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..01df81983c02a3c90cdae26504b2f60776f8df13
--- /dev/null
+++ b/media/base/android/media_codec_loop.cc
@@ -0,0 +1,414 @@
+// 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 {
+
+namespace {
+
+// TODO(liberato): the client should choose these.
+inline const base::TimeDelta DecodePollDelay() {
+  return base::TimeDelta::FromMilliseconds(10);
+}
+
+inline const base::TimeDelta NoWaitTimeout() {
+  return base::TimeDelta::FromMicroseconds(0);
+}
+
+inline const base::TimeDelta IdleTimerTimeout() {
+  return base::TimeDelta::FromSeconds(1);
+}
+
+}  // namespace (anonymous)
+
+MediaCodecLoop::InputBufferData::InputBufferData()
+    : memory(nullptr), length(0), is_eos(false), is_encrypted(false) {}
+// TODO(liberato): does anybody call this?  if not, maybe they should.
+MediaCodecLoop::InputBufferData::InputBufferData(const uint8_t* m,
+                                                 size_t l,
+                                                 const DecodeCB& cb)
+    : memory(m),
+      length(l),
+      completion_cb(cb),
+      is_eos(false),
+      is_encrypted(false) {}
+
+MediaCodecLoop::InputBufferData::InputBufferData(const InputBufferData& 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::InputBufferData::~InputBufferData() {}
+
+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) {
+  DVLOG(1) << __FUNCTION__;
+}
+
+MediaCodecLoop::~MediaCodecLoop() {
+  DVLOG(1) << __FUNCTION__;
+
+  media_codec_.reset();
+}
+
+void MediaCodecLoop::OnKeyAdded() {
+  DVLOG(1) << __FUNCTION__;
+
+  if (state_ == STATE_WAITING_FOR_KEY)
+    SetState(STATE_READY);
+
+  DoIOTask();
+}
+
+bool MediaCodecLoop::TryFlush() {
+  DVLOG(1) << __FUNCTION__;
+
+  // 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.
+
+  // Flush if we can, otherwise completely recreate and reconfigure the codec.
+  // Prior to JellyBean-MR2, flush() had several bugs (b/8125974, b/8347958) so
+  // we have to completely destroy and recreate the codec there.
+  bool success = false;
+  if (state_ != STATE_ERROR && state_ != STATE_DRAINED &&
+      base::android::BuildInfo::GetInstance()->sdk_int() >= 18) {
+    io_timer_.Stop();
+
+    // media_codec_->Reset() calls MediaCodec.flush().
+    success = (media_codec_->Reset() == MEDIA_CODEC_OK);
+
+    // Transition to the error state if the flush failed.
+    SetState(success ? STATE_READY : STATE_ERROR);
+  }
+
+  return success;
+}
+
+void MediaCodecLoop::DoIOTask() {
+  if (state_ == STATE_ERROR)
+    return;
+
+  const bool did_input = QueueInput();
+  const bool did_output = DequeueOutput();
+
+  ManageTimer(did_input || did_output);
+}
+
+bool MediaCodecLoop::QueueInput() {
+  DVLOG(2) << __FUNCTION__;
+
+  bool did_work = false;
+  while (QueueOneInputBuffer())
+    did_work = true;
+
+  return did_work;
+}
+
+bool MediaCodecLoop::QueueOneInputBuffer() {
+  DVLOG(2) << __FUNCTION__;
+
+  // 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;
+
+  if (state_ == STATE_WAITING_FOR_KEY || state_ == STATE_DRAINING ||
+      state_ == STATE_DRAINED)
+    return false;
+
+  // DequeueInputBuffer() may set STATE_ERROR.
+  InputBufferInfo input_info = DequeueInputBuffer();
