media/webm/webm_info_parser.cc

   1 // Copyright (c) 2011 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/webm/webm_info_parser.h"
   6
   7 #include "base/logging.h"
   8 #include "media/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   return true;
  78 }
  79
  80 bool WebMInfoParser::OnString(int id, const std::string& str) {
  81   return true;
  82 }
  83
  84 }  // namespace media