media/blink/webmediaplayer_impl.cc

// Copyright 2013 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/blink/webmediaplayer_impl.h"

#include <algorithm>
#include <limits>
#include <string>
#include <vector>

#include "base/bind.h"
#include "base/callback.h"
#include "base/callback_helpers.h"
#include "base/debug/alias.h"
#include "base/debug/crash_logging.h"
#include "base/float_util.h"
#include "base/message_loop/message_loop_proxy.h"
#include "base/metrics/histogram.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/waitable_event.h"
#include "base/trace_event/trace_event.h"
#include "cc/blink/web_layer_impl.h"
#include "cc/layers/video_layer.h"
#include "gpu/blink/webgraphicscontext3d_impl.h"
#include "media/audio/null_audio_sink.h"
#include "media/base/bind_to_current_loop.h"
#include "media/base/cdm_context.h"
#include "media/base/limits.h"
#include "media/base/media_log.h"
#include "media/base/pipeline.h"
#include "media/base/text_renderer.h"
#include "media/base/video_frame.h"
#include "media/blink/buffered_data_source.h"
#include "media/blink/encrypted_media_player_support.h"
#include "media/blink/texttrack_impl.h"
#include "media/blink/webaudiosourceprovider_impl.h"
#include "media/blink/webcontentdecryptionmodule_impl.h"
#include "media/blink/webinbandtexttrack_impl.h"
#include "media/blink/webmediaplayer_delegate.h"
#include "media/blink/webmediaplayer_util.h"
#include "media/blink/webmediasource_impl.h"
#include "media/filters/chunk_demuxer.h"
#include "media/filters/ffmpeg_demuxer.h"
#include "third_party/WebKit/public/platform/WebMediaSource.h"
#include "third_party/WebKit/public/platform/WebRect.h"
#include "third_party/WebKit/public/platform/WebSize.h"
#include "third_party/WebKit/public/platform/WebString.h"
#include "third_party/WebKit/public/platform/WebURL.h"
#include "third_party/WebKit/public/web/WebLocalFrame.h"
#include "third_party/WebKit/public/web/WebRuntimeFeatures.h"
#include "third_party/WebKit/public/web/WebSecurityOrigin.h"
#include "third_party/WebKit/public/web/WebView.h"

using blink::WebCanvas;
using blink::WebMediaPlayer;
using blink::WebRect;
using blink::WebSize;
using blink::WebString;

namespace {

// Limits the range of playback rate.
//
// TODO(kylep): Revisit these.
//
// Vista has substantially lower performance than XP or Windows7.  If you speed
// up a video too much, it can't keep up, and rendering stops updating except on
// the time bar. For really high speeds, audio becomes a bottleneck and we just
// use up the data we have, which may not achieve the speed requested, but will
// not crash the tab.
//
// A very slow speed, ie 0.00000001x, causes the machine to lock up. (It seems
// like a busy loop). It gets unresponsive, although its not completely dead.
//
// Also our timers are not very accurate (especially for ogg), which becomes
// evident at low speeds and on Vista. Since other speeds are risky and outside
// the norms, we think 1/16x to 16x is a safe and useful range for now.
const double kMinRate = 0.0625;
const double kMaxRate = 16.0;

}  // namespace

namespace media {

class BufferedDataSourceHostImpl;

#define STATIC_ASSERT_MATCHING_ENUM(name) \
  static_assert(static_cast<int>(WebMediaPlayer::CORSMode ## name) == \
                static_cast<int>(BufferedResourceLoader::k ## name), \
                "mismatching enum values: " #name)
STATIC_ASSERT_MATCHING_ENUM(Unspecified);
STATIC_ASSERT_MATCHING_ENUM(Anonymous);
STATIC_ASSERT_MATCHING_ENUM(UseCredentials);
#undef STATIC_ASSERT_MATCHING_ENUM

#define BIND_TO_RENDER_LOOP(function) \
  (DCHECK(main_task_runner_->BelongsToCurrentThread()), \
  BindToCurrentLoop(base::Bind(function, AsWeakPtr())))

#define BIND_TO_RENDER_LOOP1(function, arg1) \
  (DCHECK(main_task_runner_->BelongsToCurrentThread()), \
  BindToCurrentLoop(base::Bind(function, AsWeakPtr(), arg1)))

static void LogMediaSourceError(const scoped_refptr<MediaLog>& media_log,
                                const std::string& error) {
  media_log->AddEvent(media_log->CreateMediaSourceErrorEvent(error));
}

