The guts of the video renderer logic that relate to timing and queuing of frames have been moved into a base class. This class now

simply interracts with the delegate to paint the current frame when a repaint is needed.
Review URL: http://codereview.chromium.org/20345

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@10296 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 80 insertions, 418 deletions

diff --git a/chrome/renderer/media/video_renderer_impl.cc b/chrome/renderer/media/video_renderer_impl.cc
index d400e58..2cdf9a9 100644
--- a/chrome/renderer/media/video_renderer_impl.cc
+++ b/chrome/renderer/media/video_renderer_impl.cc
@@ -3,308 +3,63 @@
 // LICENSE file.
 
 #include "chrome/renderer/media/video_renderer_impl.h"
-#include "media/base/buffers.h"
-#include "media/base/filter_host.h"
-#include "media/base/pipeline.h"
-
-using media::MediaFormat;
-using media::VideoFrame;
-
-
-// The amount of time allowed to pre-submit a frame.  If UpdateQueue is called
-// with a time within this limit, it will skip to the next frame in the queue
-// even though the value for time it is called with is not yet at the frame's
-// timestamp.  Time is specified in microseconds.
-static const int64 kFrameSkipAheadLimit = 5000;
-
-// If there are no frames in the queue, then this value is used for the
-// amount of time to sleep until the next time update callback.  Time is
-// specified in microseconds.
-static const int64 kSleepIfNoFrame = 15000;
-
-// Number of reads to have pending.
-// TODO(ralph): Re-examine the pull model -- perhaps I was wrong.  I think
-// that perhaps the demuxer is the point where pull becomes push.
-static const size_t kDefaultNumberOfFrames = 4;
-
-// Value used for the current_frame_timestamp_ to indicate that the
-// |current_frame_| member should be treated as invalid.
-static const int64 kNoCurrentFrame = -1;
-
-//------------------------------------------------------------------------------
 
 VideoRendererImpl::VideoRendererImpl(WebMediaPlayerDelegateImpl* delegate)
     : delegate_(delegate),
-      submit_reads_task_(NULL),
-      number_of_reads_needed_(kDefaultNumberOfFrames),
-      current_frame_timestamp_(
-          base::TimeDelta::FromMicroseconds(kNoCurrentFrame)),
-      preroll_complete_(false) {
-}
-
-VideoRendererImpl::~VideoRendererImpl() {
-  Stop();
-}
-
-// static
-bool VideoRendererImpl::IsMediaFormatSupported(
-    const media::MediaFormat* media_format) {
-  int width;
-  int height;
-  return ParseMediaFormat(media_format, &width, &height);
-}
-
-// static
-bool VideoRendererImpl::ParseMediaFormat(const media::MediaFormat* media_format,
-                                         int* width_out,
-                                         int* height_out) {
-  DCHECK(media_format && width_out && height_out);
-  std::string mime_type;
-  return (media_format->GetAsString(MediaFormat::kMimeType, &mime_type) &&
-          mime_type.compare(media::mime_type::kUncompressedVideo) == 0 &&
-          media_format->GetAsInteger(MediaFormat::kWidth, width_out) &&
-          media_format->GetAsInteger(MediaFormat::kHeight, height_out));
-}
-
-void VideoRendererImpl::Stop() {
-  AutoLock auto_lock(lock_);
-  DiscardAllFrames();
-  if (submit_reads_task_) {
-    // The task is owned by the message loop, so we don't delete it here.  We
-    // know the task won't call us because we canceled it, and we know we are
-    // on the pipeline thread, since we're in the filer's Stop method, so there
-    // is no threading problem.  Just let the task be run by the message loop
-    // and then be killed
-    submit_reads_task_->Cancel();
-    submit_reads_task_ = NULL;
-  }
-  delegate_ = NULL;  // This indicates we're no longer running
-  decoder_ = NULL;   // Release reference to the decoder
+      last_converted_frame_(NULL) {
 }
 
