MediaCodecPlayer implementation (stage 4 - preroll)

media/base/android/media_codec_decoder.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 "media/base/android/media_codec_decoder.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
@@ skipping 28 matching lines @@
     const base::Closure& error_cb,
     const char* decoder_thread_name)
     : media_task_runner_(media_task_runner),
       decoder_thread_(decoder_thread_name),
       needs_reconfigure_(false),
       external_request_data_cb_(external_request_data_cb),
       starvation_cb_(starvation_cb),
       stop_done_cb_(stop_done_cb),
       error_cb_(error_cb),
       state_(kStopped),
+      needs_preroll_(true),
       eos_enqueued_(false),
       completed_(false),
       last_frame_posted_(false),
       is_data_request_in_progress_(false),
       is_incoming_data_invalid_(false),
 #ifndef NDEBUG
       verify_next_frame_is_key_(false),
 #endif
       weak_factory_(this) {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   DVLOG(1) << "Decoder::Decoder() " << decoder_thread_name;
 
   internal_error_cb_ =
       base::Bind(&MediaCodecDecoder::OnCodecError, weak_factory_.GetWeakPtr());
+  internal_preroll_done_cb_ =
+      base::Bind(&MediaCodecDecoder::OnPrerollDone, weak_factory_.GetWeakPtr());
   request_data_cb_ =
       base::Bind(&MediaCodecDecoder::RequestData, weak_factory_.GetWeakPtr());
 }
 
 MediaCodecDecoder::~MediaCodecDecoder() {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   DVLOG(1) << "Decoder::~Decoder()";
 
   // NB: ReleaseDecoderResources() is virtual
   ReleaseDecoderResources();
 }
 
 const char* MediaCodecDecoder::class_name() const {
   return "Decoder";
 }
 
 void MediaCodecDecoder::ReleaseDecoderResources() {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   DVLOG(1) << class_name() << "::" << __FUNCTION__;
 
   // Set [kInEmergencyStop| state to block already posted ProcessNextFrame().
   SetState(kInEmergencyStop);
 
   decoder_thread_.Stop();  // synchronous
 
   SetState(kStopped);
-  media_codec_bridge_.reset();
+  ReleaseMediaCodec();
+
+  needs_preroll_ = true;
 }
 
 void MediaCodecDecoder::Flush() {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   DVLOG(1) << class_name() << "::" << __FUNCTION__;
 
   DCHECK_EQ(GetState(), kStopped);
 
   // Flush() is a part of the Seek request. Whenever we request a seek we need
   // to invalidate the current data request.
   if (is_data_request_in_progress_)
     is_incoming_data_invalid_ = true;
 
   eos_enqueued_ = false;
   completed_ = false;
   au_queue_.Flush();
 
 #ifndef NDEBUG
   // We check and reset |verify_next_frame_is_key_| on Decoder thread.
   // This DCHECK ensures we won't need to lock this variable.
   DCHECK(!decoder_thread_.IsRunning());
 
   // For video the first frame after flush must be key frame.
   verify_next_frame_is_key_ = true;
 #endif
 
+  needs_preroll_ = true;
+
   if (media_codec_bridge_) {
     // MediaCodecBridge::Reset() performs MediaCodecBridge.flush()
     MediaCodecStatus flush_status = media_codec_bridge_->Reset();
     if (flush_status != MEDIA_CODEC_OK) {
       DVLOG(0) << class_name() << "::" << __FUNCTION__
                << "MediaCodecBridge::Reset() failed";
       media_task_runner_->PostTask(FROM_HERE, internal_error_cb_);
     }
   }
 }
 
 void MediaCodecDecoder::ReleaseMediaCodec() {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   DVLOG(1) << class_name() << "::" << __FUNCTION__;
 
