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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
05522 Misc. Minor Always Apr 12, 2014, 15:06 Apr 25, 2014, 01:58
Tester MetalliC View Status Public Platform MAME (Official Binary)
Assigned To R. Belmont Resolution Fixed OS Windows Vista/7/8 (64-bit)
Status [?] Resolved Driver
Version 0.153 Fixed in Version 0.154 Build 64-bit
Fixed in Git Commit Github Pull Request #
Summary 05522: chdman: *CD* FLAC compresion doesn't work for GDI images
Description CD FLAC compresion codec doesn't work for GDI images.
Steps To Reproduce 1. Take some Dreamcast image with a lot of CDDA tracks,
"Airforce Delta v1.000 (1999)(Konami)(NTSC)(US)[!][1S T-9501NAF]" for example.
2. convert it to chd
chdman.exe createcd -i "Airforce Delta v1.000 (1999)(Konami)(NTSC)(US)[!][1S T-9501NAF].gdi" -o "Airforce Delta v1.000 (1999)(Konami)(NTSC)(US)[!][1S T-9501NAF].chd"
3. check percentage of used compression codecs
 chdman.exe info -v -i "Airforce Delta v1.000 (1999)(Konami)(NTSC)(US)[!][1S T-9501NAF].chd"
     Hunks Percent Name
---------- ------- --------------
     6,489 9.5% Copy from self
    61,890 90.2% CD LZMA
       268 0.4% CD Deflate
         1 0.0% CD FLAC
Additional Information Expected a lot of data hunks FLAC compressed, but it is not used, except 1 hunk.

I've also compressed this image with -c cdlz,cdzl switch (eg manually disabled FLAC) and got almost the same in size chd as previous -> its not the bug of "info" command, but something wrong during "createcd".

This only happens on GDI, for CUE/BIN with CDDA FLAC works fine.
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User avatar
No.10562
Firewave
Senior Tester
Apr 13, 2014, 07:31
This just means, that the FLAC compression is ineffective for GDI images. chdman compresses each block with all the specified compression methods and only stores the smallest one.
User avatar
No.10564
MetalliC
Developer
Apr 13, 2014, 15:51
edited on: Apr 13, 2014, 16:14
"This just means, that the FLAC compression is ineffective for GDI images" -- indeed, but why this happens ? GDI is just kind of TOC-file like CUE, the data tracks is the same as CUE/ISO/etc

one more test case:
1. take TOSEC's "Airforce Delta v1.000 (1999)(Konami)(NTSC)(US)[!][1S T-9501NAF]" from previous example.
(I can post direct links to it, but not sure its legal and allowed here)
2. unpack it somewhere
so we have such GDI file http://pastebin.com/1hUU0PWE and a couple of auidio and data tracks.
3. take a .cue file http://pastebin.com/rhuX8T7q I've made, save this paste as "Airforce Delta.cue" to the same folder.
4.compress it to CHD from .cue
chdman createcd -i "Airforce Delta.cue" -o "Airforce Delta cue.chd"
5. compare resulting file sizes -
from GDI - 780Mb
from CUE - 637Mb
6. check compression used
chdman info -v -i "Airforce Delta cue.chd"
     Hunks Percent Name
---------- ------- --------------
       928 1.5% Copy from self
    15,307 24.3% CD LZMA
       265 0.4% CD Deflate
    46,585 73.8% CD FLAC

as you can see - 73.8% compressed as FLAC, not 0.0% as in the case of GDI ;)
note: in both cases used the same data/audio tracks (track01.bin - track30.bin), the difference only is GDI or CUE TOC files used as input for chdman.

PS: I've noted one more difference:
in CHD from GDI tracks have Tag='CHGT' tag.
in CHD from CUE tracks have Tag='CHT2' tag
maybe its somehow related to problem ?
User avatar
No.10565
MetalliC
Developer
Apr 13, 2014, 17:38
edited on: Apr 13, 2014, 17:40
isolated problem a bit more - compress test GDI image using various codecs:
default or -c cdlz,cdzl,cdfl --- result image 780Mb, 0.0% CD FLAC
-c cdlz,cdzl,flac --- result image 664Mb 67.9% FLAC

so, somewhere is definitelly fuckup in "CD" flac in the case of GDI.