So with recent interest in the Dreamcast on my side, I have a couple GDIs that I want to get playing on my Dreamcast, but there's been one roadblock giving me issues. I have all the tools to convert a GDI to a CDI, but after data extraction I'm at a complete loss of what to do. I read about downsampling the data to make it fit the CD-R but how i go about doing this I'm absolutely lost. I know I'm probably missing something but any simple guide would be appreciated as there's a lot I would love to start getting good footage of but it's been hard as the SD loader I have is a bit too finnicky to work reasonably. Any help is appreciated.
I have only done games that have already been dumped and downsampled but were not bootable, as well as emulators, dreamkey 3 and planet web 3. My advice is to try and create a bootable emulator disc to get the hang of how it works before you move on to games. When I converted mine ~14 years ago you had two options to selfboot - data-data and audio-data. bin2boot was quite easy to use while audio-data discs I found a bit harder and also some of the tools like cdrecord and CDR-WIN don't play nice on newer Windows, can't remember if I used Windows 98 for that reason... Echelon's selfboot tutorial is a great read. With down-sampling you have to find the video and audio files yourself and try and make the game fit on 700 MB. Depending on the game this can be easy or very hard. Echelon had to split Grandia 2 into 2 discs because there wasn't much they could remove. Music files would sometimes had to be downsampled to mono or completely removed. Lastly, I remember adx was one of the audio formats and sfd was video. I wouldn't be surprised if there is an all in one selfboot program these days but I would rather try and get the scene releases as long as they used the original sorting
The Easy Way Most of the games have been released by scene groups on CDs with the dawn sample or split work already done. So you can search for scene release on the internet. The Hard Way As Pikmin told you if the extracted data+audio is beyond 700-710mb you need to start making alchemies. Without Loosing Quality Ex. If the game have 10 audio tracks you burn 2 CDs the first with All data+ First 5 audio tracks and the second All data+ Last 5 audio (so on the half game you can use the CD1 and continue the game with CD2) Ex. if game have no Audio tracks you need to find which files is for each levels and burn 2 CDs on the first CD you burn the first level files + dummy files of the last level files on the the second CD you burn the last level files + dummy files of the first level files (this can take more than 2 CDs) Loosing Quality You need to understand what audio and video formats the game use and try to dawn sample it or remove it complete so make the game fit on 700mb this is the concept but for each game you need to do different things there is no generic Guide
Just adding to the post above by @madsheep... the easy way sure is that! I personally would use something like the Dreamcast Clean Merge Project which are, from what I'm told, ripped from GDI and all the hard work done for you (or me). There's about 200-odd out there somewhere. Very interesting to read about how it is all done though, gives me even more appreciation for folks who do this sort of thing free of charge for the good of the scene
Use my Selfboot pack for games without cdda, or SiZiOUS's cdi4dc/mds4dc for cdda games. Otherwise you'll have to burn a disc manually, which is a tad more complicated, but echelon's docs are quite comprehensive on the matter.