   media_codec_bridge_.reset();
 }
 
 bool MediaCodecDecoder::IsPrefetchingOrPlaying() const {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
+  // Whether decoder needs to be stopped.
   base::AutoLock lock(state_lock_);
-  return state_ == kPrefetching || state_ == kRunning;
+  switch (state_) {
+    case kPrefetching:
+    case kPrefetched:
+    case kPrerolling:
+    case kPrerolled:
+    case kRunning:
+      return true;
+    case kStopped:
+    case kStopping:
+    case kInEmergencyStop:
+    case kError:
+      return false;
+  }
+  NOTREACHED();
+  return false;
 }
 
 bool MediaCodecDecoder::IsStopped() const {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   return GetState() == kStopped;
 }
 
 bool MediaCodecDecoder::IsCompleted() const {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   return completed_;
 }
 
+bool MediaCodecDecoder::NeedsPreroll() const {
+  DCHECK(media_task_runner_->BelongsToCurrentThread());
+
+  return HasStream() && needs_preroll_ && !completed_;
+}
+
 base::android::ScopedJavaLocalRef<jobject> MediaCodecDecoder::GetMediaCrypto() {
   base::android::ScopedJavaLocalRef<jobject> media_crypto;
 
   // TODO(timav): implement DRM.
   // drm_bridge_ is not implemented
   // if (drm_bridge_)
   //   media_crypto = drm_bridge_->GetMediaCrypto();
   return media_crypto;
 }
 
@@ skipping 17 matching lines @@
 
   if (GetState() == kError) {
     DVLOG(0) << class_name() << "::" << __FUNCTION__ << ": wrong state kError";
     return kConfigFailure;
   }
 
   if (needs_reconfigure_) {
     DVLOG(1) << class_name() << "::" << __FUNCTION__
              << ": needs reconfigure, deleting MediaCodec";
     needs_reconfigure_ = false;
-    media_codec_bridge_.reset();
-
-    // No need to release these buffers since the MediaCodec is deleted, just
-    // remove their indexes from |delayed_buffers_|.
-
-    ClearDelayedBuffers(false);
+    ReleaseMediaCodec();
   }
 
   MediaCodecDecoder::ConfigStatus result;
   if (media_codec_bridge_) {
     DVLOG(1) << class_name() << "::" << __FUNCTION__
              << ": reconfiguration is not required, ignoring";
     result = kConfigOk;
   } else {
     result = ConfigureInternal();
 
 #ifndef NDEBUG
     // We check and reset |verify_next_frame_is_key_| on Decoder thread.
     // This DCHECK ensures we won't need to lock this variable.
     DCHECK(!decoder_thread_.IsRunning());
 
     // For video the first frame after reconfiguration must be key frame.
     if (result == kConfigOk)
       verify_next_frame_is_key_ = true;
 #endif
   }
 
   return result;
 }
 
-bool MediaCodecDecoder::Start(base::TimeDelta current_time) {
+bool MediaCodecDecoder::Preroll(base::TimeDelta preroll_timestamp,
+                                const base::Closure& preroll_done_cb) {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   DVLOG(1) << class_name() << "::" << __FUNCTION__
-           << " current_time:" << current_time;
+           << " preroll_timestamp:" << preroll_timestamp;
 
   DecoderState state = GetState();
-  if (state == kRunning) {
-    DVLOG(1) << class_name() << "::" << __FUNCTION__ << ": already started";
-    return true;  // already started
-  }
-
   if (state != kPrefetched) {
     DVLOG(0) << class_name() << "::" << __FUNCTION__ << ": wrong state "
              << AsString(state) << ", ignoring";
     return false;
   }
 
   if (!media_codec_bridge_) {
     DVLOG(0) << class_name() << "::" << __FUNCTION__
              << ": not configured, ignoring";
     return false;
   }
 
   DCHECK(!decoder_thread_.IsRunning());
+  DCHECK(needs_preroll_);
+
+  preroll_done_cb_ = preroll_done_cb;
 
