Separate MediaCodecLoop from MediaCodecAudioDecoder

media/base/android/media_codec_loop.cc

Index: media/base/android/media_codec_loop.cc
diff --git a/media/base/android/media_codec_loop.cc b/media/base/android/media_codec_loop.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7a8132b8db6815514796f5a84a0209fef927828d
--- /dev/null
+++ b/media/base/android/media_codec_loop.cc
@@ -0,0 +1,363 @@
+// 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/base/android/media_codec_loop.h"
+
+#include "base/android/build_info.h"
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/logging.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "media/base/android/sdk_media_codec_bridge.h"
+#include "media/base/audio_buffer.h"
+#include "media/base/audio_timestamp_helper.h"
+#include "media/base/bind_to_current_loop.h"
+#include "media/base/timestamp_constants.h"
+
+namespace media {
+
+constexpr base::TimeDelta kDecodePollDelay =
+    base::TimeDelta::FromMilliseconds(10);
+constexpr base::TimeDelta kNoWaitTimeout = base::TimeDelta::FromMicroseconds(0);
+constexpr base::TimeDelta kIdleTimerTimeout = base::TimeDelta::FromSeconds(1);
+
+static inline bool codec_flush_requires_destruction() {
+  // Return true if and only if Flush() isn't supported / doesn't work.
+  // Prior to JellyBean-MR2, flush() had several bugs (b/8125974, b/8347958) so
+  // we have to completely destroy and recreate the codec there.
+  return base::android::BuildInfo::GetInstance()->sdk_int() < 18;
+}
+
+MediaCodecLoop::InputData::InputData() {}
+
+MediaCodecLoop::InputData::InputData(const InputData& other)
+    : memory(other.memory),
+      length(other.length),
+      key_id(other.key_id),
+      iv(other.iv),
+      subsamples(other.subsamples),
+      presentation_time(other.presentation_time),
+      completion_cb(other.completion_cb),
+      is_eos(other.is_eos),
+      is_encrypted(other.is_encrypted) {}
+
+MediaCodecLoop::InputData::~InputData() {}
+
+MediaCodecLoop::MediaCodecLoop(Client* client,
+                               std::unique_ptr<MediaCodecBridge> media_codec)
+    : state_(STATE_READY),
+      client_(client),
+      media_codec_(std::move(media_codec)),
+      pending_input_buf_index_(kInvalidBufferIndex),
+      weak_factory_(this) {
+  // TODO(liberato): should this DCHECK?
+  if (media_codec_ == nullptr)
+    SetState(STATE_ERROR);
+}
+
+MediaCodecLoop::~MediaCodecLoop() {}
+
+void MediaCodecLoop::OnKeyAdded() {
+  if (state_ == STATE_WAITING_FOR_KEY)
+    SetState(STATE_READY);
+
+  DoPendingWork();
+}
+
+bool MediaCodecLoop::TryFlush() {
+  // We do not clear the input queue here.  It depends on the caller.
+  // For decoder reset, then it is appropriate.  Otherwise, the requests might
+  // simply be sent to us later, such as on a format change.
+
+  // STATE_DRAINED seems like it allow flush, but it causes test failures.
+  // crbug.com/624878
+  if (state_ == STATE_ERROR || state_ == STATE_DRAINED)
+    return false;
+
+  if (codec_flush_requires_destruction())
+    return false;
+
+  // Actually try to flush!
+  io_timer_.Stop();
+
+  if (media_codec_->Flush() != MEDIA_CODEC_OK) {
+    // TODO(liberato): we might not want to notify the client about this.
+    SetState(STATE_ERROR);
+    return false;
+  }
+
+  SetState(STATE_READY);
+  return true;
+}
+
+void MediaCodecLoop::DoPendingWork() {
+  if (state_ == STATE_ERROR)
+    return;
+
+  bool did_work = false, did_input = false, did_output = false;
+  do {
+    did_input = ProcessOneInputBuffer();
+    did_output = ProcessOneOutputBuffer();
+    if (did_input || did_output)
+      did_work = true;
+  } while (did_input || did_output);
+
+  // TODO(liberato): add "start_timer" for AVDA.
+  ManageTimer(did_work);
+}
+
+bool MediaCodecLoop::ProcessOneInputBuffer() {
+  if (state_ != STATE_READY)
+    return false;
+
+  // We can only queue a buffer if there is input from the client, or if we
+  // tried previously but had to wait for a key.  In the latter case, MediaCodec
+  // already has the data.
+  if (pending_input_buf_index_ == kInvalidBufferIndex &&
+      !client_->IsAnyInputPending()) {
+    return false;
+  }
+
+  // DequeueInputBuffer() may set STATE_ERROR.