-bool VideoRendererImpl::Initialize(media::VideoDecoder* decoder) {
-  int width;
-  int height;
-  if (!ParseMediaFormat(decoder_->GetMediaFormat(), &width, &height)) {
-    return false;
-  }
-  current_frame_.setConfig(SkBitmap::kARGB_8888_Config, width, height);
-  if (!current_frame_.allocPixels(NULL, NULL)) {
-    NOTREACHED();
-    return false;
-  }
-  rect_.SetRect(0, 0, width, height);
-  delegate_->SetVideoRenderer(this);
-  host_->SetVideoSize(width, height);
-  host_->SetTimeUpdateCallback(
-      NewCallback(this, &VideoRendererImpl::TimeUpdateCallback));
-  SubmitReads();
-  return true;
-}
-
-void VideoRendererImpl::SubmitReads() {
-  int number_to_read;
-  {
-    AutoLock auto_lock(lock_);
-    submit_reads_task_ = NULL;
-    number_to_read = number_of_reads_needed_;
-    number_of_reads_needed_ = 0;
-  }
-  while (number_to_read > 0) {
-    decoder_->Read(new media::AssignableBuffer<VideoRendererImpl,
-                                               media::VideoFrame>(this));
-    --number_to_read;
+bool VideoRendererImpl::OnInitialize(size_t width, size_t height) {
+  video_size_.SetSize(width, height);
+  bitmap_.setConfig(SkBitmap::kARGB_8888_Config, width, height);
+  if (bitmap_.allocPixels(NULL, NULL)) {
+    bitmap_.eraseRGB(0x00, 0x00, 0x00);
+    return true;
   }
+  NOTREACHED();
+  return false;
 }
 
-void VideoRendererImpl::SetRect(const gfx::Rect& rect) {
-  rect_ = rect;
-  // TODO(ralphl) What are all these rects???
+void VideoRendererImpl::OnPaintNeeded() {
+  delegate_->PostRepaintTask();
 }
 
-// This method is always called on the renderer's thread, so it will not be
-// reentered.  However, it does maniuplate the queue and the current frame
-// timestamp, so those manipulations need to happen with the lock held.
-void VideoRendererImpl::Paint(skia::PlatformCanvas *canvas,
-                              const gfx::Rect& rect) {
-  VideoFrame* video_frame;
-  base::TimeDelta time_of_next_frame;
-  bool need_to_convert_frame = false;
-  {
-    AutoLock auto_lock(lock_);
-    UpdateQueue(host_->GetPipelineStatus()->GetTime(), NULL, &video_frame,
-                &time_of_next_frame);
-    if (video_frame) {
-      // if the |current_frame_| bitmap already has the RGB image of the
-      // front video_frame then there's on no need to call CopyToCurentFrame
-      // to convert the video_frame to RBG.  If we do need to convert a new
-      // frame, then remember the time of the frame so we might be able to skip
-      // this step if asked to repaint multiple times.  Note that the
-      // |current_frame_timestamp_| member needs to only be accessed with the
-      // |lock_| acquired, so we set the timestamp here even though the
-      // conversion won't take place until we call CopyToCurrentFrame.  It's
-      // not a problem because this method is the only place where the current
-      // frame is updated, and it is always called on the renderer's thread.
-      const base::TimeDelta frame_timestamp = video_frame->GetTimestamp();
-      need_to_convert_frame = (current_frame_timestamp_ != frame_timestamp);
-      if (need_to_convert_frame) {
-        current_frame_timestamp_ = frame_timestamp;
-      }
-    }
-  }
-
-  // We no longer hold the |lock_|. Don't access members other than |host_| and
-  // |current_frame_|.
-  if (video_frame) {
-    if (need_to_convert_frame) {
-      CopyToCurrentFrame(video_frame);
-    }
-    video_frame->Release();
-    SkMatrix matrix;
-    matrix.setTranslate(static_cast<SkScalar>(rect.x()),
-                        static_cast<SkScalar>(rect.y()));
-    // TODO(ralphl): I have no idea what's going on here.  How are these
-    // rects related to eachother?  What does SetRect() mean?
-    matrix.preScale(static_cast<SkScalar>(rect.width() / rect_.width()),
-                    static_cast<SkScalar>(rect.height() / rect_.height()));
-    canvas->drawBitmapMatrix(current_frame_, matrix, NULL);
-  }
-  host_->ScheduleTimeUpdateCallback(time_of_next_frame);
+// This method is always called on the renderer's thread.
+void VideoRendererImpl::Paint(skia::PlatformCanvas* canvas,
+                              const gfx::Rect& dest_rect) {
+  scoped_refptr<media::VideoFrame> video_frame;
+  GetCurrentFrame(&video_frame);
+  if (video_frame.get()) {
+    CopyToCurrentFrame(video_frame);
+    video_frame = NULL;
+  }
+  SkMatrix matrix;
+  matrix.setTranslate(static_cast<SkScalar>(dest_rect.x()),
+                      static_cast<SkScalar>(dest_rect.y()));
+  if (dest_rect.width()  != video_size_.width() ||
+      dest_rect.height() != video_size_.height()) {
+    matrix.preScale(
+        static_cast<SkScalar>(dest_rect.width()  / video_size_.width()),
+        static_cast<SkScalar>(dest_rect.height() / video_size_.height()));
+  }
+  canvas->drawBitmapMatrix(bitmap_, matrix, NULL);
 }
 
