Did every Dreamcast CDI release need downsampling?

[SparkThaMetal]

Hi, Im trying to solve a disagreement on another forum about Dreamcast CDI releases. This guy is claiming every single CDI release over the years is downsampled in some way because cdr's on dc dont read at the same speed as GD-roms, and therefore according to him cant support the games without downsampling....And that we shouldn't trust 'those dodgy guys' who made those releases over the years.

I've said to him those guys aren't dodgy they are part of the 'retro community' still, people like atreyu187. I've quoted him nfo's from nbs releases like Sega Bass fishing that say '' no downsampling needed. no files changed etc''. I've told him about optimising file sorting, told him about YZB compression methods. Told him about dummy files, hardlinking, deleting unused files/unused audio tracks.

I've asked him why he thinks all games needed the max spec of the gdrom drive to work properly etc. His response was basically '' sega q and a forced them to use max transfer speed of gd-roms'', so nothing will work on cdrs if they tried without downsampling. He is basing this off his 'real world testing' making sfd movie discs.
It's worth noting this guy seems to be some sort of 'homebrew' dev for dc stuff so its even more baffling.

So Im hoping atreyu187 or some other members here can put this argument to rest for me lol.

So TLDR:
Are all Dreamcast CDI releases downsampled in some way, or are the nfos correct when they say nothing downsampled? Specifically NBS, RDC , DCCM , DCRES releases.

Cheers.

 

[Berion]

I think it is not true. GD-ROMs are... slower than CD-ROMs. So it is one of the methods to just shrink the game size, in this case CDDA to fit into CD-R. Some games are even smaller by default to fit on GDR so there was no need any ripping beside dummy files, reorganizing stuff to put it on fake MIL-CD. But that was so long ago that I cannot remember such game example. Today those rips are useless as emulators and ODE support GDI dumps, so why even bother of warez rips?

 

[SparkThaMetal]

I think it is not true. GD-ROMs are... slower than CD-ROMs. So it is one of the methods to just shrink the game size, in this case CDDA to fit into CD-R. Some games are even smaller by default to fit on GDR so there was no need any ripping beside dummy files, reorganizing stuff to put it on fake MIL-CD. But that was so long ago that I cannot remember such game example. Today those rips are useless as emulators and ODE support GDI dumps, so why even bother of warez rips?

Yeah I'm 100% certain he is incorrect as some games were tiny and had no cutscenes or cdda , so the data they were transferring was small. Street Fighter 2x. Sega Bass Fishing (https://pastebin.com/PRk6hYyL) etc.
I believe he is correct that cd's run slower on dc, Iirc on dreamcast the cdr's use the mil cd method to boot without a modchip, which limits the cd read speed to 6x.
But im saying for half/a lot of the games that 6x limitation didnt matter as it was enough to cover the data that game needed to pull off the disc at each specific time.
And in other cases the gdi wasnt file sorted well so wasnt using all of gdi spec anyway, so cdr releases can macth that games disc transfer speed needs fine.

Im not sure how to prove it to him, I think im going to have make a cdi and record myself doing it for him to admit he is wrong lol. I think he would even argue with atreyu187 if he chipped in to the discussion

 

[Berion]

You can open *.gdi in IsoBuster and convert GDDA to *.wav. Do the same with target fake MIL-CD of the same game and with CDDA. Then compare both audio streams.

 

[SparkThaMetal]

Cheers, I used isobuster to compare the file sizes for Sega Bass Fishing (U)-NBS release and the Sega Bass Fishing (U) TOSEC GDI and from what i can tell all files on the gdi are exactly the same size as the files on the cdi https://imgur.com/a/kmDl5Cq. Seems like that puts it to rest right? Not all cdi releases are downsampled from what i can see.

 

[Berion]

I have in mind more like spectrum analysis of audio, but if output files are binary the same, it also means they wasn't altered (in assumption that You can trust GDI dump of course).

edit: I see on screenshot that this game keeps audio and/or video in *.adx, yet I have in mind CDDA/GDDA tracks which this game don't have. I don't remember if there was any CRI tools available so maybe it is not possible to tinker with them? I dunno. I remember that Okami on PS2 using encrypted ADX and key was obfuscated inside main executable, so maybe on DC it is the same with games which using this technology? Again, I don't know. Just point that this could not be the best example of game.

 

[SparkThaMetal]

I have in mind more like spectrum analysis of audio, but if output files are binary the same, it also means they wasn't altered (in assumption that You can trust GDI dump of course).

edit: I see on screenshot that this game keeps audio and/or video in *.adx, yet I have in mind CDDA/GDDA tracks which this game don't have. I don't remember if there was any CRI tools available so maybe it is not possible to tinker with them? I dunno. I remember that Okami on PS2 using encrypted ADX and key was obfuscated inside main executable, so maybe on DC it is the same with games which using this technology? Again, I don't know. Just point that this could not be the best example of game.

Yeah its kool he has now backtracked, admitted i am right about sega bass fishing, but now he is trying to claim he didnt say all cdi releases needed to be downsampled and is now adding a modifier to it, claiming he said 'only games that have low enough data transfer to be under cdr max spec dont have to be downsampled'....,,,,,,Even though him claiming it was every single cdi release is right there in the thread multiple times

Then he came out with 'you didnt prove anything'' and ''look at my post count youre just adding to it'.

He that type of idiot. But he has the 'dev' tag on his name there so i just rubbed it in he got proven wrong by a non dev. That forum needs to ban that guy.