Query and select tracks
[Decoding of multimedia streams]

Functions
BGAV_PUBLIC int	bgav_num_tracks (bgav_t *bgav)
	Get the number of tracks.
BGAV_PUBLIC const char *	bgav_get_description (bgav_t *bgav)
	Get a technical description of the format.
BGAV_PUBLIC gavl_time_t	bgav_get_duration (bgav_t *bgav, int track)
	Get the duration of a track.
BGAV_PUBLIC int	bgav_num_audio_streams (bgav_t *bgav, int track)
	Get the number of audio streams of a track.
BGAV_PUBLIC int	bgav_num_video_streams (bgav_t *bgav, int track)
	Get the number of video streams of a track.
BGAV_PUBLIC int	bgav_num_subtitle_streams (bgav_t *bgav, int track)
	Get the number of subtitle streams of a track.
BGAV_PUBLIC const char *	bgav_get_track_name (bgav_t *bgav, int track)
	Get the name a track.
BGAV_PUBLIC const bgav_metadata_t *	bgav_get_metadata (bgav_t *bgav, int track)
	Get metadata for a track.
BGAV_PUBLIC int	bgav_select_track (bgav_t *bgav, int track)
	Select a track.
BGAV_PUBLIC int	bgav_get_num_chapters (bgav_t *bgav, int track, int *timescale)
	Get the number of chapters.
BGAV_PUBLIC const char *	bgav_get_chapter_name (bgav_t *bgav, int track, int chapter)
	Get the name of a chapter.
BGAV_PUBLIC int64_t	bgav_get_chapter_time (bgav_t *bgav, int track, int chapter)
	Get the name of a chapter.

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Detailed Description

Each opened decoder can have multiple tracks. You must select the track you wish to decode before you can do anything else.

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Function Documentation

BGAV_PUBLIC int bgav_num_tracks

(

bgav_t *

bgav

)

Get the number of tracks.

Parameters:

bgav

A decoder instance

Returns:

The number of tracks.

BGAV_PUBLIC const char* bgav_get_description

(

bgav_t *

bgav

)

Get a technical description of the format.

Parameters:

bgav

A decoder instance

Returns:

Description

BGAV_PUBLIC gavl_time_t bgav_get_duration	(	bgav_t *	bgav,
		int	track
	)

Get the duration of a track.

Parameters:

	bgav	A decoder instance
	track	Track index (starting with 0)

Returns:

The duration of a track or GAVL_TIME_UNDEFINED if the duration is not known.

BGAV_PUBLIC int bgav_num_audio_streams	(	bgav_t *	bgav,
		int	track
	)

Get the number of audio streams of a track.

Parameters:

	bgav	A decoder instance
	track	Track index (starting with 0)

Returns:

The number of audio streams

BGAV_PUBLIC int bgav_num_video_streams	(	bgav_t *	bgav,
		int	track
	)

Get the number of video streams of a track.

Parameters:

	bgav	A decoder instance
	track	Track index (starting with 0)

Returns:

The number of video streams

BGAV_PUBLIC int bgav_num_subtitle_streams	(	bgav_t *	bgav,
		int	track
	)

Get the number of subtitle streams of a track.

Parameters:

	bgav	A decoder instance
	track	Track index (starting with 0)

Returns:

The number of subtitle streams

BGAV_PUBLIC const char* bgav_get_track_name	(	bgav_t *	bgav,
		int	track
	)

Get the name a track.

Parameters:

	bgav	A decoder instance
	track	Track index (starting with 0)

Returns:

The track name if present or NULL.

BGAV_PUBLIC const bgav_metadata_t* bgav_get_metadata	(	bgav_t *	bgav,
		int	track
	)

Get metadata for a track.

Parameters:

	bgav	A decoder instance
	track	Track index (starts with 0)

Returns:

A metadata container (see Metadata)

BGAV_PUBLIC int bgav_select_track	(	bgav_t *	bgav,
		int	track
	)

Select a track.

Parameters:

	bgav	A decoder instance
	track	Track index (starts with 0)

Returns:

0 if there was no such track, 1 else

Select the track. All subsequent function calls will refer to the track you selected.

BGAV_PUBLIC int bgav_get_num_chapters	(	bgav_t *	bgav,
		int	track,
		int *	timescale
	)

Get the number of chapters.

Parameters:

	bgav	A decoder instance
	track	Track index (starts with 0)
	timescale	Returns the timescale of the seekpoints

Returns:

The number of chapters or 0 if the format doesn't support chapters

Chapters are simply named seekpoints. Use bgav_get_chapter_time and bgav_get_chapter_name to query the chapters.

BGAV_PUBLIC const char* bgav_get_chapter_name	(	bgav_t *	bgav,
		int	track,
		int	chapter
	)

Get the name of a chapter.

Parameters:

	bgav	A decoder instance
	track	Track index (starts with 0)
	chapter	Chapter index (starts with 0)

Returns:

The name of the chapter or NULL

BGAV_PUBLIC int64_t bgav_get_chapter_time	(	bgav_t *	bgav,
		int	track,
		int	chapter
	)

Get the name of a chapter.

Parameters:

	bgav	A decoder instance
	track	Track index (starts with 0)
	chapter	Chapter index (starts with 0)

Returns:

The time of the chapter