+  InputBuffer input_buffer = DequeueInputBuffer();
+
+  if (input_buffer.index == kInvalidBufferIndex)
+    return false;
+
+  // EnqueueInputBuffer() may change the state.
+  EnqueueInputBuffer(input_buffer);
+  return state_ != STATE_ERROR;
+}
+
+MediaCodecLoop::InputBuffer MediaCodecLoop::DequeueInputBuffer() {
+  DVLOG(2) << __FUNCTION__;
+
+  // Do not dequeue a new input buffer if we failed with MEDIA_CODEC_NO_KEY.
+  // That status does not return the input buffer back to the pool of
+  // available input buffers. We have to reuse it later when calling
+  // MediaCodec's QueueSecureInputBuffer().
+  if (pending_input_buf_index_ != kInvalidBufferIndex) {
+    InputBuffer result(pending_input_buf_index_, true);
+    pending_input_buf_index_ = kInvalidBufferIndex;
+    return result;
+  }
+
+  int input_buf_index = kInvalidBufferIndex;
+
+  media::MediaCodecStatus status =
+      media_codec_->DequeueInputBuffer(kNoWaitTimeout, &input_buf_index);
+  switch (status) {
+    case media::MEDIA_CODEC_DEQUEUE_INPUT_AGAIN_LATER:
+      break;
+
+    case media::MEDIA_CODEC_ERROR:
+      DLOG(ERROR) << __FUNCTION__
+                  << ": MEDIA_CODEC_ERROR from DequeInputBuffer";
+      SetState(STATE_ERROR);
+      break;
+
+    case media::MEDIA_CODEC_OK:
+      break;
+
+    default:
+      NOTREACHED() << "Unknown DequeueInputBuffer status " << status;
+      SetState(STATE_ERROR);
+      break;
+  }
+
+  return InputBuffer(input_buf_index, false);
+}
+
+void MediaCodecLoop::EnqueueInputBuffer(const InputBuffer& input_buffer) {
+  DCHECK_NE(input_buffer.index, kInvalidBufferIndex);
+
+  InputData input_data;
+  if (input_buffer.is_pending) {
+    // A pending buffer is already filled with data, no need to copy it again.
+    input_data = pending_input_buf_data_;
+  } else {
+    input_data = client_->ProvideInputData();
+  }
+
+  if (input_data.is_eos) {
+    media_codec_->QueueEOS(input_buffer.index);
+    SetState(STATE_DRAINING);
+
+    // For EOS, the completion callback is called when the EOS arrives at the
+    // output queue.
+    pending_eos_completion_cb_ = input_data.completion_cb;
+    return;
+  }
+
+  media::MediaCodecStatus status = MEDIA_CODEC_OK;
+
+  if (input_data.is_encrypted) {
+    // Note that input_data might not have a valid memory ptr if this is a
+    // re-send of a buffer that was sent before decryption keys arrived.
+
+    status = media_codec_->QueueSecureInputBuffer(
+        input_buffer.index, input_data.memory, input_data.length,
+        input_data.key_id, input_data.iv, input_data.subsamples,
+        input_data.presentation_time);
+
+  } else {
+    status = media_codec_->QueueInputBuffer(
+        input_buffer.index, input_data.memory, input_data.length,
+        input_data.presentation_time);
+  }
+
+  switch (status) {
+    case MEDIA_CODEC_ERROR:
+      DLOG(ERROR) << __FUNCTION__
+                  << ": MEDIA_CODEC_ERROR from QueueInputBuffer";
+      input_data.completion_cb.Run(DecodeStatus::DECODE_ERROR);
+      // Transition to the error state after running the completion cb, to keep
+      // it in order if the client chooses to flush its queue.
+      SetState(STATE_ERROR);
+      break;
+
+    case MEDIA_CODEC_NO_KEY:
+      // Do not call the completion cb here.  It will be called when we retry
+      // after getting the key.
+      pending_input_buf_index_ = input_buffer.index;
+      pending_input_buf_data_ = input_data;
+      // MediaCodec has a copy of the data already.  When we call again, be sure
+      // to send in nullptr for the source.  Note that the client doesn't
+      // guarantee that the pointer will remain valid after we return anyway.
