Update FFmpegDemuxer unknown duration logic to work for video-only streams.

media/filters/ffmpeg_demuxer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/ffmpeg_demuxer.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/base64.h"
@@ skipping 774 matching lines @@
 void FFmpegDemuxer::OnReadFrameDone(ScopedAVPacket packet, int result) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(pending_read_);
   pending_read_ = false;
 
   if (!blocking_thread_.IsRunning() || pending_seek_) {
     return;
   }
 
   if (result < 0) {
-    // Update the duration based on the audio stream if
-    // it was previously unknown http://crbug.com/86830
+    // Update the duration based on the highest elapsed time across all streams
+    // if it was previously unknown.
     if (!duration_known_) {
-      // Search streams for AUDIO one.
+      base::TimeDelta max_duration;
+
       for (StreamVector::iterator iter = streams_.begin();
            iter != streams_.end();
            ++iter) {
-        if (*iter && (*iter)->type() == DemuxerStream::AUDIO) {
-          base::TimeDelta duration = (*iter)->GetElapsedTime();
-          if (duration != kNoTimestamp() && duration > base::TimeDelta()) {
-            host_->SetDuration(duration);
-            duration_known_ = true;
-          }
-          break;
-        }
+        base::TimeDelta duration = (*iter)->GetElapsedTime();
+        if (duration != kNoTimestamp() && duration > max_duration)

[xhwang, 2014/01/04 01:12:38]

nit: the check duration != kNoTimestamp() seems redundant?

+          max_duration = duration;
+      }
+
+      if (max_duration > base::TimeDelta()) {
+        host_->SetDuration(max_duration);
+        duration_known_ = true;
       }
     }
     // If we have reached the end of stream, tell the downstream filters about
     // the event.
     StreamHasEnded();
     return;
   }
 
   // Queue the packet with the appropriate stream.
   DCHECK_GE(packet->stream_index, 0);
@@ skipping 114 matching lines @@
   }
   for (size_t i = 0; i < buffered.size(); ++i)
     host_->AddBufferedTimeRange(buffered.start(i), buffered.end(i));
 }
 
 void FFmpegDemuxer::OnDataSourceError() {
   host_->OnDemuxerError(PIPELINE_ERROR_READ);
 }
 
 }  // namespace media