WebMediaPlayerImpl::WebMediaPlayerImpl(
    blink::WebLocalFrame* frame,
    blink::WebMediaPlayerClient* client,
    base::WeakPtr<WebMediaPlayerDelegate> delegate,
    scoped_ptr<RendererFactory> renderer_factory,
    scoped_ptr<CdmFactory> cdm_factory,
    const WebMediaPlayerParams& params)
    : frame_(frame),
      network_state_(WebMediaPlayer::NetworkStateEmpty),
      ready_state_(WebMediaPlayer::ReadyStateHaveNothing),
      preload_(BufferedDataSource::AUTO),
      main_task_runner_(base::MessageLoopProxy::current()),
      media_task_runner_(params.media_task_runner()),
      media_log_(params.media_log()),
      pipeline_(media_task_runner_, media_log_.get()),
      load_type_(LoadTypeURL),
      opaque_(false),
      paused_(true),
      seeking_(false),
      playback_rate_(0.0f),
      ended_(false),
      pending_seek_(false),
      pending_seek_seconds_(0.0f),
      should_notify_time_changed_(false),
      client_(client),
      delegate_(delegate),
      defer_load_cb_(params.defer_load_cb()),
      context_3d_cb_(params.context_3d_cb()),
      supports_save_(true),
      chunk_demuxer_(NULL),
      compositor_task_runner_(params.compositor_task_runner()),
      compositor_(new VideoFrameCompositor(
          BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnNaturalSizeChanged),
          BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnOpacityChanged))),
      encrypted_media_support_(
          cdm_factory.Pass(),
          client,
          params.media_permission(),
          base::Bind(&WebMediaPlayerImpl::SetCdm, AsWeakPtr())),
      renderer_factory_(renderer_factory.Pass()) {
  // Threaded compositing isn't enabled universally yet.
  if (!compositor_task_runner_.get())
    compositor_task_runner_ = base::MessageLoopProxy::current();

  media_log_->AddEvent(
      media_log_->CreateEvent(MediaLogEvent::WEBMEDIAPLAYER_CREATED));

  if (params.initial_cdm()) {
    SetCdm(
        ToWebContentDecryptionModuleImpl(params.initial_cdm())->GetCdmContext(),
        base::Bind(&IgnoreCdmAttached));
  }

  // TODO(xhwang): When we use an external Renderer, many methods won't work,
  // e.g. GetCurrentFrameFromCompositor(). See http://crbug.com/434861

  // Use the null sink if no sink was provided.
  audio_source_provider_ = new WebAudioSourceProviderImpl(
      params.audio_renderer_sink().get()
          ? params.audio_renderer_sink()
          : new NullAudioSink(media_task_runner_));
}

WebMediaPlayerImpl::~WebMediaPlayerImpl() {
  client_->setWebLayer(NULL);

  DCHECK(main_task_runner_->BelongsToCurrentThread());
  media_log_->AddEvent(
      media_log_->CreateEvent(MediaLogEvent::WEBMEDIAPLAYER_DESTROYED));

  if (delegate_)
    delegate_->PlayerGone(this);

  // Abort any pending IO so stopping the pipeline doesn't get blocked.
  if (data_source_)
    data_source_->Abort();
  if (chunk_demuxer_) {
    chunk_demuxer_->Shutdown();
    chunk_demuxer_ = NULL;
  }

  renderer_factory_.reset();

  // Make sure to kill the pipeline so there's no more media threads running.
  // Note: stopping the pipeline might block for a long time.
  base::WaitableEvent waiter(false, false);
  pipeline_.Stop(
      base::Bind(&base::WaitableEvent::Signal, base::Unretained(&waiter)));
  waiter.Wait();

  compositor_task_runner_->DeleteSoon(FROM_HERE, compositor_);
}

void WebMediaPlayerImpl::load(LoadType load_type, const blink::WebURL& url,
                              CORSMode cors_mode) {
  DVLOG(1) << __FUNCTION__ << "(" << load_type << ", " << url << ", "
           << cors_mode << ")";
  if (!defer_load_cb_.is_null()) {
    defer_load_cb_.Run(base::Bind(
        &WebMediaPlayerImpl::DoLoad, AsWeakPtr(), load_type, url, cors_mode));
    return;
  }
  DoLoad(load_type, url, cors_mode);
}

void WebMediaPlayerImpl::DoLoad(LoadType load_type,
                                const blink::WebURL& url,
                                CORSMode cors_mode) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  GURL gurl(url);
  ReportMediaSchemeUma(gurl);

  // Set subresource URL for crash reporting.
  base::debug::SetCrashKeyValue("subresource_url", gurl.spec());

  load_type_ = load_type;

