什么是etc1tool？

Question

我见过android SDK platform-tools文件夹有一个名为etc1tool的程序.

它说它将PNG文件转换为ETC1,但什么是ETC1文件？

我不明白它是什么以及什么时候使用它.

帮助(下面),ubuntu手册页和android doc似乎也没有解释它.

$ ./etc1tool --help
./etc1tool infile [--help | --encode | --encodeNoHeader | --decode] [--showDifference difffile] [-o outfile]
    Default is --encode
        --help           print this usage information.
        --encode         create an ETC1 file from a PNG file.
        --encodeNoHeader create a raw ETC1 data file (without a header) from a PNG file.
        --decode         create a PNG file from an ETC1 file.
        --showDifference difffile    Write difference between original and encoded
                                     image to difffile. (Only valid when encoding).
    If outfile is not specified, an outfile path is constructed from infile,
    with the apropriate suffix (.pkm or .png).

注意[sic]为"适当".

Answer 1

压缩的纹理.规格在这里.