   // We only synchronize video stream.
-  // When audio is present, the |current_time| is audio time.
-  SynchronizePTSWithTime(current_time);
+  DissociatePTSFromTime();  // associaton will happen after preroll is done.
+  preroll_timestamp_ = preroll_timestamp;
 
   last_frame_posted_ = false;
 
   // Start the decoder thread
   if (!decoder_thread_.Start()) {
     DVLOG(0) << class_name() << "::" << __FUNCTION__
              << ": cannot start decoder thread";
     return false;
   }
 
-  DVLOG(0) << class_name() << "::" << __FUNCTION__ << " decoder thread started";
+  SetState(kPrerolling);
+
+  decoder_thread_.task_runner()->PostTask(
+      FROM_HERE,
+      base::Bind(&MediaCodecDecoder::ProcessNextFrame, base::Unretained(this)));
+
+  return true;
+}
+
+bool MediaCodecDecoder::Start(base::TimeDelta start_timestamp) {
+  DCHECK(media_task_runner_->BelongsToCurrentThread());
+
+  DVLOG(1) << class_name() << "::" << __FUNCTION__
+           << " start_timestamp:" << start_timestamp;
+
+  DecoderState state = GetState();
+
+  if (state != kPrefetched && state != kPrerolled) {
+    DVLOG(0) << class_name() << "::" << __FUNCTION__ << ": wrong state "
+             << AsString(state) << ", ignoring";
+    return false;
+  }
+
+  if (!media_codec_bridge_) {
+    DVLOG(0) << class_name() << "::" << __FUNCTION__
+             << ": not configured, ignoring";
+    return false;
+  }
+
+  // We only synchronize video stream.
+  AssociateCurrentTimeWithPTS(start_timestamp);
+  preroll_timestamp_ = base::TimeDelta();
+
+  // Start the decoder thread
+  if (!decoder_thread_.IsRunning()) {
+    last_frame_posted_ = false;
+    if (!decoder_thread_.Start()) {
+      DVLOG(1) << class_name() << "::" << __FUNCTION__
+               << ": cannot start decoder thread";
+      return false;
+    }
+  }
 
   SetState(kRunning);
 
   decoder_thread_.task_runner()->PostTask(
       FROM_HERE,
       base::Bind(&MediaCodecDecoder::ProcessNextFrame, base::Unretained(this)));
 
   return true;
 }
 
@@ skipping 10 matching lines @@
 
   // After this method returns, decoder thread will not be running.
 
   // Set [kInEmergencyStop| state to block already posted ProcessNextFrame().
   SetState(kInEmergencyStop);
 
   decoder_thread_.Stop();  // synchronous
 
   SetState(kStopped);
 
-  ClearDelayedBuffers(true);  // release prior to clearing  |delayed_buffers_|.
+  ReleaseDelayedBuffers();
 }
 
 void MediaCodecDecoder::RequestToStop() {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   DVLOG(1) << class_name() << "::" << __FUNCTION__;
 
   DecoderState state = GetState();
   switch (state) {
     case kError:
       DVLOG(0) << class_name() << "::" << __FUNCTION__
                << ": wrong state kError, ignoring";
       break;
     case kRunning:
       SetState(kStopping);
       break;
+    case kPrerolling:
+    case kPrerolled:
+      DCHECK(decoder_thread_.IsRunning());
+      // Synchronous stop.
+      decoder_thread_.Stop();
+      SetState(kStopped);
+      media_task_runner_->PostTask(FROM_HERE, stop_done_cb_);
+      break;
     case kStopping:
       break;  // ignore
     case kStopped:
     case kPrefetching:
     case kPrefetched:
       // There is nothing to wait for, we can sent nofigication right away.
       DCHECK(!decoder_thread_.IsRunning());
       SetState(kStopped);
       media_task_runner_->PostTask(FROM_HERE, stop_done_cb_);
       break;
     default:
       NOTREACHED();
       break;
   }
 }
 
 void MediaCodecDecoder::OnLastFrameRendered(bool completed) {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   DVLOG(0) << class_name() << "::" << __FUNCTION__
            << " completed:" << completed;
 
   decoder_thread_.Stop();  // synchronous
 
   SetState(kStopped);
   completed_ = completed;
 
