Fine tuning of quicktime atoms

Functions
int	lqt_set_fiel (quicktime_t *file, int track, int nfields, int dominance)
	Set the field attributes of a video track.
int	lqt_get_fiel (quicktime_t *file, int track, int *nfields, int *dominance)
	Get the field attributes of a video track.
int	lqt_set_pasp (quicktime_t *file, int track, quicktime_pasp_t *pasp)
	Set the pixel aspect atom of a video track.
int	lqt_get_pasp (quicktime_t *file, int track, quicktime_pasp_t *pasp)
	Get the pixel aspect atom of a video track.
int	lqt_set_clap (quicktime_t *file, int track, quicktime_clap_t *clap)
	Set the clean aperture attributes of a video track.
int	lqt_get_clap (quicktime_t *file, int track, quicktime_clap_t *clap)
	Get the clean aperture attributes of a video track.
int	lqt_set_colr (quicktime_t *file, int track, quicktime_colr_t *colr)
	Set the 'colr' ImageDescription Extension of a video track.
int	lqt_get_colr (quicktime_t *file, int track, quicktime_colr_t *colr)
	Get the 'colr' ImageDescription Extension of a video track.

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Detailed Description

Libquicktime tries it's best to produce proper files, with all the information neccesary for decoding the file with the right parameters. In some cases however, it might be useful to tweak the corresponding atoms individually. Please note that the functions described here, allow you full control over the atoms. But they also allow you to create horribly incompatible and undecodable files. Don't say you haven't been warned.

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Function Documentation

int lqt_set_fiel	(	quicktime_t *	file,
		int	track,
		int	nfields,
		int	dominance
	)

Set the field attributes of a video track.

Parameters:

file	A quicktime handle
track	Track index (starting with 0)
nfields	number of fields (1 = progressive, 2 = interlaced)
dominance	field order/dominance (9 = top first, 14 = bottom first)

Returns:

1 if the call was successful, 0 if there is no such track or invalid number of fields or invalid dominance

The dominance parameter may also have the values 0, 1 and 6 but those are rarely used. The Apple documentation at

http://developer.apple.com/quicktime/icefloe/dispatch019.html#fiel

has more detailed information about the 'fiel' atom.

int lqt_get_fiel	(	quicktime_t *	file,
		int	track,
		int *	nfields,
		int *	dominance
	)

Get the field attributes of a video track.

Parameters:

file	A quicktime handle
track	Track index (starting with 0)
nfields	number of fields
dominance	field order/dominance

Returns:

1 if the call was successful, 0 if there is no such track

The Apple documentation at

http://developer.apple.com/quicktime/icefloe/dispatch019.html#fiel

has more detailed information about the 'fiel' atom.

int lqt_set_pasp	(	quicktime_t *	file,
		int	track,
		quicktime_pasp_t *	pasp
	)

Set the pixel aspect atom of a video track.

Parameters:

file	A quicktime handle
track	Track index (starting with 0)
pasp	Pixel aspect atom

Returns:

1 if the call was successful, 0 if there is no such track

int lqt_get_pasp	(	quicktime_t *	file,
		int	track,
		quicktime_pasp_t *	pasp
	)

Get the pixel aspect atom of a video track.

Parameters:

file	A quicktime handle
track	Track index (starting with 0)
pasp	Pixel aspect atom

Returns:

1 if the call was successful, 0 if there is no such track

int lqt_set_clap	(	quicktime_t *	file,
		int	track,
		quicktime_clap_t *	clap
	)

Set the clean aperture attributes of a video track.

Parameters:

file	A quicktime handle
track	Track index (starting with 0)
clap	Clean aperture atom

Returns:

1 if the call was successful, 0 if there is no such track

The Apple documentation at

http://developer.apple.com/quicktime/icefloe/dispatch019.html#clap

has more detailed information about the 'clap' atom.

int lqt_get_clap	(	quicktime_t *	file,
		int	track,
		quicktime_clap_t *	clap
	)

Get the clean aperture attributes of a video track.

Parameters:

file	A quicktime handle
track	Track index (starting with 0)
clap	Clean aperture atom

Returns:

1 if the call was successful, 0 if there is no such track

The Apple documentation at

http://developer.apple.com/quicktime/icefloe/dispatch019.html#clap

has more detailed information about the 'clap' atom.

int lqt_set_colr	(	quicktime_t *	file,
		int	track,
		quicktime_colr_t *	colr
	)

Set the 'colr' ImageDescription Extension of a video track.

Parameters:

file	A quicktime handle
track	Track index (starting with 0)
colr	Colr atom

Returns:

1 if the call was successful, 0 if there is no such track

The Apple documentation at

http://developer.apple.com/quicktime/icefloe/dispatch019.html#colr

has more detailed information about the 'colr' atom.

int lqt_get_colr	(	quicktime_t *	file,
		int	track,
		quicktime_colr_t *	colr
	)

Get the 'colr' ImageDescription Extension of a video track.

Parameters:

file	A quicktime handle
track	Track index (starting with 0)
colr	Colr atom

Returns:

1 if the call was successful, 0 if there is no such track

The Apple documentation at

http://developer.apple.com/quicktime/icefloe/dispatch019.html#colr

has more detailed information about the 'colr' atom.