DCT Homebrew Bands

[marchegiano]

My bit deleted for space.

Just have to remember to run on cdr the songs have to be downsampled you only have 400 kb/sec total streaming ..
and other files to run on slow mil cd..

I use the extract mod rebuild gdi to do the work.. you can take the 1ST_read.bin from the old cdi release and the files you modded on the gdi to make your own cdi.. making sure there downsampled enff to run on cdr.. non modded full bitrate files on gdi need to be modded or it will stutter like crap on cdr..

Here is my optimized GDI for the serial port so it runs correct with proper fmv's etc and music..

https://www.dreamcast-talk.com/forum/vi ... 92#p163192

Glad i could lead you in the right way..

Got you, thanks bud. I'll have a look and see what I can learn.

[marchegiano]

Kind of struggling with all things GDI. Give youse a bit of an update. This is mostly just me speaking to my little journey openly but any help offered is always appreciated.



The method I used for MVC2 was super basic. Just mp3 to wav and wav to adx and then rename and repack with lazyboot. As cdi of course.

That seems very hit and miss. Zero Gunner, for example, could not possibly have easier to identify songs but when I did the swaperooni I got another just boots like a music CD result like my first go with MVC2. Happened to me with a few games but I have done more than MVC2 so I know a few others it works fine with. I assume it's something to do with the fact that adx files are different sizes but this is just a shot in the dark.

I didn't linger on the issue long given I'm really wanting to muck with GDI.


Mucking with GDIs got me distracted a bit and I just kind of started to explore what exactly a GDI really is. You know, beyond the it's a direct rip rather than a compressed for CD rip. What exactly each file is and what they do, how you pack them, that sort of what is a gdi.

I have a habit of learning what files are or do by dropping them into programs that might give it away. For example, I learned the .gdi is just a text file by dropping it into notepad++. that's as far as I got with that method.

Inside a GDI, Blue Dolphin for example, I see what some numbers but only deduced one of them. From the tools.

3 45000 4 2048 track03.iso 0 - of that I recognize 45000 = LBA

I think I know what an iso is but if it's more than a compression/disc image file type then maybe I do not

.raw? Seen them with images before but this is definitely not something as simple as pop into gimp and have a look-see

I understand .bins to be binaries but that's just assumption. Along that assumption though I assume the 1st_read and ip bins are in one of these? Probably track03.bin?

I messed around with lazyboot's GDI options and GDI builder. I got a track03.bin but I don't actually know what to do with it. That is the full extent of my reasoning for assuming track03.bin has the 1st_read and ip.

GDI builder seems like an excellent program but like damn near every single tutorial I've ever found dealing with Dreamcast, the info I find speaks to the reader like as if the reader knows something about what they are doing. I really don't understand why devs do this. Seems like a real good way to ensure your user base grows very slowly. Which, in turn, just means less games and stuffs for us all.

TBF, not every tutorial, the old ones are pretty excellent, they're just old and out of date....with dead links and the like.

I became very, very, curious as to why cdi is the preferred method for homebrew. I have never seen any of these emus or dreambor mods or even homebrew games created from scratch/source distributed as gdi's.

Except! well, I used Blue Dolphin as an example for a reason. Seems like with the Atomwave ports gdi is the main go to and cdi's are a bit rarer. I assume for space but it still makes me question why folks opt for cdi in most cases.

Just a waste of time to produce something like DreamBOR in GDI or maybe something more to it than that?

I tried to repack a homebrew into GDI, that's how I got to the track03.bin, but I have no idea what to do with it or how exactly I make a .gdi for it. So I stopped and started looking for tools and tutorials and that's where I am now.


Searching google for gdi track03.bin just brings me a bunch of links to GDI Builder that basically explain how one uses GDI Builder to produce a track03.bin but does not explain what one actually does with the track03.bin.

Searching here, 3 pages of results all of which by and speaking to fellas who already know what they are doing and explaining stuff like hacks. Again, just a bunch of info that assumes I know what to do with a track03.bin. - I am not complaining, these are hits on convos and lots of them were super interesting.

dropping track03.bin and just searching things like "what is a gdi" in some form is just a real bad idea anywhere you search because it's so, so common you're going to get a 100 million version of GDI = GD rip, CDI = CD compression.

It is just super hard to find tutorials that start at the beginning and assumes you know nothing but are also up to date. Old tutorials are pretty impressive with how concisely they lay out info and how they assume you don't know anything beyond what is in the tutorial. Newer ones are exciting because of what you can potentially do, seems like there's been little to no effort in linking the two.

So, that's become my major goal for this DC Homebrew stuffs. Making games is super neat and a super exciting potential, but, imo, what dreamcast homebrew really needs is an explainer. If I can do the learning I'll do the teaching and really everything I make will just be for example so other can learn step by step and know exactly what I know. No allusions and bit crap like that. This ADX/GDI business will be my first go at it. I know basically if not all of everyone who responded could probably do this themselves and wouldn't find a guide very useful, but, I would have so I'll do it for the next me.

