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 added '''-F''' (to use pixel_order = faster) is because PSP GIM format uses it
*The removed '''-X''' and the added '''-R''' 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)
*The removed '''-viewer''' is because is intended to trigger 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 custom RGBA based GIM formats used on PSP, this list includes some formats that was not used oficially 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

*'''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

*'''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)

==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===