeakPtr();
+}
+
+MojoVideoDecoderService::~MojoVideoDecoderService() {}
+
+void MojoVideoDecoderService::Construct(
+    mojom::VideoDecoderClientPtr client,
+    mojo::ScopedDataPipeConsumerHandle decoder_buffer_pipe) {
+  DVLOG(1) << __FUNCTION__;
+
+  if (decoder_)
+    return;
+
+  // TODO(sandersd): Provide callback for requesting a stub.
+  decoder_ = mojo_media_client_->CreateVideoDecoder(
+      base::ThreadTaskRunnerHandle::Get());
+
+  client_ = std::move(client);
+  decoder_buffer_pipe_ = std::move(decoder_buffer_pipe);
+}
+
+void MojoVideoDecoderService::Initialize(mojom::VideoDecoderConfigPtr config,
+                                         bool low_delay,
+                                         const InitializeCallback& callback) {
+  DVLOG(1) << __FUNCTION__;
+
+  if (!decoder_) {
+    callback.Run(false);
+    return;
+  }
+
+  decoder_->Initialize(
+      config.To<VideoDecoderConfig>(), low_delay, nullptr,
+      base::Bind(&MojoVideoDecoderService::OnDecoderInitialized, weak_this_,
+                 callback),
+      base::Bind(&MojoVideoDecoderService::OnDecoderOutput, weak_this_));
+}
+
+void MojoVideoDecoderService::OnDecoderInitialized(
+    const InitializeCallback& callback,
+    bool success) {
+  DVLOG(1) << __FUNCTION__;
+  callback.Run(success);
+}
+
+void MojoVideoDecoderService::OnDecoderOutput(
+    const scoped_refptr<VideoFrame>& frame) {
+  DVLOG(1) << __FUNCTION__;
+  DCHECK(client_);
+  client_->OnVideoFrameDecoded(mojom::VideoFrame::From(frame));
+}
+
+void MojoVideoDecoderService::Decode(mojom::DecoderBufferPtr buffer,
+                                     const DecodeCallback& callback) {
+  DVLOG(1) << __FUNCTION__;
+
+  if (!decoder_) {
+    callback.Run(mojom::DecodeStatus::DECODE_ERROR);
+    return;
+  }
+
+  // TODO(sandersd): After a decode error, we should enter an error state and
+  // reject all future method calls.
+  // TODO(sandersd): Extract and share with MojoAudioDecoderService.
+  scoped_refptr<DecoderBuffer> media_buffer(
+      buffer.To<scoped_refptr<DecoderBuffer>>());
+  if (!media_buffer->end_of_stream()) {
+    MojoResult result;
+    MojoHandleSignalsState state;
+
+    // TODO(sandersd): Do not wait indefinitely.
+    result =
+        MojoWait(decoder_buffer_pipe_.get().value(),
+                 MOJO_HANDLE_SIGNAL_READABLE, MOJO_DEADLINE_INDEFINITE, &state);
+    if (result != MOJO_RESULT_OK ||
+        !(state.satisfied_signals & MOJO_HANDLE_SIGNAL_READABLE)) {
+      callback.Run(mojom::DecodeStatus::DECODE_ERROR);
+      return;
+    }
+
+    uint32_t data_size = buffer->data_size;
+    CHECK_EQ(data_size, media_buffer->data_size());

[dcheng, 2016/05/20 22:52:59]

Nit: DCHECK_EQ? This should "never happen" since it's sent across the wire as a
uint32.

[sandersd (OOO until July 31), 2016/05/20 23:42:12]

That depends on what we're checking for; the code being outright wrong or
specific cases that may be broken and untested. I'll let you make that call, but
I prefer a real check before overwriting a buffer.

[dcheng, 2016/05/20 23:48:14]

That's why I suggested a static_assert in the TypeConverter.

static_assert(sizeof(buffer->data_size) <= sizeof(media_buffer->data_size)) is
essentially what we want to assert, right?

[sandersd (OOO until July 31), 2016/05/20 23:56:14]

In that case, you are more trusting of cross-file code paths than I.

Done.

+    uint32_t bytes_read = data_size;
+    result =
+        ReadDataRaw(decoder_buffer_pipe_.get(), media_buffer->writable_data(),
+                    &bytes_read, MOJO_READ_DATA_FLAG_ALL_OR_NONE);
+    if (result != MOJO_RESULT_OK || bytes_read != data_size) {
+      callback.Run(mojom::DecodeStatus::DECODE_ERROR);
+      return;
+    }
+  }
+
+  decoder_->Decode(media_buffer,
+                   base::Bind(&MojoVideoDecoderService::OnDecoderDecoded,
+                              weak_this_, callback));
+}
+
+void MojoVideoDecoderService::OnDecoderDecoded(const DecodeCallback& callback,
+                                               DecodeStatus status) {
+  DVLOG(1) << __FUNCTION__;
+  callback.Run(static_cast<mojom::DecodeStatus>(status));
+}
+
+void MojoVideoDecoderService::Reset(const ResetCallback& callback) {
+  DVLOG(1) << __FUNCTION__;
+
+  if (!decoder_) {
+    callback.Run();
+    return;
+  }
+
+  decoder_->Reset(base::Bind(&MojoVideoDecoderService::OnDecoderReset,
+                             weak_this_, callback));
+}
+
+void MojoVideoDecoderService::OnDecoderReset(const ResetCallback& callback) {
+  DVLOG(1) << __FUNCTION__;
+  callback.Run();
+}
+
+}  // namespace media