UMINEKO NO NAKU KORO NI CHIRU libpng errors on VNDS

[Nikokaro]

Have any of you played ("read" is perhaps more appropriate) this visual novel (which includes 4 final episodes) of Umineko series on DS phat/lite via VNDS on a flashcart?
This is the pre-converted version that is easily found online (on mega.nz) containing sprites and voice acting from the PS3 version.
Unlike the first title (which includes the first 4 episodes) that works well, this one immediately gives a number of errors, as shown in the picture.

My guess is that there are too many files (over 2000 PNG images involving the foreground) some of which fail to register in DS memory, and in fact graphic effects are missing on the screen. I also tried extracting the "foreground" folder from the archive, but it still gives the same error. However, up to where I've played, it doesn't seem to crash, and you can save without any problems. Does this defect also result to you all?
Does anyone have a solution for this problem? Thank you.

Edit:
While waiting for someone to answer me, God willing, I will add another issue, concerning this time the first title in the series: it often crashes during saving, but fortunately, after a dozen or so attempts, it has never created a corrupt file or even corrupted the entire SD card. It basically crashes before writing the save file. After several trials, I found that the save goes through if done when only the background is on the screen, with no characters in the foreground.
Otherwise, the probability of it crashing is much greater. I leave it to others to confirm this discovery.
I know that VNDS on DS is not widely used nowadays, but I still hope that someone is still interested in the topic.

 

[mrparrot2]

I dont know how the files are distributed, but I expect the image to be in png Format scattered around some folder.

If you take a look at (1) there seems to bem ways to check If the png files are sane. And there are even ways of fixing those kind of errors.

But this errors seems to be more of a warning than a errors itself. Does the execution of the game halts?

(1) https://stackoverflow.com/questions...g-error-iend-crc-error-and-not-loading-images

 

[Nikokaro]

First of all, thank you for replyig, chief.

I expect the image to be in png Format scattered around some folder.

Yeah, as mentioned in the opening post the images (more than 2000) in PNG format are all in a "foreground" folder inside an uncompressed .zip archive.

If you take a look at (1) there seems to bem ways to check If the png files are sane. And there are even ways of fixing those kind of errors.

Unfortunately, I am a simple gamer and have no knowledge of programming. Anyway the "crc error" always occurs after the first error ("too many idats"), so it is related to that. In itself, all the images are regular, at first glance.

But this errors seems to be more of a warning than a errors itself. Does the execution of the game halts

As I wrote in the opening post, the game doesnt crash and still goes on smoothly despite frequent warnings.

However, all these pre-converted VNs (e.g. Tsukihime, Kanon, ever17, Fate Stay Night, Sekien no Inganok, Saya no Uta etc.) have been thoroughly tested over the years, even by the author himself. If the error depends on the excessive number of files in a folder, I am afraid it is not remediable, for the way this homebrew novel player (VNDS) was programmed: simple personal opinion.
Anyway I will take a look at the technical thread you suggested.

 

[Nikokaro]

Update: I just finished the first episode of the first game in the Umineko series, and unfortunately the game, while saving, crashes in some places even if only the background image is present (without characters) but bgm is active. In the rare times when neither music nor acting is present, saving never crashes.
So strictly speaking, I am afraid this defect is due to insufficient ram available on the console.
Therefore it is convenient to save in multiple slots alternately. Saves are never corrupted; it always crashes before writing the file to the SD.
I have noticed that fortunately it is possible to start, from the initial menu, from any chapter of any individual title; this shows that the author of the DS conversion was aware of these random save crashes, and has placed a useful alternative workaround. Thank God, otherwise it would have been highly frustrating if not unplayable.
In the end highly engaging and exciting visual novel, but very dramatic and shocking (more for certain descriptions than for the pictures) in some places; not for the faint of heart.

 

[mrparrot2]

DS screen is 256x192 so assuming 16bit depth each full screen should take 100kb of memory. music can be streamed compressed from card and so does text, therefore I assume 4mb is more than enough for this.

In what dimensions are the images?

 

[Nikokaro]

In what dimensions are the images?

Yeah, I think 256x192. Unfortunately, I have not been able to find online the Umineko converter tool that automatically modifies and resizes backgrounds, foregrounds, bgms and voice-acting from the PC to DS version, instead tracked down easily for other titles:
https://archive.org/download/vnds-tools-game-converters
The only information I could find is below.
https://github.com/BASLQC/vnds/wiki/Visual-Novel-Porting-Guide
https://github.com/BASLQC/vnds/wiki/VNDS-Nintendo-DS
https://github.com/BASLQC/vnds/wiki/List-of-VNDS-Visual-Novels
https://web.archive.org/web/20140218230102/http://www.digital-haze.net/ch/vnds/kareha.pl/1239593737
Pre-converted novels are here:
https://mega.nz/folder/sl4ygIpK#sVHBXVCumZUn_wge8Kqx0A
Thank you for your interest.