Editing Talk:GimConv

=GimConv.cfg modifications made for rcomage=
[[Rcomage]] uses a GimConv.cfg (configuration file) edited by Zinga Burga to improve compatibility with rcoedit/rcomage and the GIM formats used in PSP

See: a comparison [https://i.imgur.com/0jIOifM.jpg GimConv.cfg official vs rcomage], and this [http://www.psx-place.com/threads/adding-rco-image-files.2867/#post-22246 talk]

==Help screen==
The help screen is just informative, is posted here just to complete the list of changes accuratelly, and because is related with some of the other changes  made to the file

*'''Removed at help screen:'''
{{Boxcode|content=<syntaxhighlight lang="c">
//================================================================
//  gimconv configuration
//================================================================

usage {
	puts "        -F              output in faster pixel storage format"
	puts "        -R              re-convert ( don't swap RGBA <-> ABGR )"
	puts "        -viewer         start gimview.exe when process ends"

}
</syntaxhighlight>}}

*'''Added at help screen:'''
{{Boxcode|content=<syntaxhighlight lang="c">
//================================================================
//  gimconv configuration
//================================================================

usage {

	puts "        -bpp<n>         color output bit depth; n is: 4, 8, 16, 16p, 16a or 32"
	puts "                        4, 8 are indexed; 16, 16a, 16p, 32 are RGBA format"
	puts "        -ps3            output ps3 style GIM"
	puts "        -X              swap RGBA <-> ABGR"

}
</syntaxhighlight>}}

===Help screen Talk===
*The removed '''-F''' (to use pixel_order = faster) is because all PSP GIM format uses it, so it was modifyed as one of the default settings (more info below)
*The removed '''-R''' and the added '''-X''' are related with the order of how RGBA channels are stored in the GIM, it seems -X was useful for PSP (and -R was not useful for PSP). This options are a bit pointless anyway, you should not swap RGBA channels this way by using this options directly
*The removed '''-viewer''' is because was intended to start an official gimviewer.exe that has never been published or leaked (the program doesnt exists, so the option -viewer is pointless)
*The added '''-bpp<n>''' are the RGBA based GIM formats used on PSP, this list includes some custom formats that was not used officially by sony (but works on PSP)
*The added '''-ps3''' loads a custom option that was intended for PS3 GIM files, but is wrong (more info about this problem below)

==Default settings==
The default settings used in the GimConv.cfg used by rcomage are problematic for PS3... up to an exent because as mentioned in frontpage at the time you write a command line for GimConv.exe you can write a long line with lot of settings (that are going to override any default setting you consider is problematic or critical for what you want to achieve)

The real problem is when you write a short command line for GimConv.exe (without overriding any default settings), by doing this you are using all the default settings... and this breaks GIM files for PS3

*'''Changed default settings:'''
{{Boxcode|content=<syntaxhighlight lang="c">
//----------------------------------------------------------------
//  default settings
//----------------------------------------------------------------
	pixel_order = faster		// default normal faster
	limit_image_width = 512		// off $count
	limit_image_height = 512	// off $count
	output_sequence = off		// off on
</syntaxhighlight>}}

*'''Removed default settings:'''
{{Boxcode|content=<syntaxhighlight lang="c">
//----------------------------------------------------------------
//  default settings
//----------------------------------------------------------------
	//  PS3 OSD default settings
	format_endian = big		// -B
	pixel_order = normal		// -N
	pixel_channel = default		// -R
	image_format = rgba8888		// --image_format rgba8888
</syntaxhighlight>}}

===Default settings Talk===
*'''pixel_order'''
**Originally (in the GimConv.cfg released by sony, intended for PS3) it was set to '''normal''' (this matches with the GIM format most used in PS3, and doesnt matches with the second most used GIM format in PS3 that needs to be '''default'''). For rcomage was changed to '''faster''' because all the GIM formats in PSP uses it
**As you can see there is not a way to choose a default value for '''pixel_order''' that fits with the requirements of all known GIM formats, because one way or the other we are breaking some GIM files (either PSP or some for PS3), the solution to bypass this problem is to override this setting in every "option" you want to use (more info below)
**In short... this change causes an small harm to PS3 GIM formats, but considering there is not really a single solution to fix this problem... is ok like this

