MSE: Record counts of detected MSE audio, video and text tracks

media/formats/mp4/box_definitions.cc

 // Copyright 2014 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/formats/mp4/box_definitions.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 443 matching lines @@
     // Check that the length of the Pascal-style string is correct.
     RCHECK(name_bytes[0] == (name_bytes.size() - 1));
     // Skip the first byte, containing the length of the Pascal-string.
     name = std::string(name_bytes.begin() + 1, name_bytes.end());
   }
 
   if (hdlr_type == FOURCC_VIDE) {
     type = kVideo;
   } else if (hdlr_type == FOURCC_SOUN) {
     type = kAudio;
+  } else if (hdlr_type == FOURCC_META || hdlr_type == FOURCC_SUBT ||
+             hdlr_type == FOURCC_TEXT || hdlr_type == FOURCC_SBTL) {
+    // For purposes of detection, we include 'sbtl' handler here. Note, though
+    // that ISO-14496-12 and its 2012 Amendment 2, and the spec for sourcing
+    // inband tracks all reference only 'text' or 'subt', and 14496-30
+    // references only 'subt'. Yet ffmpeg can encode subtitles as 'sbtl'.
+    type = kText;
   } else {
     type = kInvalid;
   }
   return true;
 }
 
 AVCDecoderConfigurationRecord::AVCDecoderConfigurationRecord()
     : version(0),
       profile_indication(0),
       profile_compatibility(0),
@@ skipping 673 matching lines @@
 SampleDependsOn IndependentAndDisposableSamples::sample_depends_on(
     size_t i) const {
   if (i >= sample_depends_on_.size())
     return kSampleDependsOnUnknown;
 
   return sample_depends_on_[i];
 }
 
 }  // namespace mp4
 }  // namespace media