C++程序  |  93行  |  3.2 KB

// Copyright (c) 2012 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_DEMUXER_H_
#define MEDIA_BASE_DEMUXER_H_

#include <vector>

#include "base/time/time.h"
#include "media/base/data_source.h"
#include "media/base/demuxer_stream.h"
#include "media/base/media_export.h"
#include "media/base/pipeline_status.h"

namespace media {

class TextTrackConfig;

class MEDIA_EXPORT DemuxerHost : public DataSourceHost {
 public:
  // Sets the duration of the media in microseconds.
  // Duration may be kInfiniteDuration() if the duration is not known.
  virtual void SetDuration(base::TimeDelta duration) = 0;

  // Stops execution of the pipeline due to a fatal error.  Do not call this
  // method with PIPELINE_OK.
  virtual void OnDemuxerError(PipelineStatus error) = 0;

  // Add |text_stream| to the collection managed by the text renderer.
  virtual void AddTextStream(DemuxerStream* text_stream,
                             const TextTrackConfig& config) = 0;

  // Remove |text_stream| from the presentation.
  virtual void RemoveTextStream(DemuxerStream* text_stream) = 0;

 protected:
  virtual ~DemuxerHost();
};

class MEDIA_EXPORT Demuxer {
 public:
  // A new potentially encrypted stream has been parsed.
  // First parameter - The type of initialization data.
  // Second parameter - The initialization data associated with the stream.
  typedef base::Callback<void(const std::string& type,
                              const std::vector<uint8>& init_data)> NeedKeyCB;

  Demuxer();
  virtual ~Demuxer();

  // Completes initialization of the demuxer.
  //
  // The demuxer does not own |host| as it is guaranteed to outlive the
  // lifetime of the demuxer. Don't delete it!
  virtual void Initialize(DemuxerHost* host,
                          const PipelineStatusCB& status_cb,
                          bool enable_text_tracks) = 0;

  // Carry out any actions required to seek to the given time, executing the
  // callback upon completion.
  virtual void Seek(base::TimeDelta time,
                    const PipelineStatusCB& status_cb) = 0;

  // Starts stopping this demuxer, executing the callback upon completion.
  //
  // After the callback completes the demuxer may be destroyed. It is illegal to
  // call any method (including Stop()) after a demuxer has stopped.
  virtual void Stop(const base::Closure& callback) = 0;

  // This method is called from the pipeline when the audio renderer
  // is disabled. Demuxers can ignore the notification if they do not
  // need to react to this event.
  //
  // TODO(acolwell): Change to generic DisableStream(DemuxerStream::Type).
  // TODO(scherkus): this might not be needed http://crbug.com/234708
  virtual void OnAudioRendererDisabled() = 0;

  // Returns the first stream of the given stream type (which is not allowed
  // to be DemuxerStream::TEXT), or NULL if that type of stream is not present.
  virtual DemuxerStream* GetStream(DemuxerStream::Type type) = 0;

  // Returns the starting time for the media file.
  virtual base::TimeDelta GetStartTime() const = 0;

 private:
  DISALLOW_COPY_AND_ASSIGN(Demuxer);
};

}  // namespace media

#endif  // MEDIA_BASE_DEMUXER_H_