media/base/audio_video_metadata_extractor.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/base/audio_video_metadata_extractor.h"
   6
   7 #include "base/bind.h"
   8 #include "base/strings/string_number_conversions.h"
   9 #include "base/strings/string_util.h"
  10 #include "base/time/time.h"
  11 #include "media/ffmpeg/ffmpeg_common.h"
  12 #include "media/filters/blocking_url_protocol.h"
  13 #include "media/filters/ffmpeg_glue.h"
  14
  15 namespace media {
  16
  17 namespace {
  18
  19 void OnError(bool* succeeded) {
  20   *succeeded = false;
  21 }
  22
  23 // Returns true if the |tag| matches |expected_key|.
  24 bool ExtractString(AVDictionaryEntry* tag, const char* expected_key,
  25                    std::string* destination) {
  26   if (!LowerCaseEqualsASCII(std::string(tag->key), expected_key))
  27     return false;
  28
  29   if (destination->empty())
  30     *destination = tag->value;
  31
  32   return true;
  33 }
  34
  35 // Returns true if the |tag| matches |expected_key|.
  36 bool ExtractInt(AVDictionaryEntry* tag, const char* expected_key,
  37                 int* destination) {
  38   if (!LowerCaseEqualsASCII(std::string(tag->key), expected_key))
  39     return false;
  40
  41   int temporary = -1;
  42   if (*destination < 0 && base::StringToInt(tag->value, &temporary) &&
  43       temporary >= 0) {
  44     *destination = temporary;
  45   }
  46
  47   return true;
  48 }
  49
  50 }  // namespace
  51
  52 AudioVideoMetadataExtractor::AudioVideoMetadataExtractor()
  53     : extracted_(false),
  54       duration_(-1),
  55       width_(-1),
  56       height_(-1),
  57       disc_(-1),
  58       track_(-1) {
  59 }
  60
  61 AudioVideoMetadataExtractor::~AudioVideoMetadataExtractor() {
  62 }
  63
  64 bool AudioVideoMetadataExtractor::Extract(DataSource* source) {
  65   DCHECK(!extracted_);
  66
  67   bool read_ok = true;
  68   media::BlockingUrlProtocol protocol(source, base::Bind(&OnError, &read_ok));
  69   media::FFmpegGlue glue(&protocol);
  70   AVFormatContext* format_context = glue.format_context();
  71
  72   if (!glue.OpenContext())
  73     return false;
  74
  75   if (!read_ok)
  76     return false;
  77
  78   if (!format_context->iformat)
  79     return false;
  80
  81   if (avformat_find_stream_info(format_context, NULL) < 0)
  82     return false;
  83
  84   if (format_context->duration != AV_NOPTS_VALUE)
  85     duration_ = static_cast<double>(format_context->duration) / AV_TIME_BASE;
  86
  87   ExtractDictionary(format_context->metadata);
  88
  89   for (unsigned int i = 0; i < format_context->nb_streams; ++i) {
  90     AVStream* stream = format_context->streams[i];
  91     if (!stream)
  92       continue;
  93
  94     // Ignore attached pictures for metadata extraction.
  95     if ((stream->disposition & AV_DISPOSITION_ATTACHED_PIC) != 0)
  96       continue;
  97
  98     // Extract dictionary from streams also. Needed for containers that attach
  99     // metadata to contained streams instead the container itself, like OGG.
 100     ExtractDictionary(stream->metadata);
 101
 102     if (!stream->codec)
 103       continue;
 104
 105     // Extract dimensions of largest stream that's not an attached picture.
 106     if (stream->codec->width > 0 && stream->codec->width > width_ &&
 107         stream->codec->height > 0 && stream->codec->height > height_) {
 108       width_ = stream->codec->width;
 109       height_ = stream->codec->height;
 110     }
 111   }
 112
 113   extracted_ = true;
 114   return true;
 115 }
 116
 117 double AudioVideoMetadataExtractor::duration() const {
 118   DCHECK(extracted_);
 119   return duration_;
 120 }
 121
 122 int AudioVideoMetadataExtractor::width() const {
 123   DCHECK(extracted_);
 124   return width_;
 125 }
 126
 127 int AudioVideoMetadataExtractor::height() const {
 128   DCHECK(extracted_);
 129   return height_;
 130 }
 131
 132 const std::string& AudioVideoMetadataExtractor::album() const {
 133   DCHECK(extracted_);
 134   return album_;
 135 }
 136
 137 const std::string& AudioVideoMetadataExtractor::artist() const {
 138   DCHECK(extracted_);
 139   return artist_;
 140 }
 141
 142 const std::string& AudioVideoMetadataExtractor::comment() const {
 143   DCHECK(extracted_);
 144   return comment_;
 145 }
 146
 147 const std::string& AudioVideoMetadataExtractor::copyright() const {
 148   DCHECK(extracted_);
 149   return copyright_;
 150 }
 151
 152 const std::string& AudioVideoMetadataExtractor::date() const {
 153   DCHECK(extracted_);
 154   return date_;
 155 }
 156
 157 int AudioVideoMetadataExtractor::disc() const {
 158   DCHECK(extracted_);
 159   return disc_;
 160 }
 161
 162 const std::string& AudioVideoMetadataExtractor::encoder() const {
 163   DCHECK(extracted_);
 164   return encoder_;
 165 }
 166
 167 const std::string& AudioVideoMetadataExtractor::encoded_by() const {
 168   DCHECK(extracted_);
 169   return encoded_by_;
 170 }
 171
 172 const std::string& AudioVideoMetadataExtractor::genre() const {
 173   DCHECK(extracted_);
 174   return genre_;
 175 }
 176
 177 const std::string& AudioVideoMetadataExtractor::language() const {
 178   DCHECK(extracted_);
 179   return language_;
 180 }
 181
 182 const std::string& AudioVideoMetadataExtractor::title() const {
 183   DCHECK(extracted_);
 184   return title_;
 185 }
 186
 187 int AudioVideoMetadataExtractor::track() const {
 188   DCHECK(extracted_);
 189   return track_;
 190 }
 191
 192 void AudioVideoMetadataExtractor::ExtractDictionary(AVDictionary* metadata) {
 193   if (!metadata)
 194     return;
 195
 196   AVDictionaryEntry* tag = NULL;
 197   while ((tag = av_dict_get(metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {
 198     if (ExtractString(tag, "album", &album_)) continue;
 199     if (ExtractString(tag, "artist", &artist_)) continue;
 200     if (ExtractString(tag, "comment", &comment_)) continue;
 201     if (ExtractString(tag, "copyright", &copyright_)) continue;
 202     if (ExtractString(tag, "date", &date_)) continue;
 203     if (ExtractInt(tag, "disc", &disc_)) continue;
 204     if (ExtractString(tag, "encoder", &encoder_)) continue;
 205     if (ExtractString(tag, "encoded_by", &encoded_by_)) continue;
 206     if (ExtractString(tag, "genre", &genre_)) continue;
 207     if (ExtractString(tag, "language", &language_)) continue;
 208     if (ExtractString(tag, "title", &title_)) continue;
 209     if (ExtractInt(tag, "track", &track_)) continue;
 210   }
 211 }
 212
 213 }  // namespace media