ZIP 存档中用于 Brotli 压缩的 ID 号是多少？

Question

ZIP文件格式支持多种压缩算法并为它们分配编号，例如0是store，8是deflate，14是lzma。什么数字表示 Brotli 压缩？此压缩算法是否需要任何其他 zip 级元数据？

Answer 1

截至撰写本文时，还没有。 ZIP文件格式压缩方式的官方列表见PKWare's ZIP Appnote，最新版本为6.3.4，日期为2014年10月1日。下面是其中定义的压缩方式：

   4.4.5 compression method: (2 bytes)

        0 - The file is stored (no compression)
        1 - The file is Shrunk
        2 - The file is Reduced with compression factor 1
        3 - The file is Reduced with compression factor 2
        4 - The file is Reduced with compression factor 3
        5 - The file is Reduced with compression factor 4
        6 - The file is Imploded
        7 - Reserved for Tokenizing compression algorithm
        8 - The file is Deflated
        9 - Enhanced Deflating using Deflate64(tm)
       10 - PKWARE Data Compression Library Imploding (old IBM TERSE)
       11 - Reserved by PKWARE
       12 - File is compressed using BZIP2 algorithm
       13 - Reserved by PKWARE
       14 - LZMA (EFS)
       15 - Reserved by PKWARE
       16 - Reserved by PKWARE
       17 - Reserved by PKWARE
       18 - File is compressed using IBM TERSE (new)
       19 - IBM LZ77 z Architecture (PFS)
       97 - WavPack compressed data
       98 - PPMd version I, Rev 1

我想您可以定义自己的方法编号并使用它，但这种使用是非标准的。（这是一个双字节字段，因此您可以选择一个 PKWare 不太可能定义为其他内容的大数字。）

不，解压缩 brotli 流不需要其他信息。

更新：

截至 2020 年 7 月的应用说明 (6.3.9)，更多的压缩方法，特别是 zstd 和 xz，但仍然没有 brotli。

   4.4.5 compression method: (2 bytes)

        0 - The file is stored (no compression)
        1 - The file is Shrunk
        2 - The file is Reduced with compression factor 1
        3 - The file is Reduced with compression factor 2
        4 - The file is Reduced with compression factor 3
        5 - The file is Reduced with compression factor 4
        6 - The file is Imploded
        7 - Reserved for Tokenizing compression algorithm
        8 - The file is Deflated
        9 - Enhanced Deflating using Deflate64(tm)
       10 - PKWARE Data Compression Library Imploding (old IBM TERSE)
       11 - Reserved by PKWARE
       12 - File is compressed using BZIP2 algorithm
       13 - Reserved by PKWARE
       14 - LZMA
       15 - Reserved by PKWARE
       16 - IBM z/OS CMPSC Compression
       17 - Reserved by PKWARE
       18 - File is compressed using IBM TERSE (new)
       19 - IBM LZ77 z Architecture 
       20 - deprecated (use method 93 for zstd)
       93 - Zstandard (zstd) Compression 
       94 - MP3 Compression 
       95 - XZ Compression 
       96 - JPEG variant
       97 - WavPack compressed data
       98 - PPMd version I, Rev 1
       99 - AE-x encryption marker (see APPENDIX E)

ZIP 存档中用于 Brotli 压缩的 ID 号是多少？

What is the id number for Brotli compression inside a ZIP archive?

zip

brotli