Resource Container (RCO)

Description

The file extension in PSP and PS3 is RCO that seems to be the acronym of Resource Container Objet

The file signature (aka magic number) from PSP (in little endian) is PRF that seems to be the acronym of Playstation Resource File

RCO contents are loaded by other firmware functions as XMBML setting files, and XMB modules (also known as .sprx plugins), see Plugin Interfaces and VSH

Contents

• RCO contents (See Multimedia Formats and Tools):

Text for all languages, textures, sounds (for cursor navigation, trophy unlocking, etc...) and models

RCO format	Embedded code	Text	Textures	Sounds	Models	Script
Generic	RCOXML	utf8, utf16, utf32	gim, png, jpg, tif, gif, bmp	vag, unknown0x0	gmo	PlayStation JavaScript
PS3 specific	RCOXML	utf16	gim, png, jpg	vag	n/a	n/a

Versions

RCO version	Firmware	Release date	RCO format specifications
			Toc trees	Toc compression	Other Notes
0x55	0.6.5	pre-retail	9	uncompressed	archaic rco format, header is 16 bytes smaller
0x70	1.00	2004 / 12 / 12	10	uncompressed
0x71	1.50~2.50	2005 / 3 / 24	10	uncompressed	normal toc up to this version
0x90	2.60	2005 / 11 / 29	10		zlib compressed toc implemented
0x95	2.70~2.71	2006 / 4 / 25	10		rlz compressed toc implemented
0x96	2.80~3.40	2006 / 7 / 27	10		the toc seems to be compressed in parts
0x97	1.00~1.54	2006 / 11 / 11	10
0x100	3.50~6.61	2007 / 5 / 31	10
0x102	1.60~1.70	2007 / 3 / 22	10
0x104	1.80~1.82	2007 / 5 / 24	10
0x105	1.90~1.94	2007 / 7 / 24	10
0x106	2.00~2.17	2007 / 11 / 8	10
0x107	2.20~2.80	2008 / 3 / 25	10
0x108	3.00~3.01	2009 / 9 / 1	10
0x110	3.10~3.74	2009 / 11 / 19	10
0x120	4.00~4.25	2011 / 11 / 29	10
0x130	4.30~4.76	2012 / 10 / 24	10

RCO Structure

Based on RCO File Format (outdated) and rcomage source

Header

Offset	Length	Example	Name	Notes
0x00	0x04	46 52 50 00	prf_signature	In PS3 is "FRP" (big endian). In PSP is "PRF" (little endian)
0x04	0x04	00 00 00 97	prf_version	named minFirmwareVer in Rcomage, see Discussion page
0x08	0x04	00 00 00 00	prf_unknown
0x0C	0x04	00 00 00 00	prf_compression	0x00=uncompressed, 0x10=ZLIB, 0x20=RLZ It can be combined with UMDflag, see Discussion page
0x10	0x04	00 00 00 A4	toc_maintree_absolute_offset
0x14	0x04	FF FF FF FF	toc_scripttree_absolute_offset
0x18	0x04	FF FF FF FF	toc_languagetree_absolute_offset
0x1C	0x04	FF FF FF FF	toc_soundtree_absolute_offset
0x20	0x04	FF FF FF FF	toc_modeltree_absolute_offset
0x24	0x04	FF FF FF FF	toc_imagetree_absolute_offset
0x28	0x04	FF FF FF FF	toc_unknown
0x2C	0x04	FF FF FF FF	toc_fonttree_absolute_offset
0x30	0x04	00 00 00 CC	toc_objecttree_absolute_offset
0x34	0x04	FF FF FF FF	toc_animationtree_absolute_offset
0x38	0x04	00 00 01 D4	str_language_table_absolute_offset
0x3C	0x04	00 00 00 00	str_language_table_length
0x40	0x04	00 00 01 D4	str_label_table_absolute_offset
0x44	0x04	00 00 00 1C	str_label_table_length
0x48	0x04	00 00 01 F0	str_event_table_absolute_offset
0x4C	0x04	00 00 00 04	str_event_table_length
0x50	0x04	FF FF FF FF	ptr_language_table_absolute_offset
0x54	0x04	00 00 00 00	ptr_language_table_length
0x58	0x04	FF FF FF FF	ptr_image_table_absolute_offset
0x5C	0x04	00 00 00 00	ptr_image_table_length
0x60	0x04	FF FF FF FF	ptr_model_table_absolute_offset
0x64	0x04	00 00 00 00	ptr_model_table_length
0x68	0x04	FF FF FF FF	ptr_sound_table_absolute_offset
0x6C	0x04	00 00 00 00	ptr_sound_table_length
0x70	0x04	00 00 01 CC	ptr_object_table_absolute_offset
0x74	0x04	00 00 00 08	ptr_object_table_length
0x78	0x04	FF FF FF FF	ptr_animation_table_absolute_offset
0x7C	0x04	00 00 00 00	ptr_animation_table_length
0x80	0x04	FF FF FF FF	dat_image_table_absolute_offset
0x84	0x04	00 00 00 00	dat_image_table_length
0x88	0x04	FF FF FF FF	dat_sound_table_absolute_offset
0x8C	0x04	00 00 00 00	dat_sound_table_length
0x90	0x04	FF FF FF FF	dat_model_table_absolute_offset
0x94	0x04	00 00 00 00	dat_model_table_length
0x98	0x04	FF FF FF FF	dat_unknown_1
0x9C	0x04	FF FF FF FF	dat_unknown_2
0xA0	0x04	FF FF FF FF	dat_unknown_3

