media/formats/webm/webm_info_parser.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/formats/webm/webm_info_parser.h"
   6
   7 #include "base/logging.h"
   8 #include "media/formats/webm/webm_constants.h"
   9
  10 namespace media {
  11
  12 // Default timecode scale if the TimecodeScale element is
  13 // not specified in the INFO element.
  14 static const int kWebMDefaultTimecodeScale = 1000000;
  15
  16 WebMInfoParser::WebMInfoParser()
  17     : timecode_scale_(-1),
  18       duration_(-1) {
  19 }
  20
  21 WebMInfoParser::~WebMInfoParser() {}
  22
  23 int WebMInfoParser::Parse(const uint8* buf, int size) {
  24   timecode_scale_ = -1;
  25   duration_ = -1;
  26
  27   WebMListParser parser(kWebMIdInfo, this);
  28   int result = parser.Parse(buf, size);
  29
  30   if (result <= 0)
  31     return result;
  32
  33   // For now we do all or nothing parsing.
  34   return parser.IsParsingComplete() ? result : 0;
  35 }
  36
  37 WebMParserClient* WebMInfoParser::OnListStart(int id) { return this; }
  38
  39 bool WebMInfoParser::OnListEnd(int id) {
  40   if (id == kWebMIdInfo && timecode_scale_ == -1) {
  41     // Set timecode scale to default value if it isn't present in
  42     // the Info element.
  43     timecode_scale_ = kWebMDefaultTimecodeScale;
  44   }
  45   return true;
  46 }
  47
  48 bool WebMInfoParser::OnUInt(int id, int64 val) {
  49   if (id != kWebMIdTimecodeScale)
  50     return true;
  51
  52   if (timecode_scale_ != -1) {
  53     DVLOG(1) << "Multiple values for id " << std::hex << id << " specified";
  54     return false;
  55   }
  56
  57   timecode_scale_ = val;
  58   return true;
  59 }
  60
  61 bool WebMInfoParser::OnFloat(int id, double val) {
  62   if (id != kWebMIdDuration) {
  63     DVLOG(1) << "Unexpected float for id" << std::hex << id;
  64     return false;
  65   }
  66
  67   if (duration_ != -1) {
  68     DVLOG(1) << "Multiple values for duration.";
  69     return false;
  70   }
  71
  72   duration_ = val;
  73   return true;
  74 }
  75
  76 bool WebMInfoParser::OnBinary(int id, const uint8* data, int size) {
  77   if (id == kWebMIdDateUTC) {
  78     if (size != 8)
  79       return false;
  80
  81     int64 date_in_nanoseconds = 0;
  82     for (int i = 0; i < size; ++i)
  83       date_in_nanoseconds = (date_in_nanoseconds << 8) | data[i];
  84
  85     base::Time::Exploded exploded_epoch;
  86     exploded_epoch.year = 2001;
  87     exploded_epoch.month = 1;
  88     exploded_epoch.day_of_month = 1;
  89     exploded_epoch.hour = 0;
  90     exploded_epoch.minute = 0;
  91     exploded_epoch.second = 0;
  92     exploded_epoch.millisecond = 0;
  93     date_utc_ = base::Time::FromUTCExploded(exploded_epoch) +
  94         base::TimeDelta::FromMicroseconds(date_in_nanoseconds / 1000);
  95   }
  96   return true;
  97 }
  98
  99 bool WebMInfoParser::OnString(int id, const std::string& str) {
 100   return true;
 101 }
 102
 103 }  // namespace media