diff --git a/content/base/test/file_mozfiledataurl_inner.html b/content/base/test/file_mozfiledataurl_inner.html
index 83df19efb80..56ad08dd28f 100644
--- a/content/base/test/file_mozfiledataurl_inner.html
+++ b/content/base/test/file_mozfiledataurl_inner.html
@@ -62,7 +62,7 @@ onload = function() {
   iframe = document.getElementById('iframe');
   iframe.onerror = iframe.onload = iframeNotifyParent;
   audio = document.getElementById('audio');
-  audio.onerror = audio.oncanplay = audioNotifyParent;
+  audio.onerror = audio.onloadedmetadata = audioNotifyParent;
 }
 
 </script>
diff --git a/content/base/test/test_mozfiledataurl.html b/content/base/test/test_mozfiledataurl.html
index c32cf354715..80df5b4b495 100644
--- a/content/base/test/test_mozfiledataurl.html
+++ b/content/base/test/test_mozfiledataurl.html
@@ -12,7 +12,7 @@
 <iframe id=inner></iframe>
 <iframe id=iframe></iframe>
 <img id=img onload="gen.send(event);">
-<audio id=audio oncanplay="gen.send(event);">
+<audio id=audio onloadedmetadata="gen.send(event);">
 <input type=file id=fileList>
 </p>
 <div id="content" style="display: none">
@@ -90,11 +90,11 @@ function runTest() {
   var fileurl = URL.createObjectURL(file);
   audio.src = fileurl;
   var e = (yield);
-  is(e.type, "canplay", "loaded successfully");
+  is(e.type, "loadedmetadata", "loaded successfully");
 
   // Revoke url and attempt to load a audio in this document
   audio.src = "file_mozfiledataurl_audio.ogg";
-  is((yield).type, "canplay", "successfully reset audio");
+  is((yield).type, "loadedmetadata", "successfully reset audio");
   URL.revokeObjectURL(fileurl);
   todo(false, "urls need to act like 404s, not fail to parse");
 /*  img.src = fileurl;
@@ -113,7 +113,7 @@ function runTest() {
   yield;
   inner.contentWindow.postMessage(JSON.stringify({audio:fileurl}), "*");
   var res = (yield);
-  is(res.type, "canplay", "loaded successfully");
+  is(res.type, "loadedmetadata", "loaded successfully");
   
   // Attempt to load an audio in a different cross-origin document
   inner.src = innerCrossSiteURI;
diff --git a/content/html/content/public/nsHTMLMediaElement.h b/content/html/content/public/nsHTMLMediaElement.h
index 09846c6fe53..b62a2db6da4 100644
--- a/content/html/content/public/nsHTMLMediaElement.h
+++ b/content/html/content/public/nsHTMLMediaElement.h
@@ -328,6 +328,19 @@ public:
    */
   PRBool GetPlayedOrSeeked() const { return mHasPlayedOrSeeked; }
 
+  /**
+   * The preloading action to perform. These dictate how we react to the 
+   * preload attribute. See mPreloadAction.
+   */
+  enum PreloadAction {
+    PRELOAD_UNDEFINED = 0, // not determined - used only for initialization
+    PRELOAD_NONE = 1,      // do not preload
+    PRELOAD_METADATA = 2,  // preload only the metadata (and first frame)
+    PRELOAD_ENOUGH = 3     // preload enough data to allow uninterrupted
+                           // playback
+  };
+  PreloadAction GetPreloadAction() const { return mPreloadAction; }
+
   nsresult CopyInnerTo(nsGenericElement* aDest) const;
 
   /**
@@ -478,18 +491,6 @@ protected:
     PRELOAD_ATTR_AUTO      // set to "auto"
   };
 
-  /**
-   * The preloading action to perform. These dictate how we react to the 
-   * preload attribute. See mPreloadAction.
-   */
-  enum PreloadAction {
-    PRELOAD_UNDEFINED = 0, // not determined - used only for initialization
-    PRELOAD_NONE = 1,      // do not preload
-    PRELOAD_METADATA = 2,  // preload only the metadata (and first frame)
-    PRELOAD_ENOUGH = 3     // preload enough data to allow uninterrupted
-                           // playback
-  };
-
   /**
    * Suspends the load of resource at aURI, so that it can be resumed later
    * by ResumeLoad(). This is called when we have a media with a 'preload'
diff --git a/content/media/nsBuiltinDecoder.cpp b/content/media/nsBuiltinDecoder.cpp
index 6efaa6ed5fd..ac457f85c18 100644
--- a/content/media/nsBuiltinDecoder.cpp
+++ b/content/media/nsBuiltinDecoder.cpp
@@ -855,6 +855,10 @@ void nsBuiltinDecoder::Resume(PRBool aForceBuffering)
   }
 }
 
