Media Galleries API Metadata: Add audio video metadata extractor.

This CL adds a class for extraction of audio and video metadata using ffmpeg.

This is needed to implement the Media Galleries Metadata API for Chrome extensions.

BUG=318450

Review URL: https://codereview.chromium.org/121383002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243470 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 369 insertions, 0 deletions

diff --git a/media/base/audio_video_metadata_extractor.cc b/media/base/audio_video_metadata_extractor.cc
new file mode 100644
index 0000000..fe26d84
--- /dev/null
+++ b/media/base/audio_video_metadata_extractor.cc
@@ -0,0 +1,213 @@
+// 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/base/audio_video_metadata_extractor.h"
+
+#include "base/bind.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/time/time.h"
+#include "media/ffmpeg/ffmpeg_common.h"
+#include "media/filters/blocking_url_protocol.h"
+#include "media/filters/ffmpeg_glue.h"
+
+namespace media {
+
+namespace {
+
+void OnError(bool* succeeded) {
+  *succeeded = false;
+}
+
+// Returns true if the |tag| matches |expected_key|.
+bool ExtractString(AVDictionaryEntry* tag, const char* expected_key,
+                   std::string* destination) {
+  if (!LowerCaseEqualsASCII(std::string(tag->key), expected_key))
+    return false;
+
+  if (destination->empty())
+    *destination = tag->value;
+
+  return true;
+}
+
+// Returns true if the |tag| matches |expected_key|.
+bool ExtractInt(AVDictionaryEntry* tag, const char* expected_key,
+                int* destination) {
+  if (!LowerCaseEqualsASCII(std::string(tag->key), expected_key))
+    return false;
+
+  int temporary = -1;
+  if (*destination < 0 && base::StringToInt(tag->value, &temporary) &&
+      temporary >= 0) {
+    *destination = temporary;
+  }
+
+  return true;
+}
+
+}  // namespace
+
+AudioVideoMetadataExtractor::AudioVideoMetadataExtractor()
+    : extracted_(false),
+      duration_(-1),
+      width_(-1),
+      height_(-1),
+      disc_(-1),
+      track_(-1) {
+}
+
+AudioVideoMetadataExtractor::~AudioVideoMetadataExtractor() {
+}
+
+bool AudioVideoMetadataExtractor::Extract(DataSource* source) {
+  DCHECK(!extracted_);
+
+  bool read_ok = true;
+  media::BlockingUrlProtocol protocol(source, base::Bind(&OnError, &read_ok));
+  media::FFmpegGlue glue(&protocol);
+  AVFormatContext* format_context = glue.format_context();
+
+  if (!glue.OpenContext())
+    return false;
+
+  if (!read_ok)
+    return false;
+
+  if (!format_context->iformat)
+    return false;
+
+  if (avformat_find_stream_info(format_context, NULL) < 0)
+    return false;
+
+  if (format_context->duration != AV_NOPTS_VALUE)
+    duration_ = static_cast<double>(format_context->duration) / AV_TIME_BASE;
+
+  ExtractDictionary(format_context->metadata);
+
+  for (unsigned int i = 0; i < format_context->nb_streams; ++i) {
+    AVStream* stream = format_context->streams[i];
+    if (!stream)
+      continue;
+
+    // Ignore attached pictures for metadata extraction.
+    if ((stream->disposition & AV_DISPOSITION_ATTACHED_PIC) != 0)
+      continue;
+
+    // Extract dictionary from streams also. Needed for containers that attach
+    // metadata to contained streams instead the container itself, like OGG.
+    ExtractDictionary(stream->metadata);
+
+    if (!stream->codec)
+      continue;
+
+    // Extract dimensions of largest stream that's not an attached picture.
+    if (stream->codec->width > 0 && stream->codec->width > width_ &&
+        stream->codec->height > 0 && stream->codec->height > height_) {
+      width_ = stream->codec->width;
+      height_ = stream->codec->height;
+    }
+  }
+
+  extracted_ = true;
+  return true;
+}
+
