Introduce DecodeTimestamp class to make it easier to distiguish presentation and decode timestamps.

media/formats/mp2t/ts_section_pes.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/mp2t/ts_section_pes.h"
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "media/base/bit_reader.h"
 #include "media/base/buffers.h"
@@ skipping 249 matching lines @@
     RCHECK((((pts_section >> 36) & 0xf) == 0x3) &&
            IsTimestampSectionValid(pts_section));
     RCHECK((((dts_section >> 36) & 0xf) == 0x1) &&
            IsTimestampSectionValid(dts_section));
     is_pts_valid = true;
     is_dts_valid = true;
   }
 
   // Convert and unroll the timestamps.
   base::TimeDelta media_pts(kNoTimestamp());
-  base::TimeDelta media_dts(kNoTimestamp());
+  DecodeTimestamp media_dts(kNoDecodeTimestamp());
   if (is_pts_valid) {
     int64 pts = ConvertTimestampSectionToTimestamp(pts_section);
     if (previous_pts_valid_)
       pts = UnrollTimestamp(previous_pts_, pts);
     previous_pts_ = pts;
     previous_pts_valid_ = true;
     media_pts = base::TimeDelta::FromMicroseconds((1000 * pts) / 90);
   }
   if (is_dts_valid) {
     int64 dts = ConvertTimestampSectionToTimestamp(dts_section);
     if (previous_dts_valid_)
       dts = UnrollTimestamp(previous_dts_, dts);
     previous_dts_ = dts;
     previous_dts_valid_ = true;
-    media_dts = base::TimeDelta::FromMicroseconds((1000 * dts) / 90);
+    media_dts = DecodeTimestamp::FromMicroseconds((1000 * dts) / 90);
   }
 
   // Discard the rest of the PES packet header.
   // TODO(damienv): check if some info of the PES packet header are useful.
   DCHECK_EQ(bit_reader.bits_available() % 8, 0);
   int pes_header_remaining_size = pes_header_data_length -
       (pes_header_start_size - bit_reader.bits_available() / 8);
   RCHECK(pes_header_remaining_size >= 0);
 
   // Read the PES packet.
   DVLOG(LOG_LEVEL_PES)
       << "Emit a reassembled PES:"
       << " size=" << es_size
       << " pts=" << media_pts.InMilliseconds()
       << " dts=" << media_dts.InMilliseconds()
       << " data_alignment_indicator=" << data_alignment_indicator;
   return es_parser_->Parse(&raw_pes[es_offset], es_size, media_pts, media_dts);
 }
 
 void TsSectionPes::ResetPesState() {
   pes_byte_queue_.Reset();
   wait_for_pusi_ = true;
 }
 
 }  // namespace mp2t
 }  // namespace media
-