+
+  if (input_info.buf_index == kInvalidBufferIndex)
+    return false;
+
+  // EnqueueInputBuffer() may set STATE_DRAINING, STATE_WAITING_FOR_KEY or
+  // STATE_ERROR.
+  EnqueueInputBuffer(input_info);
+  return state_ == STATE_READY;
+}
+
+MediaCodecLoop::InputBufferInfo 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 in QueueSecureInputBuffer().
+  if (pending_input_buf_index_ != kInvalidBufferIndex) {
+    InputBufferInfo result(pending_input_buf_index_, true);
+    pending_input_buf_index_ = kInvalidBufferIndex;
+    return result;
+  }
+
+  int input_buf_index = kInvalidBufferIndex;
+
+  media::MediaCodecStatus status =
+      media_codec_->DequeueInputBuffer(NoWaitTimeout(), &input_buf_index);
+  switch (status) {
+    case media::MEDIA_CODEC_DEQUEUE_INPUT_AGAIN_LATER:
+      DVLOG(2) << __FUNCTION__ << ": MEDIA_CODEC_DEQUEUE_INPUT_AGAIN_LATER";
+      break;
+
+    case media::MEDIA_CODEC_ERROR:
+      DVLOG(1) << __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 InputBufferInfo(input_buf_index, false);
+}
+
+void MediaCodecLoop::EnqueueInputBuffer(const InputBufferInfo& input_info) {
+  DVLOG(2) << __FUNCTION__ << ": index:" << input_info.buf_index;
+
+  DCHECK_NE(input_info.buf_index, kInvalidBufferIndex);
+
+  InputBufferData input_data;
+
+  if (input_info.is_pending) {
+    // A pending buffer is already filled with data, no need to copy it again.
+    DVLOG(2) << __FUNCTION__ << ": QueueSecureInputBuffer (pending):"
+             << " index:" << input_info.buf_index
+             << " pts:" << pending_input_buf_data_.presentation_time
+             << " size:" << pending_input_buf_data_.length;
+
+    input_data = pending_input_buf_data_;
+  } else {
+    input_data = client_->ProvideInputData();
+  }
+
+  // Process this buffer.
+
+  if (input_data.is_eos) {
+    media_codec_->QueueEOS(input_info.buf_index);
+    SetState(STATE_DRAINING);
+    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.
+
+    DVLOG(2) << __FUNCTION__ << ": QueueSecureInputBuffer:"
+             << " index:" << input_info.buf_index
+             << " pts:" << input_data.presentation_time
+             << " size:" << input_data.length;
+
+    status = media_codec_->QueueSecureInputBuffer(
+        input_info.buf_index, input_data.memory, input_data.length,
+        input_data.key_id, input_data.iv, input_data.subsamples,
+        input_data.presentation_time);
+
+  } else {
+    DVLOG(2) << __FUNCTION__ << ": QueueInputBuffer:"
+             << " index:" << input_info.buf_index
+             << " pts:" << input_data.presentation_time
+             << " size:" << input_data.length;
+
+    status = media_codec_->QueueInputBuffer(
+        input_info.buf_index, input_data.memory, input_data.length,
+        input_data.presentation_time);
+  }
+
+  switch (status) {
+    case MEDIA_CODEC_ERROR:
+      DVLOG(0) << __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:
+      DVLOG(1) << "QueueSecureInputBuffer failed: 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_info.buf_index;
+      pending_input_buf_data_ = input_data;
+      // The client doesn't guarantee that these will remain valid after we

