mvEditByFrame(3dm)mvEditByFrame(3dm)NAME
mvEditByFrame: mvReadFrames, mvInsertFrames, mvAppendFrames,
mvDeleteFrames, mvPasteFrames - edit/manipulate a movie track
SYNOPSIS
#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
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 for all integer formats,
DM_AUDIO_FLOAT for 32-bit floating point format, or DM_AUDIO_DOUBLE for
64-bit floating point format.
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 for all integer formats, DM_AUDIO_FLOAT for 32-
bit floating point format, or DM_AUDIO_DOUBLE for 64-bit floating point
format.
mvAppendFrames takes frameCount frames from buffer and writes them to the
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mvEditByFrame(3dm)mvEditByFrame(3dm)
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
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);
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mvEditByFrame(3dm)mvEditByFrame(3dm)
break;
}
buffer = malloc( size * frameCount );
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 ALSOmvIntro(3dm), mvIsAppendOnly(3dm), mvAddTrack(3dm), mvGetAudioWidth(3dm),
mvGetImageWidth(3dm), mvGetErrno(3dm), mvTrackData(3dm).
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