-void VideoRendererImpl::CopyToCurrentFrame(VideoFrame* video_frame) {
-  media::VideoSurface frame_in;
-  if (video_frame->Lock(&frame_in)) {
-    // TODO(ralphl):  Actually do the color space conversion here!
-    // This is temporary code to set the bits of the current_frame_ to
-    // blue.
-    current_frame_.eraseRGB(0x00, 0x00, 0xFF);
-    video_frame->Unlock();
-  } else {
-    NOTREACHED();
-  }
-}
-
-// Assumes |lock_| has been acquired!
-bool VideoRendererImpl::UpdateQueue(base::TimeDelta time,
-                                    VideoFrame* new_frame,
-                                    VideoFrame** front_frame_out,
-                                    base::TimeDelta* time_of_next_frame) {
-  bool updated_front = false;
-
-  // If a new frame is passed in then put it at the back of the queue.  If the
-  // queue was empty, then we've updated the front too.
-  if (new_frame) {
-    updated_front = queue_.empty();
-    new_frame->AddRef();
-    queue_.push_back(new_frame);
-  }
-
-  // Now make sure that the front of the queue is the correct frame to display
-  // right now.  Discard any frames that are past the current time.  If any
-  // frames are discarded then increment the |number_of_reads_needed_| member.
-  while (queue_.size() > 1 &&
-         queue_.front()->GetTimestamp() +
-         base::TimeDelta::FromMicroseconds(kFrameSkipAheadLimit) >= time) {
-    queue_.front()->Release();
-    queue_.pop_front();
-    updated_front = true;
-    ++number_of_reads_needed_;
-  }
-
-  // If the caller wants the front frame then return it, with the reference
-  // count incremented.  The caller must call Release() on the returned frame.
-  if (front_frame_out) {
-    if (queue_.empty()) {
-      *front_frame_out = NULL;
-    } else {
-      *front_frame_out = queue_.front();
-      (*front_frame_out)->AddRef();
-    }
-  }
-
-  // If the caller wants the time of the next frame, return our best guess:
-  //   If no frame, then wait for a while
-  //   If only one frame, then use the duration of the front frame
-  //   If there is more than one frame, return the time of the next frame.
-  if (time_of_next_frame) {
-    if (queue_.empty()) {
-      *time_of_next_frame = host_->GetPipelineStatus()->GetInterpolatedTime() +
-                            base::TimeDelta::FromMicroseconds(kSleepIfNoFrame);
+void VideoRendererImpl::CopyToCurrentFrame(media::VideoFrame* video_frame) {
+  base::TimeDelta timestamp = video_frame->GetTimestamp();
+  if (video_frame != last_converted_frame_ ||
+      timestamp != last_converted_timestamp_) {
+    last_converted_frame_ = video_frame;
+    last_converted_timestamp_ = timestamp;
+    media::VideoSurface frame_in;
+    if (video_frame->Lock(&frame_in)) {
+      // TODO(ralphl):  Actually do the color space conversion here!
+      // This is temporary code to set the bits of the current_frame_ to
+      // blue.