TOC

This area works as an index of all the .rco contents, when the area is compressed there are 12 bytes at the beginning with info about this compression, after it starts the info composed by entries that follows a hierarchy of parent/children/brother, every entry defines an element with its attributes. All this info can be represented as an xml file (this is what rcomage names an RCOXML)

The container structure can be represented as an XML (see RCOXML), with rcomage is posible to generate this XML when extracting, and for rebuilding the rco using the XML as a layout

Every entry has an area at beginning that is common for all entry_types, the values that comes after this common area are specific and different for each the entry_type

RCO TOC entry common area

Offset	Length	Data type	Name			Example (TOC)	Example (XML)	Notes
0x00	0x04	int	entry_type	Yes	Yes	01 01 / 00 00	<Element name="label"/>	entry_type[2], padding[2]
0x04	0x04	int	entry_label_offset	Yes	Yes	00 00 00 00		label_string_table_offset[4] (optional)
0x08	0x04	int	attributes_offset	Yes	Yes	00 00 00 00	represents XML hierarchy	Attributes offset relative to the start of this entry (optional)
0x0C	0x04	int	children_offset	Yes	Yes	00 00 00 28		First children offset relative to the start of this entry (optional)
0x10	0x04	int	children_number	Yes	Yes	00 00 00 00		Number of subentries
0x14	0x04	int	next_sibling_offset	Yes	Yes	00 00 00 00		Next sibling offset relative to the start of this entry (optional)
0x18	0x04	int	prev_sibling_offset	Yes	Yes	00 00 00 00		Previous sibling offset relative to the start of this entry (optional)
0x1C	0x04	int	parent_offset	Yes	Yes	00 00 00 00		This entry offset relative to the start of the parent entry
0x20	0x08	unk	toc_entry_unk	Yes	Yes	00 00 00 00 .. .	no XML representation	Unknown

RCO TOC entry types

		Second byte
		0x00	0x01	0x02	0x03	0x04	0x05	0x06	0x07	0x08	0x09	0x0A	0x0B	0x0C	0x0D	0x0E	0x0F	0x10	0x11	0x12	0x13	0x14	0x15	0x16	0x17	0x18	0x19	0x1A	0x1B	0x1C	0x1D	0x1E	0x1F
First byte	0x01	unk	MainTree
	0x02	ScriptTree
	0x03	TextTree	Text
	0x04	ImageTree	Image
	0x05	ModelTree	Model
	0x06	SoundTree	Sound
	0x07	FontTree	Font
	0x08	ObjectTree	Page	Plane	Button	XMenu	XMList	XList	Progress	Scroll	MList	MItem	unk	XItem	Text	ModelObject	Spin	Action	ItemSpin	Group	LList	LItem	Edit	Clock	IList	IItem	Icon	UButton	unk	CheckboxGroup	CheckboxItem	Meter	EditBox
	0x09	AnimTree	Anim	MoveTo	Recolour	Rotate	Resize	Fade	Delay	FireEvent	Lock	Unlock	SlideOut
		Supported by and																											Supported by only

• The entry_types with the suffix Tree (as example MainTree) are special and doesnt uses attributes, MainTree is always located as the first entry, doesn't have a parent, and doesn't have any previous or next "sibling", the maximun number posible of childrens for MainTree is 8 (containing all the other "trees"). The other "trees" (as example imageTree or soundTree) are siblings and are the childrens of "MainTree", Every one of those "trees" contains a variable number of entry_types that are its childrens
• The attributes of the RCOXML Objects (entry_types starting with 0x08) and RCOXML Animations (entry_types starting with 0x09) can be grouped in standard attributes (used by most entryes of this type) and specific attributes (different for every entry_type). The standard attributes are always located before the specific attributes
• First two bytes are swapped based on architecture (PSP in little endian, PS3 in big endian). The table shows the values in big endian

After the area common for all entries it starts the info specific for each entry_type explained below

• (0x1) MainTree

Main tree doesnt uses specific attributes, only uses the default ones explained above that indicates his position at top of the RCOXML Structure hierarchy and gives it a "label" name

• (0x2) Script

This is named "ScriptTree" for simplification purposes, but is not actually a tree, only one VSMX file can be stored inside an RCO