*'''limit_image_width''' and '''limit_image_height'''
**Originally (in the GimConv.cfg released by sony, intended for PS3) both was set to '''4096''' pixels. For rcomage was changed to '''512''' because the size of the PSP screen is way smaller than PS3 (actually PSP screen is way smaller than 512 but it seems the values of this size restrictions are adjusted to an strict rule of proportions of width x height)
**This problem affects all images bigger than 512 pixels converted by GimConv.exe GIM2PNG, GIM2GIM, PNG2GIM (and any other supported input image format to GIM). If the image is bigger than 512 it will be scaled down and the output image will have 512 pixels in one of its proportions (either width or height)
**This settings allows to use the value '''off''' (to disable the image size restrictions ?) but when using it returns a '''WARNING : too large image size <width>x<height>''' (even with tiny images), it looks like it has a problem when geting the size so is not a good idea to disable this size restriction, instead is better to use the value '''4096''' that works fine and is what sony was using originally for PS3
**As explained before... this problem can be bypassed by overriding this setting, either from command line or editing the file GimConv.cfg to create a custom option with the size values specific for PS3
**Some GIM examples from PS3 with images bigger than 512 pixels in '''explore_plugin_full.rco''':
***'''tex_playing.gim''' (30x900 pixels) http://imgur.com/2rjGdbe
***'''tex_playing_shadow.gim''' (30x900 pixels)
***'''tex_opt_obi.gim''' (660x6 pixels)
**Some GIM examples from PS3 with images bigger than 512 pixels in '''custom_render_plugin.rco ''':
***'''tex_ps3logo.gim''' (1200x128 pixels)
***'''tex_scelogo.gim''' (1024x64 pixels)

*'''output_sequence'''
**Originally (in the GimConv.cfg released by sony, intended for PS3) it was set to '''on'''. For rcomage was changed to '''off'''. I dont really know why, in my tests this setting doesnt changes anything (setting it to either on/off results in the same output files), actually i have it enabled just incase eventually i find is doing something extra (and because originally was enabled by sony), but by now nothing, nada

*'''format_endian'''
**Originally (in the GimConv.cfg released by sony, intended for PS3) this was added by sony as a "override default settings <abbr title="this is one of the cases where sony doesnt wants to modify his old code and instead they adds some kind of patch that overrides the old code">patch</abbr>" applyed over GimConv.cfg (a section named '''PS3 OSD default settings''') with the value '''format_endian = big'''. For rcomage it was removed (so by default it loads '''format_endian = little''' instead, that appears some lines before in GimConv.cfg)
**This is ovbiouslly a problem for PS3, but again there is not a single way to preconfigure this setting to fill the requirements of all GIM formats. PSP needs "little", and PS3 "big", this needs to be overrided inside the "options" specific for each GIM format... or with a long command line specifying this overrides

*'''pixel_order'''
**Originally (in the GimConv.cfg released by sony, intended for PS3) this was added by sony as a "override default settings <abbr title="this is one of the cases where sony doesnt wants to modify his old code and instead they adds some kind of patch that overrides the old code">patch</abbr>" applyed over GimConv.cfg (a section named '''PS3 OSD default settings''') with the value '''pixel_order = normal'''. For rcomage it was removed (so by default it loads '''pixel_order = faster''' instead, that appears some lines before in GimConv.cfg)
**PSP needs to use "faster" always, and PS3 needs "normal" and "default" (because in PS3 there are 2 different GIM formats), so again, this needs to be overrided inside the "options" specific for each GIM format... or with a long command line specifying this overrides

*'''pixel_channel'''
**Originally (in the GimConv.cfg released by sony, intended for PS3) this was added by sony as a "override default settings <abbr title="this is one of the cases where sony doesnt wants to modify his old code and instead they adds some kind of patch that overrides the old code">patch</abbr>" applyed over GimConv.cfg (a section named '''PS3 OSD default settings''') with the value '''pixel_channel = default'''. For rcomage it was removed (so by default it loads '''pixel_channel = default''' that appears some lines before in GimConv.cfg). In other words, sony overrided pixel_channel with the same value. This setting is pointless, is not doing anything
**So the removal made for rcomage is not causing any change

*'''image_format'''
**Originally (in the GimConv.cfg released by sony, intended for PS3) this was added by sony as a "override default settings <abbr title="this is one of the cases where sony doesnt wants to modify his old code and instead they adds some kind of patch that overrides the old code">patch</abbr>" applyed over GimConv.cfg (a section named '''PS3 OSD default settings''') with the value '''image_format = rgba8888'''. For rcomage it was removed (so by default it loads '''image_format = default''' instead, that appears some lines before in GimConv.cfg)
**This is a must to override, is one of the most critical settings, there are several values that are supported by PSP and PS3 (index4, index8, rgba5551, rgba4444, rgba5650, rgba8888, dxt5... and maybe more)
**So the removal made for rcomage is not causing any harm, is needed to override this setting anyway