+      pending_input_buf_data_.memory = nullptr;
+      SetState(STATE_WAITING_FOR_KEY);
+      break;
+
+    case MEDIA_CODEC_OK:
+      input_data.completion_cb.Run(DecodeStatus::OK);
+      break;
+
+    default:
+      NOTREACHED() << "Unknown Queue(Secure)InputBuffer status " << status;
+      input_data.completion_cb.Run(DecodeStatus::DECODE_ERROR);
+      SetState(STATE_ERROR);
+      break;
+  }
+}
+
+bool MediaCodecLoop::ProcessOneOutputBuffer() {
+  // TODO(liberato): When merging AVDA, we will also have to ask the client if
+  // it can accept another output buffer.
+
+  OutputBuffer out;
+  MediaCodecStatus status = media_codec_->DequeueOutputBuffer(
+      kNoWaitTimeout, &out.index, &out.offset, &out.size, &out.pts, &out.is_eos,
+      &out.is_key_frame);
+
+  bool did_work = false;
+  switch (status) {
+    case MEDIA_CODEC_OUTPUT_BUFFERS_CHANGED:
+      // Output buffers are replaced in MediaCodecBridge, nothing to do.
+      did_work = true;
+      break;
+
+    case MEDIA_CODEC_OUTPUT_FORMAT_CHANGED:
+      if (!client_->OnOutputFormatChanged())
+        SetState(STATE_ERROR);
+      did_work = state_ != STATE_ERROR;
+      break;
+
+    case MEDIA_CODEC_OK:
+      // We got the decoded frame or EOS.
+      if (out.is_eos) {
+        // Set state STATE_DRAINED after we have received EOS frame at the
+        // output. media_decoder_job.cc says: once output EOS has occurred, we
+        // should not be asked to decode again.
+        DCHECK_EQ(state_, STATE_DRAINING);
+        SetState(STATE_DRAINED);
+
+        DCHECK_NE(out.index, kInvalidBufferIndex);
+        DCHECK(media_codec_);
+
+        media_codec_->ReleaseOutputBuffer(out.index, false);
+
+        // Run the EOS completion callback now, since we deferred it until
+        // the EOS was completely processed.
+        pending_eos_completion_cb_.Run(DecodeStatus::OK);
+        pending_eos_completion_cb_ = DecodeCB();
+
+        client_->OnDecodedEos(out);
+      } else {
+        if (!client_->OnDecodedFrame(out))
+          SetState(STATE_ERROR);
+      }
+
+      did_work = true;
+      break;
+
+    case MEDIA_CODEC_DEQUEUE_OUTPUT_AGAIN_LATER:
+      // Nothing to do.
+      break;
+
+    case MEDIA_CODEC_ERROR:
+      DLOG(ERROR) << __FUNCTION__
+                  << ": MEDIA_CODEC_ERROR from DequeueOutputBuffer";
+      SetState(STATE_ERROR);
+      break;
+
+    default:
+      NOTREACHED() << "Unknown DequeueOutputBuffer status " << status;
+      SetState(STATE_ERROR);
+      break;
+  }
+
+  return did_work;
+}
+
+void MediaCodecLoop::ManageTimer(bool did_work) {
+  bool should_be_running = true;
+
+  base::TimeTicks now = base::TimeTicks::Now();
+  if (did_work || idle_time_begin_ == base::TimeTicks()) {
+    idle_time_begin_ = now;
+  } else {
+    // Make sure that we have done work recently enough, else stop the timer.
+    if (now - idle_time_begin_ > kIdleTimerTimeout)
+      should_be_running = false;
+  }
+
+  if (should_be_running && !io_timer_.IsRunning()) {
+    io_timer_.Start(FROM_HERE, kDecodePollDelay, this,
+                    &MediaCodecLoop::DoPendingWork);
+  } else if (!should_be_running && io_timer_.IsRunning()) {
+    io_timer_.Stop();
+  }
+}
+
+void MediaCodecLoop::SetState(State new_state) {
+  const State old_state = state_;
+  state_ = new_state;
+  if (old_state != new_state && new_state == STATE_ERROR)
+    client_->OnCodecLoopError();
+}
+
+MediaCodecBridge* MediaCodecLoop::GetCodec() const {
+  return media_codec_.get();
+}
+
+// static
+const char* MediaCodecLoop::AsString(State state) {
+#define RETURN_STRING(x) \
+  case x:                \
+    return #x;
+
+  switch (state) {
+    RETURN_STRING(STATE_READY);
+    RETURN_STRING(STATE_WAITING_FOR_KEY);
+    RETURN_STRING(STATE_DRAINING);
+    RETURN_STRING(STATE_DRAINED);
+    RETURN_STRING(STATE_ERROR);
+  }
+#undef RETURN_STRING
+
+  NOTREACHED() << "Unknown state " << state;
+  return nullptr;
+}
+
+}  // namespace media