Offset	Length	Name	Example	Notes
0x00	0x04	file_offset		VSMX file offset, relative to the start offset of the vsmx data table (always 0)
0x04	0x04	file_size		VSMX file length

• (0x3) Text

"TextTree" could be renamed to LanguageTree, is more intuitive, the point is every entry here is the "parent" of several string texts, but the entry itself is not a text (is the parent of a group of texts), so is better to use a name more abstract like "LanguageTree"

For a Language first are specified the language_id and the number of "children" text strings

Offset	Length	Name	Example	Notes
0x00	0x02	language_id		0x00=Japanese 0x01=English (United States) 0x02=French 0x03=Spanish (Spain) 0x04=German 0x05=Italian 0x06=Dutch 0x07=Portuguese (Portugal) 0x08=Russian 0x09=Korean 0x0A=Chinese (Traditional) 0x0B=Chinese (Simplified) 0x0C=Finnish 0x0D=Swedish 0x0E=Danish 0x0F=Norwegian 0x10=Polish 0x11=Portuguese (Brazil) 0x12=English (United Kingdom) 0x13=Turkish
0x02	0x02	strings_format		0x00=UTF8 0x01=UTF16 0x02=UTF32
0x04	0x04	strings_number		number of text strings for this language_id

Now for every strings_number are repeated 12 bytes to define every string that are references to other tables

Offset	Length	Name	Example	Notes
0x00	0x04	label_offset		Offset to label, relative of the label table
0x04	0x04	string_length		Length of the text
0x08	0x04	string_offset		Offset of the text, relative to the text data start address

• (0x4) Image

The values marked in red are optional, the presence of the unknown specific for PS3 can be deduced based on the "rco version" in the rco header, only exists in PS3 RCO's (PSP doesnt uses it). See rcomage talk page. The presence of the other optional value file_uncompressed_size can be deduced by reading the entry itself

The file_compression feature adds a compression layer over the file format (pointless for image formats that are nativelly compressed like GIM or JPG)

Offset	Length	Name	Example	Notes
0x00	0x02	file_format		0x0=PNG 0x1=JPEG 0x2=TIFF 0x3=GIF 0x4=BMP 0x5=GIM
0x02	0x02	file_compression		0x0=NONE 0x1=ZLIB 0x2=RLZ
0x04	0x04	file_size		either compressed or uncompressed, this is the final size of the file stored inside the rco
0x08	0x04	file_offset
0x0C	0x04	unknown		PS3 RCOs seem to have this extra value - probably something to do with planes/frames?? usually 0x1
0x10	0x04	file_uncompressed_size		Optional. Doesn't exist if file_compression = NONE, for PSP is located 4 bytes before because the previous value doesn't exists

• (0x5) Model

ModelTree uses the same values than ImageTree with a couple of differences, the table is repeated here for comparison purposes

The presence of the unknown (specific for PS3) is completlly speculative because never has been found a GMO file used on PS3 official firmware, is not even known if PS3 firmware has some function able to manage GMO files

Offset	Length	Name	Example	Notes
0x00	0x02	file_format		0x0=GMO
0x02	0x02	file_compression		0x0=NONE 0x1=ZLIB 0x2=RLZ
0x04	0x04	file_size		either compressed or uncompressed, this is the final size of the file stored inside the rco
0x08	0x04	file_offset		Offset of data relative to the beginning of the image data section
0x0C	0x04	unknown		PS3 RCOs seem to have this extra value - probably something to do with planes/frames?? usually 0x1
0x10	0x04	file_uncompressed_size		Optional. Doesn't exist if file_compression = NONE, for PSP is located 4 bytes before because the previous value doesn't exists

• (0x6) Sound

Offset	Length	Name	Example	Notes
0x00	0x02	file_format		0x0=unknown 0x1=VAG
0x02	0x02	audio_channels		0x1=MONO 0x2=STEREO
0x04	0x04	file_size		either one or two channels, this is the final size of the file stored inside the rco
0x08	0x04	file_offset		Offset of the sound data to the beginning of the sound data section
0x0C	0x04	left_channel_size		This is the size of left channel file
0x10	0x04	left_channel_offset		Offset of left channel VAG to the beginning of the sound data section
0x0C	0x04	right_channel_size		Optional. Only exists if audio_channels = STEREO
0x10	0x04	right_channel_offset		Optional. Only exists if audio_channels = STEREO

• (0x7) Font
• (0x8) Object
• (0x9) Animation

RCO compression methods

When the TOC table is compressed at beginning there are 3 values related with the compression (otherway if the table is not compressed this 3 values doesnt exists)

Offset	Length	Name	Example	Notes	Speculation
0x00	0x04	lenPacked		Packed size of all the table sections
0x04	0x04	lenUnpacked		Unpacked size of all the table sections
0x08	0x04	lenLongestText		length of the longest language's text data (unpacked) if the compressed area doesn't contains any language text the value is 0