Decoding AAC FIL - Revision history

Dcsmith77 at 18:43, 10 April 2007

2007-04-10T18:43:01Z

← Older revision		Revision as of 11:43, 10 April 2007
Line 15:		Line 15:
	if (count == 15)		if (count == 15)
	8 bits: extra_count		8 bits: extra_count
	count = extra_count		count += extra_count
	4 bits: extension_type		4 bits: extension_type

Lz8N0i at 18:06, 10 April 2007

2007-04-10T18:06:26Z

← Older revision		Revision as of 11:06, 10 April 2007
Line 15:		Line 15:
	if (count == 15)		if (count == 15)
	8 bits: extra_count		8 bits: extra_count
	count += extra_count		count = extra_count
	4 bits: extension_type		4 bits: extension_type

Multimedia Mike: note the origin

2006-03-05T22:14:13Z

note the origin

← Older revision		Revision as of 15:14, 5 March 2006
Line 1:		Line 1:
			''Part of [[Understanding AAC]]''

	This can apparently be used for extension data since libfaad2 checks for SBR data in the FIL chunk which is known to be applicable to later HE-AAC variants. There are other extension data types in the syntax. According to the libfaad2 logic, a FIL element can have either an SBR chunk or a series of other extension types. These are the defined extension types:		This can apparently be used for extension data since libfaad2 checks for SBR data in the FIL chunk which is known to be applicable to later HE-AAC variants. There are other extension data types in the syntax. According to the libfaad2 logic, a FIL element can have either an SBR chunk or a series of other extension types. These are the defined extension types:

Multimedia Mike: basic FIL information

2006-03-05T22:07:28Z

basic FIL information

New page

This can apparently be used for extension data since libfaad2 checks for SBR data in the FIL chunk which is known to be applicable to later HE-AAC variants. There are other extension data types in the syntax. According to the libfaad2 logic, a FIL element can have either an SBR chunk or a series of other extension types. These are the defined extension types:

* 1: FILL_DATA
* 2: DATA_ELEMENT
* 11: DYNAMIC_RANGE
* 12: SBR_DATA
* 13: SBR_DATA_CRC

local count
local extra_count
local extension_type
4 bits: count
if (count == 15)
8 bits: extra_count
count += extra_count
4 bits: extension_type

FILL_DATA:
4 bits: must be 0000b
foreach 0..count-2
8 bits: must be 0xA5 (10100101b)

DATA_ELEMENT:
'''[unfinished]'''

DYNAMIC_RANGE:
'''[unfinished]'''

SBR_DATA:
'''[unfinished]'''

SBR_DATA_CRC:
'''[unfinished]'''