+      bitmap_.eraseRGB(0x00, 0x00, 0xFF);
+      video_frame->Unlock();
     } else {
-      if (queue_.size() == 1) {
-        *time_of_next_frame = queue_.front()->GetTimestamp() +
-                              queue_.front()->GetDuration();
-      } else {
-        *time_of_next_frame = queue_[1]->GetTimestamp();
-      }
+      NOTREACHED();
     }
   }
-
-  // If any frames have been removed we need to call the decoder again.  Note
-  // that the PostSubmitReadsTask method will only post the task if there are
-  // pending reads.
-  PostSubmitReadsTask();
-
-  // True if the front of the queue is a new frame.
-  return updated_front;
 }
-
-// Assumes |lock_| has been acquired!
-void VideoRendererImpl::DiscardAllFrames() {
-  while (!queue_.empty()) {
-    queue_.front()->Release();
-    queue_.pop_front();
-    ++number_of_reads_needed_;
-  }
-  current_frame_timestamp_ = base::TimeDelta::FromMicroseconds(kNoCurrentFrame);
-}
-
-// Assumes |lock_| has been acquired!
-void VideoRendererImpl::PostSubmitReadsTask() {
-  if (number_of_reads_needed_ > 0 && !submit_reads_task_) {
-    submit_reads_task_ = NewRunnableMethod(this,
-                                           &VideoRendererImpl::SubmitReads);
-    host_->PostTask(submit_reads_task_);
-  }
-}
-
-void VideoRendererImpl::TimeUpdateCallback(base::TimeDelta time) {
-  AutoLock auto_lock(lock_);
-  if (IsRunning() && UpdateQueue(time, NULL, NULL, NULL)) {
-    delegate_->PostRepaintTask();
-  }
-}
-
-void VideoRendererImpl::OnAssignment(VideoFrame* video_frame) {
-  bool call_initialized = false;
-  {
-    AutoLock auto_lock(lock_);
-    if (IsRunning()) {
-      // TODO(ralphl): if (!preroll_complete_ && EndOfStream) call_init = true
-      // and preroll_complete_ = true.
-      // TODO(ralphl): If(Seek()) then discard but we don't have SeekFrame().
-      if (false) {
-        // TODO(ralphl): this is the seek() logic.
-        DiscardAllFrames();
-        ++number_of_reads_needed_;
-        PostSubmitReadsTask();
-      } else {
-        if (UpdateQueue(host_->GetPipelineStatus()->GetInterpolatedTime(),
-                        video_frame, NULL, NULL)) {
-          delegate_->PostRepaintTask();
-        }
-        if (!preroll_complete_ && queue_.size() == kDefaultNumberOfFrames) {
-          preroll_complete_ = true;
-          call_initialized = true;
-        }
-      }
-    }
-  }
-  // |lock_| no longer held.  Call the pipeline if we've just entered a
-  // completed preroll state.
-  if (call_initialized) {
-    host_->InitializationComplete();
-  }
-}
-
diff --git a/chrome/renderer/media/video_renderer_impl.h b/chrome/renderer/media/video_renderer_impl.h
index 134cc9a..963b862 100644
--- a/chrome/renderer/media/video_renderer_impl.h
+++ b/chrome/renderer/media/video_renderer_impl.h
@@ -14,34 +14,29 @@
 #ifndef CHROME_RENDERER_MEDIA_VIDEO_RENDERER_IMPL_H_
 #define CHROME_RENDERER_MEDIA_VIDEO_RENDERER_IMPL_H_
 
