mvEditByFrame(3dm)					    mvEditByFrame(3dm)

NAME    [Toc]    [Back]

     mvEditByFrame:  mvReadFrames, mvInsertFrames, mvAppendFrames,
     mvDeleteFrames, mvPasteFrames - edit/manipulate a movie track

SYNOPSIS    [Toc]    [Back]

     #include <dmedia/moviefile.h>


     DMstatus mvReadFrames( MVid track,	MVframe	frameIndex,
			 MVframe frameCount, size_t bufferSize,
			 void* buffer );

     DMstatus mvInsertFrames( MVid track, MVframe frameIndex,
			 MVframe frameCount, size_t bufferSize,
			 void* buffer );

     DMstatus mvAppendFrames( MVid track, MVframe frameCount,
			 size_t	bufferSize, void* buffer );

     DMstatus mvDeleteFrames( MVid track, MVframe frameIndex,
			 MVframe frameCount );

     DMstatus mvPasteFrames( MVid fromTrack, MVframe fromFrameIndex,
			 MVframe frameCount, MVid toTrack,
			 MVframe toFrameIndex );

DESCRIPTION    [Toc]    [Back]

     mvReadFrames reads	frameCount frames from the track, starting with
     frameIndex, and places them in buffer.  The value returned	is DM_SUCCESS
     or	DM_FAILURE.  For image tracks the image	returned in the	buffer pointed
     to	by buffer are of pixel packing DM_IMAGE_PACKING_XBGR, interlacing
     DM_IMAGE_NONINTERLACED, and orientation DM_IMAGE_BOTTOM_TO_TOP.  For
     audio tracks the audio frames returned in the buffer pointed to by	buffer
     are in the	format DM_AUDIO_TWOS_COMPLEMENT.

     mvInsertFrames takes frameCount frames from buffer	and writes them	to the
     track, starting at	frameIndex.  The previous contents of the track	from
     frameIndex	on are shifted by frameCount to	make room for the new frames.
     The value returned	is DM_SUCCESS or DM_FAILURE.  For image	tracks
     mvInsertFrames expects the	data pointed to	by buffer to be	formatted as
     packing DM_IMAGE_PACKING_XBGR, interlacing	DM_IMAGE_NONINTERLACED,	and
     orientation DM_IMAGE_BOTTOM_TO_TOP.  For audio tracks mvInsertFrames
     expects the data pointed to by buffer to be formatted as
     DM_AUDIO_TWOS_COMPLEMENT.

     mvAppendFrames takes frameCount frames from buffer	and writes them	to the
     end of the	track.	The value returned is DM_SUCCESS or DM_FAILURE.	 For
     image tracks mvAppendFrames expects the data pointed to by	buffer to be
     formatted as packing DM_IMAGE_PACKING_XBGR, interlacing
     DM_IMAGE_NONINTERLACED, and orientation DM_IMAGE_BOTTOM_TO_TOP.  For



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mvEditByFrame(3dm)					    mvEditByFrame(3dm)



     audio tracks mvAppendFrames expects the data pointed to by	buffer to be
     formatted as DM_AUDIO_TWOS_COMPLEMENT and DM_AUDIO_BIG_ENDIAN (if the
     audio is more than	8 bits per sample). Some movies	cannot be read or
     edited while appending; see mvIsAppendOnly(3dm).

     mvDeleteFrames removes frameCount frames from the track, starting at
     frameIndex.  Any subsequent frames	are shifted back into the empty	space,
     making the	track shorter.	The value returned is DM_SUCCESS or
     DM_FAILURE.

     mvPasteFrames is provided for convenience and efficiency.	It is
     equivalent	to reading frames from one track and inserting them into
     another track, but	is much	more efficient.	 The example below is
     equivalent, assuming that a large enough buffer can be allocated:


	  DMstatus mvPasteFrames( MVid	  fromTrack,
				  MVframe fromFrameIndex,
				  MVframe frameCount,
				  MVid	  toTrack,
				  MVframe toFrameIndex )
	  {
	      size_t	size;
	      void*	buffer;
	      DMparams*	params = mvGetParams( fromTrack	);

	      switch ( mvGetTrackMedium( fromTrack ) ) {
		  case DM_IMAGE:
		  /* mvReadFrames on image tracks always returns xbgr,
			bottom to top, non interlaced data */
		     dmParamsSetEnum( params,
				      DM_IMAGE_PACKING,
				      DM_IMAGE_PACKING_XBGR );
		     dmParamsSetEnum( params,
				      DM_IMAGE_INTERLACING,
				      DM_IMAGE_NONINTERLACED );
		     dmParamsSetEnum( params,
				      DM_IMAGE_ORIENTATION,
				      DM_IMAGE_BOTTOM_TO_TOP );
		     size = dmImageFrameSize(params);
		     break;
		  case DM_AUDIO:
		  /* mvReadFrames on audio tracks always returns
			twos complement	audio data */
		     dmParamsSetEnum( params,
				      DM_AUDIO_FORMAT,
				      DM_AUDIO_TWOS_COMPLEMENT );
		     size = dmAudioFrameSize(params);
		     break;
	      }

	      buffer = malloc( size * frameCount );



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mvEditByFrame(3dm)					    mvEditByFrame(3dm)




	      if ( mvReadFrames( fromTrack,
				 fromFrameIndex,
				 frameCount,
				 size *	frameCount,
				 buffer	) != DM_SUCCESS	)
		  return DM_FAILURE;

	      if ( mvInsertFrames( toTrack,
				   toFrameIndex,
				   frameCount,
				   size	* frameCount,
				   buffer ) != DM_SUCCESS )
		  return DM_FAILURE;

	      return DM_SUCCESS;
	  }

SEE ALSO    [Toc]    [Back]

     mvIntro(3dm), mvIsAppendOnly(3dm),	mvAddTrack(3dm), mvGetAudioWidth(3dm),
     mvGetImageWidth(3dm), mvGetErrno(3dm), mvTrackData(3dm).


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