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"Idea to compress terrtex and other ace route files hugely"

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timken (156 posts)
Nov-30-01, 10:24 AM (EST) "Idea to compress terrtex and other ace route files hugely" Now, I'm no programmer, so this may be a stupid idea, but here goes. An Ace file of 1M that was a Bitmap about 800K, moderately compressed as a jpg is about 50K. Could a program be written, so the ace files are sent as jpg's, then converted to bitmaps and on to ace's with the makeace utility? Then the person could place them in the appropriate folder. Maybe the program could do this too. I just added a jpg copy of my general store texture to the thread, More General Purpose Models Needed! It fits the above specs.Steve Alert Edit | Reply | Reply With Quote | Top
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Subject Author Message Date ID RE: Idea to compress terrtex and ot... olivier101 Nov-30-01 1 RE: Idea to compress terrtex and ot... timken Nov-30-01 2 RE: Idea to compress terrtex and ot... olivier101 Nov-30-01 3 RE: Idea to compress terrtex and ot... jtr1962 Nov-30-01 4 RE: Idea to compress terrtex and ot... SP9800 Dec-01-01 5 RE: Idea to compress terrtex and ot... MartinW Dec-01-01 7 RE: Idea to compress terrtex and ot... MartinW Dec-01-01 8 RE: Idea to compress terrtex and ot... MartinW Dec-01-01 6 RE: Idea to compress terrtex and ot... olivier101 Dec-01-01 9

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olivier101 (36 posts)
Nov-30-01, 11:42 AM (EST) 1. "RE: Idea to compress terrtex and other ace route files hugely" I see 2 problems in this approach:-The JPG format is "lossy", i.e. it drops part of the original information to reduce size. Most of the times this is not even visible to the human eye, but it could make a difference in textures
-The JPG format can not contain transparency information (alpha layer)For these reasons, compressing the ACE files altogether with a ZIP type utility is still the best solution, and the final compression ratio should be comparable. Remove | Alert Edit | Reply | Reply With Quote | Top
timken (156 posts)
Nov-30-01, 01:42 PM (EST) 2. "RE: Idea to compress terrtex and other ace route files hugely" I was thinking mostly of terrain textures, no transparency involved, and the slight losses wouldn't matter. I think the size reduction would be somewhere around 1/5th -1/10th of zipped sizes.Steve Remove | Alert Edit | Reply | Reply With Quote | Top
olivier101 (36 posts)
Nov-30-01, 06:26 PM (EST) 3. "RE: Idea to compress terrtex and other ace route files hugely" Well, I did a few experiments, and the results are not exactly what I expected...I took a 847 Kb ACE file, namely OEScrub1.ace that lies in Routes\Tutorial\TerrTex. - I saved it as BMP: 769 Kb
- I zipped the BMP file: The zip file is still 638 Kb...
- I saved it as JPG: 75 Kb; that was more or less expected.
- I zipped the original ACE file: The zip file is 847 Kb! this means that ACE files don't zip at all, contrary to what I thought...
- I converted the JPG back to BMP: 769 Kb, just like the original BMP! this means that there is no or little loss in this conversion to JPG and back. In conclusion, I have to say that this could actualy be an effective way to distribute terrain textures, provided that the process of ACE regeneration is automated. Remove | Alert Edit | Reply | Reply With Quote | Top
jtr1962 (22 posts)
Nov-30-01, 10:13 PM (EST) 4. "RE: Idea to compress terrtex and other ace route files hugely" I think all the ace files that came with MSTS were already compressed, so that is why they don't compress much further. On the other hand, until such programs as TGATool2 came out, reskinners weren't able to compress ace files, so many of these should compress fairly nicely. By the way, TGATool2 lets you save ace files in either compressed or uncompressed format, so that you can see the difference yourself. The compressed format will not compress much further when zipped. Remove | Alert Edit | Reply | Reply With Quote | Top
SP9800 (128 posts)
Dec-01-01, 05:10 AM (EST) 5. "RE: Idea to compress terrtex and other ace route files hugely" The .bmp file's file size will only depend on its pixel dimensions and color depth. A plain white 512x512 square, in 24-bit color, would have the same file size as one with the same dimensions and color depth created using a photograph. When you convert a .jpg back to a .bmp, the dimensions are still the same. However, the compression artifacts still remain.The only way to compress .ace files without big losses is through Martin Wright's utilities. The compression they provide is unbelievable, and the game can read them without the end-user having to reconvert them. These tools can be found at http://fly.to/mwgfx/.Using JPEG compression for distribution of routes is unnecessary, and in my opinion, fairly stupid. If I download a route and see that the textures are saved as .jpgs, I will throw it out and not install it, because I shouldn't have to do conversion that can be done by the creator. Get ACEComp and TGATool2.Off my soapbox.... Remove | Alert Edit | Reply | Reply With Quote | Top
MartinW (48 posts)
Dec-01-01, 07:45 AM (EST) 7. "RE: Idea to compress terrtex and other ace route files hugely" The ideal solution would be the same DXT1 compression used by the default terrtex textures. This gives a standardised compression to give 43k for 256x256 and 171k for 512x512.Unfortunately I don`t seem to have cracked it completely. Some textures exported from DXTBmp in ACE-DXT1 work ok while others bring up the dreaded "Do you want to report this error..." boxNormal ACE compression uses zlib (Zip-type) compression so the final size varies depending on the complexity of the image. Some compress massively while others will only show smaller reductions. It is a LossLess compression though - no data is lost during the compression Remove | Alert Edit | Reply | Reply With Quote | Top
MartinW (48 posts)
Dec-01-01, 07:53 AM (EST) 8. "RE: Idea to compress terrtex and other ace route files hugely" Getting the same filesize back after converting jpeg back to bmp is exactly what you would expect. A bmp file of given dimensions always gives the same filesize.
The conversion to jpeg will lose data. The conversion back to bmp will recreate the full image using less "real" data so the quality will be reduced. Try compressing any image using Jpeg and a quality setting of 10% then convert it back and see how bad it looks.You can`t get something for nothing I`m afraid.Compressed Ace files won`t compress more when put into a zip file. They are already compressed as much as possible (and with the same compression algorithm as zip uses)
Uncompressed Ace files should compress in a zip file to roughly the same size as if you compressed them originally. Remove | Alert Edit | Reply | Reply With Quote | Top
MartinW (48 posts)
Dec-01-01, 07:37 AM (EST) 6. "RE: Idea to compress terrtex and other ace route files hugely" It could be done technicly.
However Jpeg is a Lossy compression format (it gets a lot of its compression-success by throwing away data) and the quality of the images would suffer. The more you compress with Jpeg the worse the quality. Remove | Alert Edit | Reply | Reply With Quote | Top
olivier101 (36 posts)
Dec-01-01, 05:14 PM (EST) 9. "RE: Idea to compress terrtex and other ace route files hugely" So, to sum it up:
-avoid JPG for textures because of the data loss
-stick to compressed ACE Remove | Alert Edit | Reply | Reply With Quote | Top

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