// Copyright 2013 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 CHROME_UTILITY_MEDIA_GALLERIES_MEDIA_METADATA_PARSER_H_
#define CHROME_UTILITY_MEDIA_GALLERIES_MEDIA_METADATA_PARSER_H_
#include "base/callback.h"
#include "base/memory/scoped_ptr.h"
#include "chrome/common/extensions/api/media_galleries.h"
namespace base {
class Thread;
}
namespace media {
class DataSource;
}
namespace metadata {
// This class takes a MIME type and data source and parses its metadata. It
// handles audio, video, and images. It delegates its operations to FFMPEG,
// libexif, etc. This class lives and operates on the utility thread of the
// utility process, as we wish to sandbox potentially dangerous operations
// on user-provided data.
class MediaMetadataParser {
public:
typedef extensions::api::media_galleries::MediaMetadata MediaMetadata;
typedef base::Callback<void(scoped_ptr<MediaMetadata>)> MetadataCallback;
// Does not take ownership of |source|. Caller is responsible for ensuring
// that |source| outlives this object.
MediaMetadataParser(media::DataSource* source, const std::string& mime_type);
~MediaMetadataParser();
// |callback| is called on same message loop.
void Start(const MetadataCallback& callback);
private:
// Only accessed on |media_thread_| from this class.
media::DataSource* const source_;
const std::string mime_type_;
// Thread that blocking media parsing operations run on while the main thread
// handles messages from the browser process.
// TODO(tommycli): Replace with a reference to a WorkerPool if we ever use
// this class in batch mode.
scoped_ptr<base::Thread> media_thread_;
DISALLOW_COPY_AND_ASSIGN(MediaMetadataParser);
};
} // namespace metadata
#endif // CHROME_UTILITY_MEDIA_GALLERIES_MEDIA_METADATA_PARSER_H_