  SetNetworkState(WebMediaPlayer::NetworkStateLoading);
  SetReadyState(WebMediaPlayer::ReadyStateHaveNothing);
  media_log_->AddEvent(media_log_->CreateLoadEvent(url.spec()));

  // Media source pipelines can start immediately.
  if (load_type == LoadTypeMediaSource) {
    supports_save_ = false;
    StartPipeline();
    return;
  }

  // Otherwise it's a regular request which requires resolving the URL first.
  data_source_.reset(new BufferedDataSource(
      url,
      static_cast<BufferedResourceLoader::CORSMode>(cors_mode),
      main_task_runner_,
      frame_,
      media_log_.get(),
      &buffered_data_source_host_,
      base::Bind(&WebMediaPlayerImpl::NotifyDownloading, AsWeakPtr())));
  data_source_->SetPreload(preload_);
  data_source_->Initialize(
      base::Bind(&WebMediaPlayerImpl::DataSourceInitialized, AsWeakPtr()));
}

void WebMediaPlayerImpl::play() {
  DVLOG(1) << __FUNCTION__;
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  paused_ = false;
  pipeline_.SetPlaybackRate(playback_rate_);
  if (data_source_)
    data_source_->MediaIsPlaying();

  media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::PLAY));

  if (delegate_ && playback_rate_ > 0)
    delegate_->DidPlay(this);
}

void WebMediaPlayerImpl::pause() {
  DVLOG(1) << __FUNCTION__;
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  const bool was_already_paused = paused_ || playback_rate_ == 0;
  paused_ = true;
  pipeline_.SetPlaybackRate(0.0f);
  if (data_source_)
    data_source_->MediaIsPaused();
  UpdatePausedTime();

  media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::PAUSE));

  if (!was_already_paused && delegate_)
    delegate_->DidPause(this);
}

bool WebMediaPlayerImpl::supportsSave() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return supports_save_;
}

void WebMediaPlayerImpl::seek(double seconds) {
  DVLOG(1) << __FUNCTION__ << "(" << seconds << "s)";
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  ended_ = false;

  ReadyState old_state = ready_state_;
  if (ready_state_ > WebMediaPlayer::ReadyStateHaveMetadata)
    SetReadyState(WebMediaPlayer::ReadyStateHaveMetadata);

  base::TimeDelta seek_time = ConvertSecondsToTimestamp(seconds);

  if (seeking_) {
    pending_seek_ = true;
    pending_seek_seconds_ = seconds;
    if (chunk_demuxer_)
      chunk_demuxer_->CancelPendingSeek(seek_time);
    return;
  }

  media_log_->AddEvent(media_log_->CreateSeekEvent(seconds));

  // Update our paused time.
  // In paused state ignore the seek operations to current time if the loading
  // is completed and generate OnPipelineBufferingStateChanged event to
  // eventually fire seeking and seeked events
  if (paused_) {
    if (paused_time_ != seek_time) {
      paused_time_ = seek_time;
    } else if (old_state == ReadyStateHaveEnoughData) {
      main_task_runner_->PostTask(
          FROM_HERE,
          base::Bind(&WebMediaPlayerImpl::OnPipelineBufferingStateChanged,
                     AsWeakPtr(), BUFFERING_HAVE_ENOUGH));
      return;
    }
  }

  seeking_ = true;

  if (chunk_demuxer_)
    chunk_demuxer_->StartWaitingForSeek(seek_time);

  // Kick off the asynchronous seek!
  pipeline_.Seek(
      seek_time,
      BIND_TO_RENDER_LOOP1(&WebMediaPlayerImpl::OnPipelineSeeked, true));
}

void WebMediaPlayerImpl::setRate(double rate) {
  DVLOG(1) << __FUNCTION__ << "(" << rate << ")";
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  // TODO(kylep): Remove when support for negatives is added. Also, modify the
  // following checks so rewind uses reasonable values also.
  if (rate < 0.0)
    return;

  // Limit rates to reasonable values by clamping.
  if (rate != 0.0) {
    if (rate < kMinRate)
      rate = kMinRate;
    else if (rate > kMaxRate)
      rate = kMaxRate;
    if (playback_rate_ == 0 && !paused_ && delegate_)
      delegate_->DidPlay(this);
  } else if (playback_rate_ != 0 && !paused_ && delegate_) {
    delegate_->DidPause(this);
  }

  playback_rate_ = rate;
  if (!paused_) {
    pipeline_.SetPlaybackRate(rate);
    if (data_source_)
      data_source_->MediaPlaybackRateChanged(rate);
  }
}

void WebMediaPlayerImpl::setVolume(double volume) {
  DVLOG(1) << __FUNCTION__ << "(" << volume << ")";
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  pipeline_.SetVolume(volume);
}

