text: /*
   * Copyright 2002-2010, Haiku, Inc. All rights reserved.
   * Distributed under the terms of the MIT License.
   */
  #ifndef _MEDIA_TRACK_H
  #define _MEDIA_TRACK_H
  
  
  #include <MediaFormats.h>
  
  
  namespace BCodecKit {
  	class BDecoder;
  	class BEncoder;
  	class BMediaExtractor;
  	class BMediaWriter;
  }
  
  class BMessage;
  class BView;
  class BParameterWeb;
  
  
  enum media_seek_type {
  	B_MEDIA_SEEK_CLOSEST_FORWARD	= 1,
  	B_MEDIA_SEEK_CLOSEST_BACKWARD	= 2,
  	B_MEDIA_SEEK_DIRECTION_MASK		= 3
  };
  
  
  // BMediaTrack gives access to a particular media track in a media file
  // (as represented by BMediaFile).
  //
  // You always instantiate a BMediaTrack through BMediaFile::TrackAt()
  // or BMediaFile::CreateTrack().  When a BMediaTrack object is
  // constructed it finds the necessary decoder or encoder for the type
  // of data stored in the track.
  //
  // Unless you created the BMediaFile() in B_MEDIA_REPLACE_MODE, you
  // can only access a track for reading or writing, not both.
  //
  // If InitCheck() indicates no errors, then the track is ready to be
  // used to read and write frames using ReadFrames() and WriteFrames().
  // For video data you should always only read one frame.
  //
  // You can seek a track with SeekToTime() and SeekToFrame().
  //
  // If no codec could be found for the track, it is still possible to
  // access the encoded data using ReadChunk().
  class BMediaTrack {
  protected:
  	// Use BMediaFile::ReleaseTrack() instead -- or it will go away
  	// on its own when the MediaFile is deleted.
  	virtual						~BMediaTrack();
  
  public:
  
  	// for read-only access the BMediaTrack should be instantiated
  	// through BMediaFile::TrackAt()
  
  	// for write-only access the BMediaTrack should be instantiated
  	// through BMediaFile::CreateTrack()
  
  			status_t			InitCheck() const;
  
  	// Get information about the codec being used.
  			status_t			GetCodecInfo(
  									media_codec_info* _codecInfo) const;
  
  
  	// EncodedFormat returns information about the track's
  	// "native" encoded format.
  
  			status_t			EncodedFormat(media_format* _format) const;
  
  	// DecodedFormat is used to negotiate the format that the codec will
  	// use when decoding the track's data.  You pass in the format that
  	// that you want; the codec will find and return its "best fit"
  	// format.  (inout_format is used as both the input and the returned
  	// format.)  The format is typically of the B_MEDIA_RAW_AUDIO or
  	// B_MEDIA_RAW_VIDEO flavor.
  	// The data returned through ReadFrames() will be in the format that's
   	// returned by this function.
  
  			status_t			DecodedFormat(media_format* _format,
  									uint32 flags = 0);
  
  	// CountFrames and Duration return the total number of frame and the
  	// total duration (expressed in microseconds) of a track.
  
  			int64				CountFrames() const;
  			bigtime_t			Duration() const;
  
  	// Returns in _data hierarchical meta-data about the track.
  	// The fields in the message shall follow a defined naming-scheme,
  	// such that applications can find the same information in different
  	// types of tracks.
  			status_t			GetMetaData(BMessage* _data) const;
  
  	// CurrentFrame and CurrentTime return the current position (expressed in
  	// microseconds) within the track, expressed in frame index and time.
  
  			int64				CurrentFrame() const;
  			bigtime_t			CurrentTime() const;
  
  	// ReadFrames() fills a buffer with the next frames/samples. For a video
  	// track,  it decodes the next frame of video in the passed buffer. For
  	// an audio track, it fills the buffers with the next N samples, as
  	// negotiated by DecodedFormat().  However, if it reaches the end of the
  	// file and was not able to fill the whole  buffer, it returns a partial
  	// buffer.  Upon return, out_frameCount contains the actual number of
  	// frame/samples returned, and the start time for the frame, expressed
  	// in microseconds, is in the media_header structure.
  
  			status_t			ReadFrames(void* buffer, int64* _frameCount,
  									media_header* header = NULL);
  
  			status_t			ReadFrames(void* buffer, int64* _frameCount,
  									media_header* header,
  									media_decode_info* info);
  
  			status_t			ReplaceFrames(const void* buffer,
  									int64* _frameCount,
  									const media_header* header);
  
  
  	// SeekToTime and SeekToFrame are used for seeking to a particular
  	// position in a track, expressed in either frames or microseconds.
  	// They return whatever position they were able to seek to. For example,
  	// a video codec may not be able to seek to arbitrary frames, but only to
  	// key frames. In this case, it would return the closest key frame before
  	// the specified seek point.
  	//
  	// If you want to explicitly seek to the nearest keyframe _before_ this
  	// frame or _after_ this frame, pass B_MEDIA_SEEK_CLOSEST_FORWARD or
  	// B_MEDIA_SEEK_CLOSEST_BACKWARD as the flags field.
  
