Simplified frame rate control in the chromoting host.

Insted of keeping semi-fixed frame rate, now capturing rate is controlled
by how fast we can send data to the client. Capturing of frame n is
started only after frame n-2 is sent (while n-1 is being encoded). This
guarantees that we don't clog the video channel buffers, and that we start
capturing only if we know that the frame will not need to wait for too long
in the buffer.

TEST=None
BUG=None

Review URL: http://codereview.chromium.org/5634002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68688 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 30 insertions, 4 deletions

diff --git a/remoting/base/decoder_row_based.cc b/remoting/base/decoder_row_based.cc
index a657331..25e738f 100644
--- a/remoting/base/decoder_row_based.cc
+++ b/remoting/base/decoder_row_based.cc
@@ -46,10 +46,22 @@ void DecoderRowBased::Reset() {
   frame_ = NULL;
   decompressor_->Reset();
   state_ = kUninitialized;
+  updated_rects_.clear();
 }
 
 bool DecoderRowBased::IsReadyForData() {
-  return state_ == kReady || state_ == kProcessing || state_ == kDone;
+  switch (state_) {
+    case kUninitialized:
+    case kError:
+      return false;
+    case kReady:
+    case kProcessing:
+    case kPartitionDone:
+    case kDone:
+      return true;
+  }
+  NOTREACHED();
+  return false;
 }
 
 void DecoderRowBased::Initialize(scoped_refptr<media::VideoFrame> frame) {
@@ -119,14 +131,18 @@ Decoder::DecodeResult DecoderRowBased::DecodePacket(const VideoPacket* packet) {
     }
   }
 
-  if (state_ == kDone) {
+  if (state_ == kPartitionDone || state_ == kDone) {
     if (row_y_ < clip_.height()) {
       state_ = kError;
       LOG(WARNING) << "Received LAST_PACKET, but didn't get enough data.";
       return DECODE_ERROR;
     }
 
+    updated_rects_.push_back(clip_);
     decompressor_->Reset();
+  }
+
+  if (state_ == kDone) {
     return DECODE_DONE;
   } else {
     return DECODE_IN_PROGRESS;
@@ -139,7 +155,7 @@ void DecoderRowBased::UpdateStateForPacket(const VideoPacket* packet) {
   }
 
   if (packet->flags() & VideoPacket::FIRST_PACKET) {
-    if (state_ != kReady && state_ != kDone) {
+    if (state_ != kReady && state_ != kDone && state_ != kPartitionDone) {
       state_ = kError;
       LOG(WARNING) << "Received unexpected FIRST_PACKET.";
       return;
@@ -165,6 +181,15 @@ void DecoderRowBased::UpdateStateForPacket(const VideoPacket* packet) {
       LOG(WARNING) << "Received unexpected LAST_PACKET.";
       return;
     }
+    state_ = kPartitionDone;
+  }
+
+  if (packet->flags() & VideoPacket::LAST_PARTITION) {
+    if (state_ != kPartitionDone) {
+      state_ = kError;
+      LOG(WARNING) << "Received unexpected LAST_PARTITION.";
+      return;
+    }
     state_ = kDone;
   }
 
@@ -172,7 +197,8 @@ void DecoderRowBased::UpdateStateForPacket(const VideoPacket* packet) {
 }
 
 void DecoderRowBased::GetUpdatedRects(UpdatedRects* rects) {
-  rects->push_back(clip_);
+  rects->swap(updated_rects_);
+  updated_rects_.clear();
 }
 
 VideoPacketFormat::Encoding DecoderRowBased::Encoding() {