#define STATIC_ASSERT_MATCHING_ENUM(webkit_name, chromium_name) \
    static_assert(static_cast<int>(WebMediaPlayer::webkit_name) == \
                  static_cast<int>(BufferedDataSource::chromium_name), \
                  "mismatching enum values: " #webkit_name)
STATIC_ASSERT_MATCHING_ENUM(PreloadNone, NONE);
STATIC_ASSERT_MATCHING_ENUM(PreloadMetaData, METADATA);
STATIC_ASSERT_MATCHING_ENUM(PreloadAuto, AUTO);
#undef STATIC_ASSERT_MATCHING_ENUM

void WebMediaPlayerImpl::setPreload(WebMediaPlayer::Preload preload) {
  DVLOG(1) << __FUNCTION__ << "(" << preload << ")";
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  preload_ = static_cast<BufferedDataSource::Preload>(preload);
  if (data_source_)
    data_source_->SetPreload(preload_);
}

bool WebMediaPlayerImpl::hasVideo() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  return pipeline_metadata_.has_video;
}

bool WebMediaPlayerImpl::hasAudio() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  return pipeline_metadata_.has_audio;
}

blink::WebSize WebMediaPlayerImpl::naturalSize() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  return blink::WebSize(pipeline_metadata_.natural_size);
}

bool WebMediaPlayerImpl::paused() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  return pipeline_.GetPlaybackRate() == 0.0f;
}

bool WebMediaPlayerImpl::seeking() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  if (ready_state_ == WebMediaPlayer::ReadyStateHaveNothing)
    return false;

  return seeking_;
}

double WebMediaPlayerImpl::duration() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  if (ready_state_ == WebMediaPlayer::ReadyStateHaveNothing)
    return std::numeric_limits<double>::quiet_NaN();

  return GetPipelineDuration();
}

double WebMediaPlayerImpl::timelineOffset() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  if (pipeline_metadata_.timeline_offset.is_null())
    return std::numeric_limits<double>::quiet_NaN();

  return pipeline_metadata_.timeline_offset.ToJsTime();
}

double WebMediaPlayerImpl::currentTime() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  DCHECK_NE(ready_state_, WebMediaPlayer::ReadyStateHaveNothing);

  // TODO(scherkus): Replace with an explicit ended signal to HTMLMediaElement,
  // see http://crbug.com/409280
  if (ended_)
    return duration();

  return (paused_ ? paused_time_ : pipeline_.GetMediaTime()).InSecondsF();
}

WebMediaPlayer::NetworkState WebMediaPlayerImpl::networkState() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return network_state_;
}

WebMediaPlayer::ReadyState WebMediaPlayerImpl::readyState() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return ready_state_;
}

blink::WebTimeRanges WebMediaPlayerImpl::buffered() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  Ranges<base::TimeDelta> buffered_time_ranges =
      pipeline_.GetBufferedTimeRanges();

  const base::TimeDelta duration = pipeline_.GetMediaDuration();
  if (duration != kInfiniteDuration()) {
    buffered_data_source_host_.AddBufferedTimeRanges(
        &buffered_time_ranges, duration);
  }
  return ConvertToWebTimeRanges(buffered_time_ranges);
}

blink::WebTimeRanges WebMediaPlayerImpl::seekable() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  if (ready_state_ < WebMediaPlayer::ReadyStateHaveMetadata)
    return blink::WebTimeRanges();

  const double seekable_end = duration();

  // Allow a special exception for seeks to zero for streaming sources with a
  // finite duration; this allows looping to work.
  const bool allow_seek_to_zero = data_source_ && data_source_->IsStreaming() &&
                                  base::IsFinite(seekable_end);

  // TODO(dalecurtis): Technically this allows seeking on media which return an
  // infinite duration so long as DataSource::IsStreaming() is false.  While not
  // expected, disabling this breaks semi-live players, http://crbug.com/427412.
  const blink::WebTimeRange seekable_range(
      0.0, allow_seek_to_zero ? 0.0 : seekable_end);
  return blink::WebTimeRanges(&seekable_range, 1);
}

bool WebMediaPlayerImpl::didLoadingProgress() {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  bool pipeline_progress = pipeline_.DidLoadingProgress();
  bool data_progress = buffered_data_source_host_.DidLoadingProgress();
  return pipeline_progress || data_progress;
}

void WebMediaPlayerImpl::paint(blink::WebCanvas* canvas,
                               const blink::WebRect& rect,
                               unsigned char alpha,
                               SkXfermode::Mode mode) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  TRACE_EVENT0("media", "WebMediaPlayerImpl:paint");