==Options==
*'''Added options:'''
{{Boxcode|content=<syntaxhighlight lang="c">
//--------------------------------------------------------
//  process option
//--------------------------------------------------------
option -ps3 {
	format_style = ps3
	format_endian = big
}
option -bpp4 {
	image_format = index4
}
option -bpp8 {
	image_format = index8
}
option -bpp16 {
	image_format = rgba5551
}
option -bpp16a {
	image_format = rgba4444
}
option -bpp16p {
	image_format = rgba5650
}
option -bpp32 {
	image_format = rgba8888
</syntaxhighlight>}}

*'''Removed options:'''
{{Boxcode|content=<syntaxhighlight lang="c">
//--------------------------------------------------------
//  mode option
//--------------------------------------------------------
option -viewer {
	object_viewer = "GimView.exe"
}
//--------------------------------------------------------
//  process option
//--------------------------------------------------------
option -F {
	pixel_order = faster
//--------------------------------------------------------
//  PS3 OSD specific options
//--------------------------------------------------------
option -B {
	format_endian = big
}
option -R {
	pixel_channel = default
}
option -DXT {
	pixel_order = default
	pixel_channel = default
	image_format = default
}
</syntaxhighlight>}}

===Options Talk===

*'''-ps3'''
**Biggest problem when using this option is you are going to load all the default settings, and there are some default settings that results in a GIM file incompatible with PS3
**The second problem related with this is wrong in concept, because inside PS3 RCO files are used (at least) 2 different GIM formats (that needs to be build by using different GIM settings), to make this problem even worse in most of the RCO files from PS3 firmware are included GIM files build with different GIM formats... so aplying a single collection of settings for all the GIM files inside a single RCO doesnt works ! (you can be sure some are going to be broken... becaue there are 2 GIM formats you are going to have broken a group of them... or the other)
**Is not compatible with how rcomage automatizes the PNG-to-GIM conversions (for the same reason explained in the line above), with the actual code of rcomage is imposible to automatize the PNG-to-GIM conversions
**"format_style = ps3". For some reason sony implemented this "tag" at the time of coding GimConv.exe '''but is not used in PS3 GIM files !''', actually the GIM files for PS3 uses the tag "psp"

*'''-bpp4, -bpp8, -bpp16, -bpp16a, -bpp16p, -bpp32'''
**Are the GIM formats used in PSP, keep in mind this definitions are not including some critical settings that are hardcoded in GimView.cfg as defaults (such the endianess)
**All this options are optionals anyway, so is not causing any harm to PS3 compatibility, if you dont need them simply dont use them

*'''The other removed options'''
**Doesnt have much importance, could cause problems depending in what you have for default settings in the lines at top of GimView.cfg you should not use this options directly or individually

=Examples=
This is an image created in photoshop with size 2x2 pixels, filled with color 0xC0FFEE (RGB), and saved as a [https://en.wikipedia.org/wiki/BMP_file_format BMP] 32 bits color depth

The pixel color info is stored in the bytes colored (4x4 = 16 pixels in total, 4 bytes each)
 Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
 
 00000000  42 4D 78 00 00 00 00 00 00 00 36 00 00 00 28 00  BMx.......6...(.
 00000010  00 00 04 00 00 00 04 00 00 00 01 00 20 00 00 00  ............ ...
 00000020  00 00 00 00 00 00 12 0B 00 00 12 0B 00 00 00 00  ................
 00000030  00 00 00 00 00 00 <span style="background:#C0FFEE;">EE FF C0 00 EE FF C0 00 EE FF</span>  ......îÿÀ.îÿÀ.îÿ
 00000040  <span style="background:#C0FFEE;">C0 00 EE FF C0 00 EE FF C0 00 EE FF C0 00 EE FF</span>  À.îÿÀ.îÿÀ.îÿÀ.îÿ
 00000050  <span style="background:#C0FFEE;">C0 00 EE FF C0 00 EE FF C0 00 EE FF C0 00 EE FF</span>  À.îÿÀ.îÿÀ.îÿÀ.îÿ
 00000060  <span style="background:#C0FFEE;">C0 00 EE FF C0 00 EE FF C0 00 EE FF C0 00 EE FF</span>  À.îÿÀ.îÿÀ.îÿÀ.îÿ
 00000070  <span style="background:#C0FFEE;">C0 00 EE FF C0 00</span> 00 00                          À.îÿÀ...