+nsHTMLMediaElement::PreloadAction nsBuiltinDecoder::GetPreloadAction() {
+  return mElement->GetPreloadAction();
+}
+
 void nsBuiltinDecoder::StopProgressUpdates()
 {
   NS_ASSERTION(IsCurrentThread(mStateMachineThread), "Should be on state machine thread.");
diff --git a/content/media/nsBuiltinDecoder.h b/content/media/nsBuiltinDecoder.h
index 82dd1b41fe7..f3623f43d08 100644
--- a/content/media/nsBuiltinDecoder.h
+++ b/content/media/nsBuiltinDecoder.h
@@ -450,6 +450,9 @@ class nsBuiltinDecoder : public nsMediaDecoder
   }
 
  public:
+  // Return the preloadAction
+  nsHTMLMediaElement::PreloadAction GetPreloadAction();
+
   // Return the current state. Can be called on any thread. If called from
   // a non-main thread, the decoder monitor must be held.
   PlayState GetState() {
diff --git a/content/media/nsBuiltinDecoderStateMachine.cpp b/content/media/nsBuiltinDecoderStateMachine.cpp
index 7b78e8e031a..724d3a5b9a4 100644
--- a/content/media/nsBuiltinDecoderStateMachine.cpp
+++ b/content/media/nsBuiltinDecoderStateMachine.cpp
@@ -987,11 +987,14 @@ nsresult nsBuiltinDecoderStateMachine::Run()
           MonitorAutoExit exitMon(mDecoder->GetMonitor());
           RenderVideoFrame(videoData);
         }
-
-        // Start the decode threads, so that we can pre buffer the streams.
-        // and calculate the start time in order to determine the duration.
-        if (NS_FAILED(StartDecodeThreads())) {
-          continue;
+        if (mDecoder->GetPreloadAction() == nsHTMLMediaElement::PRELOAD_ENOUGH ||
+            mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING)
+        {
+          // Start the decode threads, so that we can pre buffer the streams
+          // and calculate the start time in order to determine the duration.
+          if (NS_FAILED(StartDecodeThreads())) {
+            continue;
+          }
         }
 
         NS_ASSERTION(mStartTime != -1, "Must have start time");
@@ -1023,12 +1026,39 @@ nsresult nsBuiltinDecoderStateMachine::Run()
         if (mState == DECODER_STATE_DECODING_METADATA) {
           LOG(PR_LOG_DEBUG, ("%p Changed state from DECODING_METADATA to DECODING", mDecoder));
           mState = DECODER_STATE_DECODING;
-        }
 
-        // Start playback.
-        if (mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING) {
-          if (!IsPlaying()) {
-            StartPlayback();
+          // Start playback.
+          if (mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING) {
+            if (!IsPlaying()) {
+              StartPlayback();
+            }
+          } else if (mDecoder->GetPreloadAction() != nsHTMLMediaElement::PRELOAD_ENOUGH) {
+            if (mReader) {
+              // Clear any frames queued up during FindStartTime() and reset
+              // to the start of the stream  to save memory.
+              MonitorAutoExit exitMon(mDecoder->GetMonitor());
+              mReader->ResetDecode();
+
+              nsMediaStream* stream = mDecoder->GetCurrentStream();
+              PRInt64 offset = mReader->GetInfo().mDataOffset;
+              if (NS_FAILED(stream->Seek(nsISeekableStream::NS_SEEK_SET, offset))) {
+                mState = DECODER_STATE_SHUTDOWN;
+              }
+            }
+            // Note state can change when we release the decoder monitor to
+            // call ResetDecode() above, so we must re-verify the state here.
+            if (mState != DECODER_STATE_DECODING ||
+                mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING) {
+              continue;
+            }
+
+            // Shutdown the state machine thread, in order to save
+            // memory on thread stacks, particuarly on Linux.
+            nsCOMPtr<nsIRunnable> event = new ShutdownThreadEvent(mDecoder->mStateMachineThread);
+            NS_DispatchToMainThread(event, NS_DISPATCH_NORMAL);
+            mDecoder->mStateMachineThread = nsnull;
+
+            return NS_OK;
           }
         }
       }
diff --git a/content/media/nsMediaCache.cpp b/content/media/nsMediaCache.cpp
index ee617109a6b..998c503066d 100644
--- a/content/media/nsMediaCache.cpp
+++ b/content/media/nsMediaCache.cpp
@@ -2067,23 +2067,28 @@ nsMediaCacheStream::Seek(PRInt32 aWhence, PRInt64 aOffset)
     return NS_ERROR_FAILURE;
 
   PRInt64 oldOffset = mStreamOffset;
+  PRInt64 newOffset = mStreamOffset;
   switch (aWhence) {
   case PR_SEEK_END:
     if (mStreamLength < 0)
       return NS_ERROR_FAILURE;
-    mStreamOffset = mStreamLength + aOffset;
+    newOffset = mStreamLength + aOffset;
     break;
   case PR_SEEK_CUR:
-    mStreamOffset += aOffset;
+    newOffset += aOffset;
     break;
   case PR_SEEK_SET:
-    mStreamOffset = aOffset;
+    newOffset = aOffset;
     break;
   default:
     NS_ERROR("Unknown whence");
     return NS_ERROR_FAILURE;
   }
 
+  if (newOffset < 0)
+    return NS_ERROR_FAILURE;
+  mStreamOffset = newOffset;
+
   LOG(PR_LOG_DEBUG, ("Stream %p Seek to %lld", this, (long long)mStreamOffset));
   gMediaCache->NoteSeek(this, oldOffset);