  // TODO(scherkus): Clarify paint() API contract to better understand when and
  // why it's being called. For example, today paint() is called when:
  //   - We haven't reached HAVE_CURRENT_DATA and need to paint black
  //   - We're painting to a canvas
  // See http://crbug.com/341225 http://crbug.com/342621 for details.
  scoped_refptr<VideoFrame> video_frame =
      GetCurrentFrameFromCompositor();

  gfx::Rect gfx_rect(rect);
  Context3D context_3d;
  if (video_frame.get() &&
      video_frame->format() == VideoFrame::NATIVE_TEXTURE) {
    if (!context_3d_cb_.is_null()) {
      context_3d = context_3d_cb_.Run();
    }
    // GPU Process crashed.
    if (!context_3d.gl)
      return;
  }
  skcanvas_video_renderer_.Paint(video_frame, canvas, gfx_rect, alpha, mode,
                                 pipeline_metadata_.video_rotation, context_3d);
}

bool WebMediaPlayerImpl::hasSingleSecurityOrigin() const {
  if (data_source_)
    return data_source_->HasSingleOrigin();
  return true;
}

bool WebMediaPlayerImpl::didPassCORSAccessCheck() const {
  if (data_source_)
    return data_source_->DidPassCORSAccessCheck();
  return false;
}

double WebMediaPlayerImpl::mediaTimeForTimeValue(double timeValue) const {
  return ConvertSecondsToTimestamp(timeValue).InSecondsF();
}

unsigned WebMediaPlayerImpl::decodedFrameCount() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  PipelineStatistics stats = pipeline_.GetStatistics();
  return stats.video_frames_decoded;
}

unsigned WebMediaPlayerImpl::droppedFrameCount() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  PipelineStatistics stats = pipeline_.GetStatistics();
  return stats.video_frames_dropped;
}

unsigned WebMediaPlayerImpl::audioDecodedByteCount() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  PipelineStatistics stats = pipeline_.GetStatistics();
  return stats.audio_bytes_decoded;
}

unsigned WebMediaPlayerImpl::videoDecodedByteCount() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  PipelineStatistics stats = pipeline_.GetStatistics();
  return stats.video_bytes_decoded;
}

bool WebMediaPlayerImpl::copyVideoTextureToPlatformTexture(
    blink::WebGraphicsContext3D* web_graphics_context,
    unsigned int texture,
    unsigned int level,
    unsigned int internal_format,
    unsigned int type,
    bool premultiply_alpha,
    bool flip_y) {
  TRACE_EVENT0("media", "WebMediaPlayerImpl:copyVideoTextureToPlatformTexture");

  scoped_refptr<VideoFrame> video_frame =
      GetCurrentFrameFromCompositor();

  if (!video_frame.get() ||
      video_frame->format() != VideoFrame::NATIVE_TEXTURE) {
    return false;
  }

  // TODO(dshwang): need more elegant way to convert WebGraphicsContext3D to
  // GLES2Interface.
  gpu::gles2::GLES2Interface* gl =
      static_cast<gpu_blink::WebGraphicsContext3DImpl*>(web_graphics_context)
          ->GetGLInterface();
  SkCanvasVideoRenderer::CopyVideoFrameTextureToGLTexture(
      gl, video_frame.get(), texture, level, internal_format, type,
      premultiply_alpha, flip_y);
  return true;
}

WebMediaPlayer::MediaKeyException
WebMediaPlayerImpl::generateKeyRequest(const WebString& key_system,
                                       const unsigned char* init_data,
                                       unsigned init_data_length) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  return encrypted_media_support_.GenerateKeyRequest(
      frame_, key_system, init_data, init_data_length);
}

WebMediaPlayer::MediaKeyException WebMediaPlayerImpl::addKey(
    const WebString& key_system,
    const unsigned char* key,
    unsigned key_length,
    const unsigned char* init_data,
    unsigned init_data_length,
    const WebString& session_id) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  return encrypted_media_support_.AddKey(
      key_system, key, key_length, init_data, init_data_length, session_id);
}