[Tima Vaisburd, 2016/06/02 00:35:21]

I still do not understand this comment. Sorry me being slow :-)
I think later you'd assign input_data = pending_input_buf_data_ back and pass it
to QueueSecureInputBuffer() to try again. MediaCodec buffer has a copy of the
data, indeed, but the API requires all the fields again, including length,
key_id, iv, subsamples, pts. Why do you say we do not need them? And why do you
assign |length| to 0?

[liberato (no reviews please), 2016/06/03 16:23:28]

comment: i'll update it.

key_id, iv, ...: these are preserved in |pending_input_buf_data_|
memory: this is cleared, just like
https://code.google.com/p/chromium/codesearch#chromium/src/media/filters/andr...

length: good catch, fixed.

+      // return, and in any event we don't need them.  MediaCodec has a copy of
+      // the data already.
+      pending_input_buf_data_.memory = nullptr;
+      pending_input_buf_data_.length = 0;
+      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::DequeueOutput() {
+  DVLOG(2) << __FUNCTION__;
+
+  MediaCodecStatus status;
+  OutputBufferInfo out;
+  bool did_work = false;
+  do {
+    status = media_codec_->DequeueOutputBuffer(NoWaitTimeout(), &out.buf_index,
+                                               &out.offset, &out.size, &out.pts,
+                                               &out.is_eos, &out.is_key_frame);
+
+    switch (status) {
+      case MEDIA_CODEC_OUTPUT_BUFFERS_CHANGED:
+        // Output buffers are replaced in MediaCodecBridge, nothing to do.
+        DVLOG(2) << __FUNCTION__ << " MEDIA_CODEC_OUTPUT_BUFFERS_CHANGED";
+        did_work = true;
+        break;
+
+      case MEDIA_CODEC_OUTPUT_FORMAT_CHANGED:
+        DVLOG(2) << __FUNCTION__ << " 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.
+        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.buf_index, kInvalidBufferIndex);
+          DCHECK(media_codec_);
+
+          media_codec_->ReleaseOutputBuffer(out.buf_index, false);
+
+          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.
+        DVLOG(2) << __FUNCTION__ << " MEDIA_CODEC_DEQUEUE_OUTPUT_AGAIN_LATER";
+        break;
+
+      case MEDIA_CODEC_ERROR:
+        DVLOG(0) << __FUNCTION__
+                 << ": MEDIA_CODEC_ERROR from DequeueOutputBuffer";
+
+        // Next Decode() will report the error to the pipeline.
+        SetState(STATE_ERROR);
+        break;
+
+      default:
+        NOTREACHED() << "Unknown DequeueOutputBuffer status " << status;
+        // Next Decode() will report the error to the pipeline.
+        SetState(STATE_ERROR);
+        break;
+    }
+  } while (status != MEDIA_CODEC_DEQUEUE_OUTPUT_AGAIN_LATER &&
+           status != MEDIA_CODEC_ERROR && !out.is_eos);
+
+  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_ > IdleTimerTimeout())
+      should_be_running = false;
+  }
+
+  if (should_be_running && !io_timer_.IsRunning()) {
+    io_timer_.Start(FROM_HERE, DecodePollDelay(), this,
+                    &MediaCodecLoop::DoIOTask);
+  } else if (!should_be_running && io_timer_.IsRunning()) {
+    io_timer_.Stop();
+  }
+}
+
+MediaCodecLoop::State MediaCodecLoop::GetState() const {
+  return state_;
+}
+
+void MediaCodecLoop::SetState(State new_state) {
+  DVLOG(1) << __FUNCTION__ << ": " << AsString(state_) << "->"
+           << AsString(new_state);
+  if (state_ != new_state && state_ == STATE_ERROR)
+    client_->OnError();
+  state_ = new_state;
+}
+
+MediaCodecBridge* MediaCodecLoop::GetCodec() const {
+  return media_codec_.get();
+}
+
+#undef RETURN_STRING
+#define RETURN_STRING(x) \
+  case x:                \
+    return #x;
+
+// static
+const char* MediaCodecLoop::AsString(State state) {
+  switch (state) {
+    RETURN_STRING(STATE_READY);
+    RETURN_STRING(STATE_WAITING_FOR_KEY);
+    RETURN_STRING(STATE_DRAINING);
+    RETURN_STRING(STATE_DRAINED);
+    RETURN_STRING(STATE_ERROR);
+  }
+  NOTREACHED() << "Unknown state " << state;
+  return nullptr;
+}
+
+#undef RETURN_STRING
+
+}  // namespace media