Reading text

Decode text. More...

Functions
int	lqt_text_tracks (quicktime_t *file)
	Get the number of text tracks. More...
int	lqt_get_text_language (quicktime_t *file, int track, char *language)
	Get the text language. More...
int	lqt_text_time_scale (quicktime_t *file, int track)
	Get the timescale for a text track. More...
void	lqt_get_text_box (quicktime_t *file, int track, uint16_t *top, uint16_t *left, uint16_t *bottom, uint16_t *right)
	Set the text box of a text track. More...
int	lqt_read_text (quicktime_t *file, int track, char **text, int *text_alloc, int64_t *timestamp, int64_t *duration)
	Read a text sample. More...
int	lqt_is_chapter_track (quicktime_t *file, int track)
	Check if a track is a chapter track. More...
int64_t	lqt_text_samples (quicktime_t *file, int track)
	Get the total number of text samples. More...
void	lqt_set_text_position (quicktime_t *file, int track, int64_t position)
	Go to a specific sample. More...
void	lqt_set_text_time (quicktime_t *file, int track, int64_t time)
	Go to a specific time. More...
void	lqt_get_text_fg_color (quicktime_t *file, int track, uint16_t *r, uint16_t *g, uint16_t *b, uint16_t *a)
	Get the foreground color of a text track. More...
void	lqt_get_text_bg_color (quicktime_t *file, int track, uint16_t *r, uint16_t *g, uint16_t *b, uint16_t *a)
	Get the background color of a text track. More...
int64_t	lqt_get_text_pts_offset (quicktime_t *file, int track)
	Get an video pts offset. More...

Detailed Description

Decode text.

Function Documentation

int lqt_text_tracks

(

quicktime_t *

file

)

Get the number of text tracks.

Parameters

file	A quicktime handle

Returns

The number of text tracks found in the file

int lqt_get_text_language	(	quicktime_t *	file,
		int	track,
		char *	language
	)

Get the text language.

Parameters

file	A quicktime handle
track	Track index (starting with 0)
language	Returns ISO-639 Language code

Returns

1 on success, 0 on error.

The language code is a 3-character code, English is "eng", Japanese is "jpn".

int lqt_text_time_scale	(	quicktime_t *	file,
		int	track
	)

Get the timescale for a text track.

Parameters

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

Returns

The timescale of the track.

void lqt_get_text_box	(	quicktime_t *	file,
		int	track,
		uint16_t *	top,
		uint16_t *	left,
		uint16_t *	bottom,
		uint16_t *	right
	)

Set the text box of a text track.

Parameters

file	A quicktime handle
track	Track index (starting with 0)
top	Returns the top border
left	Returns the left border
bottom	Returns the bottom border
right	Returns the right border

int lqt_read_text	(	quicktime_t *	file,
		int	track,
		char **	text,
		int *	text_alloc,
		int64_t *	timestamp,
		int64_t *	duration
	)

Read a text sample.

Parameters

file	A quicktime handle
track	Track index (starting with 0)
text	Address of a buffer
text_alloc	Allocated bytes for this buffer (will be changed)
timestamp	Returns the timestamp of the sample
duration	Returns the duration of the sample

Returns

1 if a sample was decoded, 0 if the track is finished

This funtion calls realloc() to make sure there is enough space for for the text. It's a good idea to always pass the same buffer to this function (set to NULL initially) and free it after the file is closed.

int lqt_is_chapter_track	(	quicktime_t *	file,
		int	track
	)

Check if a track is a chapter track.

Parameters

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

Returns

1 if the text track is a chapter track, 0 else

int64_t lqt_text_samples	(	quicktime_t *	file,
		int	track
	)

Get the total number of text samples.

Parameters

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

Returns

The number of samples

void lqt_set_text_position	(	quicktime_t *	file,
		int	track,
		int64_t	position
	)

Go to a specific sample.

Parameters

file	A quicktime handle
track	Track index (starting with 0)
position	The sample position (starting with 0)

void lqt_set_text_time	(	quicktime_t *	file,
		int	track,
		int64_t	time
	)

Go to a specific time.

Parameters

file	A quicktime handle
track	Track index (starting with 0)
time	Time

This wil reposition the text track such, that the next call to lqt_read_text will return a sample with at least the timestamp you specified.

void lqt_get_text_fg_color	(	quicktime_t *	file,
		int	track,
		uint16_t *	r,
		uint16_t *	g,
		uint16_t *	b,
		uint16_t *	a
	)

Get the foreground color of a text track.

Parameters

file	A quicktime handle
track	Track index (starting with 0)
r	Returns red
g	Returns green
b	Returns blue
a	Returns alpha

Color values are between 0x0000 and 0xffff.

void lqt_get_text_bg_color	(	quicktime_t *	file,
		int	track,
		uint16_t *	r,
		uint16_t *	g,
		uint16_t *	b,
		uint16_t *	a
	)

Get the background color of a text track.

Parameters

file	A quicktime handle
track	Track index (starting with 0)
r	Returns red
g	Returns green
b	Returns blue
a	Returns alpha

Color values are between 0x0000 and 0xffff.

int64_t lqt_get_text_pts_offset	(	quicktime_t *	file,
		int	track
	)

Get an video pts offset.

Parameters

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

Returns

PTS offset of the subtitles (in timescale units)