+double AudioVideoMetadataExtractor::duration() const {
+  DCHECK(extracted_);
+  return duration_;
+}
+
+int AudioVideoMetadataExtractor::width() const {
+  DCHECK(extracted_);
+  return width_;
+}
+
+int AudioVideoMetadataExtractor::height() const {
+  DCHECK(extracted_);
+  return height_;
+}
+
+const std::string& AudioVideoMetadataExtractor::album() const {
+  DCHECK(extracted_);
+  return album_;
+}
+
+const std::string& AudioVideoMetadataExtractor::artist() const {
+  DCHECK(extracted_);
+  return artist_;
+}
+
+const std::string& AudioVideoMetadataExtractor::comment() const {
+  DCHECK(extracted_);
+  return comment_;
+}
+
+const std::string& AudioVideoMetadataExtractor::copyright() const {
+  DCHECK(extracted_);
+  return copyright_;
+}
+
+const std::string& AudioVideoMetadataExtractor::date() const {
+  DCHECK(extracted_);
+  return date_;
+}
+
+int AudioVideoMetadataExtractor::disc() const {
+  DCHECK(extracted_);
+  return disc_;
+}
+
+const std::string& AudioVideoMetadataExtractor::encoder() const {
+  DCHECK(extracted_);
+  return encoder_;
+}
+
+const std::string& AudioVideoMetadataExtractor::encoded_by() const {
+  DCHECK(extracted_);
+  return encoded_by_;
+}
+
+const std::string& AudioVideoMetadataExtractor::genre() const {
+  DCHECK(extracted_);
+  return genre_;
+}
+
+const std::string& AudioVideoMetadataExtractor::language() const {
+  DCHECK(extracted_);
+  return language_;
+}
+
+const std::string& AudioVideoMetadataExtractor::title() const {
+  DCHECK(extracted_);
+  return title_;
+}
+
+int AudioVideoMetadataExtractor::track() const {
+  DCHECK(extracted_);
+  return track_;
+}
+
+void AudioVideoMetadataExtractor::ExtractDictionary(AVDictionary* metadata) {
+  if (!metadata)
+    return;
+
+  AVDictionaryEntry* tag = NULL;
+  while ((tag = av_dict_get(metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {
+    if (ExtractString(tag, "album", &album_)) continue;
+    if (ExtractString(tag, "artist", &artist_)) continue;
+    if (ExtractString(tag, "comment", &comment_)) continue;
+    if (ExtractString(tag, "copyright", &copyright_)) continue;
+    if (ExtractString(tag, "date", &date_)) continue;
+    if (ExtractInt(tag, "disc", &disc_)) continue;
+    if (ExtractString(tag, "encoder", &encoder_)) continue;
+    if (ExtractString(tag, "encoded_by", &encoded_by_)) continue;
+    if (ExtractString(tag, "genre", &genre_)) continue;
+    if (ExtractString(tag, "language", &language_)) continue;
+    if (ExtractString(tag, "title", &title_)) continue;
+    if (ExtractInt(tag, "track", &track_)) continue;
+  }
+}
+
+}  // namespace media
diff --git a/media/base/audio_video_metadata_extractor.h b/media/base/audio_video_metadata_extractor.h
new file mode 100644
index 0000000..affe794
--- /dev/null
+++ b/media/base/audio_video_metadata_extractor.h
@@ -0,0 +1,78 @@
+// 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.
+
+#ifndef MEDIA_BASE_AUDIO_VIDEO_METADATA_EXTRACTOR_H_
+#define MEDIA_BASE_AUDIO_VIDEO_METADATA_EXTRACTOR_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "media/base/media_export.h"
+
+struct AVDictionary;
+
+namespace media {
+
+class DataSource;
+
+// This class extracts a string dictionary of metadata tags for audio and video
+// files. It also provides the format name.
+class MEDIA_EXPORT AudioVideoMetadataExtractor {
+ public:
+  AudioVideoMetadataExtractor();
+  ~AudioVideoMetadataExtractor();
+
+  // Returns whether or not the fields were successfully extracted. Should only
+  // be called once.
+  bool Extract(DataSource* source);
+
+  // Returns -1 if we cannot extract the duration. In seconds.
+  double duration() const;
+
+  // Returns -1 for containers without video.
+  int width() const;
+  int height() const;
+