-#include <deque>
-
-#include "base/lock.h"
-#include "base/task.h"
 #include "base/gfx/platform_canvas.h"
-#include "chrome/renderer/webmediaplayer_delegate_impl.h"
 #include "base/gfx/rect.h"
+#include "base/gfx/size.h"
+#include "chrome/renderer/webmediaplayer_delegate_impl.h"
+#include "media/base/buffers.h"
 #include "media/base/factory.h"
 #include "media/base/filters.h"
+#include "media/filters/video_renderer_base.h"
 #include "webkit/glue/webmediaplayer_delegate.h"
 
-class SubmitReadsTask;
-
-class VideoRendererImpl : public media::VideoRenderer {
+class VideoRendererImpl : public media::VideoRendererBase {
  public:
-  // media::MediaFilter implementation.
-  virtual void Stop();
-
-  // media::VideoRenderer implementation.
-  virtual bool Initialize(media::VideoDecoder* decoder);
-
   // Methods for painting called by the WebMediaPlayerDelegateImpl
-  // TODO(ralphl): What the *$*%##@ is this?  What does it mean?  How do we
-  // treat the "rect"?  Is is clipping?
-  virtual void SetRect(const gfx::Rect& rect);
 
-  // TODO(ralphl): What is this rect?  Is it relative to the canvas?
-  virtual void Paint(skia::PlatformCanvas* canvas, const gfx::Rect& rect);
+  // This method is called with the same rect as the Paint method and could
+  // be used by future implementations to implement an improved color space +
+  // scale code on a seperate thread.  Since we always do the streach on the
+  // same thread as the Paint method, we just ignore the call for now.
+  virtual void SetRect(const gfx::Rect& rect) {}
+
+  // Paint the current front frame on the |canvas| streaching it to fit the
+  // |dest_rect|
+  virtual void Paint(skia::PlatformCanvas* canvas, const gfx::Rect& dest_rect);
 
   // Static method for creating factory for this object.
   static media::FilterFactory* CreateFactory(
@@ -50,131 +45,43 @@ class VideoRendererImpl : public media::VideoRenderer {
         VideoRendererImpl, WebMediaPlayerDelegateImpl*>(delegate);
   }
 
-  // Implementation of AssignableBuffer<this>::OnAssignment method.
-  void OnAssignment(media::VideoFrame* video_frame);
-
  private:
-  friend class SubmitReadsTask;
+  // Method called by base class during initialization.
+  virtual bool OnInitialize(size_t width, size_t height);
+
+  // Method called by the VideoRendererBase when a repaint is needed.
+  virtual void OnPaintNeeded();
+
   friend class media::FilterFactoryImpl1<VideoRendererImpl,
                                          WebMediaPlayerDelegateImpl*>;
 
   // Constructor and destructor are private.  Only the filter factory is
   // allowed to create instances.
   explicit VideoRendererImpl(WebMediaPlayerDelegateImpl* delegate);
-  virtual ~VideoRendererImpl();
-
-  // Answers question from the factory to see if we accept |format|.
-  static bool IsMediaFormatSupported(const media::MediaFormat* format);
-
-  // Used by the IsMediaFormatSupported and Initialize methods.  Examines the
-  // |media_format| and returns true if the format is supported.  Both output
-  // parameters, |width_out| and |height_out| are required and must not be NULL.
-  static bool ParseMediaFormat(const media::MediaFormat* media_format,
-                               int* width_out,
-                               int* height_out);
-
-  // Used internally to post a task that will call the SubmitReads() method.
-  // The |lock_| must be acquired before calling this method.  If the value of
-  // |number_of_reads_needed_| is 0 or if there is already a pending task then
-  // this method simply returns and does not post a new task.
-  void PostSubmitReadsTask();
-
-  // Examines the |number_of_reads_needed_| member and calls the decoder to
-  // read the necessary number of frames.
-  void SubmitReads();
-
-  // For simplicity, we use the |delegate_| member to indicate if we have been
-  // stopped or not.
-  bool IsRunning() const { return (delegate_ != NULL); }
-
-  // Throw away all frames in the queue.  The |lock_| must have been acquired
-  // before calling this method.
-  void DiscardAllFrames();
-
-  // This method is always called with the object's |lock_| acquired..
-  // The bool return value indicates weather or not the front of the queue has
-  // been updated.  If this method returns true, then the front of the queue
-  // is a new video frame, otherwise, the front is the same as the last call.
-  // Given the current |time|, this method updates the state of the video frame
-  // queue.  The caller may pass in a |new_frame| which will be added to the
-  // queue in the appropriate position based on the frame's timestamp.  The
-  // |front_frame_out| and |time_next_frame_out| parameters are both optional
-  // and can be NULL.  If |front_frame_out| is non-NULL, then it is returned as
-  // either NULL, which indicates that there are no frames in the queue, or
-  // it will be a pointer to the frame at the front of the queue.  NOTE:  THIS
-  // FRAME'S REFERENCE COUNT HAS BEEN INCREMENTED BY THIS CALL.  THE
-  // CALLING FUNCTION MUST CALL |front_frame_out|->Release();
-  // If the |time_next_frame_out| parameter is non-NULL then it will be assigned
-  // the stream time of the next frame in the queue.  This is used by the Paint
-  // method to schedule a time update callback at the appropriate presentation
-  // time for the next frame.
-  bool UpdateQueue(base::TimeDelta time,
-                   media::VideoFrame* new_frame,
-                   media::VideoFrame** front_frame_out,
-                   base::TimeDelta* time_next_frame_out);
+  virtual ~VideoRendererImpl() {}
 
