Implementation of Pipeline and FilterHost interfaces. This is a large change...

media/base/filters.h

 // Copyright (c) 2006-2009 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.
 
 // Filters are connected in a strongly typed manner, with downstream filters
 // always reading data from upstream filters.  Upstream filters have no clue
 // who is actually reading from them, and return the results via OnAssignment
 // using the AssignableInterface<SomeBufferType> interface:
 //
 //                         DemuxerStream(Video) <- VideoDecoder <- VideoRenderer
@@ skipping 11 matching lines @@
 // use the scheduler to signal errors and shutdown playback.
 
 #ifndef MEDIA_BASE_FILTERS_H_
 #define MEDIA_BASE_FILTERS_H_
 
 #include <limits>
 #include <string>
 
 #include "base/logging.h"
 #include "base/ref_counted.h"
+#include "base/time.h"
+#include "media/base/media_format.h"
 
 namespace media {
 
 template <class TBuffer> class Assignable;
 class Buffer;
 class Decoder;
 class DemuxerStream;
 class FilterHost;
-class MediaFormat;
 class VideoFrame;
 class WritableBuffer;
 
 // Identifies the type of filter implementation.  Used in conjunction with some
 // template wizardry to enforce strongly typed operations.  More or less a
 // knock off of MSVC's __uuidof() operator.
 enum FilterType {
   FILTER_DATA_SOURCE,
   FILTER_DEMUXER,
   FILTER_AUDIO_DECODER,
@@ skipping 20 matching lines @@
   // The pipeline is being stopped either as a result of an error or because
   // the client called Stop().
   virtual void Stop() = 0;
 
   // The pipeline playback rate has been changed.  Filters may implement this
   // method if they need to respond to this call.
   virtual void SetPlaybackRate(float playback_rate) {}
 
   // The pipeline is being seeked to the specified time.  Filters may implement
   // this method if they need to respond to this call.
-  virtual void Seek(int64 time) {}
+  virtual void Seek(base::TimeDelta time) {}
 
  protected:
   FilterHost* host_;
   friend class base::RefCountedThreadSafe<MediaFilter>;
   virtual ~MediaFilter() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MediaFilter);
 };
 
 
 class DataSource : public MediaFilter {
  public:
-  static const FilterType kFilterType = FILTER_DATA_SOURCE;
+  static const FilterType filter_type() {
+    return FILTER_DATA_SOURCE;
+  }
+
   static const size_t kReadError = static_cast<size_t>(-1);
 
   // Initializes this filter, returns true if successful, false otherwise.
-  virtual bool Initialize(const std::string& uri) = 0;
+  virtual bool Initialize(const std::string& url) = 0;
 
   // Returns the MediaFormat for this filter.
   virtual const MediaFormat* GetMediaFormat() = 0;
 
   // Read the given amount of bytes into data, returns the number of bytes read
   // if successful, kReadError otherwise.
   virtual size_t Read(char* data, size_t size) = 0;
 
   // Returns true and the current file position for this file, false if the
   // file position could not be retrieved.
   virtual bool GetPosition(int64* position_out) = 0;
 
   // Returns true if the file position could be set, false otherwise.
   virtual bool SetPosition(int64 position) = 0;
 
   // Returns true and the file size, false if the file size could not be
   // retrieved.
   virtual bool GetSize(int64* size_out) = 0;
 };
 
 
 class Demuxer : public MediaFilter {
  public:
-  static const FilterType kFilterType = FILTER_DEMUXER;
+  static const FilterType filter_type() {
+    return FILTER_DEMUXER;
+  }
 
   // Initializes this filter, returns true if successful, false otherwise.
   virtual bool Initialize(DataSource* data_source) = 0;
 
   // Returns the number of streams available
   virtual size_t GetNumberOfStreams() = 0;
 
   // Returns the stream for the given index, NULL otherwise
   virtual DemuxerStream* GetStream(int stream_id) = 0;
 };
 
 
 class DemuxerStream {
  public:
   // Returns the MediaFormat for this filter.
   virtual const MediaFormat* GetMediaFormat() = 0;
 
   // Schedules a read and takes ownership of the given buffer.
   virtual void Read(Assignable<Buffer>* buffer) = 0;
 
  protected:
   virtual ~DemuxerStream() = 0;
 };
 
 
 class VideoDecoder : public MediaFilter {
  public:
-  static const FilterType kFilterType = FILTER_VIDEO_DECODER;
+  static const FilterType filter_type() {
+    return FILTER_VIDEO_DECODER;
+  }
+
+  static const char* major_mime_type() {
+    return mime_type::kMajorTypeVideo;
+  }
 
   // Initializes this filter, returns true if successful, false otherwise.
   virtual bool Initialize(DemuxerStream* demuxer_stream) = 0;
 
   // Returns the MediaFormat for this filter.
   virtual const MediaFormat* GetMediaFormat() = 0;
 
   // Schedules a read and takes ownership of the given buffer.
   virtual void Read(Assignable<VideoFrame>* video_frame) = 0;
 };
 
 
 class AudioDecoder : public MediaFilter {
  public:
-  static const FilterType kFilterType = FILTER_AUDIO_DECODER;
+  static const FilterType filter_type() {
+    return FILTER_AUDIO_DECODER;
+  }
+
+  static const char* major_mime_type() {
+    return mime_type::kMajorTypeAudio;
+  }
 
   // Initializes this filter, returns true if successful, false otherwise.
   virtual bool Initialize(DemuxerStream* demuxer_stream) = 0;
 
   // Returns the MediaFormat for this filter.
   virtual const MediaFormat* GetMediaFormat() = 0;
 
   // Schedules a read and takes ownership of the given buffer.
   virtual void Read(Assignable<Buffer>* buffer) = 0;
 };
 
 
 class VideoRenderer : public MediaFilter {
  public:
-  static const FilterType kFilterType = FILTER_VIDEO_RENDERER;
+  static const FilterType filter_type() {
+    return FILTER_VIDEO_RENDERER;
+  }
+
+  static const char* major_mime_type() {
+    return mime_type::kMajorTypeVideo;
+  }
 
   // Initializes this filter, returns true if successful, false otherwise.
   virtual bool Initialize(VideoDecoder* decoder) = 0;
 };
 
 
 class AudioRenderer : public MediaFilter {
  public:
-  static const FilterType kFilterType = FILTER_AUDIO_RENDERER;
+  static const FilterType filter_type() {
+    return FILTER_AUDIO_RENDERER;
+  }
+
+  static const char* major_mime_type() {
+    return mime_type::kMajorTypeAudio;
+  }
 
   // Initializes this filter, returns true if successful, false otherwise.
   virtual bool Initialize(AudioDecoder* decoder) = 0;
 
   // Sets the output volume.
   virtual void SetVolume(float volume) = 0;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_FILTERS_H_