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未知的JPEG压缩技术？

[英]Unknown JPEG compression technique?

原文 2015-05-20 05:01:53 4 1 android/ jpeg

Well, so I've been digging through an android game's files trying to get sprites and the like. 好吧，所以我一直在研究一个android游戏的文件，试图获取精灵等。 So I've managed to come across this folder called "raw", and inside were jpg files like imagelocal2.jpg (along with imagelocal2.list) and such. 因此，我设法遇到了名为“ raw”的文件夹，并且里面有jpg文件，例如imagelocal2.jpg（以及imagelocal2.list）等。 These files aren't valid images and can't be viewed normally, but they're big enough to contain many images inside of them. 这些文件不是有效的图像，无法正常查看，但它们足够大，可以在其中包含许多图像。

What I'm wondering is, is there some unknown JPG compression-like method where they manage to squish a bunch of files into one? 我想知道的是，是否存在一些未知的类似于JPG压缩的方法，他们设法将一堆文件压缩为一个？ I opened the files with a hex editor but I couldn't make heads or tails of them (the fact that I have no experience with hex editors doesn't really help), so if anyone knows anything about how these files are compressed, please help. 我使用十六进制编辑器打开了文件，但无法使它们成对出现（我没有十六进制编辑器的经验也无济于事），因此，如果有人对这些文件的压缩方式有所了解，请救命。

1 个解决方案

There is no standard multi-image JPEG format. 没有标准的多图像JPEG格式。 it would be anything with a JPG extension. 会有JPG扩展名的东西。 No competently-written decoder would rely on the extension anyway. 无论如何，任何称职的解码器都不会依赖该扩展。

You could take a look at the first few bytes and try to match the file signature. 您可以看一下前几个字节，然后尝试匹配文件签名。

http://en.wikipedia.org/wiki/List_of_file_signatures http://en.wikipedia.org/wiki/List_of_file_signatures