Final thought - IMO, to join this community, properly, I mean to actually start contributing, and coming in with 0 knowledge of anything, 0 code, 0 art, 0 hardware, 0 knowledge. I knew how to load a disc and play a game before I joined. Coming from that far behind I think you have to be real comfortable looking stupid and that's just not fair. I'm sure there's plenty of folks who want to know the same stuff I ask from time to time and they're just less likely to allow themselves look stupid and be vulnerable than I am. I do not see another me any place on this section of the forum. I'm like the only guy who knows nothing and asks about the stuff he's trying to figure out. Most y'all talk about stuff way, way, way over my head....I mean I found three pages of GDI track03.bin talk and every single one of them are from a guy who already knows exactly what it is talking to another who already knows exactly what it is about what can be modified to what extent.

I'm pretty sure I'm alone in that, or abouts, because I am basically the only clown willing to look like a clown in front of everyone.

[Bob Dobbs]

It's all good, you do not look like a clown. One look at me and that will prove I am the one who looks like a clown.

[fraggle200]

Kind of struggling with all things GDI. Give youse a bit of an update. This is mostly just me speaking to my little journey openly but any help offered is always appreciated.
...

I'm pretty sure I'm alone in that, or abouts, because I am basically the only clown willing to look like a clown in front of everyone.

I totally get where you're coming from with the GDI stuff but here's what I think I've worked out from just reading stuff over the last 20 years without actually building things. This could all be a load of shit if I've misunderstood things so I'm more than happy to be corrected on these:

*** CDI was initially used as discjuggler could do what CDRWin couldn't and it could handle the the audio/data format (i think) the boot disc and later the selfboot images had, which over time turned into data/audio or data/data as people worked out how to get the DC to do what they wanted so it gave rise to difference formats depending on what the game needed.
*** As you can't burn a GDI, then CDI is the weapon of choice when it comes to homebrew as it means a far bigger audience. i don't think it's any more complicated than that, other than possibly the extra tinkering for 1st_read.bin that you'd need for the GDI vs the CDI ( i'm prob worng on this front)
*** track3 in GDI is more or less just all files required for the game. if you extract a GDI in totality and look at the file and then extract just track3 (where there's only a track 3 and nothing else after it) and do the same, there's a good chance you'll see the same output. track1 and 2 are the inital track and leadin i think. so think of a audio/data CDI format, track 1 = audio, track 2 is the next bit and track 3 is the data.
*** at its most basic understanding GDI is nothing more than say a bin/cue but split out differently and with different file types. the GDI file is the cue and everything else is the bins. they both behave quite differently but their similarities are that they both have a text file as an index and both have data within containers.
*** There's 2 main types of GDI out there. full and truncated. Full is just a straight 1:1 rip of the disc and what you'll see in a TOSEC set. Truncated is mostly what you'll see in Dubcitys amazing collections in the downloads section. These have been processed to remove junk/padding data but confirmed still to work as was intended. Crazy Taxi goes from 1.1GB in the TOSEC set to about 150MB when truncated. If you compare both of these then you'll see slightly different filetypes in the 2 GDIs as well. track3.bin (full) VS track3.iso (truncated) for example. This is just how the truncation works as it handles the files slightly differently.
*** As for the Atomiswave stuff you mentioned, I'm sure the reason they used GDI as the base images was just down to the speed the data is needing to be dealt with and GDI primarily forces people to use GDEMU/MODE etc rather than a CDI which could be besieged with issues as the GDROM can't get enough data through fast enough due to seek times. ( good chance this is absolute horseshit but it's my general understanding of things)
*** I could never work out why there was a track4 in the Atomiswave stuff when I had a snoop around them but I have 0 skill with this stuff so I just left it.

If I was wanting to really learn the nuts and bolts of how CDI vs GDI work then I'd get a good CDI rip of a game ( a RDC one or something like that) Crazy taxi springs to mind as it's only about 150MB so nothing should have been changed and then look at the full GDI, truncated GDI and then see what's changed to make it work from 1 to the other.

[megavolt85]

*** I could never work out why there was a track4 in the Atomiswave stuff when I had a snoop around them but I have 0 skill with this stuff so I just left it.

there is only one file in track04, this is 1ST_READ, the LBA of this track is always 450000 (pay attention to the number of zeros, this is not a typo), the thing is that the BIOS has protection and if the LBA of the executable file is less than 450000, then it will not pass the test authenticity

If I was wanting to really learn the nuts and bolts of how CDI vs GDI work then I'd get a good CDI rip of a game ( a RDC one or something like that) Crazy taxi springs to mind as it's only about 150MB so nothing should have been changed and then look at the full GDI, truncated GDI and then see what's changed to make it work from 1 to the other.

the problem is not only the size, the dreamcast drive spins the disk at a constant speed, so the data at the end of the disk is read faster, and due to the high density of the GD disk, more data could be placed on it at the end of the disk, the pirates had to compress the video and sound quality not to save places, but in order for them to be played without lags