   // Internal method used by the Paint method to convert the specified video
   // frame to RGB, placing the converted pixels in the |current_frame_| bitmap.
   void CopyToCurrentFrame(media::VideoFrame* video_frame);
 
-  // Called when the clock is updated by the audio renderer of when a scheduled
-  // callback is called based on the interpolated current position of the media
-  // stream.
-  void TimeUpdateCallback(base::TimeDelta time);
-
-  // Critical section.  There is only one for this object.  Used to serialize
-  // access to the following members:
-  //  |queue_| for obvious reasons
-  //  |delegate_| because it is used by methods that can be called from random
-  //      threads to determine if the render has been stopped (it will
-  //      be NULL if stopped)
-  //  |submit_reads_task_| to prevent multiple scheduling of the task and to
-  //      allow for safe cancelation of the task.
-  //  |current_frame_timestamp_| because member is used by the render
-  //      thread in the Paint method and by DiscardAllFrames which can be
-  //      called on the decoder's thread when a seek occurs.
-  //  |number_of_reads_needed_| is modified by UpdateQueue from the decoder
-  //      thread, the renderer thread, and the pipeline thread.
-  //  |preroll_complete_| has a very small potential race condition if the
-  //      OnAssignment method were reentered for the last frame in the queue
-  //      and an end-of-stream frame.
-  Lock lock_;
-
   // Pointer to our parent object that is called to request repaints.
   WebMediaPlayerDelegateImpl* delegate_;
 
-  // Pointer to the decoder that will feed us with video frames.
-  scoped_refptr<media::VideoDecoder> decoder_;
-
-  // If non-NULL then a task has been scheduled to submit read requests to the
-  // video decoder.
-  CancelableTask* submit_reads_task_;
-
-  // The number of buffers we need to request.  This member is updated by any
-  // method that removes frames from the queue, such as UpdateQueue and
-  // DiscardAllFrames.
-  int number_of_reads_needed_;
-
-  // An RGB bitmap of the current frame.  Note that we use the timestamp to
-  // determine if the frame contents need to be color space converted, or if the
-  // |current_frame_| member contains the correct image for the queue front.
-  SkBitmap current_frame_;
-  base::TimeDelta current_frame_timestamp_;
-
-  // TODO(ralphl):  Try to understand all of the various "rect" and dimension
-  // aspects of the renderer and document it so that other people can understand
-  // it too.  I can not accurately describe what the role of this member is now.
-  gfx::Rect rect_;
-
-  // The queue of video frames.  The front of the queue is the frame that should
-  // be displayed.
-  typedef std::deque<media::VideoFrame*> VideoFrameQueue;
-  VideoFrameQueue queue_;
-
-  // True if we have received a full queue of video frames from the decoder.
-  // We don't call FilterHost::InitializationComplete() until the the queue
-  // is full.
-  bool preroll_complete_;
+  // An RGB bitmap used to convert the video frames.
+  SkBitmap bitmap_;
+
+  // These two members are used to determine if the |bitmap_| contains
+  // an already converted image of the current frame.  IMPORTANT NOTE:  The
+  // value of |last_converted_frame_| must only be used for comparison purposes,
+  // and it should be assumed that the value of the pointer is INVALID unless
+  // it matches the pointer returned from GetCurrentFrame().  Even then, just
+  // to make sure, we compare the timestamp to be sure the bits in the
+  // |current_frame_bitmap_| are valid.
+  media::VideoFrame* last_converted_frame_;
+  base::TimeDelta last_converted_timestamp_;
+
+  // The size of the video.
+  gfx::Size video_size_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoRendererImpl);
 };