WebMediaPlayer::MediaKeyException WebMediaPlayerImpl::cancelKeyRequest(
    const WebString& key_system,
    const WebString& session_id) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  return encrypted_media_support_.CancelKeyRequest(key_system, session_id);
}

void WebMediaPlayerImpl::setContentDecryptionModule(
    blink::WebContentDecryptionModule* cdm,
    blink::WebContentDecryptionModuleResult result) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  // TODO(xhwang): Support setMediaKeys(0) if necessary: http://crbug.com/330324
  if (!cdm) {
    result.completeWithError(
        blink::WebContentDecryptionModuleExceptionNotSupportedError, 0,
        "Null MediaKeys object is not supported.");
    return;
  }

  SetCdm(ToWebContentDecryptionModuleImpl(cdm)->GetCdmContext(),
         BIND_TO_RENDER_LOOP1(&WebMediaPlayerImpl::OnCdmAttached, result));
}

void WebMediaPlayerImpl::OnEncryptedMediaInitData(
    const std::string& init_data_type,
    const std::vector<uint8>& init_data) {
  DCHECK(!init_data_type.empty());

  // Do not fire "encrypted" event if encrypted media is not enabled.
  // TODO(xhwang): Handle this in |client_|.
  if (!blink::WebRuntimeFeatures::isPrefixedEncryptedMediaEnabled() &&
      !blink::WebRuntimeFeatures::isEncryptedMediaEnabled()) {
    return;
  }

  // TODO(xhwang): Update this UMA name.
  UMA_HISTOGRAM_COUNTS("Media.EME.NeedKey", 1);

  encrypted_media_support_.SetInitDataType(init_data_type);

  const uint8* init_data_ptr = init_data.empty() ? nullptr : &init_data[0];
  client_->encrypted(WebString::fromUTF8(init_data_type), init_data_ptr,
                     base::saturated_cast<unsigned int>(init_data.size()));
}

void WebMediaPlayerImpl::SetCdm(CdmContext* cdm_context,
                                const CdmAttachedCB& cdm_attached_cb) {
  pipeline_.SetCdm(cdm_context, cdm_attached_cb);
}

void WebMediaPlayerImpl::OnCdmAttached(
    blink::WebContentDecryptionModuleResult result,
    bool success) {
  if (success) {
    result.complete();
    return;
  }

  result.completeWithError(
      blink::WebContentDecryptionModuleExceptionNotSupportedError, 0,
      "Unable to set MediaKeys object");
}

void WebMediaPlayerImpl::OnPipelineSeeked(bool time_changed,
                                          PipelineStatus status) {
  DVLOG(1) << __FUNCTION__ << "(" << time_changed << ", " << status << ")";
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  seeking_ = false;
  if (pending_seek_) {
    pending_seek_ = false;
    seek(pending_seek_seconds_);
    return;
  }

  if (status != PIPELINE_OK) {
    OnPipelineError(status);
    return;
  }

  // Update our paused time.
  if (paused_)
    UpdatePausedTime();

  should_notify_time_changed_ = time_changed;
}

void WebMediaPlayerImpl::OnPipelineEnded() {
  DVLOG(1) << __FUNCTION__;
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  // Ignore state changes until we've completed all outstanding seeks.
  if (seeking_ || pending_seek_)
    return;

  ended_ = true;
  client_->timeChanged();
}

void WebMediaPlayerImpl::OnPipelineError(PipelineStatus error) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  DCHECK_NE(error, PIPELINE_OK);

  if (ready_state_ == WebMediaPlayer::ReadyStateHaveNothing) {
    // Any error that occurs before reaching ReadyStateHaveMetadata should
    // be considered a format error.
    SetNetworkState(WebMediaPlayer::NetworkStateFormatError);
    return;
  }

  SetNetworkState(PipelineErrorToNetworkState(error));

  if (error == PIPELINE_ERROR_DECRYPT)
    encrypted_media_support_.OnPipelineDecryptError();
}

void WebMediaPlayerImpl::OnPipelineMetadata(
    PipelineMetadata metadata) {
  DVLOG(1) << __FUNCTION__;

  pipeline_metadata_ = metadata;

  UMA_HISTOGRAM_ENUMERATION("Media.VideoRotation",
                            metadata.video_rotation,
                            VIDEO_ROTATION_MAX + 1);
  SetReadyState(WebMediaPlayer::ReadyStateHaveMetadata);

  if (hasVideo()) {
    DCHECK(!video_weblayer_);
    scoped_refptr<cc::VideoLayer> layer =
        cc::VideoLayer::Create(compositor_, pipeline_metadata_.video_rotation);

    if (pipeline_metadata_.video_rotation == VIDEO_ROTATION_90 ||
        pipeline_metadata_.video_rotation == VIDEO_ROTATION_270) {
      gfx::Size size = pipeline_metadata_.natural_size;
      pipeline_metadata_.natural_size = gfx::Size(size.height(), size.width());
    }

    video_weblayer_.reset(new cc_blink::WebLayerImpl(layer));
    video_weblayer_->setOpaque(opaque_);
    client_->setWebLayer(video_weblayer_.get());
  }
}

void WebMediaPlayerImpl::OnPipelineBufferingStateChanged(
    BufferingState buffering_state) {
  DVLOG(1) << __FUNCTION__ << "(" << buffering_state << ")";