+  // Returns -1 or an empty string if the value is undefined.
+  const std::string& album() const;
+  const std::string& artist() const;
+  const std::string& comment() const;
+  const std::string& copyright() const;
+  const std::string& date() const;
+  int disc() const;
+  const std::string& encoder() const;
+  const std::string& encoded_by() const;
+  const std::string& genre() const;
+  const std::string& language() const;
+  const std::string& title() const;
+  int track() const;
+
+ private:
+  void ExtractDictionary(AVDictionary* metadata);
+
+  bool extracted_;
+
+  int duration_;
+  int width_;
+  int height_;
+
+  std::string album_;
+  std::string artist_;
+  std::string comment_;
+  std::string copyright_;
+  std::string date_;
+  int disc_;
+  std::string encoder_;
+  std::string encoded_by_;
+  std::string genre_;
+  std::string language_;
+  std::string title_;
+  int track_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioVideoMetadataExtractor);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_AUDIO_VIDEO_METADATA_EXTRACTOR_H_
diff --git a/media/base/audio_video_metadata_extractor_unittest.cc b/media/base/audio_video_metadata_extractor_unittest.cc
new file mode 100644
index 0000000..c55cd5d
--- /dev/null
+++ b/media/base/audio_video_metadata_extractor_unittest.cc
@@ -0,0 +1,78 @@
+// 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 "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "build/build_config.h"
+#include "media/base/audio_video_metadata_extractor.h"
+#include "media/base/test_data_util.h"
+#include "media/filters/file_data_source.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+
+scoped_ptr<AudioVideoMetadataExtractor> GetExtractor(
+    const std::string& filename,
+    bool expected_result,
+    double expected_duration,
+    int expected_width,
+    int expected_height) {
+  FileDataSource source;
+  EXPECT_TRUE(source.Initialize(GetTestDataFilePath(filename)));
+
+  scoped_ptr<AudioVideoMetadataExtractor> extractor(
+      new AudioVideoMetadataExtractor);
+  bool extracted = extractor->Extract(&source);
+  EXPECT_EQ(expected_result, extracted);
+
+  if (!extracted)
+    return extractor.Pass();
+
+  EXPECT_EQ(expected_duration, extractor->duration());
+
+  EXPECT_EQ(expected_width, extractor->width());
+  EXPECT_EQ(expected_height, extractor->height());
+
+  return extractor.Pass();
+}
+
+TEST(AudioVideoMetadataExtractorTest, InvalidFile) {
+  GetExtractor("ten_byte_file", false, 0, -1, -1);
+}
+
+TEST(AudioVideoMetadataExtractorTest, AudioOGG) {
+  scoped_ptr<AudioVideoMetadataExtractor> extractor =
+      GetExtractor("9ch.ogg", true, 0, -1, -1);
+  EXPECT_EQ("Processed by SoX", extractor->comment());
+}
+
+TEST(AudioVideoMetadataExtractorTest, AudioWAV) {
+  scoped_ptr<AudioVideoMetadataExtractor> extractor =
+      GetExtractor("sfx_u8.wav", true, 0, -1, -1);
+  EXPECT_EQ("Lavf54.37.100", extractor->encoder());
+  EXPECT_EQ("Amadeus Pro", extractor->encoded_by());
+}
+
+TEST(AudioVideoMetadataExtractorTest, VideoWebM) {
+  scoped_ptr<AudioVideoMetadataExtractor> extractor =
+      GetExtractor("bear-320x240-multitrack.webm", true, 2, 320, 240);
+  EXPECT_EQ("Lavf53.9.0", extractor->encoder());
+}
+
+#if defined(USE_PROPRIETARY_CODECS)
+TEST(AudioVideoMetadataExtractorTest, AudioMP3) {
+  scoped_ptr<AudioVideoMetadataExtractor> extractor =
+      GetExtractor("id3_png_test.mp3", true, 1, -1, -1);
+
+  EXPECT_EQ("Airbag", extractor->title());
+  EXPECT_EQ("Radiohead", extractor->artist());
+  EXPECT_EQ("OK Computer", extractor->album());
+  EXPECT_EQ(1, extractor->track());
+  EXPECT_EQ("Alternative", extractor->genre());
+  EXPECT_EQ("1997", extractor->date());
+  EXPECT_EQ("Lavf54.4.100", extractor->encoder());
+}
+#endif
+
+}  // namespace media