From 5b7120c81b2506f1bd91d5562cf39a6d970b6a1e Mon Sep 17 00:00:00 2001
From: "stefan@webrtc.org"
 <stefan@webrtc.org@4adac7df-926f-26a2-2b94-8c16560cd09d>
Date: Mon, 29 Apr 2013 16:41:30 +0000
Subject: [PATCH] Fix two issues where we might end up busy looping in
 decoder_render mode.

This happens if
- Next frame is far into the future (> 200 ms).
- Next frame is ready for decode/render but incomplete.

BUG=1696
TESTS=trybots

Review URL: https://webrtc-codereview.appspot.com/1354005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3914 4adac7df-926f-26a2-2b94-8c16560cd09d
---
 webrtc/modules/video_coding/main/source/receiver.cc | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/webrtc/modules/video_coding/main/source/receiver.cc b/webrtc/modules/video_coding/main/source/receiver.cc
index 65d7a6839f..ae0f1cec92 100644
--- a/webrtc/modules/video_coding/main/source/receiver.cc
+++ b/webrtc/modules/video_coding/main/source/receiver.cc
@@ -296,15 +296,21 @@ VCMEncodedFrame* VCMReceiver::FrameForRendering(uint16_t max_wait_time_ms,
   uint32_t wait_time_ms = timing_->MaxWaitingTime(
       next_render_time_ms, clock_->TimeInMilliseconds());
   if (max_wait_time_ms < wait_time_ms) {
-    // If we're not allowed to wait until the frame is supposed to be rendered
-    // we will have to return NULL for now.
+    // If we're not allowed to wait until the frame is supposed to be rendered,
+    // waiting as long as we're allowed to avoid busy looping, and then return
+    // NULL. Next call to this function might return the frame.
+    render_wait_event_->Wait(max_wait_time_ms);
     return NULL;
   }
   // Wait until it's time to render.
   render_wait_event_->Wait(wait_time_ms);
 
   // Get a complete frame if possible.
-  VCMEncodedFrame* frame = jitter_buffer_.GetCompleteFrameForDecoding(0);
+  // Note: This might cause us to wait more than a total of |max_wait_time_ms|.
+  // This is necessary to avoid a possible busy loop if no complete frame
+  // has been received.
+  VCMEncodedFrame* frame = jitter_buffer_.GetCompleteFrameForDecoding(
+      max_wait_time_ms);
 
   if (frame == NULL) {
     // Get an incomplete frame.