  // Ignore buffering state changes until we've completed all outstanding seeks.
  if (seeking_ || pending_seek_)
    return;

  // TODO(scherkus): Handle other buffering states when Pipeline starts using
  // them and translate them ready state changes http://crbug.com/144683
  DCHECK_EQ(buffering_state, BUFFERING_HAVE_ENOUGH);
  SetReadyState(WebMediaPlayer::ReadyStateHaveEnoughData);

  // Blink expects a timeChanged() in response to a seek().
  if (should_notify_time_changed_)
    client_->timeChanged();
}

void WebMediaPlayerImpl::OnDemuxerOpened() {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  client_->mediaSourceOpened(new WebMediaSourceImpl(
      chunk_demuxer_, base::Bind(&LogMediaSourceError, media_log_)));
}

void WebMediaPlayerImpl::OnAddTextTrack(
    const TextTrackConfig& config,
    const AddTextTrackDoneCB& done_cb) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  const WebInbandTextTrackImpl::Kind web_kind =
      static_cast<WebInbandTextTrackImpl::Kind>(config.kind());
  const blink::WebString web_label =
      blink::WebString::fromUTF8(config.label());
  const blink::WebString web_language =
      blink::WebString::fromUTF8(config.language());
  const blink::WebString web_id =
      blink::WebString::fromUTF8(config.id());

  scoped_ptr<WebInbandTextTrackImpl> web_inband_text_track(
      new WebInbandTextTrackImpl(web_kind, web_label, web_language, web_id));

  scoped_ptr<TextTrack> text_track(new TextTrackImpl(
      main_task_runner_, client_, web_inband_text_track.Pass()));

  done_cb.Run(text_track.Pass());
}

void WebMediaPlayerImpl::DataSourceInitialized(bool success) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  if (!success) {
    SetNetworkState(WebMediaPlayer::NetworkStateFormatError);
    return;
  }

  StartPipeline();
}

void WebMediaPlayerImpl::NotifyDownloading(bool is_downloading) {
  if (!is_downloading && network_state_ == WebMediaPlayer::NetworkStateLoading)
    SetNetworkState(WebMediaPlayer::NetworkStateIdle);
  else if (is_downloading && network_state_ == WebMediaPlayer::NetworkStateIdle)
    SetNetworkState(WebMediaPlayer::NetworkStateLoading);
  media_log_->AddEvent(
      media_log_->CreateBooleanEvent(
          MediaLogEvent::NETWORK_ACTIVITY_SET,
          "is_downloading_data", is_downloading));
}

void WebMediaPlayerImpl::StartPipeline() {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  // Keep track if this is a MSE or non-MSE playback.
  UMA_HISTOGRAM_BOOLEAN("Media.MSE.Playback",
                        (load_type_ == LoadTypeMediaSource));

  LogCB mse_log_cb;
  Demuxer::EncryptedMediaInitDataCB encrypted_media_init_data_cb =
      BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnEncryptedMediaInitData);

  // Figure out which demuxer to use.
  if (load_type_ != LoadTypeMediaSource) {
    DCHECK(!chunk_demuxer_);
    DCHECK(data_source_);

    demuxer_.reset(new FFmpegDemuxer(media_task_runner_, data_source_.get(),
                                     encrypted_media_init_data_cb, media_log_));
  } else {
    DCHECK(!chunk_demuxer_);
    DCHECK(!data_source_);

    mse_log_cb = base::Bind(&LogMediaSourceError, media_log_);

    chunk_demuxer_ = new ChunkDemuxer(
        BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnDemuxerOpened),
        encrypted_media_init_data_cb, mse_log_cb, media_log_, true);
    demuxer_.reset(chunk_demuxer_);
  }