+  if (completed_ && !preroll_done_cb_.is_null())
+    media_task_runner_->PostTask(FROM_HERE,
+                                 base::ResetAndReturn(&preroll_done_cb_));
+
   media_task_runner_->PostTask(FROM_HERE, stop_done_cb_);
 }
 
+void MediaCodecDecoder::OnPrerollDone() {
+  DCHECK(media_task_runner_->BelongsToCurrentThread());
+
+  DVLOG(1) << class_name() << "::" << __FUNCTION__;
+
+  if (GetState() == kPrerolling) {
+    SetState(kPrerolled);
+    needs_preroll_ = false;
+    media_task_runner_->PostTask(FROM_HERE,
+                                 base::ResetAndReturn(&preroll_done_cb_));
+  }
+}
+
 void MediaCodecDecoder::OnDemuxerDataAvailable(const DemuxerData& data) {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   // If |data| contains an aborted data, the last AU will have kAborted status.
   bool aborted_data =
       !data.access_units.empty() &&
       data.access_units.back().status == DemuxerStream::kAborted;
 
 #ifndef NDEBUG
   const char* explain_if_skipped =
@@ skipping 12 matching lines @@
 
   is_incoming_data_invalid_ = false;
   is_data_request_in_progress_ = false;
 
   // Do not request data if we got kAborted. There is no point to request the
   // data after kAborted and before the OnDemuxerSeekDone.
   if (GetState() == kPrefetching && !aborted_data)
     PrefetchNextChunk();
 }
 
+bool MediaCodecDecoder::IsPrerollingForTests() const {
+  // UI task runner.
+  return GetState() == kPrerolling;
+}
+
 int MediaCodecDecoder::NumDelayedRenderTasks() const {
   return 0;
 }
 
 void MediaCodecDecoder::CheckLastFrame(bool eos_encountered,
                                        bool has_delayed_tasks) {
   DCHECK(decoder_thread_.task_runner()->BelongsToCurrentThread());
 
   bool last_frame_when_stopping = GetState() == kStopping && !has_delayed_tasks;
 
@@ skipping 49 matching lines @@
   request_data_cb_.Run();
 }
 
 void MediaCodecDecoder::ProcessNextFrame() {
   DCHECK(decoder_thread_.task_runner()->BelongsToCurrentThread());
 
   DVLOG(2) << class_name() << "::" << __FUNCTION__;
 
   DecoderState state = GetState();
 
-  if (state != kRunning && state != kStopping) {
+  if (state != kPrerolling && state != kRunning && state != kStopping) {
     DVLOG(1) << class_name() << "::" << __FUNCTION__ << ": not running";
     return;
   }
 
   if (state == kStopping) {
     if (NumDelayedRenderTasks() == 0 && !last_frame_posted_) {
       DVLOG(1) << class_name() << "::" << __FUNCTION__
                << ": kStopping, posting OnLastFrameRendered";
       media_task_runner_->PostTask(
           FROM_HERE, base::Bind(&MediaCodecDecoder::OnLastFrameRendered,
                                 weak_factory_.GetWeakPtr(), false));
       last_frame_posted_ = true;
     }
 
     // We can stop processing, the |au_queue_| and MediaCodec queues can freeze.
     // We only need to let finish the delayed rendering tasks.
     return;
   }
 
-  DCHECK(state == kRunning);
+  DCHECK(state == kPrerolling || state == kRunning);
 
   if (!EnqueueInputBuffer())
     return;
 
   if (!DepleteOutputBufferQueue())
     return;
 
   // We need a small delay if we want to stop this thread by
   // decoder_thread_.Stop() reliably.
   // The decoder thread message loop processes all pending
@@ skipping 124 matching lines @@
 