  			status_t			SeekToTime(bigtime_t* _time, int32 flags = 0);
  			status_t			SeekToFrame(int64* _frame, int32 flags = 0);
  
  			status_t			FindKeyFrameForTime(bigtime_t* _time,
  									int32 flags = 0) const;
  			status_t			FindKeyFrameForFrame(int64* _frame,
  									int32 flags = 0) const;
  
  	// ReadChunk returns, in _buffer, the next _size bytes of
  	// data from the track.  The data is not decoded -- it will be
  	// in its native encoded format (as specified by EncodedFormat()).
  	// You can not mix calling ReadChunk() and ReadFrames() -- either
  	// you access the track raw (i.e. with ReadChunk) or you access
  	// it with ReadFrames.
  
  			status_t			ReadChunk(char** _buffer, int32* _size,
  									media_header* _header = NULL);
  
  
  	//
  	// Write-only Functions
  	//
  			status_t			AddCopyright(const char* copyright);
  			status_t			AddTrackInfo(uint32 code, const void* data,
  									size_t size, uint32 flags = 0);
  
  	// Write frameCount of data to the track. This data is passed
  	// through the encoder that was specified when the MediaTrack
  	// was constructed.
  	// Pass B_MEDIA_KEY_FRAME for flags if it is.
  
  			status_t			WriteFrames(const void* data, int32 frameCount,
  									int32 flags = 0);
  			status_t			WriteFrames(const void* data, int64 frameCount,
  									media_encode_info* info);
  
  	// Write a raw chunk of (presumably already encoded data) to
  	// the file.
  	// Pass B_MEDIA_KEY_FRAME for flags if it is.
  
  			status_t			WriteChunk(const void* data, size_t size,
  									uint32 flags = 0);
  			status_t			WriteChunk(const void* data, size_t size,
  									media_encode_info* info);
  
  	// Flush all buffered encoded datas to disk. You should call it after
  	// writing the last frame to be sure all datas are flushed at the right
  	// offset into the file.
  			status_t			Flush();
  
  	// These are for controlling the underlying encoder and track parameters
  	// returns a copy of the parameter web
  			status_t			GetParameterWeb(BParameterWeb** _web);
  			status_t 			GetParameterValue(int32 id, void* value,
  									size_t* size);
  			status_t			SetParameterValue(int32 id, const void* value,
  									size_t size);
  			BView*				GetParameterView();
  
  	// This is a simplified control API, only one parameter low=0.0, high=1.0
  	// Return B_ERROR if it's not supported by the current encoder.
  			status_t			GetQuality(float* _quality);
  			status_t			SetQuality(float quality);
  
  			status_t 			GetEncodeParameters(
  									encode_parameters* parameters) const;
  			status_t 			SetEncodeParameters(
  									encode_parameters* parameters);
  
  
  	virtual	status_t			Perform(int32 code, void* data);
  
  private:
  	friend class BMediaFile;
  
  	// deprecated, but for BeOS R5 compatibility
  			BParameterWeb*	Web();
  
  	// Does nothing, returns B_ERROR, for Zeta compatiblity only
  			status_t			ControlCodec(int32 selector, void* _inOutData,
  									size_t size);
  
  	// For read-only access to a BMediaTrack
  								BMediaTrack(
  									BCodecKit::BMediaExtractor* extractor,
  									int32 streamIndex);
  
  	// For write-only access to a BMediaTrack
  								BMediaTrack(
  									BCodecKit::BMediaWriter* writer,
  									int32 streamIndex, media_format* format,
  									const media_codec_info* codecInfo);
  
  			void				SetupWorkaround();
  			bool				SetupFormatTranslation(
  									const media_format& from,
  									media_format* _to);
  
  private:
  			status_t			fInitStatus;
  			BCodecKit::BDecoder* fDecoder;
  			BCodecKit::BDecoder* fRawDecoder;
  			BCodecKit::BMediaExtractor* fExtractor;
  
  			int32				fStream;
  			int64				fCurrentFrame;
  			bigtime_t			fCurrentTime;
  
  			media_codec_info	fCodecInfo;
  
  			BCodecKit::BEncoder* fEncoder;
  			int32				fEncoderID;
  			BCodecKit::BMediaWriter* fWriter;
  			media_format		fFormat;
  
  			uint32				fWorkaroundFlags;
  
  protected:
  			int32				EncoderID() { return fEncoderID; };
  
  private:
  								BMediaTrack();
  								BMediaTrack(const BMediaTrack&);
  			BMediaTrack&		operator=(const BMediaTrack&);
  
  
  			double				_FrameRate() const;
  
  	// FBC data and virtuals
  			uint32				_reserved_BMediaTrack_[31];
  
  	virtual	status_t			_Reserved_BMediaTrack_0(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_1(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_2(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_3(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_4(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_5(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_6(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_7(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_8(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_9(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_10(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_11(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_12(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_13(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_14(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_15(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_16(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_17(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_18(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_19(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_20(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_21(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_22(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_23(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_24(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_25(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_26(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_27(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_28(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_29(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_30(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_31(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_32(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_33(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_34(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_35(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_36(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_37(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_38(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_39(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_40(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_41(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_42(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_43(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_44(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_45(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_46(int32 arg, ...);
  	virtual	status_t			_Reserved_BMediaTrack_47(int32 arg, ...);
  };
  
  #endif // _MEDIA_TRACK_H
  