  // ... and we're ready to go!
  seeking_ = true;

  pipeline_.Start(
      demuxer_.get(),
      renderer_factory_->CreateRenderer(media_task_runner_,
                                        audio_source_provider_.get()),
      BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnPipelineEnded),
      BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnPipelineError),
      BIND_TO_RENDER_LOOP1(&WebMediaPlayerImpl::OnPipelineSeeked, false),
      BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnPipelineMetadata),
      BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnPipelineBufferingStateChanged),
      base::Bind(&WebMediaPlayerImpl::FrameReady, base::Unretained(this)),
      BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnDurationChanged),
      BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnAddTextTrack));
}

void WebMediaPlayerImpl::SetNetworkState(WebMediaPlayer::NetworkState state) {
  DVLOG(1) << __FUNCTION__ << "(" << state << ")";
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  network_state_ = state;
  // Always notify to ensure client has the latest value.
  client_->networkStateChanged();
}

void WebMediaPlayerImpl::SetReadyState(WebMediaPlayer::ReadyState state) {
  DVLOG(1) << __FUNCTION__ << "(" << state << ")";
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  if (state == WebMediaPlayer::ReadyStateHaveEnoughData && data_source_ &&
      data_source_->assume_fully_buffered() &&
      network_state_ == WebMediaPlayer::NetworkStateLoading)
    SetNetworkState(WebMediaPlayer::NetworkStateLoaded);

  ready_state_ = state;
  // Always notify to ensure client has the latest value.
  client_->readyStateChanged();
}

blink::WebAudioSourceProvider* WebMediaPlayerImpl::audioSourceProvider() {
  return audio_source_provider_.get();
}

double WebMediaPlayerImpl::GetPipelineDuration() const {
  base::TimeDelta duration = pipeline_.GetMediaDuration();

  // Return positive infinity if the resource is unbounded.
  // http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#dom-media-duration
  if (duration == kInfiniteDuration())
    return std::numeric_limits<double>::infinity();

  return duration.InSecondsF();
}

void WebMediaPlayerImpl::OnDurationChanged() {
  if (ready_state_ == WebMediaPlayer::ReadyStateHaveNothing)
    return;

  client_->durationChanged();
}

void WebMediaPlayerImpl::OnNaturalSizeChanged(gfx::Size size) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  DCHECK_NE(ready_state_, WebMediaPlayer::ReadyStateHaveNothing);
  TRACE_EVENT0("media", "WebMediaPlayerImpl::OnNaturalSizeChanged");

  media_log_->AddEvent(
      media_log_->CreateVideoSizeSetEvent(size.width(), size.height()));
  pipeline_metadata_.natural_size = size;

  client_->sizeChanged();
}

void WebMediaPlayerImpl::OnOpacityChanged(bool opaque) {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  DCHECK_NE(ready_state_, WebMediaPlayer::ReadyStateHaveNothing);

  opaque_ = opaque;
  if (video_weblayer_)
    video_weblayer_->setOpaque(opaque_);
}

void WebMediaPlayerImpl::FrameReady(
    const scoped_refptr<VideoFrame>& frame) {
  compositor_task_runner_->PostTask(
      FROM_HERE,
      base::Bind(&VideoFrameCompositor::UpdateCurrentFrame,
                 base::Unretained(compositor_),
                 frame));
}

static void GetCurrentFrameAndSignal(
    VideoFrameCompositor* compositor,
    scoped_refptr<VideoFrame>* video_frame_out,
    base::WaitableEvent* event) {
  TRACE_EVENT0("media", "GetCurrentFrameAndSignal");
  *video_frame_out = compositor->GetCurrentFrame();
  event->Signal();
}

scoped_refptr<VideoFrame>
WebMediaPlayerImpl::GetCurrentFrameFromCompositor() {
  TRACE_EVENT0("media", "WebMediaPlayerImpl::GetCurrentFrameFromCompositor");
  if (compositor_task_runner_->BelongsToCurrentThread())
    return compositor_->GetCurrentFrame();

  // Use a posted task and waitable event instead of a lock otherwise
  // WebGL/Canvas can see different content than what the compositor is seeing.
  scoped_refptr<VideoFrame> video_frame;
  base::WaitableEvent event(false, false);
  compositor_task_runner_->PostTask(FROM_HERE,
                                    base::Bind(&GetCurrentFrameAndSignal,
                                               base::Unretained(compositor_),
                                               &video_frame,
                                               &event));
  event.Wait();
  return video_frame;
}

void WebMediaPlayerImpl::UpdatePausedTime() {
  DCHECK(main_task_runner_->BelongsToCurrentThread());

  // pause() may be called after playback has ended and the HTMLMediaElement
  // requires that currentTime() == duration() after ending.  We want to ensure
  // |paused_time_| matches currentTime() in this case or a future seek() may
  // incorrectly discard what it thinks is a seek to the existing time.
  paused_time_ =
      ended_ ? pipeline_.GetMediaDuration() : pipeline_.GetMediaTime();
}

}  // namespace media