MSE: Log buffered audio splice generation to media-internals

media/base/media_log_event.h

 // 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.
 
 #ifndef MEDIA_BASE_MEDIA_LOG_EVENT_H_
 #define MEDIA_BASE_MEDIA_LOG_EVENT_H_
 
 #include "base/time/time.h"
 #include "base/values.h"
 
@@ skipping 59 matching lines @@
 
     // Text stream playback has ended.
     TEXT_ENDED,
 
     // The extents of the sliding buffer have changed.
     // params: "buffer_start": <first buffered byte>.
     //         "buffer_current": <current offset>.
     //         "buffer_end": <last buffered byte>.
     BUFFERED_EXTENTS_CHANGED,
 
+    // Buffered audio splice frame statistics have changed.
+    // params: "audio_splice_count": <count of splice frames buffered>
+    //         "audio_splice_degenerate_count": <count of degenerate splices>
+    //           A degenerate splice is any splice that was prevented from
+    //           generation due to exact buffer overlap, overlap of previous
+    //           splice, overlap of preroll, or overlap duration below minimum
+    //           threshold.
+    //         "audio_splice_duration_average": <seconds>
+    //         "audio_splice_duration_min": <seconds>
+    //         "audio_splice_duration_max": <seconds>
+    BUFFERED_AUDIO_SPLICE_STATISTICS_CHANGED,

[xhwang, 2015/07/15 00:46:50]

+dalecurtis

When I first looked at this list (Type), I found it a bit arbitrary. 
For example, what's the fundamental difference between an event with a
specialized "type", and those general ERROR/INFO/DEBUG events below? Somehow I
feel we have two systems here.

Can we simply replace the "Type type" with a "string type" so that we don't need
most of this list here? The downside is that we'll need to send a "type" string
over the wire instead of a "type" integer, but that should be small compared to
the whole data we are sending. We can still keep ERROR/INFO/DEBUG as log
"Level"s so that we can filter them if we need to.

+
     // Error log reported by media code such as reasons of playback error.
     MEDIA_ERROR_LOG_ENTRY,
     // params: "error": Error string describing the error detected.
 
     // Informative log reported by media code.
     MEDIA_INFO_LOG_ENTRY,
     // params: "info": String with details of an informative log entry.
 
     // Debug log reported by media code.
     MEDIA_DEBUG_LOG_ENTRY,
     // params: "debug": String with details of a debug log entry.
 
     // A property has changed without any special event occurring.
     PROPERTY_CHANGE,
 
     TYPE_LAST = PROPERTY_CHANGE
   };
 
   int32 id;
   Type type;
   base::DictionaryValue params;
   base::TimeTicks time;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MEDIA_LOG_EVENT_H_