   DVLOG(2) << class_name() << "::" << __FUNCTION__;
 
   int buffer_index = 0;
   size_t offset = 0;
   size_t size = 0;
   base::TimeDelta pts;
   MediaCodecStatus status;
   bool eos_encountered = false;
 
+  RenderMode render_mode;
+
   base::TimeDelta timeout =
       base::TimeDelta::FromMilliseconds(kOutputBufferTimeout);
 
   // Extract all output buffers that are available.
   // Usually there will be only one, but sometimes it is preceeded by
   // MEDIA_CODEC_OUTPUT_BUFFERS_CHANGED or MEDIA_CODEC_OUTPUT_FORMAT_CHANGED.
   do {
     status = media_codec_bridge_->DequeueOutputBuffer(
         timeout, &buffer_index, &offset, &size, &pts, &eos_encountered,
         nullptr);
 
     // Reset the timeout to 0 for the subsequent DequeueOutputBuffer() calls
     // to quickly break the loop after we got all currently available buffers.
     timeout = base::TimeDelta::FromMilliseconds(0);
 
     switch (status) {
       case MEDIA_CODEC_OUTPUT_BUFFERS_CHANGED:
         // Output buffers are replaced in MediaCodecBridge, nothing to do.
         break;
 
       case MEDIA_CODEC_OUTPUT_FORMAT_CHANGED:
         DVLOG(2) << class_name() << "::" << __FUNCTION__
                  << " MEDIA_CODEC_OUTPUT_FORMAT_CHANGED";
         OnOutputFormatChanged();
         break;
 
       case MEDIA_CODEC_OK:
-        // We got the decoded frame
-        Render(buffer_index, size, true, pts, eos_encountered);
+        // We got the decoded frame.
+
+        if (pts < preroll_timestamp_)
+          render_mode = kRenderSkip;
+        else if (GetState() == kPrerolling)
+          render_mode = kRenderAfterPreroll;
+        else
+          render_mode = kRenderNow;
+
+        Render(buffer_index, size, render_mode, pts, eos_encountered);
+
+        if (render_mode == kRenderAfterPreroll) {
+          DVLOG(1) << class_name() << "::" << __FUNCTION__ << " pts:" << pts
+                   << " preroll done, stopping frame processing";
+          media_task_runner_->PostTask(FROM_HERE, internal_preroll_done_cb_);
+          return false;
+        }
         break;
 
       case MEDIA_CODEC_DEQUEUE_OUTPUT_AGAIN_LATER:
         // Nothing to do.
         break;
 
       case MEDIA_CODEC_ERROR:
         DVLOG(0) << class_name() << "::" << __FUNCTION__
                  << ": MEDIA_CODEC_ERROR from DequeueOutputBuffer";
         media_task_runner_->PostTask(FROM_HERE, internal_error_cb_);
@@ skipping 32 matching lines @@
 
   base::AutoLock lock(state_lock_);
   state_ = state;
 }
 
 #undef RETURN_STRING
 #define RETURN_STRING(x) \
   case x:                \
     return #x;
 
+const char* MediaCodecDecoder::AsString(RenderMode render_mode) {
+  switch (render_mode) {
+    RETURN_STRING(kRenderSkip);
+    RETURN_STRING(kRenderAfterPreroll);
+    RETURN_STRING(kRenderNow);
+  }
+  return nullptr;  // crash early
+}
+
 const char* MediaCodecDecoder::AsString(DecoderState state) {
   switch (state) {
     RETURN_STRING(kStopped);
     RETURN_STRING(kPrefetching);
     RETURN_STRING(kPrefetched);
+    RETURN_STRING(kPrerolling);
+    RETURN_STRING(kPrerolled);
     RETURN_STRING(kRunning);
     RETURN_STRING(kStopping);
     RETURN_STRING(kInEmergencyStop);
     RETURN_STRING(kError);
-    default:
-      return "Unknown DecoderState";
   }
+  return nullptr;  // crash early
 }
 
 #undef RETURN_STRING
 
 }  // namespace media