Cleanup OPUS decoder. Remove extraneous transforms and copies.

media/filters/audio_renderer_impl.cc

Index: media/filters/audio_renderer_impl.cc
diff --git a/media/filters/audio_renderer_impl.cc b/media/filters/audio_renderer_impl.cc
index fdfb45df916a5a1d3b376ceb9151b5b0c44d383a..6f8c0d354fb7e2939da4b9bdb4d15af8759225af 100644
--- a/media/filters/audio_renderer_impl.cc
+++ b/media/filters/audio_renderer_impl.cc
@@ -402,8 +402,19 @@ bool AudioRendererImpl::HandleSplicerBuffer(
     if (state_ == kPrerolling && IsBeforePrerollTime(buffer))
       return true;
 
-    if (state_ != kUninitialized && state_ != kStopped)
+    if (state_ != kUninitialized && state_ != kStopped) {
+      if (state_ == kPrerolling) {

[acolwell GONE FROM CHROMIUM, 2013/12/12 23:46:19]

nit: move this into the kPrerolling block above?

if (state_ == kPrerolling) {
  if (IsBeforePrerollTime(buffer))
    return true;

  ....
}

[DaleCurtis, 2013/12/13 03:19:11]

Done.

+        // Trim off any additional time before the preroll timestamp.
+        const base::TimeDelta trim_time =
+            preroll_timestamp_ - buffer->timestamp();
+        if (trim_time > base::TimeDelta()) {
+          buffer->TrimStart(buffer->frame_count() *
+                            (static_cast<double>(trim_time.InMicroseconds()) /
+                             buffer->duration().InMicroseconds()));
+        }
+      }
       algorithm_->EnqueueBuffer(buffer);
+    }
   }
 
   switch (state_) {