Subsamples

Collaboration diagram for Subsamples:

Functions
u8 *	gf_isom_sample_get_subsamples_buffer (GF_ISOFile *isom_file, u32 trackNumber, u32 sampleNumber, u32 *osize)
u32	gf_isom_sample_has_subsamples (GF_ISOFile *isom_file, u32 trackNumber, u32 sampleNumber, u32 flags)
GF_Err	gf_isom_sample_get_subsample (GF_ISOFile *isom_file, u32 trackNumber, u32 sampleNumber, u32 flags, u32 subSampleNumber, u32 *size, u8 *priority, u32 *reserved, Bool *discardable)
GF_Err	gf_isom_add_subsample (GF_ISOFile *isom_file, u32 trackNumber, u32 sampleNumber, u32 flags, u32 subSampleSize, u8 priority, u32 reserved, Bool discardable)
GF_Err	gf_isom_fragment_add_subsample (GF_ISOFile *isom_file, GF_ISOTrackID TrackID, u32 flags, u32 subSampleSize, u8 priority, u32 reserved, Bool discardable)

Detailed Description

Function Documentation

gf_isom_sample_get_subsamples_buffer()

u8* gf_isom_sample_get_subsamples_buffer	(	GF_ISOFile *	isom_file,
		u32	trackNumber,
		u32	sampleNumber,
		u32 *	osize
	)

gets serialized subsample info for the sample The buffer is formatted as N times [(u32)flags(u32)sub_size(u32)codec_param(u8)priority(u8) discardable] If several subsample info are present, they are gathered by flags

Parameters

isom_file	the target ISO file
trackNumber	the target track
sampleNumber	the target sample number
osize	set to output buffer size

Returns

the serialized buffer, or NULL oif no associated subsample

gf_isom_sample_has_subsamples()

u32 gf_isom_sample_has_subsamples	(	GF_ISOFile *	isom_file,
		u32	trackNumber,
		u32	sampleNumber,
		u32	flags
	)

checks if a sample has subsample information

Parameters

isom_file	the target ISO file
trackNumber	the target track
sampleNumber	the target sample number. Set to 0 to check for presence of subsample info (will return 1 or 0 in this case)
flags	the subsample flags to query (may be 0)

Returns

the number of subsamples in the given sample for the given flags

gf_isom_sample_get_subsample()

GF_Err gf_isom_sample_get_subsample	(	GF_ISOFile *	isom_file,
		u32	trackNumber,
		u32	sampleNumber,
		u32	flags,
		u32	subSampleNumber,
		u32 *	size,
		u8 *	priority,
		u32 *	reserved,
		Bool *	discardable
	)

gets subsample information on a sample

Parameters

isom_file	the target ISO file
trackNumber	the target track
sampleNumber	the target sample number
flags	the subsample flags to query (may be 0)
subSampleNumber	the 1-based index of the subsample (see gf_isom_sample_has_subsamples)
size	set to the subsample size
priority	set to the subsample priority
reserved	set to the subsample reserved value (may be used by derived specifications)
discardable	set to GF_TRUE if subsample is discardable

Returns

error if any

gf_isom_add_subsample()

GF_Err gf_isom_add_subsample	(	GF_ISOFile *	isom_file,
		u32	trackNumber,
		u32	sampleNumber,
		u32	flags,
		u32	subSampleSize,
		u8	priority,
		u32	reserved,
		Bool	discardable
	)

adds subsample information to a given sample. Subsample information shall be added in increasing order of sampleNumbers, insertion of information is not supported

Note

it is possible to add subsample information for samples not yet added to the file

specifying 0 as subSampleSize will remove the last subsample information if any

Parameters

isom_file	the target ISO file
trackNumber	the target track
sampleNumber	the target sample number
flags	the subsample flags to query (may be 0)
subSampleSize	size of the subsample. If 0, this will remove the last subsample information if any
priority	the subsample priority
reserved	the subsample reserved value (may be used by derived specifications)
discardable	indicates if the subsample is discardable

Returns

error if any

gf_isom_fragment_add_subsample()

GF_Err gf_isom_fragment_add_subsample	(	GF_ISOFile *	isom_file,
		GF_ISOTrackID	TrackID,
		u32	flags,
		u32	subSampleSize,
		u8	priority,
		u32	reserved,
		Bool	discardable
	)

adds subsample information for the latest sample added to the current track fragment

Parameters

isom_file	the target ISO file
TrackID	the ID of the target track
flags	the subsample flags to query (may be 0)
subSampleSize	size of the subsample. If 0, this will remove the last subsample information if any
priority	the subsample priority
reserved	the subsample reserved value (may be used by derived specifications)
discardable	indicates if the subsample is discardable

Returns

error if any